{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2022-49079", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-02-26T01:49:39.247Z", "datePublished": "2025-02-26T01:54:40.697Z", "dateUpdated": "2026-05-11T18:52:37.257Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-11T18:52:37.257Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: zoned: traverse devices under chunk_mutex in btrfs_can_activate_zone\n\nbtrfs_can_activate_zone() can be called with the device_list_mutex already\nheld, which will lead to a deadlock:\n\ninsert_dev_extents() // Takes device_list_mutex\n`-> insert_dev_extent()\n `-> btrfs_insert_empty_item()\n `-> btrfs_insert_empty_items()\n `-> btrfs_search_slot()\n `-> btrfs_cow_block()\n `-> __btrfs_cow_block()\n `-> btrfs_alloc_tree_block()\n `-> btrfs_reserve_extent()\n `-> find_free_extent()\n `-> find_free_extent_update_loop()\n `-> can_allocate_chunk()\n `-> btrfs_can_activate_zone() // Takes device_list_mutex again\n\nInstead of using the RCU on fs_devices->device_list we\ncan use fs_devices->alloc_list, protected by the chunk_mutex to traverse\nthe list of active devices.\n\nWe are in the chunk allocation thread. The newer chunk allocation\nhappens from the devices in the fs_device->alloc_list protected by the\nchunk_mutex.\n\n btrfs_create_chunk()\n lockdep_assert_held(&info->chunk_mutex);\n gather_device_info\n list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list)\n\nAlso, a device that reappears after the mount won't join the alloc_list\nyet and, it will be in the dev_list, which we don't want to consider in\nthe context of the chunk alloc.\n\n [15.166572] WARNING: possible recursive locking detected\n [15.167117] 5.17.0-rc6-dennis #79 Not tainted\n [15.167487] --------------------------------------------\n [15.167733] kworker/u8:3/146 is trying to acquire lock:\n [15.167733] ffff888102962ee0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: find_free_extent+0x15a/0x14f0 [btrfs]\n [15.167733]\n [15.167733] but task is already holding lock:\n [15.167733] ffff888102962ee0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: btrfs_create_pending_block_groups+0x20a/0x560 [btrfs]\n [15.167733]\n [15.167733] other info that might help us debug this:\n [15.167733] Possible unsafe locking scenario:\n [15.167733]\n [15.171834] CPU0\n [15.171834] ----\n [15.171834] lock(&fs_devs->device_list_mutex);\n [15.171834] lock(&fs_devs->device_list_mutex);\n [15.171834]\n [15.171834] *** DEADLOCK ***\n [15.171834]\n [15.171834] May be due to missing lock nesting notation\n [15.171834]\n [15.171834] 5 locks held by kworker/u8:3/146:\n [15.171834] #0: ffff888100050938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1c3/0x5a0\n [15.171834] #1: ffffc9000067be80 ((work_completion)(&fs_info->async_data_reclaim_work)){+.+.}-{0:0}, at: process_one_work+0x1c3/0x5a0\n [15.176244] #2: ffff88810521e620 (sb_internal){.+.+}-{0:0}, at: flush_space+0x335/0x600 [btrfs]\n [15.176244] #3: ffff888102962ee0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: btrfs_create_pending_block_groups+0x20a/0x560 [btrfs]\n [15.176244] #4: ffff8881152e4b78 (btrfs-dev-00){++++}-{3:3}, at: __btrfs_tree_lock+0x27/0x130 [btrfs]\n [15.179641]\n [15.179641] stack backtrace:\n [15.179641] CPU: 1 PID: 146 Comm: kworker/u8:3 Not tainted 5.17.0-rc6-dennis #79\n [15.179641] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1.fc35 04/01/2014\n [15.179641] Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs]\n [15.179641] Call Trace:\n [15.179641] \n [15.179641] dump_stack_lvl+0x45/0x59\n [15.179641] __lock_acquire.cold+0x217/0x2b2\n [15.179641] lock_acquire+0xbf/0x2b0\n [15.183838] ? find_free_extent+0x15a/0x14f0 [btrfs]\n [15.183838] __mutex_lock+0x8e/0x970\n [15.183838] ? find_free_extent+0x15a/0x14f0 [btrfs]\n [15.183838] ? find_free_extent+0x15a/0x14f0 [btrfs]\n [15.183838] ? lock_is_held_type+0xd7/0x130\n [15.183838] ? find_free_extent+0x15a/0x14f0 [btrfs]\n [15.183838] find_free_extent+0x15a/0x14f0 [btrfs]\n [15.183838] ? _raw_spin_unlock+0x24/0x40\n [15.183838] ? btrfs_get_alloc_profile+0x106/0x230 [btrfs]\n [15.187601] btrfs_reserve_extent+0x131/0x260 [btrfs]\n [15.\n---truncated---" } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/btrfs/zoned.c" ], "versions": [ { "version": "a85f05e59bc15a83ad910dbcb71df5ad8fa77295", "lessThan": "09e65ae515af2b24d6dc23af21719a3b41de83e5", "status": "affected", "versionType": "git" }, { "version": "a85f05e59bc15a83ad910dbcb71df5ad8fa77295", "lessThan": "142f822bd945a7be442a2916ec6167cc102c4183", "status": "affected", "versionType": "git" }, { "version": "a85f05e59bc15a83ad910dbcb71df5ad8fa77295", "lessThan": "0b9e66762aa0cda2a9c2d5542d64e04dac528fa6", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/btrfs/zoned.c" ], "versions": [ { "version": "5.16", "status": "affected" }, { "version": "0", "lessThan": "5.16", "status": "unaffected", "versionType": "semver" }, { "version": "5.16.20", "lessThanOrEqual": "5.16.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.17.3", "lessThanOrEqual": "5.17.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.18", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "5.16.20" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "5.17.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "5.18" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/09e65ae515af2b24d6dc23af21719a3b41de83e5" }, { "url": "https://git.kernel.org/stable/c/142f822bd945a7be442a2916ec6167cc102c4183" }, { "url": "https://git.kernel.org/stable/c/0b9e66762aa0cda2a9c2d5542d64e04dac528fa6" } ], "title": "btrfs: zoned: traverse devices under chunk_mutex in btrfs_can_activate_zone", "x_generator": { "engine": "bippy-1.2.0" } } } }