High · published February 28, 2024
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.
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | ≥ 5.3, < 5.4.119 | 5.4.119 |
| linux/linux_kernel | ≥ 5.5, < 5.10.37 | 5.10.37 |
| linux/linux_kernel | ≥ 5.11, < 5.11.21 | 5.11.21 |
| linux/linux_kernel | ≥ 5.12, < 5.12.4 | 5.12.4 |