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Commit 1c9fec47 authored by Kees Cook's avatar Kees Cook Committed by Linus Torvalds
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waitid(): Avoid unbalanced user_access_end() on access_ok() error 



As pointed out by Linus and David, the earlier waitid() fix resulted in
a (currently harmless) unbalanced user_access_end() call.  This fixes it
to just directly return EFAULT on access_ok() failure.

Fixes: 96ca579a ("waitid(): Add missing access_ok() checks")
Acked-by: default avatarDavid Daney <david.daney@cavium.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 9a27ded2

kernel/exit.c

+2 −2
Original line number Diff line number Diff line
@@ -1611,7 +1611,7 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *, 
		return err;



	if (!access_ok(VERIFY_WRITE, infop, sizeof(*infop)))

		goto Efault;

		return -EFAULT;



	user_access_begin();

	unsafe_put_user(signo, &infop->si_signo, Efault);
@@ -1739,7 +1739,7 @@ COMPAT_SYSCALL_DEFINE5(waitid, 
		return err;



	if (!access_ok(VERIFY_WRITE, infop, sizeof(*infop)))

		goto Efault;

		return -EFAULT;



	user_access_begin();

	unsafe_put_user(signo, &infop->si_signo, Efault);