CVSS 7.1 · High EPSS 0,23%
Kerentanan pada linux kernel. Skor CVSS 3.1 7.1 (High) menurut NVD.
In the Linux kernel, the following vulnerability has been resolved: fsdax: dax_unshare_iter needs to copy entire blocks The code that copies data from srcmap to iomap in dax_unshare_iter is very very broken, which bfoster's recent fsx changes have exposed. If the pos and len passed to dax_file_unshare are not aligned to an fsblock boundary, the iter pos and length in the _iter function will reflect this unalignment. dax_iomap_direct_access always returns a pointer to the start of the kmapped fsdax page, even if its pos argument is in the middle of that page. This is catastrophic for data integrity when iter->pos is not aligned to a page, because daddr/saddr do not point to the same byte in the file as iter->pos. Hence we corrupt user data by copying it to the wrong place. If iter->pos + iomap_length() in the _iter function not aligned to a page, then we fail to copy a full block, and only partially populate the destination block. This is catastrophic for data confidentiality because we expose stale pmem contents. Fix both of these issues by aligning copy_pos/copy_len to a page boundary (remember, this is fsdax so 1 fsblock == 1 base page) so that we always copy full blocks. We're not done yet -- there's no call to invalidate_inode_pages2_range, so programs that have the file range mmap'd will continue accessing the old memory mapping after the file metadata updates have completed. Be careful with the return value -- if the unshare succeeds, we still need to return the number of bytes that the iomap iter thinks we're operating on.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
· uraikan di kalkulator | Vendor | Produk | Versi terdampak |
|---|---|---|
| linux | linux kernel | Versi 6.1.113 hingga sebelum 6.1.116 |
| linux | linux kernel | Versi 6.2 hingga sebelum 6.6.60 |
| linux | linux kernel | Versi 6.7 hingga sebelum 6.11.7 |
| linux | linux kernel | Versi 6.12 rc1 |
| linux | linux kernel | Versi 6.12 rc2 |
| linux | linux kernel | Versi 6.12 rc3 |
| linux | linux kernel | Versi 6.12 rc4 |
| linux | linux kernel | Versi 6.12 rc5 |