[PATCH] fcntl: don't leak fd reference when fixup_compat_flock fails

From: Jeff Layton
Date: Tue Nov 14 2017 - 15:24:42 EST


From: Jeff Layton <jlayton@xxxxxxxxxx>

Currently we just return err here, but we need to put the fd reference
first.

Fixes: 94073ad77fff (fs/locks: don't mess with the address limit in compat_fcntl64)
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/fcntl.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

I don't have a great way to test this. There's another similar bug in
the F_GETLK64 case as well, but Vitaly is looking at another problem
there.

diff --git a/fs/fcntl.c b/fs/fcntl.c
index e44a95dd3f86..0793eca4d0ec 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -632,9 +632,8 @@ COMPAT_SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,
if (err)
break;
err = fixup_compat_flock(&flock);
- if (err)
- return err;
- err = put_compat_flock(&flock, compat_ptr(arg));
+ if (!err)
+ err = put_compat_flock(&flock, compat_ptr(arg));
break;
case F_GETLK64:
case F_OFD_GETLK:
--
2.14.3