In the Linux kernel, the following vulnerability has been resolved: x86: shadow stacks: proper error handling for mmap lock 김영민 reports that shstk_pop_sigframe() doesn't check for errors from mmap_read_lock_killable(), which is a silly oversight, and also shows that we haven't marked those functions with "__must_check", which would have immediately caught it. So let's fix both issues.
https://git.kernel.org/stable/c/c64cebcc5c4f223dbcbe7dcdf74908fc092a0aa4
https://git.kernel.org/stable/c/52f657e34d7b21b47434d9d8b26fa7f6778b63a0
https://git.kernel.org/stable/c/262b6d38a81d51b135db81e1f30c13d30e38feee