bisecting fixing commit since 1bab61d3e8cd96f2badf515dcb06e4e1029bc017 building syzkaller on 4afdfa205b55633e7eb9db03a9d099d7aa324801 testing commit 1bab61d3e8cd96f2badf515dcb06e4e1029bc017 with gcc (GCC) 8.1.0 kernel signature: bd3422b019ab0d0170b49c08a5da381b024a1c5e1b77dd0b25a05e272b4d6763 all runs: crashed: kernel BUG at mm/memory.c:LINE! testing current HEAD 17a87580a8856170d59aab302226811a4ae69149 testing commit 17a87580a8856170d59aab302226811a4ae69149 with gcc (GCC) 8.1.0 kernel signature: c5724c71e9e72f4055e774b05dd9e25d840a32290dbeb359422f7cddf910bb21 all runs: crashed: kernel BUG at mm/memory.c:LINE! revisions tested: 2, total time: 25m36.161518032s (build: 18m37.98720579s, test: 6m4.818111185s) the crash still happens on HEAD commit msg: Linux 4.19.133 crash: kernel BUG at mm/memory.c:LINE! IPv6: ADDRCONF(NETDEV_UP): batadv_slave_0: link is not ready batman_adv: batadv0: Interface activated: batadv_slave_0 IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_0: link becomes ready ------------[ cut here ]------------ IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready kernel BUG at mm/memory.c:3947! invalid opcode: 0000 [#1] PREEMPT SMP KASAN IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_0: link becomes ready CPU: 0 PID: 7830 Comm: syz-executor.0 Not tainted 4.19.133-syzkaller #0 IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 RIP: 0010:wp_huge_pmd mm/memory.c:3947 [inline] RIP: 0010:__handle_mm_fault+0x2177/0x41a0 mm/memory.c:4155 Code: 49 8d b6 a0 00 00 00 48 89 da 44 89 9d 10 ff ff ff e8 2d 71 fe ff 44 8b 9d 10 ff ff ff e9 28 ec ff ff 48 89 df e8 70 a7 fd ff <0f> 0b 49 8d 84 24 60 ff ff ff 48 89 c7 e8 77 ed 0b 00 41 89 c3 e9 RSP: 0018:ffff88808dc87cc8 EFLAGS: 00010296 RAX: 0000000000000137 RBX: ffff88808d3fe210 RCX: 0000000000000000 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! RDX: 0000000000000000 RSI: ffffffff87677ce0 RDI: ffffffff8a196a60 RBP: ffff88808dc87de8 R08: ffffed1015d45081 R09: ffffed1015d45080 R10: ffffed1015d45080 R11: ffff8880aea28407 R12: ffff88808dc87dc0 R13: 1ffff11011b90fa0 R14: ffffffff873111a0 R15: ffff88808c708040 FS: 0000000001987940(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 CR2: 000055d4ade5f458 CR3: 000000008c49a000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 handle_mm_fault+0x3dd/0x8ab mm/memory.c:4202 __do_page_fault+0x50e/0xb30 arch/x86/mm/fault.c:1412 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 do_page_fault+0x64/0x3a7 arch/x86/mm/fault.c:1487 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1205 RIP: 0033:0x443d51 Code: 8d 15 b3 1b 0d 00 8b 0c 8a 8b 04 82 29 c8 c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 fa 20 48 89 f8 73 77 f6 c2 01 74 0b 0f b6 0e <88> 0f 48 ff c6 48 ff c7 f6 c2 02 74 12 0f b7 0e 66 89 0f 48 83 c6 RSP: 002b:00007ffe8d620f88 EFLAGS: 00010202 RAX: 00000000200001c0 RBX: 0000000000000000 RCX: 0000000000000063 RDX: 0000000000000013 RSI: 0000000000790398 RDI: 00000000200001c0 RBP: 0000000000790378 R08: 0000000000000000 R09: 0000000000000000 R10: 00007ffe8d621070 R11: 0000000000000246 R12: 0000000000790380 IPv6: ADDRCONF(NETDEV_UP): batadv_slave_1: link is not ready R13: 000000000000c412 R14: fffffffffffffffe R15: 000000000078c04c Modules linked in: ---[ end trace dc4277b69c8c80f5 ]--- batman_adv: batadv0: Interface activated: batadv_slave_1 RIP: 0010:wp_huge_pmd mm/memory.c:3947 [inline] RIP: 0010:__handle_mm_fault+0x2177/0x41a0 mm/memory.c:4155 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 Code: 49 8d b6 a0 00 00 00 48 89 da 44 89 9d 10 ff ff ff e8 2d 71 fe ff 44 8b 9d 10 ff ff ff e9 28 ec ff ff 48 89 df e8 70 a7 fd ff <0f> 0b 49 8d 84 24 60 ff ff ff 48 89 c7 e8 77 ed 0b 00 41 89 c3 e9 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! RSP: 0018:ffff88808dc87cc8 EFLAGS: 00010296 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 RAX: 0000000000000137 RBX: ffff88808d3fe210 RCX: 0000000000000000 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! RDX: 0000000000000000 RSI: ffffffff87677ce0 RDI: ffffffff8a196a60 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 RBP: ffff88808dc87de8 R08: ffffed1015d45081 R09: ffffed1015d45080 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! R10: ffffed1015d45080 R11: ffff8880aea28407 R12: ffff88808dc87dc0 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 R13: 1ffff11011b90fa0 R14: ffffffff873111a0 R15: ffff88808c708040 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! FS: 0000000001987940(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 IPv6: ADDRCONF(NETDEV_UP): batadv_slave_1: link is not ready CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 batman_adv: batadv0: Interface activated: batadv_slave_1 CR2: 00007fa2cde33028 CR3: 000000008c49a000 CR4: 00000000001406f0 IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready