------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 11501 at lib/refcount.c:28 refcount_warn_saturate+0x140/0x1f0 lib/refcount.c:28 Modules linked in: CPU: 0 PID: 11501 Comm: syz-executor.2 Not tainted 6.5.0-rc5-next-20230807-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023 RIP: 0010:refcount_warn_saturate+0x140/0x1f0 lib/refcount.c:28 Code: 0a 31 ff 89 de e8 30 75 64 fd 84 db 0f 85 6e ff ff ff e8 f3 79 64 fd 48 c7 c7 00 44 c8 8a c6 05 a3 b1 74 0a 01 e8 50 cf 2a fd <0f> 0b e9 4f ff ff ff e8 d4 79 64 fd 0f b6 1d 89 b1 74 0a 31 ff 89 RSP: 0018:ffffc900033cf7b8 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9000ec12000 RDX: 0000000000040000 RSI: ffffffff814d1946 RDI: 0000000000000001 RBP: ffff8880152a2aa8 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff8880152a2aa0 R13: ffff8880152a2aa8 R14: ffff88801ca43000 R15: 00000000fffffe00 FS: 00007f1f9f31c6c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555574a4938 CR3: 0000000042f83000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_sub_and_test include/linux/refcount.h:283 [inline] __refcount_dec_and_test include/linux/refcount.h:315 [inline] refcount_dec_and_test include/linux/refcount.h:333 [inline] p9_req_put+0x1f0/0x250 net/9p/client.c:401 p9_client_rpc+0x58e/0xc10 net/9p/client.c:756 p9_client_version net/9p/client.c:925 [inline] p9_client_create+0xc49/0x1210 net/9p/client.c:1029 v9fs_session_init+0x1f8/0x1a80 fs/9p/v9fs.c:410 v9fs_mount+0xc6/0xcd0 fs/9p/vfs_super.c:123 legacy_get_tree+0x109/0x220 fs/fs_context.c:611 vfs_get_tree+0x88/0x350 fs/super.c:1544 do_new_mount fs/namespace.c:3335 [inline] path_mount+0x1492/0x1ed0 fs/namespace.c:3662 do_mount fs/namespace.c:3675 [inline] __do_sys_mount fs/namespace.c:3884 [inline] __se_sys_mount fs/namespace.c:3861 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:3861 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f1f9e67cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1f9f31c0c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f1f9e79c1f0 RCX: 00007f1f9e67cae9 RDX: 0000000020000140 RSI: 0000000020000400 RDI: 0000000000000000 RBP: 00007f1f9e6c847a R08: 0000000020000480 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f1f9e79c1f0 R15: 00007fffe0a67488