CVE-2022-49769
What it is
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.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Record status
- Analyzed
Affected
- Linux Kernel < 4.9.334
- Linux Kernel < 4.14.300
- Linux Kernel < 4.19.267
- Linux Kernel < 5.4.225
- Linux Kernel < 5.10.156
- Linux Kernel < 5.15.80
- Linux Kernel < 6.0.10
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2022-49769.md and follow it. Check whether this project is affected by CVE-2022-49769. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/15c83fa0fd659dd9fbdc940a560b61236e876a80
- https://git.kernel.org/stable/c/16670534c7cff1acd918a6a5ec751b14e7436b76
- https://git.kernel.org/stable/c/1ad197097343568066a8ffaa27ee7d0ae6d9f476
- https://git.kernel.org/stable/c/28275a7c84d21c55ab3282d897f284d8d527173c
- https://git.kernel.org/stable/c/5fa30be7ba81191b0a0c7239a89befc0c94286d5
- https://git.kernel.org/stable/c/670f8ce56dd0632dc29a0322e188cc73ce3c6b92
- https://git.kernel.org/stable/c/8b6534c9ae9dba5489703a19d8ba6c8f2cfa33c2
- https://git.kernel.org/stable/c/d6b1e8ea6f3418c3b461ad5a35cdc93c996b2c87
References
- https://git.kernel.org/stable/c/15c83fa0fd659dd9fbdc940a560b61236e876a80
- https://git.kernel.org/stable/c/16670534c7cff1acd918a6a5ec751b14e7436b76
- https://git.kernel.org/stable/c/1ad197097343568066a8ffaa27ee7d0ae6d9f476
- https://git.kernel.org/stable/c/28275a7c84d21c55ab3282d897f284d8d527173c
- https://git.kernel.org/stable/c/5fa30be7ba81191b0a0c7239a89befc0c94286d5
- https://git.kernel.org/stable/c/670f8ce56dd0632dc29a0322e188cc73ce3c6b92
- https://git.kernel.org/stable/c/8b6534c9ae9dba5489703a19d8ba6c8f2cfa33c2
- https://git.kernel.org/stable/c/d6b1e8ea6f3418c3b461ad5a35cdc93c996b2c87