Description
In the Linux kernel, the following vulnerability has been resolved: ext4: fix double-free of blocks due to wrong extents moved_len In ext4_move_extents(), moved_len is only updated when all moves are successfully executed, and only discards orig_inode and donor_inode preallocations when moved_len is not zero. When the loop fails to exit after successfully moving some extents, moved_len is not updated and remains at 0, so it does not discard the preallocations. If the moved extents overlap with the preallocated extents, the overlapped extents are freed twice in ext4_mb_release_inode_pa() and ext4_process_freed_data() (as described in commit 94d7c16cbbbd ("ext4: Fix double-free of blocks with EXT4_IOC_MOVE_EXT")), and bb_free is incremented twice. Hence when trim is executed, a zero-division bug is triggered in mb_update_avg_fragment_size() because bb_free is not zero and bb_fragments is zero. Therefore, update move_len after each extent move to avoid the issue.
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
fcf6b1b729bcd23f2b49a84fb33ffbb44712ee6a to < b4fbb89d722cbb16beaaea234b7230faaaf68c71affectedfcf6b1b729bcd23f2b49a84fb33ffbb44712ee6a to < afbcad9ae7d6d11608399188f03a837451b6b3a1affectedfcf6b1b729bcd23f2b49a84fb33ffbb44712ee6a to < d033a555d9a1cf53dbf3301af7199cc4a4c8f537affectedfcf6b1b729bcd23f2b49a84fb33ffbb44712ee6a to < afba9d11320dad5ce222ac8964caf64b7b4bedb1affectedfcf6b1b729bcd23f2b49a84fb33ffbb44712ee6a to < 185eab30486ba3e7bf8b9c2e049c79a06ffd2bc1affectedfcf6b1b729bcd23f2b49a84fb33ffbb44712ee6a to < 2883940b19c38d5884c8626483811acf4d7e148faffectedfcf6b1b729bcd23f2b49a84fb33ffbb44712ee6a to < 559ddacb90da1d8786dd8ec4fd76bbfa404eaef6affectedfcf6b1b729bcd23f2b49a84fb33ffbb44712ee6a to < 55583e899a5357308274601364741a83e78d6ac4affected
Linux Linux
Default version status: affected
3.18affected0 to < 3.18unaffected4.19.307 to ≤ 4.19.*unaffected5.4.269 to ≤ 5.4.*unaffected5.10.210 to ≤ 5.10.*unaffected5.15.149 to ≤ 5.15.*unaffected6.1.79 to ≤ 6.1.*unaffected6.6.18 to ≤ 6.6.*unaffected6.7.6 to ≤ 6.7.*unaffected6.8 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/b4fbb89d722cbb16beaaea234b7230faaaf68c71 ↗
- https://git.kernel.org/stable/c/afbcad9ae7d6d11608399188f03a837451b6b3a1 ↗
- https://git.kernel.org/stable/c/d033a555d9a1cf53dbf3301af7199cc4a4c8f537 ↗
- https://git.kernel.org/stable/c/afba9d11320dad5ce222ac8964caf64b7b4bedb1 ↗
- https://git.kernel.org/stable/c/185eab30486ba3e7bf8b9c2e049c79a06ffd2bc1 ↗
- https://git.kernel.org/stable/c/2883940b19c38d5884c8626483811acf4d7e148f ↗
- https://git.kernel.org/stable/c/559ddacb90da1d8786dd8ec4fd76bbfa404eaef6 ↗
- https://git.kernel.org/stable/c/55583e899a5357308274601364741a83e78d6ac4 ↗
- https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html ↗
- https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html ↗