================================================================== BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: null-ptr-deref in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] BUG: KASAN: null-ptr-deref in smc_tcp_syn_recv_sock+0xa7/0x4b0 net/smc/af_smc.c:131 Read of size 4 at addr 00000000000009d4 by task syz.0.274/7075 CPU: 2 UID: 0 PID: 7075 Comm: syz.0.274 Not tainted 6.14.0-syzkaller-09584-g7d06015d936c #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 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 kasan_report+0xe0/0x110 mm/kasan/report.c:634 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189 instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] smc_tcp_syn_recv_sock+0xa7/0x4b0 net/smc/af_smc.c:131 tcp_check_req+0x69a/0x1f80 net/ipv4/tcp_minisocks.c:871 tcp_v4_rcv+0x19b0/0x4640 net/ipv4/tcp_ipv4.c:2283 ip_protocol_deliver_rcu+0xba/0x4c0 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x316/0x570 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip_local_deliver+0x18e/0x1f0 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:469 [inline] ip_rcv_finish net/ipv4/ip_input.c:447 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip_rcv+0x2c3/0x5d0 net/ipv4/ip_input.c:567 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5891 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6004 process_backlog+0x442/0x15e0 net/core/dev.c:6356 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7328 napi_poll net/core/dev.c:7392 [inline] net_rx_action+0xa97/0x1010 net/core/dev.c:7514 handle_softirqs+0x216/0x8e0 kernel/softirq.c:561 do_softirq kernel/softirq.c:462 [inline] do_softirq+0xb2/0xf0 kernel/softirq.c:449 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:389 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:910 [inline] __dev_queue_xmit+0x8ab/0x43e0 net/core/dev.c:4660 dev_queue_xmit include/linux/netdevice.h:3350 [inline] neigh_hh_output include/net/neighbour.h:523 [inline] neigh_output include/net/neighbour.h:537 [inline] ip_finish_output2+0xc38/0x21a0 net/ipv4/ip_output.c:235 __ip_finish_output net/ipv4/ip_output.c:313 [inline] __ip_finish_output+0x49e/0x950 net/ipv4/ip_output.c:295 ip_finish_output+0x35/0x380 net/ipv4/ip_output.c:323 NF_HOOK_COND include/linux/netfilter.h:303 [inline] ip_output+0x13b/0x2a0 net/ipv4/ip_output.c:433 dst_output include/net/dst.h:459 [inline] ip_local_out net/ipv4/ip_output.c:129 [inline] __ip_queue_xmit+0x1d7d/0x26c0 net/ipv4/ip_output.c:527 __tcp_transmit_skb+0x2686/0x3e90 net/ipv4/tcp_output.c:1479 __tcp_send_ack.part.0+0x3de/0x700 net/ipv4/tcp_output.c:4280 __tcp_send_ack net/ipv4/tcp_output.c:4286 [inline] tcp_send_ack+0x84/0xa0 net/ipv4/tcp_output.c:4286 tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:6623 [inline] tcp_rcv_state_process+0x4232/0x4df0 net/ipv4/tcp_input.c:6817 tcp_v4_do_rcv+0x1ad/0xa90 net/ipv4/tcp_ipv4.c:1948 sk_backlog_rcv include/net/sock.h:1126 [inline] __release_sock+0x31b/0x400 net/core/sock.c:3158 release_sock+0x5a/0x220 net/core/sock.c:3712 mptcp_connect+0xccd/0xfe0 net/mptcp/protocol.c:3691 __inet_stream_connect+0x3c5/0x1020 net/ipv4/af_inet.c:677 inet_stream_connect+0x57/0xa0 net/ipv4/af_inet.c:748 __sys_connect_file+0x13e/0x1a0 net/socket.c:2038 __sys_connect+0x14d/0x170 net/socket.c:2057 __do_sys_connect net/socket.c:2063 [inline] __se_sys_connect net/socket.c:2060 [inline] __ia32_sys_connect+0x71/0xb0 net/socket.c:2060 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x73/0x120 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: 0023:0xf7f94579 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:00000000f50b655c EFLAGS: 00000296 ORIG_RAX: 000000000000016a RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000080000000 RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 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