CVE-2022-47946

An issue was discovered in the Linux kernel 5.10.x before 5.10.155. A use-after-free in io_sqpoll_wait_sq in fs/io_uring.c allows an attacker to crash the kernel, resulting in denial of service. finish_wait can be skipped. An attack can occur in some situations by forking a process and then quickly terminating it. NOTE: later kernel versions, such as the 5.15 longterm series, substantially changed the implementation of io_sqpoll_wait_sq.

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 Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.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

• http://www.openwall.com/lists/oss-security/2022/12/27/1
• https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v5.10.161\u0026id=0f544353fec8e717d37724d95b92538e1de79e86
• https://www.openwall.com/lists/oss-security/2022/12/22/2
• http://www.openwall.com/lists/oss-security/2022/12/27/1
• https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v5.10.161\u0026id=0f544353fec8e717d37724d95b92538e1de79e86
• https://www.openwall.com/lists/oss-security/2022/12/22/2