9p: Unknown access argument any¨: -22 9pnet: Tag 65535 still in use ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 14150 at lib/refcount.c:28 refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28 Modules linked in: CPU: 0 UID: 0 PID: 14150 Comm: syz.4.1732 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28 Code: ff 89 de e8 d8 75 1a fd 84 db 0f 85 66 ff ff ff e8 eb 7a 1a fd c6 05 52 f9 c8 0b 01 90 48 c7 c7 c0 c6 ef 8b e8 07 fe d8 fc 90 <0f> 0b 90 90 e9 43 ff ff ff e8 c8 7a 1a fd 0f b6 1d 2d f9 c8 0b 31 RSP: 0000:ffffc90002dbf950 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc90028d70000 RDX: 0000000000080000 RSI: ffffffff817adc55 RDI: 0000000000000001 RBP: ffff88804f515dc8 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffff88804f515dc8 R13: ffff88805cc02c00 R14: dffffc0000000000 R15: 1ffff920005b7f35 FS: 0000000000000000(0000) GS:ffff88809780d000(0063) knlGS:00000000f54d6b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00007f35d4681b4c CR3: 000000004a958000 CR4: 0000000000352ef0 Call Trace: __refcount_sub_and_test include/linux/refcount.h:400 [inline] __refcount_dec_and_test include/linux/refcount.h:432 [inline] refcount_dec_and_test include/linux/refcount.h:450 [inline] p9_req_put+0x1ec/0x250 net/9p/client.c:404 p9_tag_cleanup net/9p/client.c:431 [inline] p9_client_destroy+0x22b/0x480 net/9p/client.c:1086 v9fs_session_init+0xbab/0x1a80 fs/9p/v9fs.c:489 v9fs_mount+0xc5/0xa90 fs/9p/vfs_super.c:122 legacy_get_tree+0x10c/0x220 fs/fs_context.c:663 vfs_get_tree+0x8e/0x340 fs/super.c:1758 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3642 [inline] do_new_mount fs/namespace.c:3718 [inline] path_mount+0x7b9/0x23a0 fs/namespace.c:4028 do_mount fs/namespace.c:4041 [inline] __do_sys_mount fs/namespace.c:4229 [inline] __se_sys_mount fs/namespace.c:4206 [inline] __ia32_sys_mount+0x291/0x310 fs/namespace.c:4206 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7fe6579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f54d655c EFLAGS: 00000296 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 0000000080000040 RCX: 0000000080000100 RDX: 0000000080000140 RSI: 0000000000000002 RDI: 0000000080000300 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi