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| author | Yao Liu <yotta.liu@ucloud.cn> | 2019-01-28 19:47:28 +0800 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2019-03-04 20:05:34 -0600 |
| commit | 68e2672f8fbd1e04982b8d2798dd318bf2515dd2 (patch) | |
| tree | e8b7105aebcf4b2dbba0c5b62e121e0a6bfd6885 | |
| parent | 165df9a080b6863ae286fa01780c13d87cd81076 (diff) | |
| download | linux-68e2672f8fbd1e04982b8d2798dd318bf2515dd2.tar.bz2 | |
cifs: Fix NULL pointer dereference of devname
There is a NULL pointer dereference of devname in strspn()
The oops looks something like:
CIFS: Attempting to mount (null)
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
...
RIP: 0010:strspn+0x0/0x50
...
Call Trace:
? cifs_parse_mount_options+0x222/0x1710 [cifs]
? cifs_get_volume_info+0x2f/0x80 [cifs]
cifs_setup_volume_info+0x20/0x190 [cifs]
cifs_get_volume_info+0x50/0x80 [cifs]
cifs_smb3_do_mount+0x59/0x630 [cifs]
? ida_alloc_range+0x34b/0x3d0
cifs_do_mount+0x11/0x20 [cifs]
mount_fs+0x52/0x170
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 devname in cifs_parse_devname()
Signed-off-by: Yao Liu <yotta.liu@ucloud.cn>
Signed-off-by: Steve French <stfrench@microsoft.com>
| -rw-r--r-- | fs/cifs/connect.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 8463c940e0e5..2ed773b395a4 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -1486,6 +1486,11 @@ cifs_parse_devname(const char *devname, struct smb_vol *vol) const char *delims = "/\\"; size_t len; + if (unlikely(!devname || !*devname)) { + cifs_dbg(VFS, "Device name not specified.\n"); + return -EINVAL; + } + /* make sure we have a valid UNC double delimiter prefix */ len = strspn(devname, delims); if (len != 2) |