3.18-stable review patch. If anyone has any objections, please let me know.
------------------
[ Upstream commit 80ff00172407e0aad4b10b94ef0816fc3e7813cb ]
There is a NULL pointer dereference of dev_name in nfs_parse_devname()
The oops looks something like:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
...
RIP: 0010:nfs_fs_mount+0x3b6/0xc20 [nfs]
...
Call Trace:
? ida_alloc_range+0x34b/0x3d0
? nfs_clone_super+0x80/0x80 [nfs]
? nfs_free_parsed_mount_data+0x60/0x60 [nfs]
mount_fs+0x52/0x170
? __init_waitqueue_head+0x3b/0x50
vfs_kern_mount+0x6b/0x170
do_mount+0x216/0xdc0
ksys_mount+0x83/0xd0
__x64_sys_mount+0x25/0x30
do_syscall_64+0x65/0x220
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Fix this by adding a NULL check on dev_name
Signed-off-by: Yao Liu <yotta.liu@xxxxxxxxx>
Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/nfs/super.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 655ac3a196e4..d2fcd6e9d675 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -1876,6 +1876,11 @@ static int nfs_parse_devname(const char *dev_name,
size_t len;
char *end;
+ if (unlikely(!dev_name || !*dev_name)) {
+ dfprintk(MOUNT, "NFS: device name not specified\n");
+ return -EINVAL;
+ }
+
/* Is the host name protected with square brakcets? */
if (*dev_name == '[') {
end = strchr(++dev_name, ']');
--
2.19.1
