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CVE-2021-47012high

RDMA/siw: Fix a use after free in siw_alloc_mr

21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 7.8epss 0.3%
exploitation probability
0.3%top 83% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected products
Linux · Linux