IT

Tracker / CVE-2024-47740

CVE-2024-47740

High 7.1

In the Linux kernel, the following vulnerability has been resolved: f2fs: Require FMODE_WRITE for atomic write ioctls The F2FS ioctls for starting and committing atomic writes check for inode_owner_or_capable(), but this does not give LSMs like SELinux or Landlock an opportunity to deny the write access - if the caller's FSUID matches the inode's UID, inode_owner_or_capable() immediately returns true. There are scenarios where LSMs want to deny a process the ability to write particular files, even files that the FSUID of the process owns; but this can currently partially be bypassed using atomic write ioctls in two ways: - F2FS_IOC_START_ATOMIC_REPLACE + F2FS_IOC_COMMIT_ATOMIC_WRITE can truncate an inode to size 0 - F2FS_IOC_START_ATOMIC_WRITE + F2FS_IOC_ABORT_ATOMIC_WRITE can revert changes another process concurrently made to a file Fix it by requiring FMODE_WRITE for these operations, just like for F2FS_IOC_MOVE_RANGE. Since any legitimate caller should only be using these ioctls when intending to write into the file, that seems unlikely to break anything.

Affected products and versions

linux linux_kernel · 3.18 → 4.19.323
linux linux_kernel · 4.20 → 5.4.285
linux linux_kernel · 5.11 → 5.15.168
linux linux_kernel · 5.16 → 6.1.113
linux linux_kernel · 5.5 → 5.10.227
linux linux_kernel · 6.11 → 6.11.2
linux linux_kernel · 6.2 → 6.6.54
linux linux_kernel · 6.7 → 6.10.13

Analysis

This page is not indexable yet.Until it carries original analysis — what it actually exposes, how to check in two minutes whether a system was touched, what to do if it was — the page stays noindex. The database decides that, not the template.

References