CVE-2022-49995
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-06-18

Last updated on: 2025-11-14

Assigner: kernel.org

Description
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.
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Meta Information
Published
2025-06-18
Last Modified
2025-11-14
Generated
2026-05-07
AI Q&A
2025-06-18
EPSS Evaluated
2026-05-05
NVD
CVE-2022-49995
Affected Vendors & Products
Showing 4 associated CPEs
Vendor Product Version / Range
linux linux_kernel 6.0
linux linux_kernel 6.0
linux linux_kernel From 5.15.160 (inc) to 5.16 (inc)
linux linux_kernel From 5.15.160 (inc) to 5.16 (inc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-416 The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability occurs in the Linux kernel's writeback mechanism. When a disk device is removed, the system stops further writeback operations and waits for delayed work to complete. However, a function called wb_inode_writeback_end() may schedule additional work related to bandwidth estimation after the device has been removed, potentially causing the system to access memory that has already been freed (use-after-free). This can lead to instability or crashes. The fix involves checking if the writeback structure is still valid before scheduling work and changing the locking mechanism to be safe in interrupt context.


How can this vulnerability impact me? :

This vulnerability can cause the Linux kernel to access freed memory after a disk device is removed, which may lead to system instability, crashes, or potential data corruption during writeback operations.


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