CVE-2024-53143

Summary

In the Linux kernel, the following vulnerability has been resolved:

fsnotify: Fix ordering of iput() and watched_objects decrement

Ensure the superblock is kept alive until we're done with iput(). Holding a reference to an inode is not allowed unless we ensure the superblock stays alive, which fsnotify does by keeping the watched_objects count elevated, so iput() must happen before the watched_objects decrement. This can lead to a UAF of something like sb->s_fs_info in tmpfs, but the UAF is hard to hit because race orderings that oops are more likely, thanks to the CHECK_DATA_CORRUPTION() block in generic_shutdown_super().

Also, ensure that fsnotify_put_sb_watched_objects() doesn't call fsnotify_sb_watched_objects() on a superblock that may have already been freed, which would cause a UAF read of sb->s_fsnotify_info.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxd2f277e26f521ccf6fb438463b41dba6123caabe < 45a8f8232a495221ed058191629f5c628f21601aaffected
LinuxLinuxd2f277e26f521ccf6fb438463b41dba6123caabe < 83af1cfa10d9aafdabd06b3655e07727f373b434affected
LinuxLinuxd2f277e26f521ccf6fb438463b41dba6123caabe < 21d1b618b6b9da46c5116c640ac4b1cc8d40d63aaffected
LinuxLinux6.10affected
LinuxLinux0 < 6.10unaffected
LinuxLinux6.11.11 <= 6.11.*unaffected
LinuxLinux6.12.2 <= 6.12.*unaffected
LinuxLinux6.13 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: total

References