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* dm ioctl: fix nested locking in table_clear() to remove deadlock concernMike Snitzer2023-05-171-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 3d32aaa7e66d5c1479a3c31d6c2c5d45dd0d3b89 upstream. syzkaller found the following problematic rwsem locking (with write lock already held): down_read+0x9d/0x450 kernel/locking/rwsem.c:1509 dm_get_inactive_table+0x2b/0xc0 drivers/md/dm-ioctl.c:773 __dev_status+0x4fd/0x7c0 drivers/md/dm-ioctl.c:844 table_clear+0x197/0x280 drivers/md/dm-ioctl.c:1537 In table_clear, it first acquires a write lock https://elixir.bootlin.com/linux/v6.2/source/drivers/md/dm-ioctl.c#L1520 down_write(&_hash_lock); Then before the lock is released at L1539, there is a path shown above: table_clear -> __dev_status -> dm_get_inactive_table -> down_read https://elixir.bootlin.com/linux/v6.2/source/drivers/md/dm-ioctl.c#L773 down_read(&_hash_lock); It tries to acquire the same read lock again, resulting in the deadlock problem. Fix this by moving table_clear()'s __dev_status() call to after its up_write(&_hash_lock); Cc: stable@vger.kernel.org Reported-by: Zheng Zhang <zheng.zhang@email.ucr.edu> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm flakey: fix a crash with invalid table lineMikulas Patocka2023-05-171-2/+2
| | | | | | | | | | | | | | | commit 98dba02d9a93eec11bffbb93c7c51624290702d2 upstream. This command will crash with NULL pointer dereference: dmsetup create flakey --table \ "0 `blockdev --getsize /dev/ram0` flakey /dev/ram0 0 0 1 2 corrupt_bio_byte 512" Fix the crash by checking if arg_name is non-NULL before comparing it. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm integrity: call kmem_cache_destroy() in dm_integrity_init() error pathMike Snitzer2023-05-171-3/+5
| | | | | | | | | | commit 6b79a428c02769f2a11f8ae76bf866226d134887 upstream. Otherwise the journal_io_cache will leak if dm_register_target() fails. Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* md/raid10: fix leak of 'r10bio->remaining' for recoveryYu Kuai2023-05-171-10/+13
| | | | | | | | | | | | | | | | | | [ Upstream commit 26208a7cffd0c7cbf14237ccd20c7270b3ffeb7e ] raid10_sync_request() will add 'r10bio->remaining' for both rdev and replacement rdev. However, if the read io fails, recovery_request_write() returns without issuing the write io, in this case, end_sync_request() is only called once and 'remaining' is leaked, cause an io hang. Fix the problem by decreasing 'remaining' according to if 'bio' and 'repl_bio' is valid. Fixes: 24afd80d99f8 ("md/raid10: handle recovery of replacement devices.") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230310073855.1337560-5-yukuai1@huaweicloud.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* md: avoid signed overflow in slot_store()NeilBrown2023-04-051-0/+3
| | | | | | | | | | | | | | | | | | | [ Upstream commit 3bc57292278a0b6ac4656cad94c14f2453344b57 ] slot_store() uses kstrtouint() to get a slot number, but stores the result in an "int" variable (by casting a pointer). This can result in a negative slot number if the unsigned int value is very large. A negative number means that the slot is empty, but setting a negative slot number this way will not remove the device from the array. I don't think this is a serious problem, but it could cause confusion and it is best to fix it. Reported-by: Dan Carpenter <error27@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* dm crypt: add cond_resched() to dmcrypt_write()Mikulas Patocka2023-04-051-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | commit fb294b1c0ba982144ca467a75e7d01ff26304e2b upstream. The loop in dmcrypt_write may be running for unbounded amount of time, thus we need cond_resched() in it. This commit fixes the following warning: [ 3391.153255][ C12] watchdog: BUG: soft lockup - CPU#12 stuck for 23s! [dmcrypt_write/2:2897] ... [ 3391.387210][ C12] Call trace: [ 3391.390338][ C12] blk_attempt_bio_merge.part.6+0x38/0x158 [ 3391.395970][ C12] blk_attempt_plug_merge+0xc0/0x1b0 [ 3391.401085][ C12] blk_mq_submit_bio+0x398/0x550 [ 3391.405856][ C12] submit_bio_noacct+0x308/0x380 [ 3391.410630][ C12] dmcrypt_write+0x1e4/0x208 [dm_crypt] [ 3391.416005][ C12] kthread+0x130/0x138 [ 3391.419911][ C12] ret_from_fork+0x10/0x18 Reported-by: yangerkun <yangerkun@huawei.com> Fixes: dc2676210c42 ("dm crypt: offload writes to thread") Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm stats: check for and propagate alloc_percpu failureJiasheng Jiang2023-04-053-3/+10
| | | | | | | | | | | | | | | | | commit d3aa3e060c4a80827eb801fc448debc9daa7c46b upstream. Check alloc_precpu()'s return value and return an error from dm_stats_init() if it fails. Update alloc_dev() to fail if dm_stats_init() does. Otherwise, a NULL pointer dereference will occur in dm_stats_cleanup() even if dm-stats isn't being actively used. Fixes: fd2ed4d25270 ("dm: add statistics support") Cc: stable@vger.kernel.org Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm flakey: don't corrupt the zero pageMikulas Patocka2023-03-111-2/+5
| | | | | | | | | | | | | | | | | | | | | | commit f50714b57aecb6b3dc81d578e295f86d9c73f078 upstream. When we need to zero some range on a block device, the function __blkdev_issue_zero_pages submits a write bio with the bio vector pointing to the zero page. If we use dm-flakey with corrupt bio writes option, it will corrupt the content of the zero page which results in crashes of various userspace programs. Glibc assumes that memory returned by mmap is zeroed and it uses it for calloc implementation; if the newly mapped memory is not zeroed, calloc will return non-zeroed memory. Fix this bug by testing if the page is equal to ZERO_PAGE(0) and avoiding the corruption in this case. Cc: stable@vger.kernel.org Fixes: a00f5276e266 ("dm flakey: Properly corrupt multi-page bios.") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm flakey: fix logic when corrupting a bioMikulas Patocka2023-03-111-10/+13
| | | | | | | | | | | | | | | | | | commit aa56b9b75996ff4c76a0a4181c2fa0206c3d91cc upstream. If "corrupt_bio_byte" is set to corrupt reads and corrupt_bio_flags is used, dm-flakey would erroneously return all writes as errors. Likewise, if "corrupt_bio_byte" is set to corrupt writes, dm-flakey would return errors for all reads. Fix the logic so that if fc->corrupt_bio_byte is non-zero, dm-flakey will not abort reads on writes with an error. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm cache: add cond_resched() to various workqueue loopsMike Snitzer2023-03-111-0/+4
| | | | | | | | | | [ Upstream commit 76227f6dc805e9e960128bcc6276647361e0827c ] Otherwise on resource constrained systems these workqueues may be too greedy. Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* dm thin: add cond_resched() to various workqueue loopsMike Snitzer2023-03-111-0/+2
| | | | | | | | | | [ Upstream commit e4f80303c2353952e6e980b23914e4214487f2a6 ] Otherwise on resource constrained systems these workqueues may be too greedy. Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* dm: remove flush_scheduled_work() during local_exit()Mike Snitzer2023-03-111-1/+0
| | | | | | | | | | | | | | | | | | | | [ Upstream commit 0b22ff5360f5c4e11050b89206370fdf7dc0a226 ] Commit acfe0ad74d2e1 ("dm: allocate a special workqueue for deferred device removal") switched from using system workqueue to a single workqueue local to DM. But it didn't eliminate the call to flush_scheduled_work() that was introduced purely for the benefit of deferred device removal with commit 2c140a246dc ("dm: allow remove to be deferred"). Since DM core uses its own workqueue (and queue_work) there is no need to call flush_scheduled_work() from local_exit(). local_exit()'s destroy_workqueue(deferred_remove_workqueue) handles flushing work started with queue_work(). Fixes: acfe0ad74d2e1 ("dm: allocate a special workqueue for deferred device removal") Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* dm cache: set needs_check flag after aborting metadataMike Snitzer2023-01-181-5/+5
| | | | | | | | | | | | | | | commit 6b9973861cb2e96dcd0bb0f1baddc5c034207c5c upstream. Otherwise the commit that will be aborted will be associated with the metadata objects that will be torn down. Must write needs_check flag to metadata with a reset block manager. Found through code-inspection (and compared against dm-thin.c). Cc: stable@vger.kernel.org Fixes: 028ae9f76f29 ("dm cache: add fail io mode and needs_check flag") Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm cache: Fix UAF in destroy()Luo Meng2023-01-181-0/+1
| | | | | | | | | | | | | | | commit 6a459d8edbdbe7b24db42a5a9f21e6aa9e00c2aa upstream. Dm_cache also has the same UAF problem when dm_resume() and dm_destroy() are concurrent. Therefore, cancelling timer again in destroy(). Cc: stable@vger.kernel.org Fixes: c6b4fcbad044e ("dm: add cache target") Signed-off-by: Luo Meng <luomeng12@huawei.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm thin: Fix UAF in run_timer_softirq()Luo Meng2023-01-181-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 88430ebcbc0ec637b710b947738839848c20feff upstream. When dm_resume() and dm_destroy() are concurrent, it will lead to UAF, as follows: BUG: KASAN: use-after-free in __run_timers+0x173/0x710 Write of size 8 at addr ffff88816d9490f0 by task swapper/0/0 <snip> Call Trace: <IRQ> dump_stack_lvl+0x73/0x9f print_report.cold+0x132/0xaa2 _raw_spin_lock_irqsave+0xcd/0x160 __run_timers+0x173/0x710 kasan_report+0xad/0x110 __run_timers+0x173/0x710 __asan_store8+0x9c/0x140 __run_timers+0x173/0x710 call_timer_fn+0x310/0x310 pvclock_clocksource_read+0xfa/0x250 kvm_clock_read+0x2c/0x70 kvm_clock_get_cycles+0xd/0x20 ktime_get+0x5c/0x110 lapic_next_event+0x38/0x50 clockevents_program_event+0xf1/0x1e0 run_timer_softirq+0x49/0x90 __do_softirq+0x16e/0x62c __irq_exit_rcu+0x1fa/0x270 irq_exit_rcu+0x12/0x20 sysvec_apic_timer_interrupt+0x8e/0xc0 One of the concurrency UAF can be shown as below: use free do_resume | __find_device_hash_cell | dm_get | atomic_inc(&md->holders) | | dm_destroy | __dm_destroy | if (!dm_suspended_md(md)) | atomic_read(&md->holders) | msleep(1) dm_resume | __dm_resume | dm_table_resume_targets | pool_resume | do_waker #add delay work | dm_put | atomic_dec(&md->holders) | | dm_table_destroy | pool_dtr | __pool_dec | __pool_destroy | destroy_workqueue | kfree(pool) # free pool time out __do_softirq run_timer_softirq # pool has already been freed This can be easily reproduced using: 1. create thin-pool 2. dmsetup suspend pool 3. dmsetup resume pool 4. dmsetup remove_all # Concurrent with 3 The root cause of this UAF bug is that dm_resume() adds timer after dm_destroy() skips cancelling the timer because of suspend status. After timeout, it will call run_timer_softirq(), however pool has already been freed. The concurrency UAF bug will happen. Therefore, cancelling timer again in __pool_destroy(). Cc: stable@vger.kernel.org Fixes: 991d9fa02da0d ("dm: add thin provisioning target") Signed-off-by: Luo Meng <luomeng12@huawei.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm thin: Use last transaction's pmd->root when commit failedZhihao Cheng2023-01-181-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 7991dbff6849f67e823b7cc0c15e5a90b0549b9f upstream. Recently we found a softlock up problem in dm thin pool btree lookup code due to corrupted metadata: Kernel panic - not syncing: softlockup: hung tasks CPU: 7 PID: 2669225 Comm: kworker/u16:3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) Workqueue: dm-thin do_worker [dm_thin_pool] Call Trace: <IRQ> dump_stack+0x9c/0xd3 panic+0x35d/0x6b9 watchdog_timer_fn.cold+0x16/0x25 __run_hrtimer+0xa2/0x2d0 </IRQ> RIP: 0010:__relink_lru+0x102/0x220 [dm_bufio] __bufio_new+0x11f/0x4f0 [dm_bufio] new_read+0xa3/0x1e0 [dm_bufio] dm_bm_read_lock+0x33/0xd0 [dm_persistent_data] ro_step+0x63/0x100 [dm_persistent_data] btree_lookup_raw.constprop.0+0x44/0x220 [dm_persistent_data] dm_btree_lookup+0x16f/0x210 [dm_persistent_data] dm_thin_find_block+0x12c/0x210 [dm_thin_pool] __process_bio_read_only+0xc5/0x400 [dm_thin_pool] process_thin_deferred_bios+0x1a4/0x4a0 [dm_thin_pool] process_one_work+0x3c5/0x730 Following process may generate a broken btree mixed with fresh and stale btree nodes, which could get dm thin trapped in an infinite loop while looking up data block: Transaction 1: pmd->root = A, A->B->C // One path in btree pmd->root = X, X->Y->Z // Copy-up Transaction 2: X,Z is updated on disk, Y write failed. // Commit failed, dm thin becomes read-only. process_bio_read_only dm_thin_find_block __find_block dm_btree_lookup(pmd->root) The pmd->root points to a broken btree, Y may contain stale node pointing to any block, for example X, which gets dm thin trapped into a dead loop while looking up Z. Fix this by setting pmd->root in __open_metadata(), so that dm thin will use the last transaction's pmd->root if commit failed. Fetch a reproducer in [Link]. Linke: https://bugzilla.kernel.org/show_bug.cgi?id=216790 Cc: stable@vger.kernel.org Fixes: 991d9fa02da0 ("dm: add thin provisioning target") Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Acked-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm cache: Fix ABBA deadlock between shrink_slab and dm_cache_metadata_abortMike Snitzer2023-01-181-7/+47
| | | | | | | | | | | | | | commit 352b837a5541690d4f843819028cf2b8be83d424 upstream. Same ABBA deadlock pattern fixed in commit 4b60f452ec51 ("dm thin: Fix ABBA deadlock between shrink_slab and dm_pool_abort_metadata") to DM-cache's metadata. Reported-by: Zhihao Cheng <chengzhihao1@huawei.com> Cc: stable@vger.kernel.org Fixes: 028ae9f76f29 ("dm cache: add fail io mode and needs_check flag") Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* md: fix a crash in mempool_freeMikulas Patocka2023-01-181-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 341097ee53573e06ab9fc675d96a052385b851fa upstream. There's a crash in mempool_free when running the lvm test shell/lvchange-rebuild-raid.sh. The reason for the crash is this: * super_written calls atomic_dec_and_test(&mddev->pending_writes) and wake_up(&mddev->sb_wait). Then it calls rdev_dec_pending(rdev, mddev) and bio_put(bio). * so, the process that waited on sb_wait and that is woken up is racing with bio_put(bio). * if the process wins the race, it calls bioset_exit before bio_put(bio) is executed. * bio_put(bio) attempts to free a bio into a destroyed bio set - causing a crash in mempool_free. We fix this bug by moving bio_put before atomic_dec_and_test. We also move rdev_dec_pending before atomic_dec_and_test as suggested by Neil Brown. The function md_end_flush has a similar bug - we must call bio_put before we decrement the number of in-progress bios. BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 11557f0067 P4D 11557f0067 PUD 0 Oops: 0002 [#1] PREEMPT SMP CPU: 0 PID: 73 Comm: kworker/0:1 Not tainted 6.1.0-rc3 #5 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 Workqueue: kdelayd flush_expired_bios [dm_delay] RIP: 0010:mempool_free+0x47/0x80 Code: 48 89 ef 5b 5d ff e0 f3 c3 48 89 f7 e8 32 45 3f 00 48 63 53 08 48 89 c6 3b 53 04 7d 2d 48 8b 43 10 8d 4a 01 48 89 df 89 4b 08 <48> 89 2c d0 e8 b0 45 3f 00 48 8d 7b 30 5b 5d 31 c9 ba 01 00 00 00 RSP: 0018:ffff88910036bda8 EFLAGS: 00010093 RAX: 0000000000000000 RBX: ffff8891037b65d8 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000202 RDI: ffff8891037b65d8 RBP: ffff8891447ba240 R08: 0000000000012908 R09: 00000000003d0900 R10: 0000000000000000 R11: 0000000000173544 R12: ffff889101a14000 R13: ffff8891562ac300 R14: ffff889102b41440 R15: ffffe8ffffa00d05 FS: 0000000000000000(0000) GS:ffff88942fa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000001102e99000 CR4: 00000000000006b0 Call Trace: <TASK> clone_endio+0xf4/0x1c0 [dm_mod] clone_endio+0xf4/0x1c0 [dm_mod] __submit_bio+0x76/0x120 submit_bio_noacct_nocheck+0xb6/0x2a0 flush_expired_bios+0x28/0x2f [dm_delay] process_one_work+0x1b4/0x300 worker_thread+0x45/0x3e0 ? rescuer_thread+0x380/0x380 kthread+0xc2/0x100 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x1f/0x30 </TASK> Modules linked in: brd dm_delay dm_raid dm_mod af_packet uvesafb cfbfillrect cfbimgblt cn cfbcopyarea fb font fbdev tun autofs4 binfmt_misc configfs ipv6 virtio_rng virtio_balloon rng_core virtio_net pcspkr net_failover failover qemu_fw_cfg button mousedev raid10 raid456 libcrc32c async_raid6_recov async_memcpy async_pq raid6_pq async_xor xor async_tx raid1 raid0 md_mod sd_mod t10_pi crc64_rocksoft crc64 virtio_scsi scsi_mod evdev psmouse bsg scsi_common [last unloaded: brd] CR2: 0000000000000000 ---[ end trace 0000000000000000 ]--- Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* md/raid1: stop mdx_raid1 thread when raid1 array run failedJiang Li2023-01-181-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit b611ad14006e5be2170d9e8e611bf49dff288911 ] fail run raid1 array when we assemble array with the inactive disk only, but the mdx_raid1 thread were not stop, Even if the associated resources have been released. it will caused a NULL dereference when we do poweroff. This causes the following Oops: [ 287.587787] BUG: kernel NULL pointer dereference, address: 0000000000000070 [ 287.594762] #PF: supervisor read access in kernel mode [ 287.599912] #PF: error_code(0x0000) - not-present page [ 287.605061] PGD 0 P4D 0 [ 287.607612] Oops: 0000 [#1] SMP NOPTI [ 287.611287] CPU: 3 PID: 5265 Comm: md0_raid1 Tainted: G U 5.10.146 #0 [ 287.619029] Hardware name: xxxxxxx/To be filled by O.E.M, BIOS 5.19 06/16/2022 [ 287.626775] RIP: 0010:md_check_recovery+0x57/0x500 [md_mod] [ 287.632357] Code: fe 01 00 00 48 83 bb 10 03 00 00 00 74 08 48 89 ...... [ 287.651118] RSP: 0018:ffffc90000433d78 EFLAGS: 00010202 [ 287.656347] RAX: 0000000000000000 RBX: ffff888105986800 RCX: 0000000000000000 [ 287.663491] RDX: ffffc90000433bb0 RSI: 00000000ffffefff RDI: ffff888105986800 [ 287.670634] RBP: ffffc90000433da0 R08: 0000000000000000 R09: c0000000ffffefff [ 287.677771] R10: 0000000000000001 R11: ffffc90000433ba8 R12: ffff888105986800 [ 287.684907] R13: 0000000000000000 R14: fffffffffffffe00 R15: ffff888100b6b500 [ 287.692052] FS: 0000000000000000(0000) GS:ffff888277f80000(0000) knlGS:0000000000000000 [ 287.700149] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 287.705897] CR2: 0000000000000070 CR3: 000000000320a000 CR4: 0000000000350ee0 [ 287.713033] Call Trace: [ 287.715498] raid1d+0x6c/0xbbb [raid1] [ 287.719256] ? __schedule+0x1ff/0x760 [ 287.722930] ? schedule+0x3b/0xb0 [ 287.726260] ? schedule_timeout+0x1ed/0x290 [ 287.730456] ? __switch_to+0x11f/0x400 [ 287.734219] md_thread+0xe9/0x140 [md_mod] [ 287.738328] ? md_thread+0xe9/0x140 [md_mod] [ 287.742601] ? wait_woken+0x80/0x80 [ 287.746097] ? md_register_thread+0xe0/0xe0 [md_mod] [ 287.751064] kthread+0x11a/0x140 [ 287.754300] ? kthread_park+0x90/0x90 [ 287.757974] ret_from_fork+0x1f/0x30 In fact, when raid1 array run fail, we need to do md_unregister_thread() before raid1_free(). Signed-off-by: Jiang Li <jiang.li@ugreen.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* dm ioctl: fix misbehavior if list_versions races with module loadingMikulas Patocka2022-11-251-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 4fe1ec995483737f3d2a14c3fe1d8fe634972979 upstream. __list_versions will first estimate the required space using the "dm_target_iterate(list_version_get_needed, &needed)" call and then will fill the space using the "dm_target_iterate(list_version_get_info, &iter_info)" call. Each of these calls locks the targets using the "down_read(&_lock)" and "up_read(&_lock)" calls, however between the first and second "dm_target_iterate" there is no lock held and the target modules can be loaded at this point, so the second "dm_target_iterate" call may need more space than what was the first "dm_target_iterate" returned. The code tries to handle this overflow (see the beginning of list_version_get_info), however this handling is incorrect. The code sets "param->data_size = param->data_start + needed" and "iter_info.end = (char *)vers+len" - "needed" is the size returned by the first dm_target_iterate call; "len" is the size of the buffer allocated by userspace. "len" may be greater than "needed"; in this case, the code will write up to "len" bytes into the buffer, however param->data_size is set to "needed", so it may write data past the param->data_size value. The ioctl interface copies only up to param->data_size into userspace, thus part of the result will be truncated. Fix this bug by setting "iter_info.end = (char *)vers + needed;" - this guarantees that the second "dm_target_iterate" call will write only up to the "needed" buffer and it will exit with "DM_BUFFER_FULL_FLAG" if it overflows the "needed" space - in this case, userspace will allocate a larger buffer and retry. Note that there is also a bug in list_version_get_needed - we need to add "strlen(tt->name) + 1" to the needed size, not "strlen(tt->name)". Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* md: Replace snprintf with scnprintfSaurabh Sengar2022-10-261-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 1727fd5015d8f93474148f94e34cda5aa6ad4a43 upstream. Current code produces a warning as shown below when total characters in the constituent block device names plus the slashes exceeds 200. snprintf() returns the number of characters generated from the given input, which could cause the expression “200 – len” to wrap around to a large positive number. Fix this by using scnprintf() instead, which returns the actual number of characters written into the buffer. [ 1513.267938] ------------[ cut here ]------------ [ 1513.267943] WARNING: CPU: 15 PID: 37247 at <snip>/lib/vsprintf.c:2509 vsnprintf+0x2c8/0x510 [ 1513.267944] Modules linked in: <snip> [ 1513.267969] CPU: 15 PID: 37247 Comm: mdadm Not tainted 5.4.0-1085-azure #90~18.04.1-Ubuntu [ 1513.267969] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 05/09/2022 [ 1513.267971] RIP: 0010:vsnprintf+0x2c8/0x510 <-snip-> [ 1513.267982] Call Trace: [ 1513.267986] snprintf+0x45/0x70 [ 1513.267990] ? disk_name+0x71/0xa0 [ 1513.267993] dump_zones+0x114/0x240 [raid0] [ 1513.267996] ? _cond_resched+0x19/0x40 [ 1513.267998] raid0_run+0x19e/0x270 [raid0] [ 1513.268000] md_run+0x5e0/0xc50 [ 1513.268003] ? security_capable+0x3f/0x60 [ 1513.268005] do_md_run+0x19/0x110 [ 1513.268006] md_ioctl+0x195e/0x1f90 [ 1513.268007] blkdev_ioctl+0x91f/0x9f0 [ 1513.268010] block_ioctl+0x3d/0x50 [ 1513.268012] do_vfs_ioctl+0xa9/0x640 [ 1513.268014] ? __fput+0x162/0x260 [ 1513.268016] ksys_ioctl+0x75/0x80 [ 1513.268017] __x64_sys_ioctl+0x1a/0x20 [ 1513.268019] do_syscall_64+0x5e/0x200 [ 1513.268021] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: 766038846e875 ("md/raid0: replace printk() with pr_*()") Reviewed-by: Michael Kelley <mikelley@microsoft.com> Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev> Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5dLogan Gunthorpe2022-10-261-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 5e2cf333b7bd5d3e62595a44d598a254c697cd74 ] A complicated deadlock exists when using the journal and an elevated group_thrtead_cnt. It was found with loop devices, but its not clear whether it can be seen with real disks. The deadlock can occur simply by writing data with an fio script. When the deadlock occurs, multiple threads will hang in different ways: 1) The group threads will hang in the blk-wbt code with bios waiting to be submitted to the block layer: io_schedule+0x70/0xb0 rq_qos_wait+0x153/0x210 wbt_wait+0x115/0x1b0 io_schedule+0x70/0xb0 rq_qos_wait+0x153/0x210 wbt_wait+0x115/0x1b0 __rq_qos_throttle+0x38/0x60 blk_mq_submit_bio+0x589/0xcd0 wbt_wait+0x115/0x1b0 __rq_qos_throttle+0x38/0x60 blk_mq_submit_bio+0x589/0xcd0 __submit_bio+0xe6/0x100 submit_bio_noacct_nocheck+0x42e/0x470 submit_bio_noacct+0x4c2/0xbb0 ops_run_io+0x46b/0x1a30 handle_stripe+0xcd3/0x36b0 handle_active_stripes.constprop.0+0x6f6/0xa60 raid5_do_work+0x177/0x330 Or: io_schedule+0x70/0xb0 rq_qos_wait+0x153/0x210 wbt_wait+0x115/0x1b0 __rq_qos_throttle+0x38/0x60 blk_mq_submit_bio+0x589/0xcd0 __submit_bio+0xe6/0x100 submit_bio_noacct_nocheck+0x42e/0x470 submit_bio_noacct+0x4c2/0xbb0 flush_deferred_bios+0x136/0x170 raid5_do_work+0x262/0x330 2) The r5l_reclaim thread will hang in the same way, submitting a bio to the block layer: io_schedule+0x70/0xb0 rq_qos_wait+0x153/0x210 wbt_wait+0x115/0x1b0 __rq_qos_throttle+0x38/0x60 blk_mq_submit_bio+0x589/0xcd0 __submit_bio+0xe6/0x100 submit_bio_noacct_nocheck+0x42e/0x470 submit_bio_noacct+0x4c2/0xbb0 submit_bio+0x3f/0xf0 md_super_write+0x12f/0x1b0 md_update_sb.part.0+0x7c6/0xff0 md_update_sb+0x30/0x60 r5l_do_reclaim+0x4f9/0x5e0 r5l_reclaim_thread+0x69/0x30b However, before hanging, the MD_SB_CHANGE_PENDING flag will be set for sb_flags in r5l_write_super_and_discard_space(). This flag will never be cleared because the submit_bio() call never returns. 3) Due to the MD_SB_CHANGE_PENDING flag being set, handle_stripe() will do no processing on any pending stripes and re-set STRIPE_HANDLE. This will cause the raid5d thread to enter an infinite loop, constantly trying to handle the same stripes stuck in the queue. The raid5d thread has a blk_plug that holds a number of bios that are also stuck waiting seeing the thread is in a loop that never schedules. These bios have been accounted for by blk-wbt thus preventing the other threads above from continuing when they try to submit bios. --Deadlock. To fix this, add the same wait_event() that is used in raid5_do_work() to raid5d() such that if MD_SB_CHANGE_PENDING is set, the thread will schedule and wait until the flag is cleared. The schedule action will flush the plug which will allow the r5l_reclaim thread to continue, thus preventing the deadlock. However, md_check_recovery() calls can also clear MD_SB_CHANGE_PENDING from the same thread and can thus deadlock if the thread is put to sleep. So avoid waiting if md_check_recovery() is being called in the loop. It's not clear when the deadlock was introduced, but the similar wait_event() call in raid5_do_work() was added in 2017 by this commit: 16d997b78b15 ("md/raid5: simplfy delaying of writes while metadata is updated.") Link: https://lore.kernel.org/r/7f3b87b6-b52a-f737-51d7-a4eec5c44112@deltatee.com Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* md/raid5: Ensure stripe_fill happens on non-read IO with journalLogan Gunthorpe2022-10-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit e2eed85bc75138a9eeb63863d20f8904ac42a577 ] When doing degrade/recover tests using the journal a kernel BUG is hit at drivers/md/raid5.c:4381 in handle_parity_checks5(): BUG_ON(!test_bit(R5_UPTODATE, &dev->flags)); This was found to occur because handle_stripe_fill() was skipped for stripes in the journal due to a condition in that function. Thus blocks were not fetched and R5_UPTODATE was not set when the code reached handle_parity_checks5(). To fix this, don't skip handle_stripe_fill() unless the stripe is for read. Fixes: 07e83364845e ("md/r5cache: shift complex rmw from read path to write path") Link: https://lore.kernel.org/linux-raid/e05c4239-41a9-d2f7-3cfa-4aa9d2cea8c1@deltatee.com/ Suggested-by: Song Liu <song@kernel.org> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* md: call __md_stop_writes in md_stopGuoqing Jiang2022-09-051-0/+1
| | | | | | | | | | | | | | | | | | commit 0dd84b319352bb8ba64752d4e45396d8b13e6018 upstream. From the link [1], we can see raid1d was running even after the path raid_dtr -> md_stop -> __md_stop. Let's stop write first in destructor to align with normal md-raid to fix the KASAN issue. [1]. https://lore.kernel.org/linux-raid/CAPhsuW5gc4AakdGNdF8ubpezAuDLFOYUO_sfMZcec6hQFm8nhg@mail.gmail.com/T/#m7f12bf90481c02c6d2da68c64aeed4779b7df74a Fixes: 48df498daf62 ("md: move bitmap_destroy to the beginning of __md_stop") Reported-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* drivers:md:fix a potential use-after-free bugWentao_Liang2022-08-251-1/+1
| | | | | | | | | | | | | | | | | [ Upstream commit 104212471b1c1817b311771d817fb692af983173 ] In line 2884, "raid5_release_stripe(sh);" drops the reference to sh and may cause sh to be released. However, sh is subsequently used in lines 2886 "if (sh->batch_head && sh != sh->batch_head)". This may result in an use-after-free bug. It can be fixed by moving "raid5_release_stripe(sh);" to the bottom of the function. Signed-off-by: Wentao_Liang <Wentao_Liang_g@163.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* dm raid: fix address sanitizer warning in raid_statusMikulas Patocka2022-08-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 1fbeea217d8f297fe0e0956a1516d14ba97d0396 upstream. There is this warning when using a kernel with the address sanitizer and running this testsuite: https://gitlab.com/cki-project/kernel-tests/-/tree/main/storage/swraid/scsi_raid ================================================================== BUG: KASAN: slab-out-of-bounds in raid_status+0x1747/0x2820 [dm_raid] Read of size 4 at addr ffff888079d2c7e8 by task lvcreate/13319 CPU: 0 PID: 13319 Comm: lvcreate Not tainted 5.18.0-0.rc3.<snip> #1 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 Call Trace: <TASK> dump_stack_lvl+0x6a/0x9c print_address_description.constprop.0+0x1f/0x1e0 print_report.cold+0x55/0x244 kasan_report+0xc9/0x100 raid_status+0x1747/0x2820 [dm_raid] dm_ima_measure_on_table_load+0x4b8/0xca0 [dm_mod] table_load+0x35c/0x630 [dm_mod] ctl_ioctl+0x411/0x630 [dm_mod] dm_ctl_ioctl+0xa/0x10 [dm_mod] __x64_sys_ioctl+0x12a/0x1a0 do_syscall_64+0x5b/0x80 The warning is caused by reading conf->max_nr_stripes in raid_status. The code in raid_status reads mddev->private, casts it to struct r5conf and reads the entry max_nr_stripes. However, if we have different raid type than 4/5/6, mddev->private doesn't point to struct r5conf; it may point to struct r0conf, struct r1conf, struct r10conf or struct mpconf. If we cast a pointer to one of these structs to struct r5conf, we will be reading invalid memory and KASAN warns about it. Fix this bug by reading struct r5conf only if raid type is 4, 5 or 6. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm raid: fix address sanitizer warning in raid_resumeMikulas Patocka2022-08-251-1/+1
| | | | | | | | | | | | | | commit 7dad24db59d2d2803576f2e3645728866a056dab upstream. There is a KASAN warning in raid_resume when running the lvm test lvconvert-raid.sh. The reason for the warning is that mddev->raid_disks is greater than rs->raid_disks, so the loop touches one entry beyond the allocated length. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm: return early from dm_pr_call() if DM device is suspendedMike Snitzer2022-08-251-0/+5
| | | | | | | | | | | [ Upstream commit e120a5f1e78fab6223544e425015f393d90d6f0d ] Otherwise PR ops may be issued while the broader DM device is being reconfigured, etc. Fixes: 9c72bad1f31a ("dm: call PR reserve/unreserve on each underlying device") Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* md-raid10: fix KASAN warningMikulas Patocka2022-08-251-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit d17f744e883b2f8d13cca252d71cfe8ace346f7d upstream. There's a KASAN warning in raid10_remove_disk when running the lvm test lvconvert-raid-reshape.sh. We fix this warning by verifying that the value "number" is valid. BUG: KASAN: slab-out-of-bounds in raid10_remove_disk+0x61/0x2a0 [raid10] Read of size 8 at addr ffff889108f3d300 by task mdX_raid10/124682 CPU: 3 PID: 124682 Comm: mdX_raid10 Not tainted 5.19.0-rc6 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x34/0x44 print_report.cold+0x45/0x57a ? __lock_text_start+0x18/0x18 ? raid10_remove_disk+0x61/0x2a0 [raid10] kasan_report+0xa8/0xe0 ? raid10_remove_disk+0x61/0x2a0 [raid10] raid10_remove_disk+0x61/0x2a0 [raid10] Buffer I/O error on dev dm-76, logical block 15344, async page read ? __mutex_unlock_slowpath.constprop.0+0x1e0/0x1e0 remove_and_add_spares+0x367/0x8a0 [md_mod] ? super_written+0x1c0/0x1c0 [md_mod] ? mutex_trylock+0xac/0x120 ? _raw_spin_lock+0x72/0xc0 ? _raw_spin_lock_bh+0xc0/0xc0 md_check_recovery+0x848/0x960 [md_mod] raid10d+0xcf/0x3360 [raid10] ? sched_clock_cpu+0x185/0x1a0 ? rb_erase+0x4d4/0x620 ? var_wake_function+0xe0/0xe0 ? psi_group_change+0x411/0x500 ? preempt_count_sub+0xf/0xc0 ? _raw_spin_lock_irqsave+0x78/0xc0 ? __lock_text_start+0x18/0x18 ? raid10_sync_request+0x36c0/0x36c0 [raid10] ? preempt_count_sub+0xf/0xc0 ? _raw_spin_unlock_irqrestore+0x19/0x40 ? del_timer_sync+0xa9/0x100 ? try_to_del_timer_sync+0xc0/0xc0 ? _raw_spin_lock_irqsave+0x78/0xc0 ? __lock_text_start+0x18/0x18 ? _raw_spin_unlock_irq+0x11/0x24 ? __list_del_entry_valid+0x68/0xa0 ? finish_wait+0xa3/0x100 md_thread+0x161/0x260 [md_mod] ? unregister_md_personality+0xa0/0xa0 [md_mod] ? _raw_spin_lock_irqsave+0x78/0xc0 ? prepare_to_wait_event+0x2c0/0x2c0 ? unregister_md_personality+0xa0/0xa0 [md_mod] kthread+0x148/0x180 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x1f/0x30 </TASK> Allocated by task 124495: kasan_save_stack+0x1e/0x40 __kasan_kmalloc+0x80/0xa0 setup_conf+0x140/0x5c0 [raid10] raid10_run+0x4cd/0x740 [raid10] md_run+0x6f9/0x1300 [md_mod] raid_ctr+0x2531/0x4ac0 [dm_raid] dm_table_add_target+0x2b0/0x620 [dm_mod] table_load+0x1c8/0x400 [dm_mod] ctl_ioctl+0x29e/0x560 [dm_mod] dm_compat_ctl_ioctl+0x7/0x20 [dm_mod] __do_compat_sys_ioctl+0xfa/0x160 do_syscall_64+0x90/0xc0 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Last potentially related work creation: kasan_save_stack+0x1e/0x40 __kasan_record_aux_stack+0x9e/0xc0 kvfree_call_rcu+0x84/0x480 timerfd_release+0x82/0x140 L __fput+0xfa/0x400 task_work_run+0x80/0xc0 exit_to_user_mode_prepare+0x155/0x160 syscall_exit_to_user_mode+0x12/0x40 do_syscall_64+0x42/0xc0 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Second to last potentially related work creation: kasan_save_stack+0x1e/0x40 __kasan_record_aux_stack+0x9e/0xc0 kvfree_call_rcu+0x84/0x480 timerfd_release+0x82/0x140 __fput+0xfa/0x400 task_work_run+0x80/0xc0 exit_to_user_mode_prepare+0x155/0x160 syscall_exit_to_user_mode+0x12/0x40 do_syscall_64+0x42/0xc0 entry_SYSCALL_64_after_hwframe+0x46/0xb0 The buggy address belongs to the object at ffff889108f3d200 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 0 bytes to the right of 256-byte region [ffff889108f3d200, ffff889108f3d300) The buggy address belongs to the physical page: page:000000007ef2a34c refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1108f3c head:000000007ef2a34c order:2 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=2) raw: 4000000000010200 0000000000000000 dead000000000001 ffff889100042b40 raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff889108f3d200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff889108f3d280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff889108f3d300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff889108f3d380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff889108f3d400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm raid: fix KASAN warning in raid5_add_disksMikulas Patocka2022-07-071-0/+1
| | | | | | | | | | | | | | commit 617b365872a247480e9dcd50a32c8d1806b21861 upstream. There's a KASAN warning in raid5_add_disk when running the LVM testsuite. The warning happens in the test lvconvert-raid-reshape-linear_to_raid6-single-type.sh. We fix the warning by verifying that rdev->saved_raid_disk is within limits. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm raid: fix accesses beyond end of raid member arrayHeinz Mauelshagen2022-07-071-16/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 332bd0778775d0cf105c4b9e03e460b590749916 upstream. On dm-raid table load (using raid_ctr), dm-raid allocates an array rs->devs[rs->raid_disks] for the raid device members. rs->raid_disks is defined by the number of raid metadata and image tupples passed into the target's constructor. In the case of RAID layout changes being requested, that number can be different from the current number of members for existing raid sets as defined in their superblocks. Example RAID layout changes include: - raid1 legs being added/removed - raid4/5/6/10 number of stripes changed (stripe reshaping) - takeover to higher raid level (e.g. raid5 -> raid6) When accessing array members, rs->raid_disks must be used in control loops instead of the potentially larger value in rs->md.raid_disks. Otherwise it will cause memory access beyond the end of the rs->devs array. Fix this by changing code that is prone to out-of-bounds access. Also fix validate_raid_redundancy() to validate all devices that are added. Also, use braces to help clean up raid_iterate_devices(). The out-of-bounds memory accesses was discovered using KASAN. This commit was verified to pass all LVM2 RAID tests (with KASAN enabled). Cc: stable@vger.kernel.org Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm era: commit metadata in postsuspend after worker stopsNikos Tsironis2022-07-021-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 9ae6e8b1c9bbf6874163d1243e393137313762b7 upstream. During postsuspend dm-era does the following: 1. Archives the current era 2. Commits the metadata, as part of the RPC call for archiving the current era 3. Stops the worker Until the worker stops, it might write to the metadata again. Moreover, these writes are not flushed to disk immediately, but are cached by the dm-bufio client, which writes them back asynchronously. As a result, the committed metadata of a suspended dm-era device might not be consistent with the in-core metadata. In some cases, this can result in the corruption of the on-disk metadata. Suppose the following sequence of events: 1. Load a new table, e.g. a snapshot-origin table, to a device with a dm-era table 2. Suspend the device 3. dm-era commits its metadata, but the worker does a few more metadata writes until it stops, as part of digesting an archived writeset 4. These writes are cached by the dm-bufio client 5. Load the dm-era table to another device. 6. The new instance of the dm-era target loads the committed, on-disk metadata, which don't include the extra writes done by the worker after the metadata commit. 7. Resume the new device 8. The new dm-era target instance starts using the metadata 9. Resume the original device 10. The destructor of the old dm-era target instance is called and destroys the dm-bufio client, which results in flushing the cached writes to disk 11. These writes might overwrite the writes done by the new dm-era instance, hence corrupting its metadata. Fix this by committing the metadata after the worker stops running. stop_worker uses flush_workqueue to flush the current work. However, the work item may re-queue itself and flush_workqueue doesn't wait for re-queued works to finish. This could result in the worker changing the metadata after they have been committed, or writing to the metadata concurrently with the commit in the postsuspend thread. Use drain_workqueue instead, which waits until the work and all re-queued works finish. Fixes: eec40579d8487 ("dm: add era target") Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* md/raid0: Ignore RAID0 layout if the second zone has only one devicePascal Hambourg2022-06-141-15/+16
| | | | | | | | | | | | | | | | | commit ea23994edc4169bd90d7a9b5908c6ccefd82fa40 upstream. The RAID0 layout is irrelevant if all members have the same size so the array has only one zone. It is *also* irrelevant if the array has two zones and the second zone has only one device, for example if the array has two members of different sizes. So in that case it makes sense to allow assembly even when the layout is undefined, like what is done when the array has only one zone. Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Pascal Hambourg <pascal@plouf.fr.eu.org> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* md: protect md_unregister_thread from reentrancyGuoqing Jiang2022-06-141-5/+10
| | | | | | | | | | | | | | | | | | | | [ Upstream commit 1e267742283a4b5a8ca65755c44166be27e9aa0f ] Generally, the md_unregister_thread is called with reconfig_mutex, but raid_message in dm-raid doesn't hold reconfig_mutex to unregister thread, so md_unregister_thread can be called simulitaneously from two call sites in theory. Then after previous commit which remove the protection of reconfig_mutex for md_unregister_thread completely, the potential issue could be worse than before. Let's take pers_lock at the beginning of function to ensure reentrancy. Reported-by: Donald Buczek <buczek@molgen.mpg.de> Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* md: fix an incorrect NULL check in md_reload_sbXiaomeng Tong2022-06-141-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | commit 64c54d9244a4efe9bc6e9c98e13c4bbb8bb39083 upstream. The bug is here: if (!rdev || rdev->desc_nr != nr) { The list iterator value 'rdev' will *always* be set and non-NULL by rdev_for_each_rcu(), so it is incorrect to assume that the iterator value will be NULL if the list is empty or no element found (In fact, it will be a bogus pointer to an invalid struct object containing the HEAD). Otherwise it will bypass the check and lead to invalid memory access passing the check. To fix the bug, use a new variable 'iter' as the list iterator, while using the original variable 'pdev' as a dedicated pointer to point to the found element. Cc: stable@vger.kernel.org Fixes: 70bcecdb1534 ("md-cluster: Improve md_reload_sb to be less error prone") Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* md: fix an incorrect NULL check in does_sb_need_changingXiaomeng Tong2022-06-141-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | commit fc8738343eefc4ea8afb6122826dea48eacde514 upstream. The bug is here: if (!rdev) The list iterator value 'rdev' will *always* be set and non-NULL by rdev_for_each(), so it is incorrect to assume that the iterator value will be NULL if the list is empty or no element found. Otherwise it will bypass the NULL check and lead to invalid memory access passing the check. To fix the bug, use a new variable 'iter' as the list iterator, while using the original variable 'rdev' as a dedicated pointer to point to the found element. Cc: stable@vger.kernel.org Fixes: 2aa82191ac36 ("md-cluster: Perform a lazy update") Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev> Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com> Acked-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm verity: set DM_TARGET_IMMUTABLE feature flagSarthak Kukreti2022-06-061-0/+1
| | | | | | | | | | | | | | | | | commit 4caae58406f8ceb741603eee460d79bacca9b1b5 upstream. The device-mapper framework provides a mechanism to mark targets as immutable (and hence fail table reloads that try to change the target type). Add the DM_TARGET_IMMUTABLE flag to the dm-verity target's feature flags to prevent switching the verity target with a different target type. Fixes: a4ffc152198e ("dm: add verity target") Cc: stable@vger.kernel.org Signed-off-by: Sarthak Kukreti <sarthakkukreti@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm stats: add cond_resched when looping over entriesMikulas Patocka2022-06-061-0/+8
| | | | | | | | | | | | | commit bfe2b0146c4d0230b68f5c71a64380ff8d361f8b upstream. dm-stats can be used with a very large number of entries (it is only limited by 1/4 of total system memory), so add rescheduling points to the loops that iterate over the entries. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm crypt: make printing of the key constant-timeMikulas Patocka2022-06-061-3/+11
| | | | | | | | | | | | | | | | | | | | commit 567dd8f34560fa221a6343729474536aa7ede4fd upstream. The device mapper dm-crypt target is using scnprintf("%02x", cc->key[i]) to report the current key to userspace. However, this is not a constant-time operation and it may leak information about the key via timing, via cache access patterns or via the branch predictor. Change dm-crypt's key printing to use "%c" instead of "%02x". Also introduce hex2asc() that carefully avoids any branching or memory accesses when converting a number in the range 0 ... 15 to an ascii character. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Tested-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm integrity: fix error code in dm_integrity_ctr()Dan Carpenter2022-06-061-2/+0
| | | | | | | | | | | | | | | | | | commit d3f2a14b8906df913cb04a706367b012db94a6e8 upstream. The "r" variable shadows an earlier "r" that has function scope. It means that we accidentally return success instead of an error code. Smatch has a warning for this: drivers/md/dm-integrity.c:4503 dm_integrity_ctr() warn: missing error code 'r' Fixes: 7eada909bfd7 ("dm: add integrity target") Cc: stable@vger.kernel.org Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm: interlock pending dm_io and dm_wait_for_bios_completionMike Snitzer2022-05-121-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | commit 9f6dc633761006f974701d4c88da71ab68670749 upstream. Commit d208b89401e0 ("dm: fix mempool NULL pointer race when completing IO") didn't go far enough. When bio_end_io_acct ends the count of in-flight I/Os may reach zero and the DM device may be suspended. There is a possibility that the suspend races with dm_stats_account_io. Fix this by adding percpu "pending_io" counters to track outstanding dm_io. Move kicking of suspend queue to dm_io_dec_pending(). Also, rename md_in_flight_bios() to dm_in_flight_bios() and update it to iterate all pending_io counters. Fixes: d208b89401e0 ("dm: fix mempool NULL pointer race when completing IO") Cc: stable@vger.kernel.org Co-developed-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm: fix mempool NULL pointer race when completing IOJiazi Li2022-05-121-7/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit d208b89401e073de986dc891037c5a668f5d5d95 upstream. dm_io_dec_pending() calls end_io_acct() first and will then dec md in-flight pending count. But if a task is swapping DM table at same time this can result in a crash due to mempool->elements being NULL: task1 task2 do_resume ->do_suspend ->dm_wait_for_completion bio_endio ->clone_endio ->dm_io_dec_pending ->end_io_acct ->wakeup task1 ->dm_swap_table ->__bind ->__bind_mempools ->bioset_exit ->mempool_exit ->free_io [ 67.330330] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 ...... [ 67.330494] pstate: 80400085 (Nzcv daIf +PAN -UAO) [ 67.330510] pc : mempool_free+0x70/0xa0 [ 67.330515] lr : mempool_free+0x4c/0xa0 [ 67.330520] sp : ffffff8008013b20 [ 67.330524] x29: ffffff8008013b20 x28: 0000000000000004 [ 67.330530] x27: ffffffa8c2ff40a0 x26: 00000000ffff1cc8 [ 67.330535] x25: 0000000000000000 x24: ffffffdada34c800 [ 67.330541] x23: 0000000000000000 x22: ffffffdada34c800 [ 67.330547] x21: 00000000ffff1cc8 x20: ffffffd9a1304d80 [ 67.330552] x19: ffffffdada34c970 x18: 000000b312625d9c [ 67.330558] x17: 00000000002dcfbf x16: 00000000000006dd [ 67.330563] x15: 000000000093b41e x14: 0000000000000010 [ 67.330569] x13: 0000000000007f7a x12: 0000000034155555 [ 67.330574] x11: 0000000000000001 x10: 0000000000000001 [ 67.330579] x9 : 0000000000000000 x8 : 0000000000000000 [ 67.330585] x7 : 0000000000000000 x6 : ffffff80148b5c1a [ 67.330590] x5 : ffffff8008013ae0 x4 : 0000000000000001 [ 67.330596] x3 : ffffff80080139c8 x2 : ffffff801083bab8 [ 67.330601] x1 : 0000000000000000 x0 : ffffffdada34c970 [ 67.330609] Call trace: [ 67.330616] mempool_free+0x70/0xa0 [ 67.330627] bio_put+0xf8/0x110 [ 67.330638] dec_pending+0x13c/0x230 [ 67.330644] clone_endio+0x90/0x180 [ 67.330649] bio_endio+0x198/0x1b8 [ 67.330655] dec_pending+0x190/0x230 [ 67.330660] clone_endio+0x90/0x180 [ 67.330665] bio_endio+0x198/0x1b8 [ 67.330673] blk_update_request+0x214/0x428 [ 67.330683] scsi_end_request+0x2c/0x300 [ 67.330688] scsi_io_completion+0xa0/0x710 [ 67.330695] scsi_finish_command+0xd8/0x110 [ 67.330700] scsi_softirq_done+0x114/0x148 [ 67.330708] blk_done_softirq+0x74/0xd0 [ 67.330716] __do_softirq+0x18c/0x374 [ 67.330724] irq_exit+0xb4/0xb8 [ 67.330732] __handle_domain_irq+0x84/0xc0 [ 67.330737] gic_handle_irq+0x148/0x1b0 [ 67.330744] el1_irq+0xe8/0x190 [ 67.330753] lpm_cpuidle_enter+0x4f8/0x538 [ 67.330759] cpuidle_enter_state+0x1fc/0x398 [ 67.330764] cpuidle_enter+0x18/0x20 [ 67.330772] do_idle+0x1b4/0x290 [ 67.330778] cpu_startup_entry+0x20/0x28 [ 67.330786] secondary_start_kernel+0x160/0x170 Fix this by: 1) Establishing pointers to 'struct dm_io' members in dm_io_dec_pending() so that they may be passed into end_io_acct() _after_ free_io() is called. 2) Moving end_io_acct() after free_io(). Cc: stable@vger.kernel.org Signed-off-by: Jiazi Li <lijiazi@xiaomi.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm ioctl: prevent potential spectre v1 gadgetJordy Zomer2022-04-201-0/+2
| | | | | | | | | | | | | [ Upstream commit cd9c88da171a62c4b0f1c70e50c75845969fbc18 ] It appears like cmd could be a Spectre v1 gadget as it's supplied by a user and used as an array index. Prevent the contents of kernel memory from being leaked to userspace via speculative execution by using array_index_nospec. Signed-off-by: Jordy Zomer <jordy@pwning.systems> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* dm crypt: fix get_key_size compiler warning if !CONFIG_KEYSAashish Sharma2022-04-201-1/+1
| | | | | | | | | | | | | | | | [ Upstream commit 6fc51504388c1a1a53db8faafe9fff78fccc7c87 ] Explicitly convert unsigned int in the right of the conditional expression to int to match the left side operand and the return type, fixing the following compiler warning: drivers/md/dm-crypt.c:2593:43: warning: signed and unsigned type in conditional expression [-Wsign-compare] Fixes: c538f6ec9f56 ("dm crypt: add ability to use keys from the kernel key retention service") Signed-off-by: Aashish Sharma <shraash@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* dm space map common: add bounds check to sm_ll_lookup_bitmap()Joe Thornber2022-01-271-0/+5
| | | | | | | | | | [ Upstream commit cba23ac158db7f3cd48a923d6861bee2eb7a2978 ] Corrupted metadata could warrant returning error from sm_ll_lookup_bitmap(). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* dm btree: add a defensive bounds check to insert_at()Joe Thornber2022-01-271-3/+5
| | | | | | | | | | [ Upstream commit 85bca3c05b6cca31625437eedf2060e846c4bbad ] Corrupt metadata could trigger an out of bounds write. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* dm btree remove: fix use after free in rebalance_children()Joe Thornber2021-12-221-1/+1
| | | | | | | | | | | commit 1b8d2789dad0005fd5e7d35dab26a8e1203fb6da upstream. Move dm_tm_unlock() after dm_tm_dec(). Cc: stable@vger.kernel.org Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* md: fix a lock order reversal in md_allocChristoph Hellwig2021-10-061-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 7df835a32a8bedf7ce88efcfa7c9b245b52ff139 ] Commit b0140891a8cea3 ("md: Fix race when creating a new md device.") not only moved assigning mddev->gendisk before calling add_disk, which fixes the races described in the commit log, but also added a mddev->open_mutex critical section over add_disk and creation of the md kobj. Adding a kobject after add_disk is racy vs deleting the gendisk right after adding it, but md already prevents against that by holding a mddev->active reference. On the other hand taking this lock added a lock order reversal with what is not disk->open_mutex (used to be bdev->bd_mutex when the commit was added) for partition devices, which need that lock for the internal open for the partition scan, and a recent commit also takes it for non-partitioned devices, leading to further lockdep splatter. Fixes: b0140891a8ce ("md: Fix race when creating a new md device.") Fixes: d62633873590 ("block: support delayed holder registration") Reported-by: syzbot+fadc0aaf497e6a493b9f@syzkaller.appspotmail.com Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: syzbot+fadc0aaf497e6a493b9f@syzkaller.appspotmail.com Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* dm crypt: Avoid percpu_counter spinlock contention in crypt_page_alloc()Arne Welzel2021-09-221-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 528b16bfc3ae5f11638e71b3b63a81f9999df727 upstream. On systems with many cores using dm-crypt, heavy spinlock contention in percpu_counter_compare() can be observed when the page allocation limit for a given device is reached or close to be reached. This is due to percpu_counter_compare() taking a spinlock to compute an exact result on potentially many CPUs at the same time. Switch to non-exact comparison of allocated and allowed pages by using the value returned by percpu_counter_read_positive() to avoid taking the percpu_counter spinlock. This may over/under estimate the actual number of allocated pages by at most (batch-1) * num_online_cpus(). Currently, batch is bounded by 32. The system on which this issue was first observed has 256 CPUs and 512GB of RAM. With a 4k page size, this change may over/under estimate by 31MB. With ~10G (2%) allowed dm-crypt allocations, this seems an acceptable error. Certainly preferred over running into the spinlock contention. This behavior was reproduced on an EC2 c5.24xlarge instance with 96 CPUs and 192GB RAM as follows, but can be provoked on systems with less CPUs as well. * Disable swap * Tune vm settings to promote regular writeback $ echo 50 > /proc/sys/vm/dirty_expire_centisecs $ echo 25 > /proc/sys/vm/dirty_writeback_centisecs $ echo $((128 * 1024 * 1024)) > /proc/sys/vm/dirty_background_bytes * Create 8 dmcrypt devices based on files on a tmpfs * Create and mount an ext4 filesystem on each crypt devices * Run stress-ng --hdd 8 within one of above filesystems Total %system usage collected from sysstat goes to ~35%. Write throughput on the underlying loop device is ~2GB/s. perf profiling an individual kworker kcryptd thread shows the following profile, indicating spinlock contention in percpu_counter_compare(): 99.98% 0.00% kworker/u193:46 [kernel.kallsyms] [k] ret_from_fork | --ret_from_fork kthread worker_thread | --99.92%--process_one_work | |--80.52%--kcryptd_crypt | | | |--62.58%--mempool_alloc | | | | | --62.24%--crypt_page_alloc | | | | | --61.51%--__percpu_counter_compare | | | | | --61.34%--__percpu_counter_sum | | | | | |--58.68%--_raw_spin_lock_irqsave | | | | | | | --58.30%--native_queued_spin_lock_slowpath | | | | | --0.69%--cpumask_next | | | | | --0.51%--_find_next_bit | | | |--10.61%--crypt_convert | | | | | |--6.05%--xts_crypt ... After applying this patch and running the same test, %system usage is lowered to ~7% and write throughput on the loop device increases to ~2.7GB/s. perf report shows mempool_alloc() as ~8% rather than ~62% in the profile and not hitting the percpu_counter() spinlock anymore. |--8.15%--mempool_alloc | | | |--3.93%--crypt_page_alloc | | | | | --3.75%--__alloc_pages | | | | | --3.62%--get_page_from_freelist | | | | | --3.22%--rmqueue_bulk | | | | | --2.59%--_raw_spin_lock | | | | | --2.57%--native_queued_spin_lock_slowpath | | | --3.05%--_raw_spin_lock_irqsave | | | --2.49%--native_queued_spin_lock_slowpath Suggested-by: DJ Gregor <dj@corelight.com> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Arne Welzel <arne.welzel@corelight.com> Fixes: 5059353df86e ("dm crypt: limit the number of allocated pages") Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm btree remove: assign new_root only when removal succeedsHou Tao2021-07-201-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit b6e58b5466b2959f83034bead2e2e1395cca8aeb upstream. remove_raw() in dm_btree_remove() may fail due to IO read error (e.g. read the content of origin block fails during shadowing), and the value of shadow_spine::root is uninitialized, but the uninitialized value is still assign to new_root in the end of dm_btree_remove(). For dm-thin, the value of pmd->details_root or pmd->root will become an uninitialized value, so if trying to read details_info tree again out-of-bound memory may occur as showed below: general protection fault, probably for non-canonical address 0x3fdcb14c8d7520 CPU: 4 PID: 515 Comm: dmsetup Not tainted 5.13.0-rc6 Hardware name: QEMU Standard PC RIP: 0010:metadata_ll_load_ie+0x14/0x30 Call Trace: sm_metadata_count_is_more_than_one+0xb9/0xe0 dm_tm_shadow_block+0x52/0x1c0 shadow_step+0x59/0xf0 remove_raw+0xb2/0x170 dm_btree_remove+0xf4/0x1c0 dm_pool_delete_thin_device+0xc3/0x140 pool_message+0x218/0x2b0 target_message+0x251/0x290 ctl_ioctl+0x1c4/0x4d0 dm_ctl_ioctl+0xe/0x20 __x64_sys_ioctl+0x7b/0xb0 do_syscall_64+0x40/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xae Fixing it by only assign new_root when removal succeeds Signed-off-by: Hou Tao <houtao1@huawei.com> Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
generated by cgit v1.2.3 (git 2.25.1) at 2025-04-08 17:02:48 +0000