CIFS: No dialect specified on mount. Default has changed to a more secure dialect, SMB2.1 or later (e.g. SMB3.1.1), from CIFS (SMB1). To use the less secure SMB1 dialect to access old servers which do not support SMB3.1.1 (or even SMB3 or SMB2.1) specify vers=1.0 on mount. CIFS: Attempting to mount //127.0.0.1/share CIFS: VFS: \\127.0.0.1 Error -104 sending data on socket to server ------------[ cut here ]------------ server->in_flight == 0 WARNING: fs/smb/client/smb2ops.c:104 at smb2_add_credits+0x1249/0x2b70 fs/smb/client/smb2ops.c:104, CPU#0: syz.0.0/5323 Modules linked in: CPU: 0 UID: 0 PID: 5323 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:smb2_add_credits+0x1249/0x2b70 fs/smb/client/smb2ops.c:104 Code: de 83 e6 01 31 ff e8 46 83 bc fe f6 c3 01 75 0a e8 fc 7e bc fe e9 22 13 00 00 0f 1f 44 00 00 e8 ed 7e bc fe e9 13 13 00 00 90 <0f> 0b 90 80 3d c7 a4 36 0d 01 0f 85 9e 03 00 00 e8 d2 7e bc fe 49 RSP: 0018:ffffc9000f077318 EFLAGS: 00010246 RAX: ffffffff830a8718 RBX: 1ffff110068b1461 RCX: 0000000000000002 RDX: ffff88803889ca80 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000200 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: ffffffff830ab470 R12: ffff88803458a308 R13: ffffc9000f077530 R14: ffff88803458a000 R15: 0000000000000000 FS: 00007fa90522b6c0(0000) GS:ffff88808c543000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b971ae1780 CR3: 0000000013700000 CR4: 0000000000352ef0 Call Trace: add_credits fs/smb/client/cifsglob.h:894 [inline] compound_send_recv+0x13b4/0x2b90 fs/smb/client/transport.c:979 cifs_send_recv+0x42/0x60 fs/smb/client/transport.c:1106 SMB2_negotiate+0x164d/0x4030 fs/smb/client/smb2pdu.c:1188 cifs_negotiate_protocol+0x45d/0x680 fs/smb/client/connect.c:4043 cifs_get_smb_ses+0x1104/0x1ff0 fs/smb/client/connect.c:2492 cifs_mount_get_session+0xf1/0x450 fs/smb/client/connect.c:3578 get_session fs/smb/client/dfs.c:65 [inline] dfs_mount_share+0x22e/0x990 fs/smb/client/dfs.c:275 cifs_mount+0xcc/0xbf0 fs/smb/client/connect.c:3860 cifs_smb3_do_mount+0x2d0/0x8a0 fs/smb/client/cifsfs.c:1024 smb3_get_tree_common fs/smb/client/fs_context.c:897 [inline] smb3_get_tree+0x2dd/0x400 fs/smb/client/fs_context.c:917 vfs_get_tree+0x92/0x2a0 fs/super.c:1700 vfs_cmd_create+0xa2/0x200 fs/fsopen.c:231 __do_sys_fsconfig fs/fsopen.c:463 [inline] __se_sys_fsconfig+0x6b9/0x810 fs/fsopen.c:350 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa90439de99 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa90522afe8 EFLAGS: 00000246 ORIG_RAX: 00000000000001af RAX: ffffffffffffffda RBX: 00007fa904625fa0 RCX: 00007fa90439de99 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000005 RBP: 00007fa904433eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa904626038 R14: 00007fa904625fa0 R15: 00007ffe288a3948