Description (CNA)
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 (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected a3ab7155ea21aadc8a4d5687e91b3d876973185e before fbc72f5c645155dc2ed3573243ed20f9913e3a54; affected a3ab7155ea21aadc8a4d5687e91b3d876973185e before 5822a05a841a10794ad818620dd2af490b0705d3; affected a3ab7155ea21aadc8a4d5687e91b3d876973185e before 754ff1bea3819a90c6f33cccfc1a299ef7609f07; affected a3ab7155ea21aadc8a4d5687e91b3d876973185e before 131ea3e57fc22936ed0e2c8330f2e36106172f51; affected a3ab7155ea21aadc8a4d5687e91b3d876973185e before 79f84af38c9fef9deb0e02c79eb969b5541c2644; affected a3ab7155ea21aadc8a4d5687e91b3d876973185e before 6561afc38398e3518a29c5eebb975c30468f98a6; affected a3ab7155ea21aadc8a4d5687e91b3d876973185e before 817f16ed62bc58a168417bfb5e859c2a370bab03; affected a3ab7155ea21aadc8a4d5687e91b3d876973185e before 0621c385fda1376e967f37ccd534c26c3e511d14 |
| Linux / Linux | affected 2.6.27; unaffected 0 before 2.6.27; unaffected 5.10.258 through 5.10.*; unaffected 5.15.209 through 5.15.*; unaffected 6.1.175 through 6.1.*; unaffected 6.6.141 through 6.6.*; unaffected 6.12.91 through 6.12.*; unaffected 6.18.33 through 6.18.*; unaffected 7.0.10 through 7.0.*; unaffected 7.1 through * |
CWE
No CWE identifiers supplied.
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