Steve, when mounting a cifs (vers=2.0, unfortunately...) volume on v5.1-rc1, I get the following warning (slightly edited to avoid information leaks): [ 118.326535] CIFS: Attempting to mount //some/what [ 118.667347] ------------[ cut here ]------------ [ 118.667367] refcount_t: underflow; use-after-free. [ 118.667384] WARNING: CPU: 1 PID: 1966 at lib/refcount.c:190 refcount_sub_and_test_checked+0x5c/0x70 [ 118.667387] Modules linked in: [ 118.667392] CPU: 1 PID: 1966 Comm: mount.cifs Tainted: G T 5.1.0-rc1 #1 [ 118.667395] Hardware name: Dell Inc. XPS 13 9343/0TM99H, BIOS A11 12/08/2016 [ 118.667400] RIP: 0010:refcount_sub_and_test_checked+0x5c/0x70 [ 118.667432] Call Trace: [ 118.667439] close_shroot+0x21/0xa0 [ 118.667444] smb2_query_path_info+0x16b/0x1f0 [ 118.667454] cifs_get_inode_info+0x2b3/0x860 [ 118.667467] cifs_root_iget+0x12c/0x670 [ 118.667473] cifs_smb3_do_mount+0x4f7/0x680 [ 118.667479] ? rcu_read_lock_sched_held+0x74/0x80 [ 118.667483] ? kfree+0x248/0x290 [ 118.667490] legacy_get_tree+0x24/0x40 [ 118.667494] vfs_get_tree+0x3d/0x110 [ 118.667500] do_mount+0x30a/0xef0 [ 118.667504] ? rcu_read_lock_sched_held+0x74/0x80 [ 118.667512] ksys_mount+0xbd/0xe0 [ 118.667517] __x64_sys_mount+0x22/0x30 [ 118.667522] do_syscall_64+0x50/0x160 [ 118.667527] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 118.667531] RIP: 0033:0x754fd3d1d68e Thanks, Dominik
