Description

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix inode number range checks Patch series "nilfs2: fix potential issues related to reserved inodes". This series fixes one use-after-free issue reported by syzbot, caused by nilfs2's internal inode being exposed in the namespace on a corrupted filesystem, and a couple of flaws that cause problems if the starting number of non-reserved inodes written in the on-disk super block is intentionally (or corruptly) changed from its default value. This patch (of 3): In the current implementation of nilfs2, "nilfs->ns_first_ino", which gives the first non-reserved inode number, is read from the superblock, but its lower limit is not checked. As a result, if a number that overlaps with the inode number range of reserved inodes such as the root directory or metadata files is set in the super block parameter, the inode number test macros (NILFS_MDT_INODE and NILFS_VALID_INODE) will not function properly. In addition, these test macros use left bit-shift calculations using with the inode number as the shift count via the BIT macro, but the result of a shift calculation that exceeds the bit width of an integer is undefined in the C specification, so if "ns_first_ino" is set to a large value other than the default value NILFS_USER_INO (=11), the macros may potentially malfunction depending on the environment. Fix these issues by checking the lower bound of "nilfs->ns_first_ino" and by preventing bit shifts equal to or greater than the NILFS_USER_INO constant in the inode number test macros. Also, change the type of "ns_first_ino" from signed integer to unsigned integer to avoid the need for type casting in comparisons such as the lower bound check introduced this time.

Weaknesses 1

Affected Products 13

References 9

• git.kernel.org https://git.kernel.org/stable/c/08cab183a624ba71603f3754643ae11cab34dbc4
  Patch
• git.kernel.org https://git.kernel.org/stable/c/1c91058425a01131ea30dda6cf43c67b17884d6a
  Patch
• git.kernel.org https://git.kernel.org/stable/c/3be4dcc8d7bea52ea41f87aa4bbf959efe7a5987
  Patch
• git.kernel.org https://git.kernel.org/stable/c/57235c3c88bb430043728d0d02f44a4efe386476
  Patch
• git.kernel.org https://git.kernel.org/stable/c/731011ac6c37cbe97ece229fc6daa486276052c5
  Patch
• git.kernel.org https://git.kernel.org/stable/c/9194f8ca57527958bee207919458e372d638d783
  Patch
• git.kernel.org https://git.kernel.org/stable/c/e2fec219a36e0993642844be0f345513507031f4
  Patch
• git.kernel.org https://git.kernel.org/stable/c/fae1959d6ab2c52677b113935e36ab4e25df37ea
  Patch
• lists.debian.org https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html

Remediation

• git.kernel.org https://git.kernel.org/stable/c/08cab183a624ba71603f3754643ae11cab34dbc4
  Patch
• git.kernel.org https://git.kernel.org/stable/c/1c91058425a01131ea30dda6cf43c67b17884d6a
  Patch
• git.kernel.org https://git.kernel.org/stable/c/3be4dcc8d7bea52ea41f87aa4bbf959efe7a5987
  Patch
• git.kernel.org https://git.kernel.org/stable/c/57235c3c88bb430043728d0d02f44a4efe386476
  Patch
• git.kernel.org https://git.kernel.org/stable/c/731011ac6c37cbe97ece229fc6daa486276052c5
  Patch
• git.kernel.org https://git.kernel.org/stable/c/9194f8ca57527958bee207919458e372d638d783
  Patch
• git.kernel.org https://git.kernel.org/stable/c/e2fec219a36e0993642844be0f345513507031f4
  Patch
• git.kernel.org https://git.kernel.org/stable/c/fae1959d6ab2c52677b113935e36ab4e25df37ea
  Patch