waitid(): Add missing access_ok() checks
Adds missing access_ok() checks.
CVE-2017-5123
Reported-by: Chris Salls <chrissalls5@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Fixes: 4c48abe91be0 ("waitid(): switch copyout of siginfo to unsafe_put_user()")
Cc: stable@kernel.org # 4.13
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/exit.c b/kernel/exit.c
index f2cd53e..cf28528 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1610,6 +1610,9 @@
if (!infop)
return err;
+ if (!access_ok(VERIFY_WRITE, infop, sizeof(*infop)))
+ goto Efault;
+
user_access_begin();
unsafe_put_user(signo, &infop->si_signo, Efault);
unsafe_put_user(0, &infop->si_errno, Efault);
@@ -1735,6 +1738,9 @@
if (!infop)
return err;
+ if (!access_ok(VERIFY_WRITE, infop, sizeof(*infop)))
+ goto Efault;
+
user_access_begin();
unsafe_put_user(signo, &infop->si_signo, Efault);
unsafe_put_user(0, &infop->si_errno, Efault);