Description
In the Linux kernel, the following vulnerability has been resolved: ext4: fix out-of-bounds read in ext4_read_inline_dir() ext4_read_inline_dir() can read a dirent header past the end of its inline buffer, triggering a slab-out-of-bounds read during getdents64(): BUG: KASAN: slab-out-of-bounds in __ext4_check_dir_entry Read of size 2 at addr ffff88800f3dd23c by task exploit/148 ... __ext4_check_dir_entry ext4_read_inline_dir iterate_dir The dirent payload lives in a buffer of exactly inline_size bytes: dir_buf = kmalloc(inline_size, GFP_NOFS); but iteration runs in a position space extra_offset bytes larger (extra_size = extra_offset + inline_size) so the synthetic "." and ".." land at their block-dir offsets. A dirent is formed at "dir_buf + pos - extra_offset", yet the ext4_check_dir_entry() length argument uses the larger extra_size. A position whose dirent header would extend past extra_size is therefore accepted, and the rescan loop's rec_len probe and ext4_check_dir_entry() dereference de->rec_len before the entry is rejected. Reject a position whose minimum-size dirent header would not fit within extra_size before forming de, in both the rescan and main loops, and pass inline_size rather than extra_size to ext4_check_dir_entry() so the length check matches the physical buffer.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
c4d8b0235aa98f8c26bf94d308be3fdd24154572 to < d1e7c186555ad65554fd2f2b02f5a539aa35ae48affectedc4d8b0235aa98f8c26bf94d308be3fdd24154572 to < 5fd20d4e50dd6e460b3ea8e4396f8553d4526f8faffectedc4d8b0235aa98f8c26bf94d308be3fdd24154572 to < 1a1dea633b724a1c042dbcdb1fed27f410916688affectedc4d8b0235aa98f8c26bf94d308be3fdd24154572 to < b060861f662d4826dc700a1c3584243bb3474cfeaffectedc4d8b0235aa98f8c26bf94d308be3fdd24154572 to < 6702c7da86d8cdb88d0fc57166286e115ffeb8c0affectedc4d8b0235aa98f8c26bf94d308be3fdd24154572 to < 36bf17bb90cdf7a623499b624b05acde4d2feef5affectedc4d8b0235aa98f8c26bf94d308be3fdd24154572 to < 9333cc809f0a89e001b814155a6cb8903a6274dfaffected
Linux Linux
Default version status: affected
3.10affected0 to < 3.10unaffected5.15.221 to ≤ 5.15.*unaffected6.1.188 to ≤ 6.1.*unaffected6.6.157 to ≤ 6.6.*unaffected6.12.110 to ≤ 6.12.*unaffected6.18.52 to ≤ 6.18.*unaffected7.2.6 to ≤ 7.2.*unaffected7.3 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/d1e7c186555ad65554fd2f2b02f5a539aa35ae48 ↗
- https://git.kernel.org/stable/c/5fd20d4e50dd6e460b3ea8e4396f8553d4526f8f ↗
- https://git.kernel.org/stable/c/1a1dea633b724a1c042dbcdb1fed27f410916688 ↗
- https://git.kernel.org/stable/c/b060861f662d4826dc700a1c3584243bb3474cfe ↗
- https://git.kernel.org/stable/c/6702c7da86d8cdb88d0fc57166286e115ffeb8c0 ↗
- https://git.kernel.org/stable/c/36bf17bb90cdf7a623499b624b05acde4d2feef5 ↗
- https://git.kernel.org/stable/c/9333cc809f0a89e001b814155a6cb8903a6274df ↗