Check on every iteration.
The local variable 'pos' comes from userspace. If a large number was
passed, there would be an integer overflow in the following line:
pos += n;
Signed-off-by: Wenliang Fan <fanwlexca@xxxxxxxxx>
---
fs/nilfs2/ioctl.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index a260a98..1db4319 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -92,8 +92,13 @@ static int nilfs_ioctl_wrap_copy(struct the_nilfs *nilfs,
total += nr;
if ((size_t)nr < n)
break;
- if (pos == ppos)
+ if (pos == ppos) {
+ if (pos > ULONG_MAX - n) {
+ ret = -EINVAL;
+ break;
+ }
pos += n;
+ }
}
argv->v_nmembs = total;
--
1.8.5.rc1.28.g7061504
--
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