[PATCH 137/241] fix user-triggerable panic on parisc

[Herton Ronaldo Krzesinski]

3.5.7.2 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Al Viro <viro at ZenIV.linux.org.uk>

commit 441a179dafc0f99fc8b3a8268eef66958621082e upstream.

int sys32_rt_sigprocmask(int how, compat_sigset_t __user *set, compat_sigset_t __user *oset,
                                    unsigned int sigsetsize)
{
        sigset_t old_set, new_set;
        int ret;

        if (set && get_sigset32(set, &new_set, sigsetsize))

...
static int
get_sigset32(compat_sigset_t __user *up, sigset_t *set, size_t sz)
{
        compat_sigset_t s;
        int r;

        if (sz != sizeof *set) panic("put_sigset32()");

In other words, rt_sigprocmask(69, (void *)69, 69) done by 32bit process
will promptly panic the box.

Signed-off-by: Al Viro <viro at zeniv.linux.org.uk>
Signed-off-by: James Bottomley <JBottomley at Parallels.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
 arch/parisc/kernel/signal32.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/parisc/kernel/signal32.c b/arch/parisc/kernel/signal32.c
index fd49aed..5dede04 100644
--- a/arch/parisc/kernel/signal32.c
+++ b/arch/parisc/kernel/signal32.c
@@ -65,7 +65,8 @@ put_sigset32(compat_sigset_t __user *up, sigset_t *set, size_t sz)
 {
 	compat_sigset_t s;
 
-	if (sz != sizeof *set) panic("put_sigset32()");
+	if (sz != sizeof *set)
+		return -EINVAL;
 	sigset_64to32(&s, set);
 
 	return copy_to_user(up, &s, sizeof s);
@@ -77,7 +78,8 @@ get_sigset32(compat_sigset_t __user *up, sigset_t *set, size_t sz)
 	compat_sigset_t s;
 	int r;
 
-	if (sz != sizeof *set) panic("put_sigset32()");
+	if (sz != sizeof *set)
+		return -EINVAL;
 
 	if ((r = copy_from_user(&s, up, sz)) == 0) {
 		sigset_32to64(set, &s);
-- 
1.7.9.5