CVE-2021-47012: linux kernel vulnerability

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.
CVE-2021-47012CVSS 7.8Linux

CVE-2021-47012: linux kernel vulnerability

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
7.8 HIGH
EPSS
18.45%
Активно використовується
немає в KEV
Продукт
linux kernel

Що відомо

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.

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