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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+0x92/0x420 net/smc/af_smc.c:135
Read of size 4 at addr 0000000000000d84 by task syz.0.33/6090

CPU: 1 UID: 0 PID: 6090 Comm: syz.0.33 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x2b0/0x2c0 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+0x92/0x420 net/smc/af_smc.c:135
 tcp_check_req+0xf0e/0x1800 net/ipv4/tcp_minisocks.c:874
 tcp_v4_rcv+0x1896/0x2f40 net/ipv4/tcp_ipv4.c:2291
 ip_protocol_deliver_rcu+0x221/0x440 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:239
 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
 __netif_receive_skb_one_core net/core/dev.c:5991 [inline]
 __netif_receive_skb+0x143/0x380 net/core/dev.c:6104
 process_backlog+0x31e/0x900 net/core/dev.c:6456
 __napi_poll+0xb3/0x540 net/core/dev.c:7506
 napi_poll net/core/dev.c:7569 [inline]
 net_rx_action+0x707/0xe00 net/core/dev.c:7696
 handle_softirqs+0x22f/0x710 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 __local_bh_enable_ip+0x179/0x270 kernel/softirq.c:259
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:910 [inline]
 __dev_queue_xmit+0x1d3d/0x3b70 net/core/dev.c:4752
 dev_queue_xmit include/linux/netdevice.h:3361 [inline]
 neigh_hh_output include/net/neighbour.h:531 [inline]
 neigh_output include/net/neighbour.h:545 [inline]
 ip_finish_output2+0xd5a/0x11d0 net/ipv4/ip_output.c:235
 NF_HOOK_COND include/linux/netfilter.h:307 [inline]
 ip_output+0x2a1/0x3c0 net/ipv4/ip_output.c:436
 ip_local_out net/ipv4/ip_output.c:129 [inline]
 __ip_queue_xmit+0x1106/0x1b00 net/ipv4/ip_output.c:532
 __tcp_transmit_skb+0x2215/0x3680 net/ipv4/tcp_output.c:1479
 tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:6527 [inline]
 tcp_rcv_state_process+0x2a99/0x4140 net/ipv4/tcp_input.c:6721
 tcp_v4_do_rcv+0x3fb/0xbf0 net/ipv4/tcp_ipv4.c:1949
 sk_backlog_rcv include/net/sock.h:1150 [inline]
 __release_sock+0x245/0x390 net/core/sock.c:3172
 release_sock+0x75/0x210 net/core/sock.c:3726
 mptcp_connect+0x649/0x830 net/mptcp/protocol.c:3766
 __inet_stream_connect+0x2ae/0xe80 net/ipv4/af_inet.c:677
 inet_stream_connect+0x66/0xa0 net/ipv4/af_inet.c:748
 __sys_connect_file net/socket.c:2086 [inline]
 __sys_connect+0x320/0x450 net/socket.c:2105
 __do_sys_connect net/socket.c:2111 [inline]
 __se_sys_connect net/socket.c:2108 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:2108
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f47f89ceba9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f47f6c2e038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00007f47f8c15fa0 RCX: 00007f47f89ceba9
RDX: 0000000000000010 RSI: 0000200000000080 RDI: 0000000000000006
RBP: 00007f47f8a51e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f47f8c16038 R14: 00007f47f8c15fa0 R15: 00007ffd07920518
 </TASK>
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