bisecting fixing commit since 6b6446efedb27c2766745a04f9b5d4449f51391d building syzkaller on cba33199be220cbf61f7c0c8223d88a25a913d6f testing commit 6b6446efedb27c2766745a04f9b5d4449f51391d with gcc (GCC) 8.1.0 kernel signature: aaeb60063349db5ed1b3bd4337a5f1aeec2d9e4d9fff3c0eb13f191b1aeb5264 all runs: crashed: divide error in do_journal_end testing current HEAD 1752938529c614a8ed4432ecce6ebc95d3b87207 testing commit 1752938529c614a8ed4432ecce6ebc95d3b87207 with gcc (GCC) 8.1.0 kernel signature: c9837cb1b1bd8df8f64877ab976b6b2d82806b023fa81e5f9748729518d72f83 all runs: crashed: divide error in do_journal_end revisions tested: 2, total time: 22m33.107963798s (build: 16m22.729312653s, test: 5m38.025201369s) the crash still happens on HEAD commit msg: Linux 4.14.213 crash: divide error in do_journal_end 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 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! IPv6: ADDRCONF(NETDEV_UP): batadv_slave_1: link is not ready batman_adv: batadv0: Interface activated: batadv_slave_1 divide error: 0000 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 1 PID: 7710 Comm: syz-executor.3 Not tainted 4.14.213-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ieee80211 phy6: Selected rate control algorithm 'minstrel_ht' task: ffff8881dc7e8100 task.stack: ffff8881dc7d0000 RIP: 0010:do_journal_end+0x1ffb/0x4400 fs/reiserfs/journal.c:4201 RSP: 0018:ffff8881dc7d7b68 EFLAGS: 00010246 RAX: 0000000000000005 RBX: ffffc90002339048 RCX: ffff8881eb11b400 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffff8881dc7d7c70 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: dffffc0000000000 R13: ffff8881c90e5000 R14: ffff8881d177a840 R15: 0000000000001000 FS: 00000000035b7940(0000) GS:ffff8881f6500000(0000) knlGS:0000000000000000 ieee80211 phy6: hwaddr 02:00:00:00:06:00 registered CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 ieee80211 phy6: mac80211_hwsim_start CR2: 00007ffcd4785ff8 CR3: 00000001cdc1c001 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: journal_end_sync+0x117/0x210 fs/reiserfs/journal.c:3531 reiserfs_sync_fs+0xb6/0xd0 fs/reiserfs/super.c:78 ieee80211 phy6: mac80211_hwsim_add_interface (type=1 mac_addr=02:00:00:00:06:00) __sync_filesystem fs/sync.c:39 [inline] sync_filesystem+0x158/0x1f0 fs/sync.c:67 generic_shutdown_super+0x69/0x330 fs/super.c:432 kill_block_super+0x96/0xe0 fs/super.c:1161 reiserfs_kill_sb+0x171/0x1d0 fs/reiserfs/super.c:570 deactivate_locked_super+0x62/0xb0 fs/super.c:319 deactivate_super+0x7d/0x90 fs/super.c:350 cleanup_mnt+0x9f/0x130 fs/namespace.c:1183 __cleanup_mnt+0xd/0x10 fs/namespace.c:1190 ieee80211 phy6: mac80211_hwsim_bss_info_changed(changed=0xe vif->addr=02:00:00:00:06:00) task_work_run+0xe5/0x170 kernel/task_work.c:113 ieee80211 phy6: ERP_CTS_PROT: 0 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x14a/0x190 arch/x86/entry/common.c:164 ieee80211 phy6: ERP_PREAMBLE: 0 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x416/0x5b0 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x4608e7 RSP: 002b:00007ffc7e46b028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 ieee80211 phy6: ERP_SLOT: 0 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000004608e7 RDX: 00000000004031f8 RSI: 0000000000000002 RDI: 00007ffc7e46b0d0 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000009 R10: 0000000000000005 R11: 0000000000000246 R12: 00007ffc7e46c160 R13: 00000000035b8a60 R14: 0000000000000000 R15: 00007ffc7e46c160 Code: 0f 95 c6 41 84 f3 0f 85 ieee80211 phy6: mac80211_hwsim_conf_tx (queue=0 txop=47 cw_min=3 cw_max=7 aifs=2) dc ieee80211 phy6: mac80211_hwsim_conf_tx (queue=1 txop=94 cw_min=7 cw_max=15 aifs=2) 13 00 00 41 83 e0 07 44 38 c2 40 0f 9e c6 84 d2 0f 95 c2 40 84 d6 0f 85 c3 13 00 00 41 8b 7d 14 31 d2 <48> ieee80211 phy6: mac80211_hwsim_conf_tx (queue=2 txop=0 cw_min=15 cw_max=1023 aifs=3) f7 f7 48 8d 79 18 4a 8d 34 12 48 89 f8 48 c1 e8 03 42 80 3c RIP: do_journal_end+0x1ffb/0x4400 fs/reiserfs/journal.c:4201 RSP: ffff8881dc7d7b68 ---[ end trace fb2e8d2fbddb1401 ]--- ieee80211 phy6: mac80211_hwsim_conf_tx (queue=3 txop=0 cw_min=15 cw_max=1023 aifs=7)