In the Linux kernel, the following vulnerability has been resolved: net/mlx5: E-Switch: fix use-after-free in mlx5_eswitch_termtbl_put In mlx5_eswitch_termtbl_put(), the zero-ref cleanup check reads tt->ref_count after termtbl_mutex has been released. Two concurrent callers on the same mlx5_termtbl_handle race: one decrements ref_count to zero, removes the hash entry, and calls kfree(tt) while the other has already dropped the mutex and is about to evaluate if (!tt->ref_count), producing a use-after-free. Fix this by capturing the result of the decrement into a stack-local last variable before dropping the mutex. The cleanup decision is now made entirely under termtbl_mutex, and tt is not touched after kfree.
https://git.kernel.org/stable/c/e393789e92310d7c66f57c876101779c90816a12
https://git.kernel.org/stable/c/7ee07f601f8f507c9faf25c68a49396ab8950596
https://git.kernel.org/stable/c/304ea40ef4561671503c36e47da44a0a31b71e36
https://git.kernel.org/stable/c/18b2969073879b9cce24e1a78b118bdad54518d1