CVE-2026-98872

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.