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* cifs: reconnect worker should take reference on server struct unconditionallyShyam Prasad N2023-12-062-18/+19
| | | | | | | | | | | | | | | | | | | | | | Reconnect worker currently assumes that the server struct is alive and only takes reference on the server if it needs to call smb2_reconnect. With the new ability to disable channels based on whether the server has multichannel disabled, this becomes a problem when we need to disable established channels. While disabling the channels and deallocating the server, there could be reconnect work that could not be cancelled (because it started). This change forces the reconnect worker to unconditionally take a reference on the server when it runs. Also, this change now allows smb2_reconnect to know if it was called by the reconnect worker. Based on this, the cifs_put_tcp_session can decide whether it can cancel the reconnect work synchronously or not. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
* Revert "cifs: reconnect work should have reference on server struct"Shyam Prasad N2023-12-062-34/+16
| | | | | | | | | | | | | | | This reverts commit 19a4b9d6c372cab6a3b2c9a061a236136fe95274. This earlier commit was making an assumption that each mod_delayed_work called for the reconnect work would result in smb2_reconnect_server being called twice. This assumption turns out to be untrue. So reverting this change for now. I will submit a follow-up patch to fix the actual problem in a different way. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
* cifs: Fix non-availability of dedup breaking generic/304David Howells2023-12-051-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | Deduplication isn't supported on cifs, but cifs doesn't reject it, instead treating it as extent duplication/cloning. This can cause generic/304 to go silly and run for hours on end. Fix cifs to indicate EOPNOTSUPP if REMAP_FILE_DEDUP is set in ->remap_file_range(). Note that it's unclear whether or not commit b073a08016a1 is meant to cause cifs to return an error if REMAP_FILE_DEDUP. Fixes: b073a08016a1 ("cifs: fix that return -EINVAL when do dedupe operation") Cc: stable@vger.kernel.org Suggested-by: Dave Chinner <david@fromorbit.com> cc: Xiaoli Feng <fengxiaoli0714@gmail.com> cc: Shyam Prasad N <nspmangalore@gmail.com> cc: Rohith Surabattula <rohiths.msft@gmail.com> cc: Jeff Layton <jlayton@kernel.org> cc: Darrick Wong <darrick.wong@oracle.com> cc: fstests@vger.kernel.org cc: linux-cifs@vger.kernel.org cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/3876191.1701555260@warthog.procyon.org.uk/ Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
* smb: client: fix potential NULL deref in parse_dfs_referrals()Paulo Alcantara2023-12-051-0/+2
| | | | | | | | | | | | | | | | If server returned no data for FSCTL_DFS_GET_REFERRALS, @dfs_rsp will remain NULL and then parse_dfs_referrals() will dereference it. Fix this by returning -EIO when no output data is returned. Besides, we can't fix it in SMB2_ioctl() as some FSCTLs are allowed to return no data as per MS-SMB2 2.2.32. Fixes: 9d49640a21bf ("CIFS: implement get_dfs_refer for SMB2+") Cc: stable@vger.kernel.org Reported-by: Robert Morris <rtm@csail.mit.edu> Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
* cifs: Fix flushing, invalidation and file size with FICLONEDavid Howells2023-12-041-11/+57
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix a number of issues in the cifs filesystem implementation of the FICLONE ioctl in cifs_remap_file_range(). This is analogous to the previously fixed bug in cifs_file_copychunk_range() and can share the helper functions. Firstly, the invalidation of the destination range is handled incorrectly: We shouldn't just invalidate the whole file as dirty data in the file may get lost and we can't just call truncate_inode_pages_range() to invalidate the destination range as that will erase parts of a partial folio at each end whilst invalidating and discarding all the folios in the middle. We need to force all the folios covering the range to be reloaded, but we mustn't lose dirty data in them that's not in the destination range. Further, we shouldn't simply round out the range to PAGE_SIZE at each end as cifs should move to support multipage folios. Secondly, there's an issue whereby a write may have extended the file locally, but not have been written back yet. This can leaves the local idea of the EOF at a later point than the server's EOF. If a clone request is issued, this will fail on the server with STATUS_INVALID_VIEW_SIZE (which gets translated to -EIO locally) if the clone source extends past the server's EOF. Fix this by: (0) Flush the source region (already done). The flush does nothing and the EOF isn't moved if the source region has no dirty data. (1) Move the EOF to the end of the source region if it isn't already at least at this point. If we can't do this, for instance if the server doesn't support it, just flush the entire source file. (2) Find the folio (if present) at each end of the range, flushing it and increasing the region-to-be-invalidated to cover those in their entirety. (3) Fully discard all the folios covering the range as we want them to be reloaded. (4) Then perform the extent duplication. Thirdly, set i_size after doing the duplicate_extents operation as this value may be used by various things internally. stat() hides the issue because setting ->time to 0 causes cifs_getatr() to revalidate the attributes. These were causing the cifs/001 xfstest to fail. Fixes: 04b38d601239 ("vfs: pull btrfs clone API to vfs layer") Signed-off-by: David Howells <dhowells@redhat.com> Cc: stable@vger.kernel.org cc: Christoph Hellwig <hch@lst.de> cc: Paulo Alcantara <pc@manguebit.com> cc: Shyam Prasad N <nspmangalore@gmail.com> cc: Rohith Surabattula <rohiths.msft@gmail.com> cc: Matthew Wilcox <willy@infradead.org> cc: Jeff Layton <jlayton@kernel.org> cc: linux-cifs@vger.kernel.org cc: linux-mm@kvack.org Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
* cifs: Fix flushing, invalidation and file size with copy_file_range()David Howells2023-12-041-3/+99
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix a number of issues in the cifs filesystem implementation of the copy_file_range() syscall in cifs_file_copychunk_range(). Firstly, the invalidation of the destination range is handled incorrectly: We shouldn't just invalidate the whole file as dirty data in the file may get lost and we can't just call truncate_inode_pages_range() to invalidate the destination range as that will erase parts of a partial folio at each end whilst invalidating and discarding all the folios in the middle. We need to force all the folios covering the range to be reloaded, but we mustn't lose dirty data in them that's not in the destination range. Further, we shouldn't simply round out the range to PAGE_SIZE at each end as cifs should move to support multipage folios. Secondly, there's an issue whereby a write may have extended the file locally, but not have been written back yet. This can leaves the local idea of the EOF at a later point than the server's EOF. If a copy request is issued, this will fail on the server with STATUS_INVALID_VIEW_SIZE (which gets translated to -EIO locally) if the copy source extends past the server's EOF. Fix this by: (0) Flush the source region (already done). The flush does nothing and the EOF isn't moved if the source region has no dirty data. (1) Move the EOF to the end of the source region if it isn't already at least at this point. If we can't do this, for instance if the server doesn't support it, just flush the entire source file. (2) Find the folio (if present) at each end of the range, flushing it and increasing the region-to-be-invalidated to cover those in their entirety. (3) Fully discard all the folios covering the range as we want them to be reloaded. (4) Then perform the copy. Thirdly, set i_size after doing the copychunk_range operation as this value may be used by various things internally. stat() hides the issue because setting ->time to 0 causes cifs_getatr() to revalidate the attributes. These were causing the generic/075 xfstest to fail. Fixes: 620d8745b35d ("Introduce cifs_copy_file_range()") Cc: stable@vger.kernel.org Signed-off-by: David Howells <dhowells@redhat.com> cc: Paulo Alcantara <pc@manguebit.com> cc: Shyam Prasad N <nspmangalore@gmail.com> cc: Rohith Surabattula <rohiths.msft@gmail.com> cc: Matthew Wilcox <willy@infradead.org> cc: Jeff Layton <jlayton@kernel.org> cc: linux-cifs@vger.kernel.org cc: linux-mm@kvack.org Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
* smb: client, common: fix fortify warningsDmitry Antipov2023-11-304-24/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When compiling with gcc version 14.0.0 20231126 (experimental) and CONFIG_FORTIFY_SOURCE=y, I've noticed the following: In file included from ./include/linux/string.h:295, from ./include/linux/bitmap.h:12, from ./include/linux/cpumask.h:12, from ./arch/x86/include/asm/paravirt.h:17, from ./arch/x86/include/asm/cpuid.h:62, from ./arch/x86/include/asm/processor.h:19, from ./arch/x86/include/asm/cpufeature.h:5, from ./arch/x86/include/asm/thread_info.h:53, from ./include/linux/thread_info.h:60, from ./arch/x86/include/asm/preempt.h:9, from ./include/linux/preempt.h:79, from ./include/linux/spinlock.h:56, from ./include/linux/wait.h:9, from ./include/linux/wait_bit.h:8, from ./include/linux/fs.h:6, from fs/smb/client/smb2pdu.c:18: In function 'fortify_memcpy_chk', inlined from '__SMB2_close' at fs/smb/client/smb2pdu.c:3480:4: ./include/linux/fortify-string.h:588:25: warning: call to '__read_overflow2_field' declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Wattribute-warning] 588 | __read_overflow2_field(q_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ and: In file included from ./include/linux/string.h:295, from ./include/linux/bitmap.h:12, from ./include/linux/cpumask.h:12, from ./arch/x86/include/asm/paravirt.h:17, from ./arch/x86/include/asm/cpuid.h:62, from ./arch/x86/include/asm/processor.h:19, from ./arch/x86/include/asm/cpufeature.h:5, from ./arch/x86/include/asm/thread_info.h:53, from ./include/linux/thread_info.h:60, from ./arch/x86/include/asm/preempt.h:9, from ./include/linux/preempt.h:79, from ./include/linux/spinlock.h:56, from ./include/linux/wait.h:9, from ./include/linux/wait_bit.h:8, from ./include/linux/fs.h:6, from fs/smb/client/cifssmb.c:17: In function 'fortify_memcpy_chk', inlined from 'CIFS_open' at fs/smb/client/cifssmb.c:1248:3: ./include/linux/fortify-string.h:588:25: warning: call to '__read_overflow2_field' declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Wattribute-warning] 588 | __read_overflow2_field(q_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In both cases, the fortification logic inteprets calls to 'memcpy()' as an attempts to copy an amount of data which exceeds the size of the specified field (i.e. more than 8 bytes from __le64 value) and thus issues an overread warning. Both of these warnings may be silenced by using the convenient 'struct_group()' quirk. Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
* cifs: Fix FALLOC_FL_INSERT_RANGE by setting i_size after EOF movedDavid Howells2023-11-291-0/+3
| | | | | | | | | | | | | | | | | | Fix the cifs filesystem implementations of FALLOC_FL_INSERT_RANGE, in smb3_insert_range(), to set i_size after extending the file on the server and before we do the copy to open the gap (as we don't clean up the EOF marker if the copy fails). Fixes: 7fe6fe95b936 ("cifs: add FALLOC_FL_INSERT_RANGE support") Cc: stable@vger.kernel.org Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Paulo Alcantara <pc@manguebit.com> cc: Shyam Prasad N <nspmangalore@gmail.com> cc: Rohith Surabattula <rohiths.msft@gmail.com> cc: Jeff Layton <jlayton@kernel.org> cc: linux-cifs@vger.kernel.org cc: linux-mm@kvack.org Signed-off-by: Steve French <stfrench@microsoft.com>
* cifs: Fix FALLOC_FL_ZERO_RANGE by setting i_size if EOF movedDavid Howells2023-11-291-2/+8
| | | | | | | | | | | | | | | | Fix the cifs filesystem implementations of FALLOC_FL_ZERO_RANGE, in smb3_zero_range(), to set i_size after extending the file on the server. Fixes: 72c419d9b073 ("cifs: fix smb3_zero_range so it can expand the file-size when required") Cc: stable@vger.kernel.org Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Paulo Alcantara <pc@manguebit.com> cc: Shyam Prasad N <nspmangalore@gmail.com> cc: Rohith Surabattula <rohiths.msft@gmail.com> cc: Jeff Layton <jlayton@kernel.org> cc: linux-cifs@vger.kernel.org cc: linux-mm@kvack.org Signed-off-by: Steve French <stfrench@microsoft.com>
* smb: client: report correct st_size for SMB and NFS symlinksPaulo Alcantara2023-11-281-0/+2
| | | | | | | | | | | | | We can't rely on FILE_STANDARD_INFORMATION::EndOfFile for reparse points as they will be always zero. Set it to symlink target's length as specified by POSIX. This will make stat() family of syscalls return the correct st_size for such files. Cc: stable@vger.kernel.org Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
* smb: client: fix missing mode bits for SMB symlinksPaulo Alcantara2023-11-281-1/+1
| | | | | | | | | When instantiating inodes for SMB symlinks, add the mode bits from @cifs_sb->ctx->file_mode as we already do for the other special files. Cc: stable@vger.kernel.org Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
* smb: client: introduce cifs_sfu_make_node()Paulo Alcantara2023-11-233-120/+52
| | | | | | | | Remove duplicate code and add new helper for creating special files in SFU (Services for UNIX) format that can be shared by SMB1+ code. Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
* smb: client: set correct file type from NFS reparse pointsPaulo Alcantara2023-11-238-61/+116
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Handle all file types in NFS reparse points as specified in MS-FSCC 2.1.2.6 Network File System (NFS) Reparse Data Buffer. The client is now able to set all file types based on the parsed NFS reparse point, which used to support only symlinks. This works for SMB1+. Before patch: $ mount.cifs //srv/share /mnt -o ... $ ls -l /mnt ls: cannot access 'block': Operation not supported ls: cannot access 'char': Operation not supported ls: cannot access 'fifo': Operation not supported ls: cannot access 'sock': Operation not supported total 1 l????????? ? ? ? ? ? block l????????? ? ? ? ? ? char -rwxr-xr-x 1 root root 5 Nov 18 23:22 f0 l????????? ? ? ? ? ? fifo l--------- 1 root root 0 Nov 18 23:23 link -> f0 l????????? ? ? ? ? ? sock After patch: $ mount.cifs //srv/share /mnt -o ... $ ls -l /mnt total 1 brwxr-xr-x 1 root root 123, 123 Nov 18 00:34 block crwxr-xr-x 1 root root 1234, 1234 Nov 18 00:33 char -rwxr-xr-x 1 root root 5 Nov 18 23:22 f0 prwxr-xr-x 1 root root 0 Nov 18 23:23 fifo lrwxr-xr-x 1 root root 0 Nov 18 23:23 link -> f0 srwxr-xr-x 1 root root 0 Nov 19 2023 sock Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
* smb: client: introduce ->parse_reparse_point()Paulo Alcantara2023-11-234-42/+56
| | | | | | | | Parse reparse point into cifs_open_info_data structure and feed it through cifs_open_info_to_fattr(). Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
* smb: client: implement ->query_reparse_point() for SMB1Paulo Alcantara2023-11-235-175/+113
| | | | | | | | Reparse points are not limited to symlinks, so implement ->query_reparse_point() in order to handle different file types. Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
* cifs: fix use after free for iface while disabling secondary channelsRitvik Budhiraja2023-11-231-1/+1
| | | | | | | | | | | We were deferencing iface after it has been released. Fix is to release after all dereference instances have been encountered. Signed-off-by: Ritvik Budhiraja <rbudhiraja@microsoft.com> Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <error27@gmail.com> Closes: https://lore.kernel.org/r/202311110815.UJaeU3Tt-lkp@intel.com/ Signed-off-by: Steve French <stfrench@microsoft.com>
* cifs: fix lock ordering while disabling multichannelShyam Prasad N2023-11-141-9/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | The code to handle the case of server disabling multichannel was picking iface_lock with chan_lock held. This goes against the lock ordering rules, as iface_lock is a higher order lock (even if it isn't so obvious). This change fixes the lock ordering by doing the following in that order for each secondary channel: 1. store iface and server pointers in local variable 2. remove references to iface and server in channels 3. unlock chan_lock 4. lock iface_lock 5. dec ref count for iface 6. unlock iface_lock 7. dec ref count for server 8. lock chan_lock again Since this function can only be called in smb2_reconnect, and that cannot be called by two parallel processes, we should not have races due to dropping chan_lock between steps 3 and 8. Fixes: ee1d21794e55 ("cifs: handle when server stops supporting multichannel") Reported-by: Paulo Alcantara <pc@manguebit.com> Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
* cifs: fix leak of iface for primary channelShyam Prasad N2023-11-141-0/+6
| | | | | | | | | | | | | | | | My last change in this area introduced a change which accounted for primary channel in the interface ref count. However, it did not reduce this ref count on deallocation of the primary channel. i.e. during umount. Fixing this leak here, by dropping this ref count for primary channel while freeing up the session. Fixes: fa1d0508bdd4 ("cifs: account for primary channel in the interface list") Cc: stable@vger.kernel.org Reported-by: Paulo Alcantara <pc@manguebit.com> Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
* cifs: fix check of rc in function generate_smb3signingkeyEkaterina Esina2023-11-131-3/+2
| | | | | | | | | | | | | | | Remove extra check after condition, add check after generating key for encryption. The check is needed to return non zero rc before rewriting it with generating key for decryption. Found by Linux Verification Center (linuxtesting.org) with SVACE. Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Fixes: d70e9fa55884 ("cifs: try opening channels after mounting") Signed-off-by: Ekaterina Esina <eesina@astralinux.ru> Co-developed-by: Anastasia Belova <abelova@astralinux.ru> Signed-off-by: Anastasia Belova <abelova@astralinux.ru> Signed-off-by: Steve French <stfrench@microsoft.com>
* cifs: spnego: add ';' in HOST_KEY_LENAnastasia Belova2023-11-131-2/+2
| | | | | | | | | | | | | | "host=" should start with ';' (as in cifs_get_spnego_key) So its length should be 6. Found by Linux Verification Center (linuxtesting.org) with SVACE. Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Fixes: 7c9c3760b3a5 ("[CIFS] add constants for string lengths of keynames in SPNEGO upcall string") Signed-off-by: Anastasia Belova <abelova@astralinux.ru> Co-developed-by: Ekaterina Esina <eesina@astralinux.ru> Signed-off-by: Ekaterina Esina <eesina@astralinux.ru> Signed-off-by: Steve French <stfrench@microsoft.com>
* Merge tag '6.7-rc-smb3-client-fixes-part2' of ↵Linus Torvalds2023-11-1116-88/+491
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.samba.org/sfrench/cifs-2.6 Pull smb client fixes from Steve French: - ctime caching fix (for setxattr) - encryption fix - DNS resolver mount fix - debugging improvements - multichannel fixes including cases where server stops or starts supporting multichannel after mount - reconnect fix - minor cleanups * tag '6.7-rc-smb3-client-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6: cifs: update internal module version number for cifs.ko cifs: handle when server stops supporting multichannel cifs: handle when server starts supporting multichannel Missing field not being returned in ioctl CIFS_IOC_GET_MNT_INFO smb3: allow dumping session and tcon id to improve stats analysis and debugging smb: client: fix mount when dns_resolver key is not available smb3: fix caching of ctime on setxattr smb3: minor cleanup of session handling code cifs: reconnect work should have reference on server struct cifs: do not pass cifs_sb when trying to add channels cifs: account for primary channel in the interface list cifs: distribute channels across interfaces based on speed cifs: handle cases where a channel is closed smb3: more minor cleanups for session handling routines smb3: minor RDMA cleanup cifs: Fix encryption of cleared, but unset rq_iter data buffers
| * cifs: update internal module version number for cifs.koSteve French2023-11-101-2/+2
| | | | | | | | | | | | From 2.45 to 2.46 Signed-off-by: Steve French <stfrench@microsoft.com>
| * cifs: handle when server stops supporting multichannelShyam Prasad N2023-11-106-10/+145
| | | | | | | | | | | | | | | | | | | | When a server stops supporting multichannel, we will keep attempting reconnects to the secondary channels today. Avoid this by freeing extra channels when negotiate returns no multichannel support. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * cifs: handle when server starts supporting multichannelShyam Prasad N2023-11-103-2/+34
| | | | | | | | | | | | | | | | | | | | When the user mounts with multichannel option, but the server does not support it, there can be a time in future where it can be supported. With this change, such a case is handled. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
| * Missing field not being returned in ioctl CIFS_IOC_GET_MNT_INFOSteve French2023-11-101-0/+1
| | | | | | | | | | | | | | | | | | | | The tcon_flags field was always being set to zero in the information about the mount returned by the ioctl CIFS_IOC_GET_MNT_INFO instead of being set to the value of the Flags field in the tree connection structure as intended. Reviewed-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * smb3: allow dumping session and tcon id to improve stats analysis and debuggingSteve French2023-11-102-0/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When multiple mounts are to the same share from the same client it was not possible to determine which section of /proc/fs/cifs/Stats (and DebugData) correspond to that mount. In some recent examples this turned out to be a significant problem when trying to analyze performance data - since there are many cases where unless we know the tree id and session id we can't figure out which stats (e.g. number of SMB3.1.1 requests by type, the total time they take, which is slowest, how many fail etc.) apply to which mount. The only existing loosely related ioctl CIFS_IOC_GET_MNT_INFO does not return the information needed to uniquely identify which tcon is which mount although it does return various flags and device info. Add a cifs.ko ioctl CIFS_IOC_GET_TCON_INFO (0x800ccf0c) to return tid, session id, tree connect count. Cc: stable@vger.kernel.org Reviewed-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * smb: client: fix mount when dns_resolver key is not availablePaulo Alcantara2023-11-093-7/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There was a wrong assumption that with CONFIG_CIFS_DFS_UPCALL=y there would always be a dns_resolver key set up so we could unconditionally upcall to resolve UNC hostname rather than using the value provided by mount(2). Only require it when performing automount of junctions within a DFS share so users that don't have dns_resolver key still can mount their regular shares with server hostname resolved by mount.cifs(8). Fixes: 348a04a8d113 ("smb: client: get rid of dfs code dep in namespace.c") Cc: stable@vger.kernel.org Tested-by: Eduard Bachmakov <e.bachmakov@gmail.com> Reported-by: Eduard Bachmakov <e.bachmakov@gmail.com> Closes: https://lore.kernel.org/all/CADCRUiNvZuiUZ0VGZZO9HRyPyw6x92kiA7o7Q4tsX5FkZqUkKg@mail.gmail.com/ Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * smb3: fix caching of ctime on setxattrSteve French2023-11-091-1/+4
| | | | | | | | | | | | | | | | | | | | Fixes xfstest generic/728 which had been failing due to incorrect ctime after setxattr and removexattr Update ctime on successful set of xattr Cc: stable@vger.kernel.org Signed-off-by: Steve French <stfrench@microsoft.com>
| * smb3: minor cleanup of session handling codeSteve French2023-11-091-6/+12
| | | | | | | | | | | | | | Minor cleanup of style issues found by checkpatch Reviewed-by: Bharath SM <bharathsm@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * cifs: reconnect work should have reference on server structShyam Prasad N2023-11-092-16/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The delayed work for reconnect takes server struct as a parameter. But it does so without holding a ref to it. Normally, this may not show a problem as the reconnect work is only cancelled on umount. However, since we now plan to support scaling down of channels, and the scale down can happen from reconnect work itself, we need to fix it. This change takes a reference on the server struct before it is passed to the delayed work. And drops the reference in the delayed work itself. Or if the delayed work is successfully cancelled, by the process that cancels it. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * cifs: do not pass cifs_sb when trying to add channelsShyam Prasad N2023-11-093-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The only reason why cifs_sb gets passed today to cifs_try_adding_channels is to pass the local_nls field for the new channels and binding session. However, the ses struct already has local_nls field that is setup during the first cifs_setup_session. So there is no need to pass cifs_sb. This change removes cifs_sb from the arg list for this and the functions that it calls and uses ses->local_nls instead. Cc: stable@vger.kernel.org Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * cifs: account for primary channel in the interface listShyam Prasad N2023-11-092-0/+34
| | | | | | | | | | | | | | | | | | | | | | | | The refcounting of server interfaces should account for the primary channel too. Although this is not strictly necessary, doing so will account for the primary channel in DebugData. Cc: stable@vger.kernel.org Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * cifs: distribute channels across interfaces based on speedShyam Prasad N2023-11-093-14/+88
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Today, if the server interfaces RSS capable, we simply choose the fastest interface to setup a channel. This is not a scalable approach, and does not make a lot of attempt to distribute the connections. This change does a weighted distribution of channels across all the available server interfaces, where the weight is a function of the advertised interface speed. Also make sure that we don't mix rdma and non-rdma for channels. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * cifs: handle cases where a channel is closedShyam Prasad N2023-11-096-7/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | So far, SMB multichannel could only scale up, but not scale down the number of channels. In this series of patch, we now allow the client to deal with the case of multichannel disabled on the server when the share is mounted. With that change, we now need the ability to scale down the channels. This change allows the client to deal with cases of missing channels more gracefully. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * smb3: more minor cleanups for session handling routinesSteve French2023-11-091-10/+15
| | | | | | | | | | | | | | Some trivial cleanup pointed out by checkpatch Reviewed-by: Bharath SM <bharathsm@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * smb3: minor RDMA cleanupSteve French2023-11-091-2/+2
| | | | | | | | | | | | | | | | Some minor smbdirect debug cleanup spotted by checkpatch Cc: Long Li <longli@microsoft.com> Reviewed-by: Bharath SM <bharathsm@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * cifs: Fix encryption of cleared, but unset rq_iter data buffersDavid Howells2023-11-081-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Each smb_rqst struct contains two things: an array of kvecs (rq_iov) that contains the protocol data for an RPC op and an iterator (rq_iter) that contains the data payload of an RPC op. When an smb_rqst is allocated rq_iter is it always cleared, but we don't set it up unless we're going to use it. The functions that determines the size of the ciphertext buffer that will be needed to encrypt a request, cifs_get_num_sgs(), assumes that rq_iter is always initialised - and employs user_backed_iter() to check that the iterator isn't user-backed. This used to incidentally work, because ->user_backed was set to false because the iterator has never been initialised, but with commit f1b4cb650b9a0eeba206d8f069fcdc532bfbcd74[1] which changes user_backed_iter() to determine this based on the iterator type insted, a warning is now emitted: WARNING: CPU: 7 PID: 4584 at fs/smb/client/cifsglob.h:2165 smb2_get_aead_req+0x3fc/0x420 [cifs] ... RIP: 0010:smb2_get_aead_req+0x3fc/0x420 [cifs] ... crypt_message+0x33e/0x550 [cifs] smb3_init_transform_rq+0x27d/0x3f0 [cifs] smb_send_rqst+0xc7/0x160 [cifs] compound_send_recv+0x3ca/0x9f0 [cifs] cifs_send_recv+0x25/0x30 [cifs] SMB2_tcon+0x38a/0x820 [cifs] cifs_get_smb_ses+0x69c/0xee0 [cifs] cifs_mount_get_session+0x76/0x1d0 [cifs] dfs_mount_share+0x74/0x9d0 [cifs] cifs_mount+0x6e/0x2e0 [cifs] cifs_smb3_do_mount+0x143/0x300 [cifs] smb3_get_tree+0x15e/0x290 [cifs] vfs_get_tree+0x2d/0xe0 do_new_mount+0x124/0x340 __se_sys_mount+0x143/0x1a0 The problem is that rq_iter was never set, so the type is 0 (ie. ITER_UBUF) which causes user_backed_iter() to return true. The code doesn't malfunction because it checks the size of the iterator - which is 0. Fix cifs_get_num_sgs() to ignore rq_iter if its count is 0, thereby bypassing the warnings. It might be better to explicitly initialise rq_iter to a zero-length ITER_BVEC, say, as it can always be reinitialised later. Fixes: d08089f649a0 ("cifs: Change the I/O paths to use an iterator rather than a page list") Reported-by: Damian Tometzki <damian@riscv-rocks.de> Closes: https://lore.kernel.org/r/ZUfQo47uo0p2ZsYg@fedora.fritz.box/ Tested-by: Damian Tometzki <damian@riscv-rocks.de> Cc: stable@vger.kernel.org cc: Eric Biggers <ebiggers@kernel.org> cc: linux-cifs@vger.kernel.org cc: linux-fsdevel@vger.kernel.org Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f1b4cb650b9a0eeba206d8f069fcdc532bfbcd74 [1] Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
* | Merge tag 'vfs-6.7.fsid' of ↵Linus Torvalds2023-11-071-6/+5
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs fanotify fsid updates from Christian Brauner: "This work is part of the plan to enable fanotify to serve as a drop-in replacement for inotify. While inotify is availabe on all filesystems, fanotify currently isn't. In order to support fanotify on all filesystems two things are needed: (1) all filesystems need to support AT_HANDLE_FID (2) all filesystems need to report a non-zero f_fsid This contains (1) and allows filesystems to encode non-decodable file handlers for fanotify without implementing any exportfs operations by encoding a file id of type FILEID_INO64_GEN from i_ino and i_generation. Filesystems that want to opt out of encoding non-decodable file ids for fanotify that don't support NFS export can do so by providing an empty export_operations struct. This also partially addresses (2) by generating f_fsid for simple filesystems as well as freevxfs. Remaining filesystems will be dealt with by separate patches. Finally, this contains the patch from the current exportfs maintainers which moves exportfs under vfs with Chuck, Jeff, and Amir as maintainers and vfs.git as tree" * tag 'vfs-6.7.fsid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: MAINTAINERS: create an entry for exportfs fs: fix build error with CONFIG_EXPORTFS=m or not defined freevxfs: derive f_fsid from bdev->bd_dev fs: report f_fsid from s_dev for "simple" filesystems exportfs: support encoding non-decodeable file handles by default exportfs: define FILEID_INO64_GEN* file handle types exportfs: make ->encode_fh() a mandatory method for NFS export exportfs: add helpers to check if filesystem can encode/decode file handles
| * exportfs: make ->encode_fh() a mandatory method for NFS exportAmir Goldstein2023-10-281-6/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename the default helper for encoding FILEID_INO32_GEN* file handles to generic_encode_ino32_fh() and convert the filesystems that used the default implementation to use the generic helper explicitly. After this change, exportfs_encode_inode_fh() no longer has a default implementation to encode FILEID_INO32_GEN* file handles. This is a step towards allowing filesystems to encode non-decodeable file handles for fanotify without having to implement any export_operations. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jeff Layton <jlayton@kernel.org> Acked-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/r/20231023180801.2953446-3-amir73il@gmail.com Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
* | Merge tag '6.7-rc-smb3-client-fixes-part1' of ↵Linus Torvalds2023-11-0413-89/+115
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.samba.org/sfrench/cifs-2.6 Pull smb client updates from Steve French: - use after free fixes and deadlock fix - symlink timestamp fix - hashing perf improvement - multichannel fixes - minor debugging improvements - fix creating fifos when using "sfu" mounts - NTLMSSP authentication improvement - minor fixes to include some missing create flags and structures from recently updated protocol documentation * tag '6.7-rc-smb3-client-fixes-part1' of git://git.samba.org/sfrench/cifs-2.6: cifs: force interface update before a fresh session setup cifs: do not reset chan_max if multichannel is not supported at mount cifs: reconnect helper should set reconnect for the right channel smb: client: fix use-after-free in smb2_query_info_compound() smb: client: remove extra @chan_count check in __cifs_put_smb_ses() cifs: add xid to query server interface call cifs: print server capabilities in DebugData smb: use crypto_shash_digest() in symlink_hash() smb: client: fix use-after-free bug in cifs_debug_data_proc_show() smb: client: fix potential deadlock when releasing mids smb3: fix creating FIFOs when mounting with "sfu" mount option Add definition for new smb3.1.1 command type SMB3: clarify some of the unused CreateOption flags cifs: Add client version details to NTLM authenticate message smb3: fix touch -h of symlink
| * | cifs: force interface update before a fresh session setupShyam Prasad N2023-11-021-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During a session reconnect, it is possible that the server moved to another physical server (happens in case of Azure files). So at this time, force a query of server interfaces again (in case of multichannel session), such that the secondary channels connect to the right IP addresses (possibly updated now). Cc: stable@vger.kernel.org Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * | cifs: do not reset chan_max if multichannel is not supported at mountShyam Prasad N2023-11-021-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the mount command has specified multichannel as a mount option, but multichannel is found to be unsupported by the server at the time of mount, we set chan_max to 1. Which means that the user needs to remount the share if the server starts supporting multichannel. This change removes this reset. What it means is that if the user specified multichannel or max_channels during mount, and at this time, multichannel is not supported, but the server starts supporting it at a later point, the client will be capable of scaling out the number of channels. Cc: stable@vger.kernel.org Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * | cifs: reconnect helper should set reconnect for the right channelShyam Prasad N2023-11-021-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We introduced a helper function to be used by non-cifsd threads to mark the connection for reconnect. For multichannel, when only a particular channel needs to be reconnected, this had a bug. This change fixes that by marking that particular channel for reconnect. Fixes: dca65818c80c ("cifs: use a different reconnect helper for non-cifsd threads") Cc: stable@vger.kernel.org Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * | smb: client: fix use-after-free in smb2_query_info_compound()Paulo Alcantara2023-11-021-35/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following UAF was triggered when running fstests generic/072 with KASAN enabled against Windows Server 2022 and mount options 'multichannel,max_channels=2,vers=3.1.1,mfsymlinks,noperm' BUG: KASAN: slab-use-after-free in smb2_query_info_compound+0x423/0x6d0 [cifs] Read of size 8 at addr ffff888014941048 by task xfs_io/27534 CPU: 0 PID: 27534 Comm: xfs_io Not tainted 6.6.0-rc7 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014 Call Trace: dump_stack_lvl+0x4a/0x80 print_report+0xcf/0x650 ? srso_alias_return_thunk+0x5/0x7f ? srso_alias_return_thunk+0x5/0x7f ? __phys_addr+0x46/0x90 kasan_report+0xda/0x110 ? smb2_query_info_compound+0x423/0x6d0 [cifs] ? smb2_query_info_compound+0x423/0x6d0 [cifs] smb2_query_info_compound+0x423/0x6d0 [cifs] ? __pfx_smb2_query_info_compound+0x10/0x10 [cifs] ? srso_alias_return_thunk+0x5/0x7f ? __stack_depot_save+0x39/0x480 ? kasan_save_stack+0x33/0x60 ? kasan_set_track+0x25/0x30 ? ____kasan_slab_free+0x126/0x170 smb2_queryfs+0xc2/0x2c0 [cifs] ? __pfx_smb2_queryfs+0x10/0x10 [cifs] ? __pfx___lock_acquire+0x10/0x10 smb311_queryfs+0x210/0x220 [cifs] ? __pfx_smb311_queryfs+0x10/0x10 [cifs] ? srso_alias_return_thunk+0x5/0x7f ? __lock_acquire+0x480/0x26c0 ? lock_release+0x1ed/0x640 ? srso_alias_return_thunk+0x5/0x7f ? do_raw_spin_unlock+0x9b/0x100 cifs_statfs+0x18c/0x4b0 [cifs] statfs_by_dentry+0x9b/0xf0 fd_statfs+0x4e/0xb0 __do_sys_fstatfs+0x7f/0xe0 ? __pfx___do_sys_fstatfs+0x10/0x10 ? srso_alias_return_thunk+0x5/0x7f ? lockdep_hardirqs_on_prepare+0x136/0x200 ? srso_alias_return_thunk+0x5/0x7f do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 Allocated by task 27534: kasan_save_stack+0x33/0x60 kasan_set_track+0x25/0x30 __kasan_kmalloc+0x8f/0xa0 open_cached_dir+0x71b/0x1240 [cifs] smb2_query_info_compound+0x5c3/0x6d0 [cifs] smb2_queryfs+0xc2/0x2c0 [cifs] smb311_queryfs+0x210/0x220 [cifs] cifs_statfs+0x18c/0x4b0 [cifs] statfs_by_dentry+0x9b/0xf0 fd_statfs+0x4e/0xb0 __do_sys_fstatfs+0x7f/0xe0 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 Freed by task 27534: kasan_save_stack+0x33/0x60 kasan_set_track+0x25/0x30 kasan_save_free_info+0x2b/0x50 ____kasan_slab_free+0x126/0x170 slab_free_freelist_hook+0xd0/0x1e0 __kmem_cache_free+0x9d/0x1b0 open_cached_dir+0xff5/0x1240 [cifs] smb2_query_info_compound+0x5c3/0x6d0 [cifs] smb2_queryfs+0xc2/0x2c0 [cifs] This is a race between open_cached_dir() and cached_dir_lease_break() where the cache entry for the open directory handle receives a lease break while creating it. And before returning from open_cached_dir(), we put the last reference of the new @cfid because of !@cfid->has_lease. Besides the UAF, while running xfstests a lot of missed lease breaks have been noticed in tests that run several concurrent statfs(2) calls on those cached fids CIFS: VFS: \\w22-root1.gandalf.test No task to wake, unknown frame... CIFS: VFS: \\w22-root1.gandalf.test Cmd: 18 Err: 0x0 Flags: 0x1... CIFS: VFS: \\w22-root1.gandalf.test smb buf 00000000715bfe83 len 108 CIFS: VFS: Dump pending requests: CIFS: VFS: \\w22-root1.gandalf.test No task to wake, unknown frame... CIFS: VFS: \\w22-root1.gandalf.test Cmd: 18 Err: 0x0 Flags: 0x1... CIFS: VFS: \\w22-root1.gandalf.test smb buf 000000005aa7316e len 108 ... To fix both, in open_cached_dir() ensure that @cfid->has_lease is set right before sending out compounded request so that any potential lease break will be get processed by demultiplex thread while we're still caching @cfid. And, if open failed for some reason, re-check @cfid->has_lease to decide whether or not put lease reference. Cc: stable@vger.kernel.org Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * | smb: client: remove extra @chan_count check in __cifs_put_smb_ses()Paulo Alcantara2023-11-021-14/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | If @ses->chan_count <= 1, then for-loop body will not be executed so no need to check it twice. Reviewed-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * | cifs: add xid to query server interface callShyam Prasad N2023-10-311-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We were passing 0 as the xid for the call to query server interfaces. This is not great for debugging. This change adds a real xid. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Reviewed-by: Bharath SM <bharathsm@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * | cifs: print server capabilities in DebugDataShyam Prasad N2023-10-311-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | In the output of /proc/fs/cifs/DebugData, we do not print the server->capabilities field today. With this change, we will do that. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * | smb: use crypto_shash_digest() in symlink_hash()Eric Biggers2023-10-311-14/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | Simplify symlink_hash() by using crypto_shash_digest() instead of an init+update+final sequence. This should also improve performance. Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * | smb: client: fix use-after-free bug in cifs_debug_data_proc_show()Paulo Alcantara2023-10-311-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Skip SMB sessions that are being teared down (e.g. @ses->ses_status == SES_EXITING) in cifs_debug_data_proc_show() to avoid use-after-free in @ses. This fixes the following GPF when reading from /proc/fs/cifs/DebugData while mounting and umounting [ 816.251274] general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6d81: 0000 [#1] PREEMPT SMP NOPTI ... [ 816.260138] Call Trace: [ 816.260329] <TASK> [ 816.260499] ? die_addr+0x36/0x90 [ 816.260762] ? exc_general_protection+0x1b3/0x410 [ 816.261126] ? asm_exc_general_protection+0x26/0x30 [ 816.261502] ? cifs_debug_tcon+0xbd/0x240 [cifs] [ 816.261878] ? cifs_debug_tcon+0xab/0x240 [cifs] [ 816.262249] cifs_debug_data_proc_show+0x516/0xdb0 [cifs] [ 816.262689] ? seq_read_iter+0x379/0x470 [ 816.262995] seq_read_iter+0x118/0x470 [ 816.263291] proc_reg_read_iter+0x53/0x90 [ 816.263596] ? srso_alias_return_thunk+0x5/0x7f [ 816.263945] vfs_read+0x201/0x350 [ 816.264211] ksys_read+0x75/0x100 [ 816.264472] do_syscall_64+0x3f/0x90 [ 816.264750] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 [ 816.265135] RIP: 0033:0x7fd5e669d381 Cc: stable@vger.kernel.org Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * | smb: client: fix potential deadlock when releasing midsPaulo Alcantara2023-10-313-12/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All release_mid() callers seem to hold a reference of @mid so there is no need to call kref_put(&mid->refcount, __release_mid) under @server->mid_lock spinlock. If they don't, then an use-after-free bug would have occurred anyways. By getting rid of such spinlock also fixes a potential deadlock as shown below CPU 0 CPU 1 ------------------------------------------------------------------ cifs_demultiplex_thread() cifs_debug_data_proc_show() release_mid() spin_lock(&server->mid_lock); spin_lock(&cifs_tcp_ses_lock) spin_lock(&server->mid_lock) __release_mid() smb2_find_smb_tcon() spin_lock(&cifs_tcp_ses_lock) *deadlock* Cc: stable@vger.kernel.org Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
generated by cgit v1.2.3 (git 2.25.1) at 2024-10-07 21:51:46 +0000