------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 2 PID: 31702 at lib/refcount.c:25 refcount_warn_saturate+0x1ca/0x210 lib/refcount.c:25
Modules linked in:
CPU: 2 PID: 31702 Comm: syz-executor.3 Not tainted 6.7.0-rc6-syzkaller-00044-g1a44b0073b92 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:refcount_warn_saturate+0x1ca/0x210 lib/refcount.c:25
Code: ff 89 de e8 58 a3 25 fd 84 db 0f 85 e6 fe ff ff e8 1b a8 25 fd c6 05 9a 88 a1 0a 01 90 48 c7 c7 00 9d 2e 8b e8 b7 ec eb fc 90 <0f> 0b 90 90 e9 c3 fe ff ff e8 f8 a7 25 fd c6 05 75 88 a1 0a 01 90
RSP: 0018:ffffc900296df850 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9002c40a000
RDX: 0000000000040000 RSI: ffffffff814db526 RDI: 0000000000000001
RBP: ffffffff92b5b7b0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000002 R12: 0000000000000010
R13: ffffffff92b5b7b0 R14: 0000000000000001 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88802c800000(0063) knlGS:00000000f7efdb40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f7354000 CR3: 0000000050ee3000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__refcount_add include/linux/refcount.h:199 [inline]
__refcount_inc include/linux/refcount.h:250 [inline]
refcount_inc include/linux/refcount.h:267 [inline]
kref_get include/linux/kref.h:45 [inline]
tcp_sigpool_alloc_ahash+0x9cb/0xce0 net/ipv4/tcp_sigpool.c:166
tcp_md5_alloc_sigpool+0x1b/0x40 net/ipv4/tcp.c:4379
tcp_md5_do_add+0x192/0x460 net/ipv4/tcp_ipv4.c:1403
tcp_v6_parse_md5_keys+0x68d/0x860 net/ipv6/tcp_ipv6.c:676
do_tcp_setsockopt+0x1302/0x2880 net/ipv4/tcp.c:3644
tcp_setsockopt+0xd4/0x100 net/ipv4/tcp.c:3726
do_sock_setsockopt+0x222/0x470 net/socket.c:2311
__sys_setsockopt+0x1a6/0x270 net/socket.c:2334
__do_sys_setsockopt net/socket.c:2343 [inline]
__se_sys_setsockopt net/socket.c:2340 [inline]
__ia32_sys_setsockopt+0xbc/0x150 net/socket.c:2340
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x62/0xe0 arch/x86/entry/common.c:321
do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:346
entry_SYSENTER_compat_after_hwframe+0x70/0x7a
RIP: 0023:0xf7f02579
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:00000000f7efd5ac EFLAGS: 00000292 ORIG_RAX: 000000000000016e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000000006
RDX: 000000000000000e RSI: 0000000020000000 RDI: 00000000000000d8
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
----------------
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