Re: [syzbot] Re: [syzbot] [hfs?] general protection fault in hfs_mdb_commit

From: syzbot
Date: Wed Oct 09 2024 - 17:02:57 EST

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Subject: Re: [syzbot] [hfs?] general protection fault in hfs_mdb_commit
Author: sandeen@xxxxxxxxxxx

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git ffcd06b6d13b72823aba0d7c871f7e4876e7916b

On 10/5/24 1:07 AM, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: c02d24a5af66 Add linux-next specific files for 20241003
> git tree: linux-next
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=111f2b9f980000
> kernel config: https://syzkaller.appspot.com/x/.config?x=94f9caf16c0af42d
> dashboard link: https://syzkaller.appspot.com/bug?extid=5cfa9ffce7cc5744fe24
> compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=114be307980000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16bef527980000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/641e642c9432/disk-c02d24a5.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/98aaf20c29e0/vmlinux-c02d24a5.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/c23099f2d86b/bzImage-c02d24a5.xz
> mounted in repro: https://storage.googleapis.com/syzbot-assets/d12a33e3e104/mount_0.gz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+5cfa9ffce7cc5744fe24@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> Oops: general protection fault, probably for non-canonical address 0xdffffc00000000c7: 0000 [#1] PREEMPT SMP KASAN PTI
> KASAN: null-ptr-deref in range [0x0000000000000638-0x000000000000063f]
> CPU: 1 UID: 0 PID: 116 Comm: kworker/1:2 Not tainted 6.12.0-rc1-next-20241003-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
> Workqueue: events_long flush_mdb
> RIP: 0010:hfs_mdb_commit+0x37/0xfd0 fs/hfs/mdb.c:266
> Code: 53 48 83 ec 48 48 89 fb 49 bd 00 00 00 00 00 fc ff df e8 dc 45 0a ff 48 89 5c 24 08 4c 8d a3 38 06 00 00 4c 89 e3 48 c1 eb 03 <42> 80 3c 2b 00 74 08 4c 89 e7 e8 0a 2b 74 ff 4d 8b 34 24 49 8d 6e
> RSP: 0018:ffffc90002d0fb40 EFLAGS: 00010202
> RAX: ffffffff828a89e4 RBX: 00000000000000c7 RCX: ffff88801ef68000
> RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000000
> RBP: ffffc90002d0fdc0 R08: ffff88802e32d1eb R09: 1ffff11005c65a3d
> R10: dffffc0000000000 R11: ffffed1005c65a3e R12: 0000000000000638
> R13: dffffc0000000000 R14: 0000000000000001 R15: 0000000001800000
> FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000055fc5eb2fb50 CR3: 00000000786e8000 CR4: 00000000003526f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> <TASK>
> process_one_work kernel/workqueue.c:3229 [inline]
> process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
> worker_thread+0x870/0xd30 kernel/workqueue.c:3391
> kthread+0x2f0/0x390 kernel/kthread.c:389
> ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
> </TASK>
> Modules linked in:
> ---[ end trace 0000000000000000 ]---
> RIP: 0010:hfs_mdb_commit+0x37/0xfd0 fs/hfs/mdb.c:266
> Code: 53 48 83 ec 48 48 89 fb 49 bd 00 00 00 00 00 fc ff df e8 dc 45 0a ff 48 89 5c 24 08 4c 8d a3 38 06 00 00 4c 89 e3 48 c1 eb 03 <42> 80 3c 2b 00 74 08 4c 89 e7 e8 0a 2b 74 ff 4d 8b 34 24 49 8d 6e
> RSP: 0018:ffffc90002d0fb40 EFLAGS: 00010202
> RAX: ffffffff828a89e4 RBX: 00000000000000c7 RCX: ffff88801ef68000
> RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000000
> RBP: ffffc90002d0fdc0 R08: ffff88802e32d1eb R09: 1ffff11005c65a3d
> R10: dffffc0000000000 R11: ffffed1005c65a3e R12: 0000000000000638
> R13: dffffc0000000000 R14: 0000000000000001 R15: 0000000001800000
> FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000055fc5eb2fb50 CR3: 00000000786e8000 CR4: 00000000003526f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> ----------------
> Code disassembly (best guess):
> 0: 53 push %rbx
> 1: 48 83 ec 48 sub $0x48,%rsp
> 5: 48 89 fb mov %rdi,%rbx
> 8: 49 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%r13
> f: fc ff df
> 12: e8 dc 45 0a ff call 0xff0a45f3
> 17: 48 89 5c 24 08 mov %rbx,0x8(%rsp)
> 1c: 4c 8d a3 38 06 00 00 lea 0x638(%rbx),%r12
> 23: 4c 89 e3 mov %r12,%rbx
> 26: 48 c1 eb 03 shr $0x3,%rbx
> * 2a: 42 80 3c 2b 00 cmpb $0x0,(%rbx,%r13,1) <-- trapping instruction
> 2f: 74 08 je 0x39
> 31: 4c 89 e7 mov %r12,%rdi
> 34: e8 0a 2b 74 ff call 0xff742b43
> 39: 4d 8b 34 24 mov (%r12),%r14
> 3d: 49 rex.WB
> 3e: 8d .byte 0x8d
> 3f: 6e outsb %ds:(%rsi),(%dx)
>
>
> ---
> 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.
>
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>
> If the report is already addressed, let syzbot know by replying with:
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>
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>
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>
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