{"id":"CVE-2022-50549","summary":"dm thin: Fix ABBA deadlock between shrink_slab and dm_pool_abort_metadata","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm thin: Fix ABBA deadlock between shrink_slab and dm_pool_abort_metadata\n\nFollowing concurrent processes:\n\n          P1(drop cache)                P2(kworker)\ndrop_caches_sysctl_handler\n drop_slab\n  shrink_slab\n   down_read(&shrinker_rwsem)  - LOCK A\n   do_shrink_slab\n    super_cache_scan\n     prune_icache_sb\n      dispose_list\n       evict\n        ext4_evict_inode\n\t ext4_clear_inode\n\t  ext4_discard_preallocations\n\t   ext4_mb_load_buddy_gfp\n\t    ext4_mb_init_cache\n\t     ext4_read_block_bitmap_nowait\n\t      ext4_read_bh_nowait\n\t       submit_bh\n\t        dm_submit_bio\n\t\t                 do_worker\n\t\t\t\t  process_deferred_bios\n\t\t\t\t   commit\n\t\t\t\t    metadata_operation_failed\n\t\t\t\t     dm_pool_abort_metadata\n\t\t\t\t      down_write(&pmd-\u003eroot_lock) - LOCK B\n\t\t                      __destroy_persistent_data_objects\n\t\t\t\t       dm_block_manager_destroy\n\t\t\t\t        dm_bufio_client_destroy\n\t\t\t\t         unregister_shrinker\n\t\t\t\t\t  down_write(&shrinker_rwsem)\n\t\t thin_map                            |\n\t\t  dm_thin_find_block                 ↓\n\t\t   down_read(&pmd-\u003eroot_lock) --\u003e ABBA deadlock\n\n, which triggers hung task:\n\n[   76.974820] INFO: task kworker/u4:3:63 blocked for more than 15 seconds.\n[   76.976019]       Not tainted 6.1.0-rc4-00011-g8f17dd350364-dirty #910\n[   76.978521] task:kworker/u4:3    state:D stack:0     pid:63    ppid:2\n[   76.978534] Workqueue: dm-thin do_worker\n[   76.978552] Call Trace:\n[   76.978564]  __schedule+0x6ba/0x10f0\n[   76.978582]  schedule+0x9d/0x1e0\n[   76.978588]  rwsem_down_write_slowpath+0x587/0xdf0\n[   76.978600]  down_write+0xec/0x110\n[   76.978607]  unregister_shrinker+0x2c/0xf0\n[   76.978616]  dm_bufio_client_destroy+0x116/0x3d0\n[   76.978625]  dm_block_manager_destroy+0x19/0x40\n[   76.978629]  __destroy_persistent_data_objects+0x5e/0x70\n[   76.978636]  dm_pool_abort_metadata+0x8e/0x100\n[   76.978643]  metadata_operation_failed+0x86/0x110\n[   76.978649]  commit+0x6a/0x230\n[   76.978655]  do_worker+0xc6e/0xd90\n[   76.978702]  process_one_work+0x269/0x630\n[   76.978714]  worker_thread+0x266/0x630\n[   76.978730]  kthread+0x151/0x1b0\n[   76.978772] INFO: task test.sh:2646 blocked for more than 15 seconds.\n[   76.979756]       Not tainted 6.1.0-rc4-00011-g8f17dd350364-dirty #910\n[   76.982111] task:test.sh         state:D stack:0     pid:2646  ppid:2459\n[   76.982128] Call Trace:\n[   76.982139]  __schedule+0x6ba/0x10f0\n[   76.982155]  schedule+0x9d/0x1e0\n[   76.982159]  rwsem_down_read_slowpath+0x4f4/0x910\n[   76.982173]  down_read+0x84/0x170\n[   76.982177]  dm_thin_find_block+0x4c/0xd0\n[   76.982183]  thin_map+0x201/0x3d0\n[   76.982188]  __map_bio+0x5b/0x350\n[   76.982195]  dm_submit_bio+0x2b6/0x930\n[   76.982202]  __submit_bio+0x123/0x2d0\n[   76.982209]  submit_bio_noacct_nocheck+0x101/0x3e0\n[   76.982222]  submit_bio_noacct+0x389/0x770\n[   76.982227]  submit_bio+0x50/0xc0\n[   76.982232]  submit_bh_wbc+0x15e/0x230\n[   76.982238]  submit_bh+0x14/0x20\n[   76.982241]  ext4_read_bh_nowait+0xc5/0x130\n[   76.982247]  ext4_read_block_bitmap_nowait+0x340/0xc60\n[   76.982254]  ext4_mb_init_cache+0x1ce/0xdc0\n[   76.982259]  ext4_mb_load_buddy_gfp+0x987/0xfa0\n[   76.982263]  ext4_discard_preallocations+0x45d/0x830\n[   76.982274]  ext4_clear_inode+0x48/0xf0\n[   76.982280]  ext4_evict_inode+0xcf/0xc70\n[   76.982285]  evict+0x119/0x2b0\n[   76.982290]  dispose_list+0x43/0xa0\n[   76.982294]  prune_icache_sb+0x64/0x90\n[   76.982298]  super_cache_scan+0x155/0x210\n[   76.982303]  do_shrink_slab+0x19e/0x4e0\n[   76.982310]  shrink_slab+0x2bd/0x450\n[   76.982317]  drop_slab+0xcc/0x1a0\n[   76.982323]  drop_caches_sysctl_handler+0xb7/0xe0\n[   76.982327]  proc_sys_call_handler+0x1bc/0x300\n[   76.982331]  proc_sys_write+0x17/0x20\n[   76.982334]  vfs_write+0x3d3/0x570\n[   76.982342]  ksys_write+0x73/0x160\n[   76.982347]  __x64_sys_write+0x1e/0x30\n[   76.982352]  do_syscall_64+0x35/0x80\n[   76.982357]  entry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nFunct\n---truncated---","modified":"2026-03-20T11:47:31.306894Z","published":"2025-10-07T15:21:12.006Z","related":["SUSE-SU-2025:4111-1","SUSE-SU-2025:4135-1","SUSE-SU-2025:4139-1","SUSE-SU-2025:4149-1","SUSE-SU-2025:4188-1","SUSE-SU-2025:4189-1","SUSE-SU-2025:4320-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/50xxx/CVE-2022-50549.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/200aa33b5d781e7c0fa6c0c7db9dbcc3f574ce8f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2d891cc5a1706b6908bceb56af7176a463ee6d62"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7e37578069737b04955c71dd85db8a3bc2709eff"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8111964f1b8524c4bb56b02cd9c7a37725ea21fd"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cdf7a39bcc427febbfe3c3b9fe829825ead96c27"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f8c26c33fef588ee54852cffa7cbb9f9d9869405"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/50xxx/CVE-2022-50549.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2022-50549"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"e49e582965b3694f07a106adc83ddb44aa4f0890"},{"fixed":"200aa33b5d781e7c0fa6c0c7db9dbcc3f574ce8f"},{"fixed":"7e37578069737b04955c71dd85db8a3bc2709eff"},{"fixed":"f8c26c33fef588ee54852cffa7cbb9f9d9869405"},{"fixed":"2d891cc5a1706b6908bceb56af7176a463ee6d62"},{"fixed":"cdf7a39bcc427febbfe3c3b9fe829825ead96c27"},{"fixed":"8111964f1b8524c4bb56b02cd9c7a37725ea21fd"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2022-50549.json"}}],"schema_version":"1.7.5"}