5.5

CVE-2021-47145: btrfs: do not BUG_ON in link_to_fixup_dir

Analyzed
AliasesUBUNTU-CVE-2021-47145DEBIAN-CVE-2021-47145
Published 25-03-2024Last modified 11-05-2026

Vulnerability summary

CVE-2021-47145 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.27% chance of exploitation in the next 30 days, higher than 19.1% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.27%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 5 · Related 5
SUSE-SU-2024:2493-1SUSE-SU-2024:2561-1SUSE-SU-2024:2901-1USN-8143-1USN-8143-2

Timeline

  1. 25-03-2024
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.27%

Chance of exploitation in the next 30 days

Percentile

19%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.27% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu87 products
  • linuxAll versions (No fix recorded) | < 4.4.0-279.313 | < 4.15.0-151.157 | < 5.4.0-80.90
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 4.4.0-1153.159 | < 4.4.0-1191.206 | < 4.15.0-1109.116 | < 5.4.0-1054.57
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ e02119d5a7b4396c5a872582fddc8bd6d305a70a, < 76bfd8ac20bebeae599452a03dfc5724c0475dcf | ≥ e02119d5a7b4396c5a872582fddc8bd6d305a70a, < e934c4ee17b33bafb0444f2f9766cda7166d3c40 | ≥ e02119d5a7b4396c5a872582fddc8bd6d305a70a, < 0eaf383c6a4a83c09f60fd07a1bea9f1a9181611 | ≥ e02119d5a7b4396c5a872582fddc8bd6d305a70a, < 6eccfb28f8dca70c9b1b3bb3194ca54cbe73a9fa | ≥ e02119d5a7b4396c5a872582fddc8bd6d305a70a, < 0ed102453aa1cd12fefde8f6b60b9519b0b1f003 | ≥ e02119d5a7b4396c5a872582fddc8bd6d305a70a, < 7e13db503918820e6333811cdc6f151dcea5090a | ≥ e02119d5a7b4396c5a872582fddc8bd6d305a70a, < b545442133580dcb2f2496133bf850824d41255c | ≥ e02119d5a7b4396c5a872582fddc8bd6d305a70a, < 91df99a6eb50d5a1bc70fff4a09a0b7ae6aab96d | 2.6.29
  • linux_kernel< 4.4.271 | ≥ 4.5, < 4.9.271 | ≥ 4.10, < 4.14.235 | ≥ 4.15, < 4.19.193 | ≥ 4.20, < 5.4.124 | ≥ 5.5, < 5.10.42 | ≥ 5.11, < 5.12.9 | 5.13:rc1 | 5.13:rc2
Debian1 product
  • linux< 5.14.6-1

3 vendors · 90 products

References

13 links
Show all 13 references