kernel/groups.c: fix integer overflow in groups_search
gid_t is a unsigned int. If group_info contains a gid greater than
MAX_INT, groups_search() function may look on the wrong side of the search
tree.
This solves some unfair "permission denied" problems.
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/groups.c b/kernel/groups.c
index 53b1916..253dc0f 100644
--- a/kernel/groups.c
+++ b/kernel/groups.c
@@ -143,10 +143,9 @@
right = group_info->ngroups;
while (left < right) {
unsigned int mid = (left+right)/2;
- int cmp = grp - GROUP_AT(group_info, mid);
- if (cmp > 0)
+ if (grp > GROUP_AT(group_info, mid))
left = mid + 1;
- else if (cmp < 0)
+ else if (grp < GROUP_AT(group_info, mid))
right = mid;
else
return 1;