CVE-2022-49995
What it is
In the Linux kernel, the following vulnerability has been resolved: writeback: avoid use-after-free after removing device When a disk is removed, bdi_unregister gets called to stop further writeback and wait for associated delayed work to complete. However, wb_inode_writeback_end() may schedule bandwidth estimation dwork after this has completed, which can result in the timer attempting to access the just freed bdi_writeback. Fix this by checking if the bdi_writeback is alive, similar to when scheduling writeback work. Since this requires wb->work_lock, and wb_inode_writeback_end() may get called from interrupt, switch wb->work_lock to an irqsafe lock.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.3% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Details
- Published
- Last modified
- Exploit probability
- 0.3% · EPSS, next 30 days
- Weakness
- CWE-416 · Use after free
- Record status
- Modified
Affected
- Linux Kernel < 5.15.64
- Linux Kernel < 5.19.6
- Linux Kernel 6.0
Attack profile CVSS 3.1 · 7.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Fix and advisories
- https://git.kernel.org/stable/c/9a6c710f3bc10bc9cc23e1c080b53245b7f9d5b7
- https://git.kernel.org/stable/c/f87904c075515f3e1d8f4a7115869d3b914674fd
- https://git.kernel.org/stable/c/f96b9f7c1676923bce871e728bb49c0dfa5013cc