CVE-2021-47470

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

mm, slub: fix potential use-after-free in slab_debugfs_fops

When sysfs_slab_add failed, we shouldnt call debugfs_slab_add() for s because s will be freed soon. And slab_debugfs_fops will use s later leading to a use-after-free.

Weakness

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 Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/159d8cfbd0428d487c53be4722f33cdab0d25d83
• https://git.kernel.org/stable/c/67823a544414def2a36c212abadb55b23bcda00c
• https://git.kernel.org/stable/c/159d8cfbd0428d487c53be4722f33cdab0d25d83
• https://git.kernel.org/stable/c/67823a544414def2a36c212abadb55b23bcda00c