CVE-2021-47145

btrfs: do not BUG_ON in link_to_fixup_dir

MEDIUM

5.5

CVSS Score

Published: March 25, 2024 at 09:07 AM UTC

Updated: June 17, 2026 at 04:16 AM UTC

1 product affected across 1 vendorLinux Kernel

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Severity

MEDIUM5.5

Exploit prediction

EPSS 0.3%

SSVC

No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: do not BUG_ON in link_to_fixup_dir While doing error injection testing I got the following panic kernel BUG at fs/btrfs/tree-log.c:1862! invalid opcode: 0000 [#1] SMP NOPTI CPU: 1 PID: 7836 Comm: mount Not tainted 5.13.0-rc1+ #305 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 RIP: 0010:link_to_fixup_dir+0xd5/0xe0 RSP: 0018:ffffb5800180fa30 EFLAGS: 00010216 RAX: fffffffffffffffb RBX: 00000000fffffffb RCX: ffff8f595287faf0 RDX: ffffb5800180fa37 RSI: ffff8f5954978800 RDI: 0000000000000000 RBP: ffff8f5953af9450 R08: 0000000000000019 R09: 0000000000000001 R10: 000151f408682970 R11: 0000000120021001 R12: ffff8f5954978800 R13: ffff8f595287faf0 R14: ffff8f5953c77dd0 R15: 0000000000000065 FS: 00007fc5284c8c40(0000) GS:ffff8f59bbd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc5287f47c0 CR3: 000000011275e002 CR4: 0000000000370ee0 Call Trace: replay_one_buffer+0x409/0x470 ? btree_read_extent_buffer_pages+0xd0/0x110 walk_up_log_tree+0x157/0x1e0 walk_log_tree+0xa6/0x1d0 btrfs_recover_log_trees+0x1da/0x360 ? replay_one_extent+0x7b0/0x7b0 open_ctree+0x1486/0x1720 btrfs_mount_root.cold+0x12/0xea ? __kmalloc_track_caller+0x12f/0x240 legacy_get_tree+0x24/0x40 vfs_get_tree+0x22/0xb0 vfs_kern_mount.part.0+0x71/0xb0 btrfs_mount+0x10d/0x380 ? vfs_parse_fs_string+0x4d/0x90 legacy_get_tree+0x24/0x40 vfs_get_tree+0x22/0xb0 path_mount+0x433/0xa10 __x64_sys_mount+0xe3/0x120 do_syscall_64+0x3d/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae We can get -EIO or any number of legitimate errors from btrfs_search_slot(), panicing here is not the appropriate response. The error path for this code handles errors properly, simply return the error.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Linux Kernel · Linux

95%

v < 4.4.2712.6.29 ≤ v < 4.14.2352.6.29 ≤ v < 4.19.1932.6.29 ≤ v < 4.4.2712.6.29 ≤ v < 4.9.2712.6.29 ≤ v < 5.10.422.6.29 ≤ v < 5.12.92.6.29 ≤ v < 5.132.6.29 ≤ v < 5.4.1244.10 ≤ v < 4.14.2354.15 ≤ v < 4.19.1934.20 ≤ v < 5.4.1244.5 ≤ v < 4.9.2715.11 ≤ v < 5.12.95.5 ≤ v < 5.10.425.13 rc1 5.13 rc2e02119d5a7b4396c5a872582fddc8bd6d305a70a

Vendor states this is fixed in 0eaf383c6a4a83c09f60fd07a1bea9f1a9181611 (fixed)

Vendor states this is fixed in 0ed102453aa1cd12fefde8f6b60b9519b0b1f003 (fixed)

Vendor states this is fixed in 6eccfb28f8dca70c9b1b3bb3194ca54cbe73a9fa (fixed)

Vendor states this is fixed in 76bfd8ac20bebeae599452a03dfc5724c0475dcf (fixed)

Vendor states this is fixed in 7e13db503918820e6333811cdc6f151dcea5090a (fixed)

Vendor states this is fixed in 91df99a6eb50d5a1bc70fff4a09a0b7ae6aab96d (fixed)

Vendor states this is fixed in b545442133580dcb2f2496133bf850824d41255c (fixed)

Vendor states this is fixed in e934c4ee17b33bafb0444f2f9766cda7166d3c40 (fixed)

Vendor states this is fixed in 2.6.29 (unaffected)

Vendor states this is fixed in 4.14.235 (unaffected)

Vendor states this is fixed in 4.19.193 (unaffected)

Vendor states this is fixed in 4.4.271 (unaffected)