Description
In the Linux kernel, the following vulnerability has been resolved: fs/omfs: reject s_sys_blocksize smaller than OMFS_DIR_START omfs_fill_super() rejects oversized s_sys_blocksize values (> PAGE_SIZE), but it does not reject values smaller than OMFS_DIR_START (0x1b8 = 440). Later, omfs_make_empty() uses sbi->s_sys_blocksize - OMFS_DIR_START as the length argument to memset(). Since s_sys_blocksize is u32, a crafted filesystem image with s_sys_blocksize < OMFS_DIR_START causes an unsigned underflow there, wrapping to a value near 2^32. That drives a ~4 GiB memset() from bh->b_data + OMFS_DIR_START and overwrites kernel memory far beyond the backing block buffer. Add the corresponding lower-bound check alongside the existing upper-bound check in omfs_fill_super(), so that malformed images are rejected during superblock validation before any filesystem data is processed.
Affected products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | a3ab7155ea21aadc8a4d5687e91b3d876973185e to <fbc72f5c645155dc2ed3573243ed20f9913e3a54; a3ab7155ea21aadc8a4d5687e91b3d876973185e to <5822a05a841a10794ad818620dd2af490b0705d3; a3ab7155ea21aadc8a4d5687e91b3d876973185e to <754ff1bea3819a90c6f33cccfc1a299ef7609f07; a3ab7155ea21aadc8a4d5687e91b3d876973185e to <131ea3e57fc22936ed0e2c8330f2e36106172f51; a3ab7155ea21aadc8a4d5687e91b3d876973185e to <79f84af38c9fef9deb0e02c79eb969b5541c2644; a3ab7155ea21aadc8a4d5687e91b3d876973185e to <6561afc38398e3518a29c5eebb975c30468f98a6; a3ab7155ea21aadc8a4d5687e91b3d876973185e to <817f16ed62bc58a168417bfb5e859c2a370bab03; a3ab7155ea21aadc8a4d5687e91b3d876973185e to <0621c385fda1376e967f37ccd534c26c3e511d14 |
| Linux | Linux | 2.6.27; 0 to <2.6.27; 5.10.258 to <=5.10.*; 5.15.209 to <=5.15.*; 6.1.175 to <=6.1.*; 6.6.141 to <=6.6.*; 6.12.91 to <=6.12.*; 6.18.33 to <=6.18.*; 7.0.10 to <=7.0.*; 7.1 to <=* |
References
- https://git.kernel.org/stable/c/fbc72f5c645155dc2ed3573243ed20f9913e3a54
- https://git.kernel.org/stable/c/5822a05a841a10794ad818620dd2af490b0705d3
- https://git.kernel.org/stable/c/754ff1bea3819a90c6f33cccfc1a299ef7609f07
- https://git.kernel.org/stable/c/131ea3e57fc22936ed0e2c8330f2e36106172f51
- https://git.kernel.org/stable/c/79f84af38c9fef9deb0e02c79eb969b5541c2644
- https://git.kernel.org/stable/c/6561afc38398e3518a29c5eebb975c30468f98a6
- https://git.kernel.org/stable/c/817f16ed62bc58a168417bfb5e859c2a370bab03
- https://git.kernel.org/stable/c/0621c385fda1376e967f37ccd534c26c3e511d14
Generated from the official CVE List on 25 Jun 2026 10:14 UTC.