{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-23018","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-01-13T15:37:45.940Z","datePublished":"2026-01-31T11:39:02.330Z","dateUpdated":"2026-05-11T21:58:24.780Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-05-11T21:58:24.780Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: release path before initializing extent tree in btrfs_read_locked_inode()\n\nIn btrfs_read_locked_inode() we are calling btrfs_init_file_extent_tree()\nwhile holding a path with a read locked leaf from a subvolume tree, and\nbtrfs_init_file_extent_tree() may do a GFP_KERNEL allocation, which can\ntrigger reclaim.\n\nThis can create a circular lock dependency which lockdep warns about with\nthe following splat:\n\n [6.1433] ======================================================\n [6.1574] WARNING: possible circular locking dependency detected\n [6.1583] 6.18.0+ #4 Tainted: G U\n [6.1591] ------------------------------------------------------\n [6.1599] kswapd0/117 is trying to acquire lock:\n [6.1606] ffff8d9b6333c5b8 (&delayed_node->mutex){+.+.}-{3:3}, at: __btrfs_release_delayed_node.part.0+0x39/0x2f0\n [6.1625]\n but task is already holding lock:\n [6.1633] ffffffffa4ab8ce0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x195/0xc60\n [6.1646]\n which lock already depends on the new lock.\n\n [6.1657]\n the existing dependency chain (in reverse order) is:\n [6.1667]\n -> #2 (fs_reclaim){+.+.}-{0:0}:\n [6.1677] fs_reclaim_acquire+0x9d/0xd0\n [6.1685] __kmalloc_cache_noprof+0x59/0x750\n [6.1694] btrfs_init_file_extent_tree+0x90/0x100\n [6.1702] btrfs_read_locked_inode+0xc3/0x6b0\n [6.1710] btrfs_iget+0xbb/0xf0\n [6.1716] btrfs_lookup_dentry+0x3c5/0x8e0\n [6.1724] btrfs_lookup+0x12/0x30\n [6.1731] lookup_open.isra.0+0x1aa/0x6a0\n [6.1739] path_openat+0x5f7/0xc60\n [6.1746] do_filp_open+0xd6/0x180\n [6.1753] do_sys_openat2+0x8b/0xe0\n [6.1760] __x64_sys_openat+0x54/0xa0\n [6.1768] do_syscall_64+0x97/0x3e0\n [6.1776] entry_SYSCALL_64_after_hwframe+0x76/0x7e\n [6.1784]\n -> #1 (btrfs-tree-00){++++}-{3:3}:\n [6.1794] lock_release+0x127/0x2a0\n [6.1801] up_read+0x1b/0x30\n [6.1808] btrfs_search_slot+0x8e0/0xff0\n [6.1817] btrfs_lookup_inode+0x52/0xd0\n [6.1825] __btrfs_update_delayed_inode+0x73/0x520\n [6.1833] btrfs_commit_inode_delayed_inode+0x11a/0x120\n [6.1842] btrfs_log_inode+0x608/0x1aa0\n [6.1849] btrfs_log_inode_parent+0x249/0xf80\n [6.1857] btrfs_log_dentry_safe+0x3e/0x60\n [6.1865] btrfs_sync_file+0x431/0x690\n [6.1872] do_fsync+0x39/0x80\n [6.1879] __x64_sys_fsync+0x13/0x20\n [6.1887] do_syscall_64+0x97/0x3e0\n [6.1894] entry_SYSCALL_64_after_hwframe+0x76/0x7e\n [6.1903]\n -> #0 (&delayed_node->mutex){+.+.}-{3:3}:\n [6.1913] __lock_acquire+0x15e9/0x2820\n [6.1920] lock_acquire+0xc9/0x2d0\n [6.1927] __mutex_lock+0xcc/0x10a0\n [6.1934] __btrfs_release_delayed_node.part.0+0x39/0x2f0\n [6.1944] btrfs_evict_inode+0x20b/0x4b0\n [6.1952] evict+0x15a/0x2f0\n [6.1958] prune_icache_sb+0x91/0xd0\n [6.1966] super_cache_scan+0x150/0x1d0\n [6.1974] do_shrink_slab+0x155/0x6f0\n [6.1981] shrink_slab+0x48e/0x890\n [6.1988] shrink_one+0x11a/0x1f0\n [6.1995] shrink_node+0xbfd/0x1320\n [6.1002] balance_pgdat+0x67f/0xc60\n [6.1321] kswapd+0x1dc/0x3e0\n [6.1643] kthread+0xff/0x240\n [6.1965] ret_from_fork+0x223/0x280\n [6.1287] ret_from_fork_asm+0x1a/0x30\n [6.1616]\n other info that might help us debug this:\n\n [6.1561] Chain exists of:\n &delayed_node->mutex --> btrfs-tree-00 --> fs_reclaim\n\n [6.1503] Possible unsafe locking scenario:\n\n [6.1110] CPU0 CPU1\n [6.1411] ---- ----\n [6.1707] lock(fs_reclaim);\n [6.1998] lock(btrfs-tree-00);\n [6.1291] lock(fs_reclaim);\n [6.1581] lock(&del\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/inode.c"],"versions":[{"version":"8679d2687c351824d08cf1f0e86f3b65f22a00fe","lessThan":"92a5590851144f034adc51fee55e6878ccac716e","status":"affected","versionType":"git"},{"version":"8679d2687c351824d08cf1f0e86f3b65f22a00fe","lessThan":"8731f2c50b0b1d2b58ed5b9671ef2c4bdc2f8347","status":"affected","versionType":"git"},{"version":"e8f496001e0c7832d188ab91fea294e19a128202","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/inode.c"],"versions":[{"version":"6.17","status":"affected"},{"version":"0","lessThan":"6.17","status":"unaffected","versionType":"semver"},{"version":"6.18.6","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"6.19","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":"6.17","versionEndExcluding":"6.18.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.17","versionEndExcluding":"6.19"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16.9"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/92a5590851144f034adc51fee55e6878ccac716e"},{"url":"https://git.kernel.org/stable/c/8731f2c50b0b1d2b58ed5b9671ef2c4bdc2f8347"}],"title":"btrfs: release path before initializing extent tree in btrfs_read_locked_inode()","x_generator":{"engine":"bippy-1.2.0"}}}}