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* ipv4: avoid using shared IP generator for connected socketsEric Dumazet2022-02-031-11/+10
| | | | | | | | | | | | | | | | | | | | | | | | | commit 23f57406b82de51809d5812afd96f210f8b627f3 upstream. ip_select_ident_segs() has been very conservative about using the connected socket private generator only for packets with IP_DF set, claiming it was needed for some VJ compression implementations. As mentioned in this referenced document, this can be abused. (Ref: Off-Path TCP Exploits of the Mixed IPID Assignment) Before switching to pure random IPID generation and possibly hurt some workloads, lets use the private inet socket generator. Not only this will remove one vulnerability, this will also improve performance of TCP flows using pmtudisc==IP_PMTUDISC_DONT Fixes: 73f156a6e8c1 ("inetpeer: get rid of ip_id_count") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reported-by: Ray Che <xijiache@gmail.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* net: fix information leakage in /proc/net/ptypeCongyu Liu2022-02-031-0/+1
| | | | | | | | | | | | | | | | | | | | commit 47934e06b65637c88a762d9c98329ae6e3238888 upstream. In one net namespace, after creating a packet socket without binding it to a device, users in other net namespaces can observe the new `packet_type` added by this packet socket by reading `/proc/net/ptype` file. This is minor information leakage as packet socket is namespace aware. Add a net pointer in `packet_type` to keep the net namespace of of corresponding packet socket. In `ptype_seq_show`, this net pointer must be checked when it is not NULL. Fixes: 2feb27dbe00c ("[NETNS]: Minor information leak via /proc/net/ptype file.") Signed-off-by: Congyu Liu <liu3101@purdue.edu> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* net_sched: restore "mpu xxx" handlingKevin Bracey2022-01-271-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit fb80445c438c78b40b547d12b8d56596ce4ccfeb upstream. commit 56b765b79e9a ("htb: improved accuracy at high rates") broke "overhead X", "linklayer atm" and "mpu X" attributes. "overhead X" and "linklayer atm" have already been fixed. This restores the "mpu X" handling, as might be used by DOCSIS or Ethernet shaping: tc class add ... htb rate X overhead 4 mpu 64 The code being fixed is used by htb, tbf and act_police. Cake has its own mpu handling. qdisc_calculate_pkt_len still uses the size table containing values adjusted for mpu by user space. iproute2 tc has always passed mpu into the kernel via a tc_ratespec structure, but the kernel never directly acted on it, merely stored it so that it could be read back by `tc class show`. Rather, tc would generate length-to-time tables that included the mpu (and linklayer) in their construction, and the kernel used those tables. Since v3.7, the tables were no longer used. Along with "mpu", this also broke "overhead" and "linklayer" which were fixed in 01cb71d2d47b ("net_sched: restore "overhead xxx" handling", v3.10) and 8a8e3d84b171 ("net_sched: restore "linklayer atm" handling", v3.11). "overhead" was fixed by simply restoring use of tc_ratespec::overhead - this had originally been used by the kernel but was initially omitted from the new non-table-based calculations. "linklayer" had been handled in the table like "mpu", but the mode was not originally passed in tc_ratespec. The new implementation was made to handle it by getting new versions of tc to pass the mode in an extended tc_ratespec, and for older versions of tc the table contents were analysed at load time to deduce linklayer. As "mpu" has always been given to the kernel in tc_ratespec, accompanying the mpu-based table, we can restore system functionality with no userspace change by making the kernel act on the tc_ratespec value. Fixes: 56b765b79e9a ("htb: improved accuracy at high rates") Signed-off-by: Kevin Bracey <kevin@bracey.fi> Cc: Eric Dumazet <edumazet@google.com> Cc: Jiri Pirko <jiri@resnulli.us> Cc: Vimalkumar <j.vimal@gmail.com> Link: https://lore.kernel.org/r/20220112170210.1014351-1-kevin@bracey.fi Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* uapi: fix linux/nfc.h userspace compilation errorsDmitry V. Levin2022-01-051-2/+2
| | | | | | | | | | | | | | | | | | | | commit 7175f02c4e5f5a9430113ab9ca0fd0ce98b28a51 upstream. Replace sa_family_t with __kernel_sa_family_t to fix the following linux/nfc.h userspace compilation errors: /usr/include/linux/nfc.h:266:2: error: unknown type name 'sa_family_t' sa_family_t sa_family; /usr/include/linux/nfc.h:274:2: error: unknown type name 'sa_family_t' sa_family_t sa_family; Fixes: 23b7869c0fd0 ("NFC: add the NFC socket raw protocol") Fixes: d646960f7986 ("NFC: Initial LLCP support") Cc: <stable@vger.kernel.org> Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* nfc: uapi: use kernel size_t to fix user-space buildsKrzysztof Kozlowski2022-01-051-1/+1
| | | | | | | | | | | | | | | | | commit 79b69a83705e621b258ac6d8ae6d3bfdb4b930aa upstream. Fix user-space builds if it includes /usr/include/linux/nfc.h before some of other headers: /usr/include/linux/nfc.h:281:9: error: unknown type name ‘size_t’ 281 | size_t service_name_len; | ^~~~~~ Fixes: d646960f7986 ("NFC: Initial LLCP support") Cc: <stable@vger.kernel.org> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* wait: add wake_up_pollfree()Eric Biggers2021-12-141-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 42288cb44c4b5fff7653bc392b583a2b8bd6a8c0 upstream. Several ->poll() implementations are special in that they use a waitqueue whose lifetime is the current task, rather than the struct file as is normally the case. This is okay for blocking polls, since a blocking poll occurs within one task; however, non-blocking polls require another solution. This solution is for the queue to be cleared before it is freed, using 'wake_up_poll(wq, EPOLLHUP | POLLFREE);'. However, that has a bug: wake_up_poll() calls __wake_up() with nr_exclusive=1. Therefore, if there are multiple "exclusive" waiters, and the wakeup function for the first one returns a positive value, only that one will be called. That's *not* what's needed for POLLFREE; POLLFREE is special in that it really needs to wake up everyone. Considering the three non-blocking poll systems: - io_uring poll doesn't handle POLLFREE at all, so it is broken anyway. - aio poll is unaffected, since it doesn't support exclusive waits. However, that's fragile, as someone could add this feature later. - epoll doesn't appear to be broken by this, since its wakeup function returns 0 when it sees POLLFREE. But this is fragile. Although there is a workaround (see epoll), it's better to define a function which always sends POLLFREE to all waiters. Add such a function. Also make it verify that the queue really becomes empty after all waiters have been woken up. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20211209010455.42744-2-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* HID: add hid_is_usb() function to make it simpler for USB detectionGreg Kroah-Hartman2021-12-141-0/+5
| | | | | | | | | | | | | | | | | | | | | commit f83baa0cb6cfc92ebaf7f9d3a99d7e34f2e77a8a upstream. A number of HID drivers already call hid_is_using_ll_driver() but only for the detection of if this is a USB device or not. Make this more obvious by creating hid_is_usb() and calling the function that way. Also converts the existing hid_is_using_ll_driver() functions to use the new call. Cc: Jiri Kosina <jikos@kernel.org> Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com> Cc: linux-input@vger.kernel.org Cc: stable@vger.kernel.org Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Link: https://lore.kernel.org/r/20211201183503.2373082-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* HID: introduce hid_is_using_ll_driverJason Gerecke2021-12-141-0/+11
| | | | | | | | | | | | | | | | | | | | commit fc2237a724a9e448599076d7d23497f51e2f7441 upstream. Although HID itself is transport-agnostic, occasionally a driver may want to interact with the low-level transport that a device is connected through. To do this, we need to know what kind of bus is in use. The first guess may be to look at the 'bus' field of the 'struct hid_device', but this field may be emulated in some cases (e.g. uhid). More ideally, we can check which ll_driver a device is using. This function introduces a 'hid_is_using_ll_driver' function and makes the 'struct hid_ll_driver' of the four most common transports accessible through hid.h. Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com> Acked-By: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* siphash: use _unaligned version by defaultArnd Bergmann2021-12-081-10/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit f7e5b9bfa6c8820407b64eabc1f29c9a87e8993d upstream. On ARM v6 and later, we define CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS because the ordinary load/store instructions (ldr, ldrh, ldrb) can tolerate any misalignment of the memory address. However, load/store double and load/store multiple instructions (ldrd, ldm) may still only be used on memory addresses that are 32-bit aligned, and so we have to use the CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS macro with care, or we may end up with a severe performance hit due to alignment traps that require fixups by the kernel. Testing shows that this currently happens with clang-13 but not gcc-11. In theory, any compiler version can produce this bug or other problems, as we are dealing with undefined behavior in C99 even on architectures that support this in hardware, see also https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100363. Fortunately, the get_unaligned() accessors do the right thing: when building for ARMv6 or later, the compiler will emit unaligned accesses using the ordinary load/store instructions (but avoid the ones that require 32-bit alignment). When building for older ARM, those accessors will emit the appropriate sequence of ldrb/mov/orr instructions. And on architectures that can truly tolerate any kind of misalignment, the get_unaligned() accessors resolve to the leXX_to_cpup accessors that operate on aligned addresses. Since the compiler will in fact emit ldrd or ldm instructions when building this code for ARM v6 or later, the solution is to use the unaligned accessors unconditionally on architectures where this is known to be fast. The _aligned version of the hash function is however still needed to get the best performance on architectures that cannot do any unaligned access in hardware. This new version avoids the undefined behavior and should produce the fastest hash on all architectures we support. Link: https://lore.kernel.org/linux-arm-kernel/20181008211554.5355-4-ard.biesheuvel@linaro.org/ Link: https://lore.kernel.org/linux-crypto/CAK8P3a2KfmmGDbVHULWevB0hv71P2oi2ZCHEAqT=8dQfa0=cqQ@mail.gmail.com/ Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Fixes: 2c956a60778c ("siphash: add cryptographically secure PRF") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* fs: add fget_many() and fput_many()Jens Axboe2021-12-082-1/+5
| | | | | | | | | | | | | | | | | | commit 091141a42e15fe47ada737f3996b317072afcefb upstream. Some uses cases repeatedly get and put references to the same file, but the only exposed interface is doing these one at the time. As each of these entail an atomic inc or dec on a shared structure, that cost can add up. Add fget_many(), which works just like fget(), except it takes an argument for how many references to get on the file. Ditto fput_many(), which can drop an arbitrary number of references to a file. Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kprobes: Limit max data_size of the kretprobe instancesMasami Hiramatsu2021-12-081-0/+2
| | | | | | | | | | | | | | | | | | | | | | | commit 6bbfa44116689469267f1a6e3d233b52114139d2 upstream. The 'kprobe::data_size' is unsigned, thus it can not be negative. But if user sets it enough big number (e.g. (size_t)-8), the result of 'data_size + sizeof(struct kretprobe_instance)' becomes smaller than sizeof(struct kretprobe_instance) or zero. In result, the kretprobe_instance are allocated without enough memory, and kretprobe accesses outside of allocated memory. To avoid this issue, introduce a max limitation of the kretprobe::data_size. 4KB per instance should be OK. Link: https://lkml.kernel.org/r/163836995040.432120.10322772773821182925.stgit@devnote2 Cc: stable@vger.kernel.org Fixes: f47cd9b553aa ("kprobes: kretprobe user entry-handler") Reported-by: zhangyue <zhangyue1@kylinos.cn> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* xen: sync include/xen/interface/io/ring.h with Xen's newest versionJuergen Gross2021-12-081-133/+124
| | | | | | | | | | | commit 629a5d87e26fe96bcaab44cbb81f5866af6f7008 upstream. Sync include/xen/interface/io/ring.h with Xen's newest version in order to get the RING_COPY_RESPONSE() and RING_RESPONSE_PROD_OVERFLOW() macros. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* shm: extend forced shm destroy to support objects from several IPC nsesAlexander Mikhalitsyn2021-12-083-3/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 85b6d24646e4125c591639841169baa98a2da503 upstream. Currently, the exit_shm() function not designed to work properly when task->sysvshm.shm_clist holds shm objects from different IPC namespaces. This is a real pain when sysctl kernel.shm_rmid_forced = 1, because it leads to use-after-free (reproducer exists). This is an attempt to fix the problem by extending exit_shm mechanism to handle shm's destroy from several IPC ns'es. To achieve that we do several things: 1. add a namespace (non-refcounted) pointer to the struct shmid_kernel 2. during new shm object creation (newseg()/shmget syscall) we initialize this pointer by current task IPC ns 3. exit_shm() fully reworked such that it traverses over all shp's in task->sysvshm.shm_clist and gets IPC namespace not from current task as it was before but from shp's object itself, then call shm_destroy(shp, ns). Note: We need to be really careful here, because as it was said before (1), our pointer to IPC ns non-refcnt'ed. To be on the safe side we using special helper get_ipc_ns_not_zero() which allows to get IPC ns refcounter only if IPC ns not in the "state of destruction". Q/A Q: Why can we access shp->ns memory using non-refcounted pointer? A: Because shp object lifetime is always shorther than IPC namespace lifetime, so, if we get shp object from the task->sysvshm.shm_clist while holding task_lock(task) nobody can steal our namespace. Q: Does this patch change semantics of unshare/setns/clone syscalls? A: No. It's just fixes non-covered case when process may leave IPC namespace without getting task->sysvshm.shm_clist list cleaned up. Link: https://lkml.kernel.org/r/67bb03e5-f79c-1815-e2bf-949c67047418@colorfullife.com Link: https://lkml.kernel.org/r/20211109151501.4921-1-manfred@colorfullife.com Fixes: ab602f79915 ("shm: make exit_shm work proportional to task activity") Co-developed-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Andrei Vagin <avagin@gmail.com> Cc: Pavel Tikhomirov <ptikhomirov@virtuozzo.com> Cc: Vasily Averin <vvs@virtuozzo.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* NFC: add NCI_UNREG flag to eliminate the raceLin Ma2021-12-081-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 48b71a9e66c2eab60564b1b1c85f4928ed04e406 upstream. There are two sites that calls queue_work() after the destroy_workqueue() and lead to possible UAF. The first site is nci_send_cmd(), which can happen after the nci_close_device as below nfcmrvl_nci_unregister_dev | nfc_genl_dev_up nci_close_device | flush_workqueue | del_timer_sync | nci_unregister_device | nfc_get_device destroy_workqueue | nfc_dev_up nfc_unregister_device | nci_dev_up device_del | nci_open_device | __nci_request | nci_send_cmd | queue_work !!! Another site is nci_cmd_timer, awaked by the nci_cmd_work from the nci_send_cmd. ... | ... nci_unregister_device | queue_work destroy_workqueue | nfc_unregister_device | ... device_del | nci_cmd_work | mod_timer | ... | nci_cmd_timer | queue_work !!! For the above two UAF, the root cause is that the nfc_dev_up can race between the nci_unregister_device routine. Therefore, this patch introduce NCI_UNREG flag to easily eliminate the possible race. In addition, the mutex_lock in nci_close_device can act as a barrier. Signed-off-by: Lin Ma <linma@zju.edu.cn> Fixes: 6a2968aaf50c ("NFC: basic NCI protocol implementation") Reviewed-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Link: https://lore.kernel.org/r/20211116152732.19238-1-linma@zju.edu.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* hugetlbfs: flush TLBs correctly after huge_pmd_unshareNadav Amit2021-12-081-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit a4a118f2eead1d6c49e00765de89878288d4b890 upstream. When __unmap_hugepage_range() calls to huge_pmd_unshare() succeed, a TLB flush is missing. This TLB flush must be performed before releasing the i_mmap_rwsem, in order to prevent an unshared PMDs page from being released and reused before the TLB flush took place. Arguably, a comprehensive solution would use mmu_gather interface to batch the TLB flushes and the PMDs page release, however it is not an easy solution: (1) try_to_unmap_one() and try_to_migrate_one() also call huge_pmd_unshare() and they cannot use the mmu_gather interface; and (2) deferring the release of the page reference for the PMDs page until after i_mmap_rwsem is dropeed can confuse huge_pmd_unshare() into thinking PMDs are shared when they are not. Fix __unmap_hugepage_range() by adding the missing TLB flush, and forcing a flush when unshare is successful. Fixes: 24669e58477e ("hugetlb: use mmu_gather instead of a temporary linked list for accumulating pages)" # 3.6 Signed-off-by: Nadav Amit <namit@vmware.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* net: ieee802154: handle iftypes as u32Alexander Aring2021-12-081-3/+4
| | | | | | | | | | | | | | | | | | | [ Upstream commit 451dc48c806a7ce9fbec5e7a24ccf4b2c936e834 ] This patch fixes an issue that an u32 netlink value is handled as a signed enum value which doesn't fit into the range of u32 netlink type. If it's handled as -1 value some BIT() evaluation ends in a shift-out-of-bounds issue. To solve the issue we set the to u32 max which is s32 "-1" value to keep backwards compatibility and let the followed enum values start counting at 0. This brings the compiler to never handle the enum as signed and a check if the value is above NL802154_IFTYPE_MAX should filter -1 out. Fixes: f3ea5e44231a ("ieee802154: add new interface command") Signed-off-by: Alexander Aring <aahringo@redhat.com> Link: https://lore.kernel.org/r/20211112030916.685793-1-aahringo@redhat.com Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* scsi: target: Fix ordered tag handlingMike Christie2021-11-261-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit ed1227e080990ffec5bf39006ec8a57358e6689a ] This patch fixes the following bugs: 1. If there are multiple ordered cmds queued and multiple simple cmds completing, target_restart_delayed_cmds() could be called on different CPUs and each instance could start a ordered cmd. They could then run in different orders than they were queued. 2. target_restart_delayed_cmds() and target_handle_task_attr() can race where: 1. target_handle_task_attr() has passed the simple_cmds == 0 check. 2. transport_complete_task_attr() then decrements simple_cmds to 0. 3. transport_complete_task_attr() runs target_restart_delayed_cmds() and it does not see any cmds on the delayed_cmd_list. 4. target_handle_task_attr() adds the cmd to the delayed_cmd_list. The cmd will then end up timing out. 3. If we are sent > 1 ordered cmds and simple_cmds == 0, we can execute them out of order, because target_handle_task_attr() will hit that simple_cmds check first and return false for all ordered cmds sent. 4. We run target_restart_delayed_cmds() after every cmd completion, so if there is more than 1 simple cmd running, we start executing ordered cmds after that first cmd instead of waiting for all of them to complete. 5. Ordered cmds are not supposed to start until HEAD OF QUEUE and all older cmds have completed, and not just simple. 6. It's not a bug but it doesn't make sense to take the delayed_cmd_lock for every cmd completion when ordered cmds are almost never used. Just replacing that lock with an atomic increases IOPs by up to 10% when completions are spread over multiple CPUs and there are multiple sessions/ mqs/thread accessing the same device. This patch moves the queued delayed handling to a per device work to serialze the cmd executions for each device and adds a new counter to track HEAD_OF_QUEUE and SIMPLE cmds. We can then check the new counter to determine when to run the work on the completion path. Link: https://lore.kernel.org/r/20210930020422.92578-3-michael.christie@oracle.com Signed-off-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* PCI: Add PCI_EXP_DEVCTL_PAYLOAD_* macrosPali Rohár2021-11-261-0/+6
| | | | | | | | | | | | | | | commit 460275f124fb072dca218a6b43b6370eebbab20d upstream. Define a macro PCI_EXP_DEVCTL_PAYLOAD_* for every possible Max Payload Size in linux/pci_regs.h, in the same style as PCI_EXP_DEVCTL_READRQ_*. Link: https://lore.kernel.org/r/20211005180952.6812-2-kabel@kernel.org Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Marek Behún <kabel@kernel.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Marek Behún <kabel@kernel.org> Reviewed-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* llc: fix out-of-bound array index in llc_sk_dev_hash()Eric Dumazet2021-11-261-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 8ac9dfd58b138f7e82098a4e0a0d46858b12215b ] Both ifindex and LLC_SK_DEV_HASH_ENTRIES are signed. This means that (ifindex % LLC_SK_DEV_HASH_ENTRIES) is negative if @ifindex is negative. We could simply make LLC_SK_DEV_HASH_ENTRIES unsigned. In this patch I chose to use hash_32() to get more entropy from @ifindex, like llc_sk_laddr_hashfn(). UBSAN: array-index-out-of-bounds in ./include/net/llc.h:75:26 index -43 is out of range for type 'hlist_head [64]' CPU: 1 PID: 20999 Comm: syz-executor.3 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 ubsan_epilogue+0xb/0x5a lib/ubsan.c:151 __ubsan_handle_out_of_bounds.cold+0x62/0x6c lib/ubsan.c:291 llc_sk_dev_hash include/net/llc.h:75 [inline] llc_sap_add_socket+0x49c/0x520 net/llc/llc_conn.c:697 llc_ui_bind+0x680/0xd70 net/llc/af_llc.c:404 __sys_bind+0x1e9/0x250 net/socket.c:1693 __do_sys_bind net/socket.c:1704 [inline] __se_sys_bind net/socket.c:1702 [inline] __x64_sys_bind+0x6f/0xb0 net/socket.c:1702 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fa503407ae9 Fixes: 6d2e3ea28446 ("llc: use a device based hash table to speed up multicast delivery") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
* libata: fix read log timeout valueDamien Le Moal2021-11-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 68dbbe7d5b4fde736d104cbbc9a2fce875562012 upstream. Some ATA drives are very slow to respond to READ_LOG_EXT and READ_LOG_DMA_EXT commands issued from ata_dev_configure() when the device is revalidated right after resuming a system or inserting the ATA adapter driver (e.g. ahci). The default 5s timeout (ATA_EH_CMD_DFL_TIMEOUT) used for these commands is too short, causing errors during the device configuration. Ex: ... ata9: SATA max UDMA/133 abar m524288@0x9d200000 port 0x9d200400 irq 209 ata9: SATA link up 6.0 Gbps (SStatus 133 SControl 300) ata9.00: ATA-9: XXX XXXXXXXXXXXXXXX, XXXXXXXX, max UDMA/133 ata9.00: qc timeout (cmd 0x2f) ata9.00: Read log page 0x00 failed, Emask 0x4 ata9.00: Read log page 0x00 failed, Emask 0x40 ata9.00: NCQ Send/Recv Log not supported ata9.00: Read log page 0x08 failed, Emask 0x40 ata9.00: 27344764928 sectors, multi 16: LBA48 NCQ (depth 32), AA ata9.00: Read log page 0x00 failed, Emask 0x40 ata9.00: ATA Identify Device Log not supported ata9.00: failed to set xfermode (err_mask=0x40) ata9: SATA link up 6.0 Gbps (SStatus 133 SControl 300) ata9.00: configured for UDMA/133 ... The timeout error causes a soft reset of the drive link, followed in most cases by a successful revalidation as that give enough time to the drive to become fully ready to quickly process the read log commands. However, in some cases, this also fails resulting in the device being dropped. Fix this by using adding the ata_eh_revalidate_timeouts entries for the READ_LOG_EXT and READ_LOG_DMA_EXT commands. This defines a timeout increased to 15s, retriable one time. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: use cred instead of task for selinux checksTodd Kjos2021-11-262-30/+30
| | | | | | | | | | | | | | | | | | | | | | | commit 52f88693378a58094c538662ba652aff0253c4fe upstream. Since binder was integrated with selinux, it has passed 'struct task_struct' associated with the binder_proc to represent the source and target of transactions. The conversion of task to SID was then done in the hook implementations. It turns out that there are race conditions which can result in an incorrect security context being used. Fix by using the 'struct cred' saved during binder_open and pass it to the selinux subsystem. Cc: stable@vger.kernel.org # 5.14 (need backport for earlier stables) Fixes: 79af73079d75 ("Add security hooks to binder and implement the hooks for SELinux.") Suggested-by: Jann Horn <jannh@google.com> Signed-off-by: Todd Kjos <tkjos@google.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* elfcore: correct reference to CONFIG_UMLLukas Bulwahn2021-10-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit b0e901280d9860a0a35055f220e8e457f300f40a upstream. Commit 6e7b64b9dd6d ("elfcore: fix building with clang") introduces special handling for two architectures, ia64 and User Mode Linux. However, the wrong name, i.e., CONFIG_UM, for the intended Kconfig symbol for User-Mode Linux was used. Although the directory for User Mode Linux is ./arch/um; the Kconfig symbol for this architecture is called CONFIG_UML. Luckily, ./scripts/checkkconfigsymbols.py warns on non-existing configs: UM Referencing files: include/linux/elfcore.h Similar symbols: UML, NUMA Correct the name of the config to the intended one. [akpm@linux-foundation.org: fix um/x86_64, per Catalin] Link: https://lkml.kernel.org/r/20211006181119.2851441-1-catalin.marinas@arm.com Link: https://lkml.kernel.org/r/YV6pejGzLy5ppEpt@arm.com Link: https://lkml.kernel.org/r/20211006082209.417-1-lukas.bulwahn@gmail.com Fixes: 6e7b64b9dd6d ("elfcore: fix building with clang") Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Barret Rhoden <brho@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* libata: Add ATA_HORKAGE_NO_NCQ_ON_ATI for Samsung 860 and 870 SSD.Kate Hsuan2021-10-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 7a8526a5cd51cf5f070310c6c37dd7293334ac49 upstream. Many users are reporting that the Samsung 860 and 870 SSD are having various issues when combined with AMD/ATI (vendor ID 0x1002) SATA controllers and only completely disabling NCQ helps to avoid these issues. Always disabling NCQ for Samsung 860/870 SSDs regardless of the host SATA adapter vendor will cause I/O performance degradation with well behaved adapters. To limit the performance impact to ATI adapters, introduce the ATA_HORKAGE_NO_NCQ_ON_ATI flag to force disable NCQ only for these adapters. Also, two libata.force parameters (noncqati and ncqati) are introduced to disable and enable the NCQ for the system which equipped with ATI SATA adapter and Samsung 860 and 870 SSDs. The user can determine NCQ function to be enabled or disabled according to the demand. After verifying the chipset from the user reports, the issue appears on AMD/ATI SB7x0/SB8x0/SB9x0 SATA Controllers and does not appear on recent AMD SATA adapters. The vendor ID of ATI should be 0x1002. Therefore, ATA_HORKAGE_NO_NCQ_ON_AMD was modified to ATA_HORKAGE_NO_NCQ_ON_ATI. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=201693 Signed-off-by: Kate Hsuan <hpa@redhat.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20210903094411.58749-1-hpa@redhat.com Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Cc: Krzysztof Olędzki <ole@ans.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* af_unix: fix races in sk_peer_pid and sk_peer_cred accessesEric Dumazet2021-10-091-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 35306eb23814444bd4021f8a1c3047d3cb0c8b2b upstream. Jann Horn reported that SO_PEERCRED and SO_PEERGROUPS implementations are racy, as af_unix can concurrently change sk_peer_pid and sk_peer_cred. In order to fix this issue, this patch adds a new spinlock that needs to be used whenever these fields are read or written. Jann also pointed out that l2cap_sock_get_peer_pid_cb() is currently reading sk->sk_peer_pid which makes no sense, as this field is only possibly set by AF_UNIX sockets. We will have to clean this in a separate patch. This could be done by reverting b48596d1dc25 "Bluetooth: L2CAP: Add get_peer_pid callback" or implementing what was truly expected. Fixes: 109f6e39fa07 ("af_unix: Allow SO_PEERCRED to work across namespaces.") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Jann Horn <jannh@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Cc: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: David S. Miller <davem@davemloft.net> [backport note: 4.4 and 4.9 don't have SO_PEERGROUPS, only SO_PEERCRED] [backport note: got rid of sk_get_peer_cred(), no users in 4.4/4.9] Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* cred: allow get_cred() and put_cred() to be given NULL.NeilBrown2021-10-061-5/+9
| | | | | | | | | | | | | | | commit f06bc03339ad4c1baa964a5f0606247ac1c3c50b upstream. It is common practice for helpers like this to silently, accept a NULL pointer. get_rpccred() and put_rpccred() used by NFS act this way and using the same interface will ease the conversion for NFS, and simplify the resulting code. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* compiler.h: Introduce absolute_pointer macroGuenter Roeck2021-10-061-0/+2
| | | | | | | | | | | | | | | | | | | | [ Upstream commit f6b5f1a56987de837f8e25cd560847106b8632a8 ] absolute_pointer() disassociates a pointer from its originating symbol type and context. Use it to prevent compiler warnings/errors such as drivers/net/ethernet/i825xx/82596.c: In function 'i82596_probe': arch/m68k/include/asm/string.h:72:25: error: '__builtin_memcpy' reading 6 bytes from a region of size 0 [-Werror=stringop-overread] Such warnings may be reported by gcc 11.x for string and memory operations on fixed addresses. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* sctp: validate from_addr_param returnMarcelo Ricardo Leitner2021-09-261-1/+1
| | | | | | | | | | | | | | | | | | | commit 0c5dc070ff3d6246d22ddd931f23a6266249e3db upstream. Ilja reported that, simply putting it, nothing was validating that from_addr_param functions were operating on initialized memory. That is, the parameter itself was being validated by sctp_walk_params, but it doesn't check for types and their specific sizes and it could be a 0-length one, causing from_addr_param to potentially work over the next parameter or even uninitialized memory. The fix here is to, in all calls to from_addr_param, check if enough space is there for the wanted IP address type. Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* PCI: Sync __pci_register_driver() stub for CONFIG_PCI=nAndy Shevchenko2021-09-221-2/+3
| | | | | | | | | | | | | | | [ Upstream commit 817f9916a6e96ae43acdd4e75459ef4f92d96eb1 ] The CONFIG_PCI=y case got a new parameter long time ago. Sync the stub as well. [bhelgaas: add parameter names] Fixes: 725522b5453d ("PCI: add the sysfs driver name to all modules") Link: https://lore.kernel.org/r/20210813153619.89574-1-andriy.shevchenko@linux.intel.com Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* net/af_unix: fix a data-race in unix_dgram_pollEric Dumazet2021-09-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 04f08eb44b5011493d77b602fdec29ff0f5c6cd5 upstream. syzbot reported another data-race in af_unix [1] Lets change __skb_insert() to use WRITE_ONCE() when changing skb head qlen. Also, change unix_dgram_poll() to use lockless version of unix_recvq_full() It is verry possible we can switch all/most unix_recvq_full() to the lockless version, this will be done in a future kernel version. [1] HEAD commit: 8596e589b787732c8346f0482919e83cc9362db1 BUG: KCSAN: data-race in skb_queue_tail / unix_dgram_poll write to 0xffff88814eeb24e0 of 4 bytes by task 25815 on cpu 0: __skb_insert include/linux/skbuff.h:1938 [inline] __skb_queue_before include/linux/skbuff.h:2043 [inline] __skb_queue_tail include/linux/skbuff.h:2076 [inline] skb_queue_tail+0x80/0xa0 net/core/skbuff.c:3264 unix_dgram_sendmsg+0xff2/0x1600 net/unix/af_unix.c:1850 sock_sendmsg_nosec net/socket.c:703 [inline] sock_sendmsg net/socket.c:723 [inline] ____sys_sendmsg+0x360/0x4d0 net/socket.c:2392 ___sys_sendmsg net/socket.c:2446 [inline] __sys_sendmmsg+0x315/0x4b0 net/socket.c:2532 __do_sys_sendmmsg net/socket.c:2561 [inline] __se_sys_sendmmsg net/socket.c:2558 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2558 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff88814eeb24e0 of 4 bytes by task 25834 on cpu 1: skb_queue_len include/linux/skbuff.h:1869 [inline] unix_recvq_full net/unix/af_unix.c:194 [inline] unix_dgram_poll+0x2bc/0x3e0 net/unix/af_unix.c:2777 sock_poll+0x23e/0x260 net/socket.c:1288 vfs_poll include/linux/poll.h:90 [inline] ep_item_poll fs/eventpoll.c:846 [inline] ep_send_events fs/eventpoll.c:1683 [inline] ep_poll fs/eventpoll.c:1798 [inline] do_epoll_wait+0x6ad/0xf00 fs/eventpoll.c:2226 __do_sys_epoll_wait fs/eventpoll.c:2238 [inline] __se_sys_epoll_wait fs/eventpoll.c:2233 [inline] __x64_sys_epoll_wait+0xf6/0x120 fs/eventpoll.c:2233 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x0000001b -> 0x00000001 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 25834 Comm: syz-executor.1 Tainted: G W 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: 86b18aaa2b5b ("skbuff: fix a data race in skb_queue_len()") Cc: Qian Cai <cai@lca.pw> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: 8250: Define RX trigger levels for OxSemi 950 devicesMaciej W. Rozycki2021-09-221-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit d7aff291d069c4418285f3c8ee27b0ff67ce5998 ] Oxford Semiconductor 950 serial port devices have a 128-byte FIFO and in the enhanced (650) mode, which we select in `autoconfig_has_efr' with the ECB bit set in the EFR register, they support the receive interrupt trigger level selectable with FCR bits 7:6 from the set of 16, 32, 112, 120. This applies to the original OX16C950 discrete UART[1] as well as 950 cores embedded into more complex devices. For these devices we set the default to 112, which sets an excessively high level of 112 or 7/8 of the FIFO capacity, unlike with other port types where we choose at most 1/2 of their respective FIFO capacities. Additionally we don't make the trigger level configurable. Consequently frequent input overruns happen with high bit rates where hardware flow control cannot be used (e.g. terminal applications) even with otherwise highly-performant systems. Lower the default receive interrupt trigger level to 32 then, and make it configurable. Document the trigger levels along with other port types, including the set of 16, 32, 64, 112 for the transmit interrupt as well[2]. References: [1] "OX16C950 rev B High Performance UART with 128 byte FIFOs", Oxford Semiconductor, Inc., DS-0031, Sep 05, Table 10: "Receiver Trigger Levels", p. 22 [2] same, Table 9: "Transmit Interrupt Trigger Levels", p. 22 Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2106260608480.37803@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* power: supply: max17042_battery: fix typo in MAx17042_TOFFSebastian Krzyszkowiak2021-09-221-1/+1
| | | | | | | | [ Upstream commit ed0d0a0506025f06061325cedae1bbebd081620a ] Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* vmlinux.lds.h: Handle clang's module.{c,d}tor sectionsNathan Chancellor2021-08-261-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 848378812e40152abe9b9baf58ce2004f76fb988 upstream. A recent change in LLVM causes module_{c,d}tor sections to appear when CONFIG_K{A,C}SAN are enabled, which results in orphan section warnings because these are not handled anywhere: ld.lld: warning: arch/x86/pci/built-in.a(legacy.o):(.text.asan.module_ctor) is being placed in '.text.asan.module_ctor' ld.lld: warning: arch/x86/pci/built-in.a(legacy.o):(.text.asan.module_dtor) is being placed in '.text.asan.module_dtor' ld.lld: warning: arch/x86/pci/built-in.a(legacy.o):(.text.tsan.module_ctor) is being placed in '.text.tsan.module_ctor' Fangrui explains: "the function asan.module_ctor has the SHF_GNU_RETAIN flag, so it is in a separate section even with -fno-function-sections (default)". Place them in the TEXT_TEXT section so that these technologies continue to work with the newer compiler versions. All of the KASAN and KCSAN KUnit tests continue to pass after this change. Cc: stable@vger.kernel.org Link: https://github.com/ClangBuiltLinux/linux/issues/1432 Link: https://github.com/llvm/llvm-project/commit/7b789562244ee941b7bf2cefeb3fc08a59a01865 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Fangrui Song <maskray@google.com> Acked-by: Marco Elver <elver@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210731023107.1932981-1-nathan@kernel.org [nc: Fix conflicts due to lack of cf68fffb66d60 and 266ff2a8f51f0] Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* PCI/MSI: Protect msi_desc::masked for multi-MSIThomas Gleixner2021-08-262-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 77e89afc25f30abd56e76a809ee2884d7c1b63ce upstream. Multi-MSI uses a single MSI descriptor and there is a single mask register when the device supports per vector masking. To avoid reading back the mask register the value is cached in the MSI descriptor and updates are done by clearing and setting bits in the cache and writing it to the device. But nothing protects msi_desc::masked and the mask register from being modified concurrently on two different CPUs for two different Linux interrupts which belong to the same multi-MSI descriptor. Add a lock to struct device and protect any operation on the mask and the mask register with it. This makes the update of msi_desc::masked unconditional, but there is no place which requires a modification of the hardware register without updating the masked cache. msi_mask_irq() is now an empty wrapper which will be cleaned up in follow up changes. The problem goes way back to the initial support of multi-MSI, but picking the commit which introduced the mask cache is a valid cut off point (2.6.30). Fixes: f2440d9acbe8 ("PCI MSI: Refactor interrupt masking code") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210729222542.726833414@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Bluetooth: defer cleanup of resources in hci_unregister_dev()Tetsuo Handa2021-08-151-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit e04480920d1eec9c061841399aa6f35b6f987d8b ] syzbot is hitting might_sleep() warning at hci_sock_dev_event() due to calling lock_sock() with rw spinlock held [1]. It seems that history of this locking problem is a trial and error. Commit b40df5743ee8 ("[PATCH] bluetooth: fix socket locking in hci_sock_dev_event()") in 2.6.21-rc4 changed bh_lock_sock() to lock_sock() as an attempt to fix lockdep warning. Then, commit 4ce61d1c7a8e ("[BLUETOOTH]: Fix locking in hci_sock_dev_event().") in 2.6.22-rc2 changed lock_sock() to local_bh_disable() + bh_lock_sock_nested() as an attempt to fix the sleep in atomic context warning. Then, commit 4b5dd696f81b ("Bluetooth: Remove local_bh_disable() from hci_sock.c") in 3.3-rc1 removed local_bh_disable(). Then, commit e305509e678b ("Bluetooth: use correct lock to prevent UAF of hdev object") in 5.13-rc5 again changed bh_lock_sock_nested() to lock_sock() as an attempt to fix CVE-2021-3573. This difficulty comes from current implementation that hci_sock_dev_event(HCI_DEV_UNREG) is responsible for dropping all references from sockets because hci_unregister_dev() immediately reclaims resources as soon as returning from hci_sock_dev_event(HCI_DEV_UNREG). But the history suggests that hci_sock_dev_event(HCI_DEV_UNREG) was not doing what it should do. Therefore, instead of trying to detach sockets from device, let's accept not detaching sockets from device at hci_sock_dev_event(HCI_DEV_UNREG), by moving actual cleanup of resources from hci_unregister_dev() to hci_cleanup_dev() which is called by bt_host_release() when all references to this unregistered device (which is a kobject) are gone. Since hci_sock_dev_event(HCI_DEV_UNREG) no longer resets hci_pi(sk)->hdev, we need to check whether this device was unregistered and return an error based on HCI_UNREGISTER flag. There might be subtle behavioral difference in "monitor the hdev" functionality; please report if you found something went wrong due to this patch. Link: https://syzkaller.appspot.com/bug?extid=a5df189917e79d5e59c9 [1] Reported-by: syzbot <syzbot+a5df189917e79d5e59c9@syzkaller.appspotmail.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Fixes: e305509e678b ("Bluetooth: use correct lock to prevent UAF of hdev object") Acked-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* rcu: Update documentation of rcu_read_unlock()Anna-Maria Gleixner2021-08-101-3/+1
| | | | | | | | | | | | | | | | | | | | | | [ Upstream commit ec84b27f9b3b569f9235413d1945a2006b97b0aa ] Since commit b4abf91047cf ("rtmutex: Make wait_lock irq safe") the explanation in rcu_read_unlock() documentation about irq unsafe rtmutex wait_lock is no longer valid. Remove it to prevent kernel developers reading the documentation to rely on it. Suggested-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: bigeasy@linutronix.de Link: https://lkml.kernel.org/r/20180525090507.22248-2-anna-maria@linutronix.de Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Acked-by: Joe Korty <joe.korty@concurrent-rt.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* regulator: rt5033: Fix n_voltages settings for BUCK and LDOAxel Lin2021-08-081-2/+2
| | | | | | | | | | | | | | | | | [ Upstream commit 6549c46af8551b346bcc0b9043f93848319acd5c ] For linear regulators, the n_voltages should be (max - min) / step + 1. Buck voltage from 1v to 3V, per step 100mV, and vout mask is 0x1f. If value is from 20 to 31, the voltage will all be fixed to 3V. And LDO also, just vout range is different from 1.2v to 3v, step is the same. If value is from 18 to 31, the voltage will also be fixed to 3v. Signed-off-by: Axel Lin <axel.lin@ingics.com> Reviewed-by: ChiYuan Huang <cy_huang@richtek.com> Link: https://lore.kernel.org/r/20210627080418.1718127-1-axel.lin@ingics.com Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* net: llc: fix skb_over_panicPavel Skripkin2021-08-041-8/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit c7c9d2102c9c098916ab9e0ab248006107d00d6c ] Syzbot reported skb_over_panic() in llc_pdu_init_as_xid_cmd(). The problem was in wrong LCC header manipulations. Syzbot's reproducer tries to send XID packet. llc_ui_sendmsg() is doing following steps: 1. skb allocation with size = len + header size len is passed from userpace and header size is 3 since addr->sllc_xid is set. 2. skb_reserve() for header_len = 3 3. filling all other space with memcpy_from_msg() Ok, at this moment we have fully loaded skb, only headers needs to be filled. Then code comes to llc_sap_action_send_xid_c(). This function pushes 3 bytes for LLC PDU header and initializes it. Then comes llc_pdu_init_as_xid_cmd(). It initalizes next 3 bytes *AFTER* LLC PDU header and call skb_push(skb, 3). This looks wrong for 2 reasons: 1. Bytes rigth after LLC header are user data, so this function was overwriting payload. 2. skb_push(skb, 3) call can cause skb_over_panic() since all free space was filled in llc_ui_sendmsg(). (This can happen is user passed 686 len: 686 + 14 (eth header) + 3 (LLC header) = 703. SKB_DATA_ALIGN(703) = 704) So, in this patch I added 2 new private constansts: LLC_PDU_TYPE_U_XID and LLC_PDU_LEN_U_XID. LLC_PDU_LEN_U_XID is used to correctly reserve header size to handle LLC + XID case. LLC_PDU_TYPE_U_XID is used by llc_pdu_header_init() function to push 6 bytes instead of 3. And finally I removed skb_push() call from llc_pdu_init_as_xid_cmd(). This changes should not affect other parts of LLC, since after all steps we just transmit buffer. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-and-tested-by: syzbot+5e5a981ad7cc54c4b2b4@syzkaller.appspotmail.com Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
* lib/string.c: add multibyte memset functionsMatthew Wilcox2021-08-041-0/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 3b3c4babd898715926d24ae10aa64778ace33aae upstream. Patch series "Multibyte memset variations", v4. A relatively common idiom we're missing is a function to fill an area of memory with a pattern which is larger than a single byte. I first noticed this with a zram patch which wanted to fill a page with an 'unsigned long' value. There turn out to be quite a few places in the kernel which can benefit from using an optimised function rather than a loop; sometimes text size, sometimes speed, and sometimes both. The optimised PowerPC version (not included here) improves performance by about 30% on POWER8 on just the raw memset_l(). Most of the extra lines of code come from the three testcases I added. This patch (of 8): memset16(), memset32() and memset64() are like memset(), but allow the caller to fill the destination with a value larger than a single byte. memset_l() and memset_p() allow the caller to use unsigned long and pointer values respectively. Link: http://lkml.kernel.org/r/20170720184539.31609-2-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: David Miller <davem@davemloft.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Minchan Kim <minchan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Russell King <rmk+kernel@armlinux.org.uk> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Nobuhiro Iwamatsu (CIP) <nobuhiro1.iwamatsu@toshiba.co.jp> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sctp: move 198 addresses from unusable to private scopeXin Long2021-08-041-3/+1
| | | | | | | | | | | | | | | | | [ Upstream commit 1d11fa231cabeae09a95cb3e4cf1d9dd34e00f08 ] The doc draft-stewart-tsvwg-sctp-ipv4-00 that restricts 198 addresses was never published. These addresses as private addresses should be allowed to use in SCTP. As Michael Tuexen suggested, this patch is to move 198 addresses from unusable to private scope. Reported-by: Sérgio <surkamp@gmail.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
* net: split out functions related to registering inflight socket filesJens Axboe2021-08-041-0/+1
| | | | | | | | | | | | | | | | | commit f4e65870e5cede5ca1ec0006b6c9803994e5f7b8 upstream. We need this functionality for the io_uring file registration, but we cannot rely on it since CONFIG_UNIX can be modular. Move the helpers to a separate file, that's always builtin to the kernel if CONFIG_UNIX is m/y. No functional changes in this patch, just moving code around. Reviewed-by: Hannes Reinecke <hare@suse.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jens Axboe <axboe@kernel.dk> [ backported to older kernels to get access to unix_gc_lock - gregkh ] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* net: validate lwtstate->data before returning from skb_tunnel_info()Taehee Yoo2021-07-281-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 67a9c94317402b826fc3db32afc8f39336803d97 upstream. skb_tunnel_info() returns pointer of lwtstate->data as ip_tunnel_info type without validation. lwtstate->data can have various types such as mpls_iptunnel_encap, etc and these are not compatible. So skb_tunnel_info() should validate before returning that pointer. Splat looks like: BUG: KASAN: slab-out-of-bounds in vxlan_get_route+0x418/0x4b0 [vxlan] Read of size 2 at addr ffff888106ec2698 by task ping/811 CPU: 1 PID: 811 Comm: ping Not tainted 5.13.0+ #1195 Call Trace: dump_stack_lvl+0x56/0x7b print_address_description.constprop.8.cold.13+0x13/0x2ee ? vxlan_get_route+0x418/0x4b0 [vxlan] ? vxlan_get_route+0x418/0x4b0 [vxlan] kasan_report.cold.14+0x83/0xdf ? vxlan_get_route+0x418/0x4b0 [vxlan] vxlan_get_route+0x418/0x4b0 [vxlan] [ ... ] vxlan_xmit_one+0x148b/0x32b0 [vxlan] [ ... ] vxlan_xmit+0x25c5/0x4780 [vxlan] [ ... ] dev_hard_start_xmit+0x1ae/0x6e0 __dev_queue_xmit+0x1f39/0x31a0 [ ... ] neigh_xmit+0x2f9/0x940 mpls_xmit+0x911/0x1600 [mpls_iptunnel] lwtunnel_xmit+0x18f/0x450 ip_finish_output2+0x867/0x2040 [ ... ] Fixes: 61adedf3e3f1 ("route: move lwtunnel state to dst_entry") Signed-off-by: Taehee Yoo <ap420073@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* net: ipv6: fix return value of ip6_skb_dst_mtuVadim Fedorenko2021-07-281-1/+1
| | | | | | | | | | | | | | | | | | commit 40fc3054b45820c28ea3c65e2c86d041dc244a8a upstream. Commit 628a5c561890 ("[INET]: Add IP(V6)_PMTUDISC_RPOBE") introduced ip6_skb_dst_mtu with return value of signed int which is inconsistent with actually returned values. Also 2 users of this function actually assign its value to unsigned int variable and only __xfrm6_output assigns result of this function to signed variable but actually uses as unsigned in further comparisons and calls. Change this function to return unsigned int value. Fixes: 628a5c561890 ("[INET]: Add IP(V6)_PMTUDISC_RPOBE") Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* scsi: iscsi: Add iscsi_cls_conn refcount helpersMike Christie2021-07-201-0/+2
| | | | | | | | | | | | | | | [ Upstream commit b1d19e8c92cfb0ded180ef3376c20e130414e067 ] There are a couple places where we could free the iscsi_cls_conn while it's still in use. This adds some helpers to get/put a refcount on the struct and converts an exiting user. Subsequent commits will then use the helpers to fix 2 bugs in the eh code. Link: https://lore.kernel.org/r/20210525181821.7617-11-michael.christie@oracle.com Reviewed-by: Lee Duncan <lduncan@suse.com> Signed-off-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* power: supply: ab8500: Fix an old bugLinus Walleij2021-07-201-1/+1
| | | | | | | | | | | | | | | | | | | commit f1c74a6c07e76fcb31a4bcc1f437c4361a2674ce upstream. Trying to get the AB8500 charging driver working I ran into a bit of bitrot: we haven't used the driver for a while so errors in refactorings won't be noticed. This one is pretty self evident: use argument to the macro or we end up with a random pointer to something else. Cc: stable@vger.kernel.org Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: Marcus Cooper <codekipper@gmail.com> Fixes: 297d716f6260 ("power_supply: Change ownership from driver to core") Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* random32: Fix implicit truncation warning in prandom_seed_state()Richard Fitzgerald2021-07-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit d327ea15a305024ef0085252fa3657bbb1ce25f5 ] sparse generates the following warning: include/linux/prandom.h:114:45: sparse: sparse: cast truncates bits from constant value This is because the 64-bit seed value is manipulated and then placed in a u32, causing an implicit cast and truncation. A forced cast to u32 doesn't prevent this warning, which is reasonable because a typecast doesn't prove that truncation was expected. Logical-AND the value with 0xffffffff to make explicit that truncation to 32-bit is intended. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210525122012.6336-3-rf@opensource.cirrus.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* crypto: shash - avoid comparing pointers to exported functions under CFIArd Biesheuvel2021-07-201-7/+1
| | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 22ca9f4aaf431a9413dcc115dd590123307f274f ] crypto_shash_alg_has_setkey() is implemented by testing whether the .setkey() member of a struct shash_alg points to the default version, called shash_no_setkey(). As crypto_shash_alg_has_setkey() is a static inline, this requires shash_no_setkey() to be exported to modules. Unfortunately, when building with CFI, function pointers are routed via CFI stubs which are private to each module (or to the kernel proper) and so this function pointer comparison may fail spuriously. Let's fix this by turning crypto_shash_alg_has_setkey() into an out of line function. Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
* inet: annotate date races around sk->sk_txhashEric Dumazet2021-06-301-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit b71eaed8c04f72a919a9c44e83e4ee254e69e7f3 ] UDP sendmsg() path can be lockless, it is possible for another thread to re-connect an change sk->sk_txhash under us. There is no serious impact, but we can use READ_ONCE()/WRITE_ONCE() pair to document the race. BUG: KCSAN: data-race in __ip4_datagram_connect / skb_set_owner_w write to 0xffff88813397920c of 4 bytes by task 30997 on cpu 1: sk_set_txhash include/net/sock.h:1937 [inline] __ip4_datagram_connect+0x69e/0x710 net/ipv4/datagram.c:75 __ip6_datagram_connect+0x551/0x840 net/ipv6/datagram.c:189 ip6_datagram_connect+0x2a/0x40 net/ipv6/datagram.c:272 inet_dgram_connect+0xfd/0x180 net/ipv4/af_inet.c:580 __sys_connect_file net/socket.c:1837 [inline] __sys_connect+0x245/0x280 net/socket.c:1854 __do_sys_connect net/socket.c:1864 [inline] __se_sys_connect net/socket.c:1861 [inline] __x64_sys_connect+0x3d/0x50 net/socket.c:1861 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff88813397920c of 4 bytes by task 31039 on cpu 0: skb_set_hash_from_sk include/net/sock.h:2211 [inline] skb_set_owner_w+0x118/0x220 net/core/sock.c:2101 sock_alloc_send_pskb+0x452/0x4e0 net/core/sock.c:2359 sock_alloc_send_skb+0x2d/0x40 net/core/sock.c:2373 __ip6_append_data+0x1743/0x21a0 net/ipv6/ip6_output.c:1621 ip6_make_skb+0x258/0x420 net/ipv6/ip6_output.c:1983 udpv6_sendmsg+0x160a/0x16b0 net/ipv6/udp.c:1527 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:642 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg net/socket.c:674 [inline] ____sys_sendmsg+0x360/0x4d0 net/socket.c:2350 ___sys_sendmsg net/socket.c:2404 [inline] __sys_sendmmsg+0x315/0x4b0 net/socket.c:2490 __do_sys_sendmmsg net/socket.c:2519 [inline] __se_sys_sendmmsg net/socket.c:2516 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2516 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0xbca3c43d -> 0xfdb309e0 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 31039 Comm: syz-executor.2 Not tainted 5.13.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
* HID: usbhid: fix info leak in hid_submit_ctrlAnirudh Rayabharam2021-06-301-2/+1
| | | | | | | | | | | | | | | | | | | | [ Upstream commit 6be388f4a35d2ce5ef7dbf635a8964a5da7f799f ] In hid_submit_ctrl(), the way of calculating the report length doesn't take into account that report->size can be zero. When running the syzkaller reproducer, a report of size 0 causes hid_submit_ctrl) to calculate transfer_buffer_length as 16384. When this urb is passed to the usb core layer, KMSAN reports an info leak of 16384 bytes. To fix this, first modify hid_report_len() to account for the zero report size case by using DIV_ROUND_UP for the division. Then, call it from hid_submit_ctrl(). Reported-by: syzbot+7c2bb71996f95a82524c@syzkaller.appspotmail.com Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com> Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Sasha Levin <sashal@kernel.org>
* kvm: fix previous commit for 32-bit buildsPaolo Bonzini2021-06-161-2/+2
| | | | | | | | | | | | commit 4422829e8053068e0225e4d0ef42dc41ea7c9ef5 upstream. array_index_nospec does not work for uint64_t on 32-bit builds. However, the size of a memory slot must be less than 20 bits wide on those system, since the memory slot must fit in the user address space. So just store it in an unsigned long. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kvm: avoid speculation-based attacks from out-of-range memslot accessesPaolo Bonzini2021-06-161-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit da27a83fd6cc7780fea190e1f5c19e87019da65c upstream. KVM's mechanism for accessing guest memory translates a guest physical address (gpa) to a host virtual address using the right-shifted gpa (also known as gfn) and a struct kvm_memory_slot. The translation is performed in __gfn_to_hva_memslot using the following formula: hva = slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE It is expected that gfn falls within the boundaries of the guest's physical memory. However, a guest can access invalid physical addresses in such a way that the gfn is invalid. __gfn_to_hva_memslot is called from kvm_vcpu_gfn_to_hva_prot, which first retrieves a memslot through __gfn_to_memslot. While __gfn_to_memslot does check that the gfn falls within the boundaries of the guest's physical memory or not, a CPU can speculate the result of the check and continue execution speculatively using an illegal gfn. The speculation can result in calculating an out-of-bounds hva. If the resulting host virtual address is used to load another guest physical address, this is effectively a Spectre gadget consisting of two consecutive reads, the second of which is data dependent on the first. Right now it's not clear if there are any cases in which this is exploitable. One interesting case was reported by the original author of this patch, and involves visiting guest page tables on x86. Right now these are not vulnerable because the hva read goes through get_user(), which contains an LFENCE speculation barrier. However, there are patches in progress for x86 uaccess.h to mask kernel addresses instead of using LFENCE; once these land, a guest could use speculation to read from the VMM's ring 3 address space. Other architectures such as ARM already use the address masking method, and would be susceptible to this same kind of data-dependent access gadgets. Therefore, this patch proactively protects from these attacks by masking out-of-bounds gfns in __gfn_to_hva_memslot, which blocks speculation of invalid hvas. Sean Christopherson noted that this patch does not cover kvm_read_guest_offset_cached. This however is limited to a few bytes past the end of the cache, and therefore it is unlikely to be useful in the context of building a chain of data dependent accesses. Reported-by: Artemiy Margaritov <artemiy.margaritov@gmail.com> Co-developed-by: Artemiy Margaritov <artemiy.margaritov@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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