gfs2: Check sb_bsize_shift after reading superblock

Description

In the Linux kernel, the following vulnerability has been resolved: gfs2: Check sb_bsize_shift after reading superblock Fuzzers like to scribble over sb_bsize_shift but in reality it's very unlikely that this field would be corrupted on its own. Nevertheless it should be checked to avoid the possibility of messy mount errors due to bad calculations. It's always a fixed value based on the block size so we can just check that it's the expected value. Tested with: mkfs.gfs2 -O -p lock_nolock /dev/vdb for i in 0 -1 64 65 32 33; do gfs2_edit -p sb field sb_bsize_shift $i /dev/vdb mount /dev/vdb /mnt/test && umount /mnt/test done Before this patch we get a withdraw after [ 76.413681] gfs2: fsid=loop0.0: fatal: invalid metadata block [ 76.413681] bh = 19 (type: exp=5, found=4) [ 76.413681] function = gfs2_meta_buffer, file = fs/gfs2/meta_io.c, line = 492 and with UBSAN configured we also get complaints like [ 76.373395] UBSAN: shift-out-of-bounds in fs/gfs2/ops_fstype.c:295:19 [ 76.373815] shift exponent 4294967287 is too large for 64-bit type 'long unsigned int' After the patch, these complaints don't appear, mount fails immediately and we get an explanation in dmesg.

Timeline

Scores

EPSS (exploitation in 30 days)

0.22% · top 88% of all CVEs (7 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.

Affected products

• Linux · Linux

  • affected b3b94faa5fe5968827ba0640ee9fba4b3e7f736e – < d6b1e8ea6f3418c3b461ad5a35cdc93c996b2c87
  • affected b3b94faa5fe5968827ba0640ee9fba4b3e7f736e – < 1ad197097343568066a8ffaa27ee7d0ae6d9f476
  • affected b3b94faa5fe5968827ba0640ee9fba4b3e7f736e – < 15c83fa0fd659dd9fbdc940a560b61236e876a80
  • affected b3b94faa5fe5968827ba0640ee9fba4b3e7f736e – < 8b6534c9ae9dba5489703a19d8ba6c8f2cfa33c2
  • affected b3b94faa5fe5968827ba0640ee9fba4b3e7f736e – < 5fa30be7ba81191b0a0c7239a89befc0c94286d5
  • affected b3b94faa5fe5968827ba0640ee9fba4b3e7f736e – < 28275a7c84d21c55ab3282d897f284d8d527173c
  • affected b3b94faa5fe5968827ba0640ee9fba4b3e7f736e – < 16670534c7cff1acd918a6a5ec751b14e7436b76
  • affected b3b94faa5fe5968827ba0640ee9fba4b3e7f736e – < 670f8ce56dd0632dc29a0322e188cc73ce3c6b92

• Linux · Linux

  • affected 2.6.19
  • unaffected < 2.6.19
  • unaffected 4.9.334 – ≤ 4.9.*
  • unaffected 4.14.300 – ≤ 4.14.*
  • unaffected 4.19.267 – ≤ 4.19.*
  • unaffected 5.4.225 – ≤ 5.4.*
  • unaffected 5.10.156 – ≤ 5.10.*
  • unaffected 5.15.80 – ≤ 5.15.*
  • unaffected 6.0.10 – ≤ 6.0.*
  • unaffected 6.1 – ≤ *

References (8)

• https://git.kernel.org/stable/c/d6b1e8ea6f3418c3b461ad5a35cdc93c996b2c87 (opens in a new tab)
• https://git.kernel.org/stable/c/1ad197097343568066a8ffaa27ee7d0ae6d9f476 (opens in a new tab)
• https://git.kernel.org/stable/c/15c83fa0fd659dd9fbdc940a560b61236e876a80 (opens in a new tab)
• https://git.kernel.org/stable/c/8b6534c9ae9dba5489703a19d8ba6c8f2cfa33c2 (opens in a new tab)
• https://git.kernel.org/stable/c/5fa30be7ba81191b0a0c7239a89befc0c94286d5 (opens in a new tab)
• https://git.kernel.org/stable/c/28275a7c84d21c55ab3282d897f284d8d527173c (opens in a new tab)
• https://git.kernel.org/stable/c/16670534c7cff1acd918a6a5ec751b14e7436b76 (opens in a new tab)
• https://git.kernel.org/stable/c/670f8ce56dd0632dc29a0322e188cc73ce3c6b92 (opens in a new tab)

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2022-49769](https://trackcve.app/badge/CVE-2022-49769.svg)](https://trackcve.app/cve/CVE-2022-49769)

Record last updated 5 Nov 2026, 19:49 UTC.