CVE-2026-98872 freevxfs: don't BUG() on unknown typed-extent type
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-98872?
CVE-2026-98872 is a vulnerability in Linux, published on 23 Oct 2026.
Official description
In the Linux kernel, the following vulnerability has been resolved:
freevxfs: don't BUG() on unknown typed-extent type
vxfs_bmap_typed() handles four typed-extent types and calls BUG() in its default case, so an on-disk typed extent with any other type value crashes the kernel. It is reachable from ioctl(FIBMAP) on a regular file:
kernel BUG at fs/freevxfs/vxfs_bmap.c:230! RIP: vxfs_bmap_typed fs/freevxfs/vxfs_bmap.c:230 [inline] vxfs_bmap1+0x128a/0x12d0 fs/freevxfs/vxfs_bmap.c:257
Replace the BUG() with WARN_ON_ONCE() and return 0 -- the value vxfs_bmap_typed() already returns on failure (and from the DEV4 case above); vxfs_getblk() maps 0 to -EIO, so the ioctl fails cleanly.
Which versions are affected by CVE-2026-98872?
How do I fix CVE-2026-98872?
Upgrade to a fixed version.
Is CVE-2026-98872 being exploited?
There is no known exploitation of CVE-2026-98872 in the wild and no public exploit code.
Sources
Also known as AZL-110593, BELL-CVE-2026-98872, DEBIAN-CVE-2026-98872, GHSA-35fj-5v77-5rpx, UBUNTU-CVE-2026-98872.