Description
In the Linux kernel, the following vulnerability has been resolved: btrfs: avoid potential out-of-bounds in btrfs_encode_fh() The function btrfs_encode_fh() does not properly account for the three cases it handles. Before writing to the file handle (fh), the function only returns to the user BTRFS_FID_SIZE_NON_CONNECTABLE (5 dwords, 20 bytes) or BTRFS_FID_SIZE_CONNECTABLE (8 dwords, 32 bytes). However, when a parent exists and the root ID of the parent and the inode are different, the function writes BTRFS_FID_SIZE_CONNECTABLE_ROOT (10 dwords, 40 bytes). If *max_len is not large enough, this write goes out of bounds because BTRFS_FID_SIZE_CONNECTABLE_ROOT is greater than BTRFS_FID_SIZE_CONNECTABLE originally returned. This results in an 8-byte out-of-bounds write at fid->parent_root_objectid = parent_root_id. A previous attempt to fix this issue was made but was lost. https://lore.kernel.org/all/4CADAEEC020000780001B32C@vpn.id2.novell.com/ Although this issue does not seem to be easily triggerable, it is a potential memory corruption bug that should be fixed. This patch resolves the issue by ensuring the function returns the appropriate size for all three cases and validates that *max_len is large enough before writing any data.
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
be6e8dc0ba84029997075a1ec77b4ddb863cbe15 to < 60de2f55d2aca53e81b4ef2a67d7cc9e1eb677dbaffectedbe6e8dc0ba84029997075a1ec77b4ddb863cbe15 to < 742b44342204e5dfe3926433823623c1a0c581dfaffectedbe6e8dc0ba84029997075a1ec77b4ddb863cbe15 to < d3a9a8e1275eb9b87f006b5562a287aea3f6885faffectedbe6e8dc0ba84029997075a1ec77b4ddb863cbe15 to < d91f6626133698362bba08fbc04bd72c466806d3affectedbe6e8dc0ba84029997075a1ec77b4ddb863cbe15 to < 0276c8582488022f057b4cec21975a5edf079f47affectedbe6e8dc0ba84029997075a1ec77b4ddb863cbe15 to < 361d67276eb8ec6be8f27f4ad6c6090459438feeaffectedbe6e8dc0ba84029997075a1ec77b4ddb863cbe15 to < 43143776b0a7604d873d1a6f3e552a00aa930224affectedbe6e8dc0ba84029997075a1ec77b4ddb863cbe15 to < dff4f9ff5d7f289e4545cc936362e01ed3252742affected
Linux Linux
Default version status: affected
2.6.29affected0 to < 2.6.29unaffected5.4.301 to ≤ 5.4.*unaffected5.10.246 to ≤ 5.10.*unaffected5.15.195 to ≤ 5.15.*unaffected6.1.157 to ≤ 6.1.*unaffected6.6.113 to ≤ 6.6.*unaffected6.12.54 to ≤ 6.12.*unaffected6.17.4 to ≤ 6.17.*unaffected6.18 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/60de2f55d2aca53e81b4ef2a67d7cc9e1eb677db ↗
- https://git.kernel.org/stable/c/742b44342204e5dfe3926433823623c1a0c581df ↗
- https://git.kernel.org/stable/c/d3a9a8e1275eb9b87f006b5562a287aea3f6885f ↗
- https://git.kernel.org/stable/c/d91f6626133698362bba08fbc04bd72c466806d3 ↗
- https://git.kernel.org/stable/c/0276c8582488022f057b4cec21975a5edf079f47 ↗
- https://git.kernel.org/stable/c/361d67276eb8ec6be8f27f4ad6c6090459438fee ↗
- https://git.kernel.org/stable/c/43143776b0a7604d873d1a6f3e552a00aa930224 ↗
- https://git.kernel.org/stable/c/dff4f9ff5d7f289e4545cc936362e01ed3252742 ↗