bisecting fixing commit since 97a8651cadce7c2b7c4d8f108b392eff31fe2c08 building syzkaller on 77e2b66864e69c17416614228723a1ebd3581ddc testing commit 97a8651cadce7c2b7c4d8f108b392eff31fe2c08 with gcc (GCC) 8.4.1 20210217 kernel signature: 45da0bf853ce22783a8736778f4672e2861cdd4b2a708544948ac12678b8500f all runs: crashed: divide error in do_journal_end testing current HEAD 6b7b0056defc6eb5c87bbe4690ccda547b2891aa testing commit 6b7b0056defc6eb5c87bbe4690ccda547b2891aa with gcc (GCC) 8.4.1 20210217 kernel signature: d1d3bb6f66085ab14e7279da3f6a78bfca397104e1c1be17b60d9ac227e4b209 all runs: crashed: divide error in do_journal_end revisions tested: 2, total time: 26m12.194730947s (build: 19m11.581166858s, test: 6m31.364296737s) the crash still happens on HEAD commit msg: Linux 4.19.192 crash: divide error in do_journal_end REISERFS (device loop1): checking transaction log (loop1) REISERFS (device loop3): Using rupasov hash to sort names REISERFS (device loop3): Created .reiserfs_priv - reserved for xattr storage. divide error: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 8479 Comm: syz-executor.3 Not tainted 4.19.192-syzkaller #0 REISERFS (device loop2): Using rupasov hash to sort names Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:do_journal_end+0x2129/0x4400 fs/reiserfs/journal.c:4204 Code: 95 c6 41 84 f3 0f 85 cf 14 00 00 41 83 e0 07 44 38 c2 40 0f 9e c6 84 d2 0f 95 c2 40 84 d6 0f 85 b6 14 00 00 41 8b 7d 14 31 d2 <48> f7 f7 48 8d 79 18 4a 8d 34 12 48 89 f8 48 c1 e8 03 80 3c 18 00 RSP: 0018:ffff8880a9f07b08 EFLAGS: 00010246 RAX: 0000000000000005 RBX: dffffc0000000000 RCX: ffff88809773ccc0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffff8880a9f07c10 R08: 0000000000000007 R09: ffffed1017464552 R10: 0000000000000000 R11: 0000000000000001 R12: ffffc90005d42048 R13: ffff8880816f4000 R14: ffff8880974f2780 R15: 0000000000001000 FS: 00000000016be400(0000) GS:ffff8880ba300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe3ead4bdc CR3: 00000000ab152000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: journal_end_sync+0x117/0x210 fs/reiserfs/journal.c:3534 reiserfs_sync_fs+0xcc/0xe0 fs/reiserfs/super.c:78 __sync_filesystem fs/sync.c:39 [inline] sync_filesystem fs/sync.c:67 [inline] sync_filesystem+0x165/0x1f0 fs/sync.c:48 generic_shutdown_super+0x69/0x330 fs/super.c:442 kill_block_super+0x96/0xe0 fs/super.c:1185 reiserfs_kill_sb+0x171/0x1d0 fs/reiserfs/super.c:570 deactivate_locked_super+0x77/0xd0 fs/super.c:329 deactivate_super fs/super.c:360 [inline] deactivate_super+0x13f/0x160 fs/super.c:356 cleanup_mnt+0xa3/0x130 fs/namespace.c:1098 __cleanup_mnt+0xd/0x10 fs/namespace.c:1105 task_work_run+0x108/0x180 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x185/0x1e0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x413/0x4e0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x467a57 Code: ff d0 48 89 c7 b8 3c 00 00 00 0f 05 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe3ead4bb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000467a57 RDX: 00007ffe3ead4c89 RSI: 0000000000000002 RDI: 00007ffe3ead4c80 RBP: 00007ffe3ead4c80 R08: 00000000ffffffff R09: 00007ffe3ead4a50 R10: 00000000016bf8e3 R11: 0000000000000246 R12: 00000000004bee98 R13: 00007ffe3ead5d50 R14: 00000000016bf810 R15: 00007ffe3ead5d90 Modules linked in: ---[ end trace 7ced9e8abaa37ccc ]--- REISERFS (device loop2): Created .reiserfs_priv - reserved for xattr storage. RIP: 0010:do_journal_end+0x2129/0x4400 fs/reiserfs/journal.c:4204 REISERFS (device loop4): Using rupasov hash to sort names Code: 95 c6 41 84 f3 0f 85 cf 14 00 00 41 83 e0 07 44 38 c2 40 0f 9e c6 84 d2 0f 95 c2 40 84 d6 0f 85 b6 14 00 00 41 8b 7d 14 31 d2 <48> f7 f7 48 8d 79 18 4a 8d 34 12 48 89 f8 48 c1 e8 03 80 3c 18 00 REISERFS (device loop4): Created .reiserfs_priv - reserved for xattr storage. RSP: 0018:ffff8880a9f07b08 EFLAGS: 00010246 divide error: 0000 [#2] PREEMPT SMP KASAN RAX: 0000000000000005 RBX: dffffc0000000000 RCX: ffff88809773ccc0 CPU: 0 PID: 8477 Comm: syz-executor.2 Tainted: G D 4.19.192-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:do_journal_end+0x2129/0x4400 fs/reiserfs/journal.c:4204 Code: 95 c6 41 84 f3 0f 85 cf 14 00 00 41 83 e0 07 44 38 c2 40 0f 9e c6 84 d2 0f 95 c2 40 84 d6 0f 85 b6 14 00 00 41 8b 7d 14 31 d2 <48> f7 f7 48 8d 79 18 4a 8d 34 12 48 89 f8 48 c1 e8 03 80 3c 18 00 RSP: 0018:ffff888094dafb08 EFLAGS: 00010246 RAX: 0000000000000005 RBX: dffffc0000000000 RCX: ffff888097cfeb80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffff888094dafc10 R08: 0000000000000007 R09: ffffed1011ffe77d R10: 0000000000000000 R11: 0000000000000001 R12: ffffc90005c21048 R13: ffff888081736000 R14: ffff888097666300 R15: 0000000000001000 FS: 0000000002f6b400(0000) GS:ffff8880ba200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffdd6134ff8 CR3: 00000000a9c1f000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: journal_end_sync+0x117/0x210 fs/reiserfs/journal.c:3534 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 reiserfs_sync_fs+0xcc/0xe0 fs/reiserfs/super.c:78 RBP: ffff8880a9f07c10 R08: 0000000000000007 R09: ffffed1017464552 __sync_filesystem fs/sync.c:39 [inline] sync_filesystem fs/sync.c:67 [inline] sync_filesystem+0x165/0x1f0 fs/sync.c:48 generic_shutdown_super+0x69/0x330 fs/super.c:442 kill_block_super+0x96/0xe0 fs/super.c:1185 reiserfs_kill_sb+0x171/0x1d0 fs/reiserfs/super.c:570 deactivate_locked_super+0x77/0xd0 fs/super.c:329 deactivate_super fs/super.c:360 [inline] deactivate_super+0x13f/0x160 fs/super.c:356 R10: 0000000000000000 R11: 0000000000000001 R12: ffffc90005d42048 cleanup_mnt+0xa3/0x130 fs/namespace.c:1098 __cleanup_mnt+0xd/0x10 fs/namespace.c:1105 task_work_run+0x108/0x180 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x185/0x1e0 arch/x86/entry/common.c:167 R13: ffff8880816f4000 R14: ffff8880974f2780 R15: 0000000000001000 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x413/0x4e0 arch/x86/entry/common.c:296 FS: 00000000016be400(0000) GS:ffff8880ba300000(0000) knlGS:0000000000000000 entry_SYSCALL_64_after_hwframe+0x49/0xbe CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 RIP: 0033:0x467a57 CR2: 00007fccfc297018 CR3: 00000000ab152000 CR4: 00000000001406e0 Code: ff d0 48 89 c7 b8 3c 00 00 00 0f 05 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 RSP: 002b:00007ffc0acf0de8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000467a57 RDX: 00007ffc0acf0eb9 RSI: 0000000000000002 RDI: 00007ffc0acf0eb0 RBP: 00007ffc0acf0eb0 R08: 00000000ffffffff R09: 00007ffc0acf0c80 R10: 0000000002f6c8e3 R11: 0000000000000246 R12: 00000000004bee98 R13: 00007ffc0acf1f80 R14: 0000000002f6c810 R15: 00007ffc0acf1fc0 Modules linked in: divide error: 0000 [#3] PREEMPT SMP KASAN DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 CPU: 0 PID: 8480 Comm: syz-executor.4 Tainted: G D 4.19.192-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:do_journal_end+0x2129/0x4400 fs/reiserfs/journal.c:4204 Code: 95 c6 41 84 f3 0f 85 cf 14 00 00 41 83 e0 07 44 38 c2 40 0f 9e c6 84 d2 0f 95 c2 40 84 d6 0f 85 b6 14 00 00 41 8b 7d 14 31 d2 <48> f7 f7 48 8d 79 18 4a 8d 34 12 48 89 f8 48 c1 e8 03 80 3c 18 00