Description

In the Linux kernel, the following vulnerability has been resolved: mm/damon/sysfs-schemes: protect path kfree() with damon_sysfs_lock damon_sysfs_quot_goal->path can be read and written by users, via DAMON sysfs 'path' file. It can also be indirectly read, for the parameters {on,off}line committing to DAMON. The reads for parameters committing are protected by damon_sysfs_lock to avoid the sysfs files being destroyed while any of the parameters are being read. But the user-driven direct reads and writes are not protected by any lock, while the write is deallocating the path-pointing buffer. As a result, the readers could read the already freed buffer (user-after-free). Note that the user-reads don't race when the same open file is used by the writer, due to kernfs's open file locking. Nonetheless, doing the reads and writes with separate open files would be common. Fix it by protecting both the user-direct reads and writes with damon_sysfs_lock.

Weaknesses 1

Affected Products 2

References 2

• git.kernel.org https://git.kernel.org/stable/c/a34ca3e33da4b924c66bcca3729bf68ec5936910
  Patch
• git.kernel.org https://git.kernel.org/stable/c/cf3b71421ca00807328c6d9cd242f9de3b77a4bf
  Patch

Remediation

• git.kernel.org https://git.kernel.org/stable/c/a34ca3e33da4b924c66bcca3729bf68ec5936910
  Patch
• git.kernel.org https://git.kernel.org/stable/c/cf3b71421ca00807328c6d9cd242f9de3b77a4bf
  Patch