On 2023/8/25 17:48, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 47d9bb711707 Add linux-next specific files for 20230821 > git tree: linux-next > console+strace: https://syzkaller.appspot.com/x/log.txt?x=124d6a4ba80000 > kernel config: https://syzkaller.appspot.com/x/.config?x=20999f779fa96017 > dashboard link: https://syzkaller.appspot.com/bug?extid=b3123e6d9842e526de39 > compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=110f9c0fa80000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10b8867fa80000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/ffbe03c733b7/disk-47d9bb71.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/a61a31d6caf9/vmlinux-47d9bb71.xz > kernel image: https://storage.googleapis.com/syzbot-assets/37e6f882b2d9/bzImage-47d9bb71.xz > mounted in repro: https://storage.googleapis.com/syzbot-assets/bf27f1330349/mount_0.gz > > The issue was bisected to: > > commit 99d6c5d892bfff3be40f83ec34d91d562125afd4 > Author: Zhang Yi <yi.zhang@xxxxxxxxxx> > Date: Fri Aug 11 06:36:10 2023 +0000 > > ext4: ext4_get_{dev}_journal return proper error value > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13a381cfa80000 > final oops: https://syzkaller.appspot.com/x/report.txt?x=106381cfa80000 > console output: https://syzkaller.appspot.com/x/log.txt?x=17a381cfa80000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+b3123e6d9842e526de39@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: 99d6c5d892bf ("ext4: ext4_get_{dev}_journal return proper error value") > > EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 failed (394!=20869) > EXT4-fs error (device loop0): ext4_get_journal_inode:5719: comm syz-executor999: inode #33: comm syz-executor999: iget: illegal inode # > EXT4-fs (loop0): no journal found > BUG: unable to handle page fault for address: ffffffffffffffdb Thanks for the report, It's a real issue and I'm sorry to introduce it due to my carelessness on commit '99d6c5d892bf ("ext4: ext4_get_{dev}_journal return proper error value")'. The problem is that I forgot to modify ext4_calculate_overhead() together to handle the error return value from ext4_get_journal_inode() properly. I will fix it soon. Thanks, Yi. > #PF: supervisor read access in kernel mode > #PF: error_code(0x0000) - not-present page > PGD c979067 P4D c979067 PUD c97b067 PMD 0 > Oops: 0000 [#1] PREEMPT SMP KASAN > CPU: 1 PID: 5041 Comm: syz-executor999 Not tainted 6.5.0-rc7-next-20230821-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 > RIP: 0010:ext4_calculate_overhead+0xfd2/0x1380 fs/ext4/super.c:4182 > Code: 7b 50 48 89 fa 48 c1 ea 03 44 0f b6 60 14 48 b8 00 00 00 00 00 fc ff df 80 3c 02 00 0f 85 72 03 00 00 44 89 e6 bf 3f 00 00 00 <48> 8b 6b 50 e8 95 20 43 ff 41 80 fc 3f 0f 87 cb 20 ef 07 e8 56 25 > RSP: 0018:ffffc9000399fa00 EFLAGS: 00010246 > RAX: dffffc0000000000 RBX: ffffffffffffff8b RCX: 0000000000000000 > RDX: 1ffffffffffffffb RSI: 000000000000000a RDI: 000000000000003f > RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 > R10: 0000000080000000 R11: 0000000000000001 R12: 000000000000000a > R13: ffff888020936000 R14: dffffc0000000000 R15: ffff8880242a4000 > FS: 0000555555f06380(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffffffffffffffdb CR3: 0000000074f9b000 CR4: 00000000003506e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > __ext4_fill_super fs/ext4/super.c:5391 [inline] > ext4_fill_super+0x85e3/0xade0 fs/ext4/super.c:5643 > get_tree_bdev+0x390/0x630 fs/super.c:1351 > vfs_get_tree+0x88/0x350 fs/super.c:1524 > do_new_mount fs/namespace.c:3335 [inline] > path_mount+0x1492/0x1ed0 fs/namespace.c:3662 > do_mount fs/namespace.c:3675 [inline] > __do_sys_mount fs/namespace.c:3884 [inline] > __se_sys_mount fs/namespace.c:3861 [inline] > __x64_sys_mount+0x293/0x310 fs/namespace.c:3861 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > RIP: 0033:0x7f73494babba > Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 5e 04 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 > RSP: 002b:00007fffae0148e8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 > RAX: ffffffffffffffda RBX: 00007fffae0148f0 RCX: 00007f73494babba > RDX: 00000000200000c0 RSI: 0000000020000040 RDI: 00007fffae0148f0 > RBP: 0000000000000004 R08: 00007fffae014930 R09: 00007fffae014930 > R10: 0000000001000403 R11: 0000000000000202 R12: 00007fffae014930 > R13: 0000000000000003 R14: 0000000000080000 R15: 0000000000000001 > </TASK> > Modules linked in: > CR2: ffffffffffffffdb > ---[ end trace 0000000000000000 ]--- > RIP: 0010:ext4_calculate_overhead+0xfd2/0x1380 fs/ext4/super.c:4182 > Code: 7b 50 48 89 fa 48 c1 ea 03 44 0f b6 60 14 48 b8 00 00 00 00 00 fc ff df 80 3c 02 00 0f 85 72 03 00 00 44 89 e6 bf 3f 00 00 00 <48> 8b 6b 50 e8 95 20 43 ff 41 80 fc 3f 0f 87 cb 20 ef 07 e8 56 25 > RSP: 0018:ffffc9000399fa00 EFLAGS: 00010246 > RAX: dffffc0000000000 RBX: ffffffffffffff8b RCX: 0000000000000000 > RDX: 1ffffffffffffffb RSI: 000000000000000a RDI: 000000000000003f > RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 > R10: 0000000080000000 R11: 0000000000000001 R12: 000000000000000a > R13: ffff888020936000 R14: dffffc0000000000 R15: ffff8880242a4000 > FS: 0000555555f06380(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffffffffffffffdb CR3: 0000000074f9b000 CR4: 00000000003506e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > ---------------- > Code disassembly (best guess): > 0: 7b 50 jnp 0x52 > 2: 48 89 fa mov %rdi,%rdx > 5: 48 c1 ea 03 shr $0x3,%rdx > 9: 44 0f b6 60 14 movzbl 0x14(%rax),%r12d > e: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax > 15: fc ff df > 18: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) > 1c: 0f 85 72 03 00 00 jne 0x394 > 22: 44 89 e6 mov %r12d,%esi > 25: bf 3f 00 00 00 mov $0x3f,%edi > * 2a: 48 8b 6b 50 mov 0x50(%rbx),%rbp <-- trapping instruction > 2e: e8 95 20 43 ff call 0xff4320c8 > 33: 41 80 fc 3f cmp $0x3f,%r12b > 37: 0f 87 cb 20 ef 07 ja 0x7ef2108 > 3d: e8 .byte 0xe8 > 3e: 56 push %rsi > 3f: 25 .byte 0x25 > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > For information about bisection process see: https://goo.gl/tpsmEJ#bisection > > If the bug is already fixed, let syzbot know by replying with: > #syz fix: exact-commit-title > > If you want syzbot to run the reproducer, reply with: > #syz test: git://repo/address.git branch-or-commit-hash > If you attach or paste a git patch, syzbot will apply it before testing. > > If you want to overwrite bug's subsystems, reply with: > #syz set subsystems: new-subsystem > (See the list of subsystem names on the web dashboard) > > If the bug is a duplicate of another bug, reply with: > #syz dup: exact-subject-of-another-report > > If you want to undo deduplication, reply with: > #syz undup > > . >
