From: Steve French Date: Tue, 10 Dec 2019 01:47:10 +0000 (-0600) Subject: smb3: fix refcount underflow warning on unmount when no directory leases X-Git-Tag: Ubuntu-5.13.0-19.19~7071^2~2 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=281393894af9cc3f9483204475014e89d728987c;p=mirror_ubuntu-jammy-kernel.git smb3: fix refcount underflow warning on unmount when no directory leases Fix refcount underflow warning when unmounting to servers which didn't grant directory leases. [ 301.680095] refcount_t: underflow; use-after-free. [ 301.680192] WARNING: CPU: 1 PID: 3569 at lib/refcount.c:28 refcount_warn_saturate+0xb4/0xf3 ... [ 301.682139] Call Trace: [ 301.682240] close_shroot+0x97/0xda [cifs] [ 301.682351] SMB2_tdis+0x7c/0x176 [cifs] [ 301.682456] ? _get_xid+0x58/0x91 [cifs] [ 301.682563] cifs_put_tcon.part.0+0x99/0x202 [cifs] [ 301.682637] ? ida_free+0x99/0x10a [ 301.682727] ? cifs_umount+0x3d/0x9d [cifs] [ 301.682829] cifs_put_tlink+0x3a/0x50 [cifs] [ 301.682929] cifs_umount+0x44/0x9d [cifs] Fixes: 72e73c78c446 ("cifs: close the shared root handle on tree disconnect") Signed-off-by: Steve French Acked-by: Ronnie Sahlberg Reviewed-by: Aurelien Aptel Reviewed-by: Pavel Shilovsky Reported-and-tested-by: Arthur Marsh --- diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 0ab6b1200288..d2658f51ff60 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -1847,7 +1847,8 @@ SMB2_tdis(const unsigned int xid, struct cifs_tcon *tcon) if ((tcon->need_reconnect) || (tcon->ses->need_reconnect)) return 0; - close_shroot(&tcon->crfid); + if (tcon->crfid.is_valid) + close_shroot(&tcon->crfid); rc = smb2_plain_req_init(SMB2_TREE_DISCONNECT, tcon, (void **) &req, &total_len);