In the Linux kernel, the following vulnerability has been resolved:jfs: validate AG parameters in dbMount() to prevent crashesValidate db_agheight, db_agwidth, and db_agstart in dbMount to catchcorrupted metadata early and avoid undefined behavior in dbAllocAG.Limits are derived from L2LPERCTL, LPERCTL/MAXAG, and CTLTREESIZE:- agheight: 0 to L2LPERCTL/2 (0 to 5) ensures shift (L2LPERCTL - 2*agheight) >= 0.- agwidth: 1 to min(LPERCTL/MAXAG, 2^(L2LPERCTL - 2*agheight)) ensures agperlev >= 1. - Ranges: 1-8 (agheight 0-3), 1-4 (agheight 4), 1 (agheight 5). - LPERCTL/MAXAG = 1024/128 = 8 limits leaves per AG; 2^(10 - 2*agheight) prevents division to 0.- agstart: 0 to CTLTREESIZE-1 - agwidth*(MAXAG-1) keeps ti within stree (size 1365). - Ranges: 0-1237 (agwidth 1), 0-348 (agwidth 8).UBSAN: shift-out-of-bounds in fs/jfs/jfs_dmap.c:1400:9shift exponent -335544310 is negativeCPU: 0 UID: 0 PID: 5822 Comm: syz-executor130 Not tainted 6.14.0-rc5-syzkaller #0Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025Call Trace:
No PoCs from references.
- https://github.com/w4zu/Debian_security