================================================================== BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:82 [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+0x92/0x4b0 net/smc/af_smc.c:136 Read of size 4 at addr 0000000000000db4 by task syz.0.162[ 334.812804][ C0] Read of size 4 at addr 0000000000000db4 by task syz.0.1628/10339 CPU: 0 UID: 0 PID: 10339 Comm: syz.0.1628 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 kasan_report+0x117/0x150 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x264/0x2c0 mm/kasan/generic.c:200 instrument_atomic_read include/linux/instrumented.h:82 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] smc_tcp_syn_recv_sock+0x92/0x4b0 net/smc/af_smc.c:136 tcp_check_req+0x1405/0x1f90 net/ipv4/tcp_minisocks.c:927 tcp_v4_rcv+0x1786/0x31f0 net/ipv4/tcp_ipv4.c:2242 ip_protocol_deliver_rcu+0x221/0x440 net/ipv4/ip_input.c:207 ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:241 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6164 [inline] __netif_receive_skb net/core/dev.c:6277 [inline] process_backlog+0x569/0xc60 net/core/dev.c:6628 __napi_poll+0xaf/0x580 net/core/dev.c:7692 napi_poll net/core/dev.c:7755 [inline] net_rx_action+0x696/0xe00 net/core/dev.c:7912 handle_softirqs+0x1de/0x6f0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] __local_bh_enable_ip+0x170/0x2b0 kernel/softirq.c:302 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:924 [inline] __dev_queue_xmit+0x1ebb/0x39b0 net/core/dev.c:4873 dev_queue_xmit include/linux/netdevice.h:3384 [inline] neigh_hh_output include/net/neighbour.h:540 [inline] neigh_output include/net/neighbour.h:554 [inline] ip_finish_output2+0xcab/0x10b0 net/ipv4/ip_output.c:237 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip_output+0x29f/0x450 net/ipv4/ip_output.c:438 __ip_queue_xmit+0x116a/0x1bb0 net/ipv4/ip_output.c:534 __tcp_transmit_skb+0x2b30/0x43e0 net/ipv4/tcp_output.c:1693 tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:7021 [inline] tcp_rcv_state_process+0x2f6d/0x4810 net/ipv4/tcp_input.c:7215 tcp_v4_do_rcv+0xa25/0x12b0 net/ipv4/tcp_ipv4.c:1907 sk_backlog_rcv include/net/sock.h:1185 [inline] __release_sock+0x285/0x3d0 net/core/sock.c:3213 release_sock+0x75/0x210 net/core/sock.c:3795 inet_wait_for_connect net/ipv4/af_inet.c:611 [inline] __inet_stream_connect+0x85d/0xdd0 net/ipv4/af_inet.c:705 inet_stream_connect+0x66/0xa0 net/ipv4/af_inet.c:750 kernel_connect+0x141/0x1c0 net/socket.c:3634 smc_connect+0x7a5/0xd90 net/smc/af_smc.c:1699 __sys_connect_file net/socket.c:2089 [inline] __sys_connect+0x315/0x450 net/socket.c:2108 __do_sys_connect net/socket.c:2114 [inline] __se_sys_connect net/socket.c:2111 [inline] __x64_sys_connect+0x7a/0x90 net/socket.c:2111 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f13c6edc799 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f13c5136028 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 00007f13c7155fa0 RCX: 00007f13c6edc799 RDX: 0000000000000010 RSI: 0000200000000000 RDI: 0000000000000004 RBP: 00007f13c6f72c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f13c7156038 R14: 00007f13c7155fa0 R15: 00007ffc3977d9c8 ==================================================================