bisecting fixing commit since fe5cdef29e41c8bda8cd1a11545e7c6bfe25570e building syzkaller on b0e8efcb4b0aac61f4647a76bbe54a5d38a370ba testing commit fe5cdef29e41c8bda8cd1a11545e7c6bfe25570e with gcc (GCC) 8.1.0 kernel signature: fff535caaa7d051f834ca1b8b3b168306161f09323dfeb66e87f9310c67e8cfa run #0: crashed: general protection fault in dst_dev_put run #1: crashed: general protection fault in fib6_purge_rt run #2: crashed: general protection fault in dst_dev_put run #3: crashed: general protection fault in dst_dev_put run #4: crashed: BUG: unable to handle kernel paging request in ipv6_rcv run #5: crashed: unregister_netdevice: waiting for DEV to become free run #6: crashed: general protection fault in dst_dev_put run #7: crashed: general protection fault in dst_dev_put run #8: crashed: general protection fault in fib6_purge_rt run #9: crashed: general protection fault in fib6_purge_rt testing current HEAD 1ae7efb388540adc1653a51a3bc3b2c9cef5ec1a testing commit 1ae7efb388540adc1653a51a3bc3b2c9cef5ec1a with gcc (GCC) 8.1.0 kernel signature: bac1999571d3ade62eadf1524d879390b36348690f239b0197735e00146e0bcf all runs: crashed: BUG: using smp_processor_id() in preemptible [ADDR] code: syz-executor revisions tested: 2, total time: 18m27.954699275s (build: 10m35.343479032s, test: 7m0.125297582s) the crash still happens on HEAD commit msg: Merge tag 'mmc-v5.7-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc crash: BUG: using smp_processor_id() in preemptible [ADDR] code: syz-executor tipc: Started in network mode tipc: Own node identity ac1414aa, cluster identity 4711 tipc: New replicast peer: 172.20.20.187 BUG: using smp_processor_id() in preemptible [00000000] code: syz-executor.4/7553 caller is dst_cache_get+0x33/0xa0 net/core/dst_cache.c:68 CPU: 1 PID: 7553 Comm: syz-executor.4 Not tainted 5.7.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x12d/0x187 lib/dump_stack.c:118 check_preemption_disabled lib/smp_processor_id.c:47 [inline] debug_smp_processor_id.cold.1+0x84/0x9e lib/smp_processor_id.c:57 dst_cache_get+0x33/0xa0 net/core/dst_cache.c:68 tipc_udp_xmit.isra.15+0xab/0xcd0 net/tipc/udp_media.c:164 tipc_udp_send_msg+0x229/0x3d0 net/tipc/udp_media.c:257 tipc_bearer_xmit_skb+0x1a5/0x370 net/tipc/bearer.c:526 tipc_enable_bearer+0x859/0xbb0 net/tipc/bearer.c:331 __tipc_nl_bearer_enable+0x265/0x390 net/tipc/bearer.c:995 tipc_nl_bearer_enable+0x1d/0x30 net/tipc/bearer.c:1003 genl_family_rcv_msg_doit net/netlink/genetlink.c:673 [inline] genl_family_rcv_msg net/netlink/genetlink.c:718 [inline] genl_rcv_msg+0x5e1/0x10f0 net/netlink/genetlink.c:735 netlink_rcv_skb+0x13f/0x380 net/netlink/af_netlink.c:2469 genl_rcv+0x23/0x40 net/netlink/genetlink.c:746 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x479/0x6c0 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x7ab/0xd50 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xe6/0x110 net/socket.c:672 ____sys_sendmsg+0x609/0x980 net/socket.c:2362 ___sys_sendmsg+0xe4/0x160 net/socket.c:2416 __sys_sendmsg+0xd9/0x180 net/socket.c:2449 __do_sys_sendmsg net/socket.c:2458 [inline] __se_sys_sendmsg net/socket.c:2456 [inline] __x64_sys_sendmsg+0x73/0xb0 net/socket.c:2456 do_syscall_64+0xd0/0x630 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x458c29 Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fd2606f3c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458c29 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd2606f46d4 R13: 00000000004c62bc R14: 00000000004dab98 R15: 00000000ffffffff BUG: using smp_processor_id() in preemptible [00000000] code: syz-executor.4/7553 caller is dst_cache_set_ip4+0x97/0x2e0 net/core/dst_cache.c:98 CPU: 1 PID: 7553 Comm: syz-executor.4 Not tainted 5.7.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x12d/0x187 lib/dump_stack.c:118 check_preemption_disabled lib/smp_processor_id.c:47 [inline] debug_smp_processor_id.cold.1+0x84/0x9e lib/smp_processor_id.c:57 dst_cache_set_ip4+0x97/0x2e0 net/core/dst_cache.c:98 tipc_udp_xmit.isra.15+0x7aa/0xcd0 net/tipc/udp_media.c:182 tipc_udp_send_msg+0x229/0x3d0 net/tipc/udp_media.c:257 tipc_bearer_xmit_skb+0x1a5/0x370 net/tipc/bearer.c:526 tipc_enable_bearer+0x859/0xbb0 net/tipc/bearer.c:331 __tipc_nl_bearer_enable+0x265/0x390 net/tipc/bearer.c:995 tipc_nl_bearer_enable+0x1d/0x30 net/tipc/bearer.c:1003 genl_family_rcv_msg_doit net/netlink/genetlink.c:673 [inline] genl_family_rcv_msg net/netlink/genetlink.c:718 [inline] genl_rcv_msg+0x5e1/0x10f0 net/netlink/genetlink.c:735 netlink_rcv_skb+0x13f/0x380 net/netlink/af_netlink.c:2469 genl_rcv+0x23/0x40 net/netlink/genetlink.c:746 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x479/0x6c0 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x7ab/0xd50 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xe6/0x110 net/socket.c:672 ____sys_sendmsg+0x609/0x980 net/socket.c:2362 ___sys_sendmsg+0xe4/0x160 net/socket.c:2416 __sys_sendmsg+0xd9/0x180 net/socket.c:2449 __do_sys_sendmsg net/socket.c:2458 [inline] __se_sys_sendmsg net/socket.c:2456 [inline] __x64_sys_sendmsg+0x73/0xb0 net/socket.c:2456 do_syscall_64+0xd0/0x630 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x458c29 Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fd2606f3c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458c29 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd2606f46d4 R13: 00000000004c62bc R14: 00000000004dab98 R15: 00000000ffffffff tipc: Enabled bearer , priority 10 tipc: Enabling of bearer rejected, already enabled