From: Xiaotian Feng on
With CONFIG_NFS_V4 and data version 4, nfs_get_sb will allocate memory for
export_path in nfs4_validate_text_mount_data, so we need to free it then.
This is addressed in following kmemleak report:

unreferenced object 0xffff88016bf48a50 (size 16):
comm "mount.nfs", pid 22567, jiffies 4651574704 (age 175471.200s)
hex dump (first 16 bytes):
2f 6f 70 74 2f 77 6f 72 6b 00 6b 6b 6b 6b 6b a5 /opt/work.kkkkk.
[<ffffffff814b34f9>] kmemleak_alloc+0x60/0xa7
[<ffffffff81102c76>] kmemleak_alloc_recursive.clone.5+0x1b/0x1d
[<ffffffff811046b3>] __kmalloc_track_caller+0x18f/0x1b7
[<ffffffff810e1b08>] kstrndup+0x37/0x54
[<ffffffffa0336971>] nfs_parse_devname+0x152/0x204 [nfs]
[<ffffffffa0336af3>] nfs4_validate_text_mount_data+0xd0/0xdc [nfs]
[<ffffffffa0338deb>] nfs_get_sb+0x325/0x736 [nfs]
[<ffffffff81113671>] vfs_kern_mount+0xbd/0x17c
[<ffffffff81113798>] do_kern_mount+0x4d/0xed
[<ffffffff81129a87>] do_mount+0x787/0x7fe
[<ffffffff81129b86>] sys_mount+0x88/0xc2
[<ffffffff81009b42>] system_call_fastpath+0x16/0x1b

Signed-off-by: Xiaotian Feng <dfeng(a)>
Cc: Trond Myklebust <Trond.Myklebust(a)>
Cc: Chuck Lever <chuck.lever(a)>
Cc: Benny Halevy <bhalevy(a)>
Cc: Al Viro <viro(a)>
Cc: Andy Adamson <andros(a)>
fs/nfs/super.c | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index e016372..44e6567 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -2187,6 +2187,7 @@ static int nfs_get_sb(struct file_system_type *fs_type,
if (data->version == 4) {
error = nfs4_try_mount(flags, dev_name, data, mnt);
+ kfree(data->nfs_server.export_path);
goto out;
#endif /* CONFIG_NFS_V4 */

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)
More majordomo info at
Please read the FAQ at