[PATCH next] binfmt_elf: Fix potential Oops in load_elf_binary()

[Dan Carpenter]

This function call was changed from allow_write_access() which has a NULL
check to exe_file_allow_write_access() which doesn't.  Check for NULL
before calling it.

Fixes: 871387b27c20 ("fs: don't block write during exec on pre-content watched files")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
 fs/binfmt_elf.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 8054f44d39cf..db9cb4c20125 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1354,9 +1354,10 @@ static int load_elf_binary(struct linux_binprm *bprm)
 	kfree(interp_elf_ex);
 	kfree(interp_elf_phdata);
 out_free_file:
-	exe_file_allow_write_access(interpreter);
-	if (interpreter)
+	if (interpreter) {
+		exe_file_allow_write_access(interpreter);
 		fput(interpreter);
+	}
 out_free_ph:
 	kfree(elf_phdata);
 	goto out;
-- 
2.45.2