Vulnerabilities > CVE-2021-47012 - Use After Free vulnerability in Linux Kernel
Attack vector
LOCAL Attack complexity
LOW Privileges required
LOW Confidentiality impact
HIGH Integrity impact
HIGH Availability impact
HIGH Summary
In the Linux kernel, the following vulnerability has been resolved: RDMA/siw: Fix a use after free in siw_alloc_mr Our code analyzer reported a UAF. In siw_alloc_mr(), it calls siw_mr_add_mem(mr,..). In the implementation of siw_mr_add_mem(), mem is assigned to mr->mem and then mem is freed via kfree(mem) if xa_alloc_cyclic() failed. Here, mr->mem still point to a freed object. After, the execution continue up to the err_out branch of siw_alloc_mr, and the freed mr->mem is used in siw_mr_drop_mem(mr). My patch moves "mr->mem = mem" behind the if (xa_alloc_cyclic(..)<0) {} section, to avoid the uaf.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
References
- https://git.kernel.org/stable/c/3093ee182f01689b89e9f8797b321603e5de4f63
- https://git.kernel.org/stable/c/3093ee182f01689b89e9f8797b321603e5de4f63
- https://git.kernel.org/stable/c/30b9e92d0b5e5d5dc1101ab856c17009537cbca4
- https://git.kernel.org/stable/c/30b9e92d0b5e5d5dc1101ab856c17009537cbca4
- https://git.kernel.org/stable/c/3e22b88e02c194f6c80867abfef5cc09383461f4
- https://git.kernel.org/stable/c/3e22b88e02c194f6c80867abfef5cc09383461f4
- https://git.kernel.org/stable/c/608a4b90ece039940e9425ee2b39c8beff27e00c
- https://git.kernel.org/stable/c/608a4b90ece039940e9425ee2b39c8beff27e00c
- https://git.kernel.org/stable/c/ad9ce7188432650469a6c7625bf479f5ed0b6155
- https://git.kernel.org/stable/c/ad9ce7188432650469a6c7625bf479f5ed0b6155