From: Andrew Price <anprice@redhat.com>
To: syzbot <syzbot+74edb1a3ea8f1c65a086@syzkaller.appspotmail.com>,
agruenba@redhat.com, gfs2@lists.linux.dev,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [gfs2?] general protection fault in gfs2_rindex_update
Date: Fri, 9 Feb 2024 16:10:19 +0000 [thread overview]
Message-ID: <affa6134-de19-4b73-9925-f42d3c7c9b8b@redhat.com> (raw)
In-Reply-To: <000000000000c091060610dbd67b@google.com>
On 08/02/2024 09:57, syzbot wrote:
> syzbot has found a reproducer for the following issue on:
>
> HEAD commit: 547ab8fc4cb0 Merge tag 'loongarch-fixes-6.8-2' of git://gi..
> git tree: upstream
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=150285d4180000
> kernel config: https://syzkaller.appspot.com/x/.config?x=89a5d896b14c4565
> dashboard link: https://syzkaller.appspot.com/bug?extid=74edb1a3ea8f1c65a086
> 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=11395147e80000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=126ff68fe80000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/a8d318be4c39/disk-547ab8fc.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/8178462cbfb5/vmlinux-547ab8fc.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/62939e7c5fbb/bzImage-547ab8fc.xz
> mounted in repro: https://storage.googleapis.com/syzbot-assets/93eefe621564/mount_0.gz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+74edb1a3ea8f1c65a086@syzkaller.appspotmail.com
>
> loop0: detected capacity change from 0 to 32768
> gfs2: fsid=syz:syz: Trying to join cluster "lock_nolock", "syz:syz"
> gfs2: fsid=syz:syz: Now mounting FS (format 1801)...
> gfs2: fsid=syz:syz.0: journal 0 mapped with 20 extents in 0ms
> general protection fault, probably for non-canonical address 0xdffffc0000000097: 0000 [#1] PREEMPT SMP KASAN PTI
> KASAN: null-ptr-deref in range [0x00000000000004b8-0x00000000000004bf]
> CPU: 0 PID: 5058 Comm: syz-executor337 Not tainted 6.8.0-rc3-syzkaller-00041-g547ab8fc4cb0 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
> RIP: 0010:gfs2_rindex_update+0xbc/0x3d0 fs/gfs2/rgrp.c:1037
> Code: e8 f9 65 1d fe 4c 8d 74 24 60 48 8b 03 48 89 44 24 38 48 8d 98 b8 04 00 00 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 df e8 c6 65 1d fe 48 8b 03 48 89 44 24 20
> RSP: 0018:ffffc900040671a0 EFLAGS: 00010202
> RAX: 0000000000000097 RBX: 00000000000004b8 RCX: dffffc0000000000
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88807f558000
> RBP: ffffc900040672b0 R08: ffffffff83cb50d7 R09: 1ffff1100f02e2f8
> R10: dffffc0000000000 R11: ffffed100f02e2f9 R12: 1ffff9200080ce3c
> R13: ffff88807f558000 R14: ffffc90004067200 R15: 0000000000000001
> FS: 0000555555a0f380(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000056427a53bb08 CR3: 0000000022d54000 CR4: 00000000003506f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> <TASK>
> punch_hole+0xe7b/0x3a30 fs/gfs2/bmap.c:1809
> gfs2_truncatei_resume+0x3c/0x70 fs/gfs2/bmap.c:2159
The fuzzer is setting GFS2_DIF_TRUNC_IN_PROG on the
per_node/statfs_change0 'system' inode (it's setting all of the di_flags
bits but that is the relevant one) which sends us down this resume
truncation path in inode_go_held(), before the rindex has been
initialised in init_inodes().
Is there a better solution than returning an error on the
(sdp->sd_rindex == NULL) case in gfs2_rindex_update()?
Andy
> gfs2_glock_holder_ready fs/gfs2/glock.c:1336 [inline]
> gfs2_glock_wait+0x1df/0x2b0 fs/gfs2/glock.c:1356
> gfs2_glock_nq_init fs/gfs2/glock.h:238 [inline]
> init_statfs fs/gfs2/ops_fstype.c:694 [inline]
> init_journal+0x1680/0x23f0 fs/gfs2/ops_fstype.c:816
> init_inodes+0xdc/0x320 fs/gfs2/ops_fstype.c:884
> gfs2_fill_super+0x1edb/0x26c0 fs/gfs2/ops_fstype.c:1263
> get_tree_bdev+0x3f7/0x570 fs/super.c:1619
> gfs2_get_tree+0x54/0x220 fs/gfs2/ops_fstype.c:1341
> vfs_get_tree+0x90/0x2a0 fs/super.c:1784
> do_new_mount+0x2be/0xb40 fs/namespace.c:3352
> do_mount fs/namespace.c:3692 [inline]
> __do_sys_mount fs/namespace.c:3898 [inline]
> __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3875
> do_syscall_64+0xf9/0x240
> entry_SYSCALL_64_after_hwframe+0x6f/0x77
> RIP: 0033:0x7fe98b1e18ba
> 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:00007ffe3b0f9eb8 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
> RAX: ffffffffffffffda RBX: 00007ffe3b0f9ec0 RCX: 00007fe98b1e18ba
> RDX: 0000000020000040 RSI: 0000000020000100 RDI: 00007ffe3b0f9ec0
> RBP: 0000000000000004 R08: 00007ffe3b0f9f00 R09: 0000000000012783
> R10: 0000000000008c1b R11: 0000000000000282 R12: 00007ffe3b0f9f00
> R13: 0000000000000003 R14: 0000000001000000 R15: 0000000000000001
> </TASK>
> Modules linked in:
> ---[ end trace 0000000000000000 ]---
> RIP: 0010:gfs2_rindex_update+0xbc/0x3d0 fs/gfs2/rgrp.c:1037
> Code: e8 f9 65 1d fe 4c 8d 74 24 60 48 8b 03 48 89 44 24 38 48 8d 98 b8 04 00 00 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 df e8 c6 65 1d fe 48 8b 03 48 89 44 24 20
> RSP: 0018:ffffc900040671a0 EFLAGS: 00010202
> RAX: 0000000000000097 RBX: 00000000000004b8 RCX: dffffc0000000000
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88807f558000
> RBP: ffffc900040672b0 R08: ffffffff83cb50d7 R09: 1ffff1100f02e2f8
> R10: dffffc0000000000 R11: ffffed100f02e2f9 R12: 1ffff9200080ce3c
> R13: ffff88807f558000 R14: ffffc90004067200 R15: 0000000000000001
> FS: 0000555555a0f380(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000056427a53bb08 CR3: 0000000022d54000 CR4: 00000000003506f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> ----------------
> Code disassembly (best guess):
> 0: e8 f9 65 1d fe call 0xfe1d65fe
> 5: 4c 8d 74 24 60 lea 0x60(%rsp),%r14
> a: 48 8b 03 mov (%rbx),%rax
> d: 48 89 44 24 38 mov %rax,0x38(%rsp)
> 12: 48 8d 98 b8 04 00 00 lea 0x4b8(%rax),%rbx
> 19: 48 89 d8 mov %rbx,%rax
> 1c: 48 c1 e8 03 shr $0x3,%rax
> 20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx
> 27: fc ff df
> * 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction
> 2e: 74 08 je 0x38
> 30: 48 89 df mov %rbx,%rdi
> 33: e8 c6 65 1d fe call 0xfe1d65fe
> 38: 48 8b 03 mov (%rbx),%rax
> 3b: 48 89 44 24 20 mov %rax,0x20(%rsp)
>
>
> ---
> 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.
>
next prev parent reply other threads:[~2024-02-09 16:10 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-08 9:52 [syzbot] [gfs2?] general protection fault in gfs2_rindex_update syzbot
2024-02-08 9:57 ` syzbot
2024-02-09 16:10 ` Andrew Price [this message]
2024-02-08 14:57 ` syzbot
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