Description
In the Linux kernel, the following vulnerability has been resolved: xfs: bounds-check buffer log item's dirty bitmap xlog_recover_do_reg_buffer() replays each dirty region described by a buffer log item's bitmap into the buffer read for that item: memcpy(xfs_buf_offset(bp, (uint)bit << XFS_BLF_SHIFT), item->ri_buf[i].iov_base, nbits << XFS_BLF_SHIFT); The destination offset (bit/nbits, from the logged dirty bitmap) and the buffer size (from the logged blf_len) are both attacker-controlled and otherwise unrelated, yet the only thing bounding the copy is an ASSERT(), which compiles away on production kernels. A crafted image logging a small blf_len together with a bitmap bit past the end of that buffer drives the memcpy() past the buffer's allocation, corrupting adjacent kernel heap during mount-time log recovery. This is reachable by anyone who can get a crafted image mounted -- the malicious-filesystem threat model XFS already guards against elsewhere. Turn the ASSERT() into a real XFS_IS_CORRUPT() check that aborts recovery of the buffer with -EFSCORRUPTED, consistent with the validate-and-fail idiom already used in xlog_recover_do_inode_buffer() and xfs_dquot_item_recover.c. xlog_recover_do_reg_buffer() therefore becomes STATIC int and its three callers propagate the error. Found and confirmed with KASAN on a CONFIG_XFS_DEBUG=n build: the crafted image trips a slab-out-of-bounds write before this change and fails recovery cleanly with -EFSCORRUPTED after it.
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
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < acb4e26295e7f0e685815a3fd3d70bd8329cefa1affected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < f3859c35a4fbc1c1c58431f684f808e43696891daffected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < f7b5fa83e2c192be922121b764415fa8c7549ea1affected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < b7528b42813f02724a78fce1da24d69d1bfc4d38affected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 7e32d4eebae6ca24f8a673c107fd7eca1f47afc2affected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < f8288214459ead7e87d26e5822f62c14a4f2ed6baffected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < edaf5b6bd625356893da20d69a259b34a9de2694affected1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 813f8136a2ce1fee266d02a7df73db6e8a541604affected
Linux Linux
Default version status: affected
2.6.12affected0 to < 2.6.12unaffected5.10.267 to ≤ 5.10.*unaffected5.15.218 to ≤ 5.15.*unaffected6.1.185 to ≤ 6.1.*unaffected6.6.154 to ≤ 6.6.*unaffected6.12.106 to ≤ 6.12.*unaffected6.18.46 to ≤ 6.18.*unaffected7.1.10 to ≤ 7.1.*unaffected7.2 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/acb4e26295e7f0e685815a3fd3d70bd8329cefa1 ↗
- https://git.kernel.org/stable/c/f3859c35a4fbc1c1c58431f684f808e43696891d ↗
- https://git.kernel.org/stable/c/f7b5fa83e2c192be922121b764415fa8c7549ea1 ↗
- https://git.kernel.org/stable/c/b7528b42813f02724a78fce1da24d69d1bfc4d38 ↗
- https://git.kernel.org/stable/c/7e32d4eebae6ca24f8a673c107fd7eca1f47afc2 ↗
- https://git.kernel.org/stable/c/f8288214459ead7e87d26e5822f62c14a4f2ed6b ↗
- https://git.kernel.org/stable/c/edaf5b6bd625356893da20d69a259b34a9de2694 ↗
- https://git.kernel.org/stable/c/813f8136a2ce1fee266d02a7df73db6e8a541604 ↗