Description

In the Linux kernel, the following vulnerability has been resolved: smc: Use __sk_dst_get() and dst_dev_rcu() in in smc_clc_prfx_set(). smc_clc_prfx_set() is called during connect() and not under RCU nor RTNL. Using sk_dst_get(sk)->dev could trigger UAF. Let's use __sk_dst_get() and dev_dst_rcu() under rcu_read_lock() after kernel_getsockname(). Note that the returned value of smc_clc_prfx_set() is not used in the caller. While at it, we change the 1st arg of smc_clc_prfx_set[46]_rcu() not to touch dst there.

References 2

• git.kernel.org https://git.kernel.org/stable/c/0736993bfe5c7a9c744ae3fac62d769dfdae54e1
• git.kernel.org https://git.kernel.org/stable/c/935d783e5de9b64587f3adb25641dd8385e64ddb

Remediation