[syzbot] [btrfs?] general protection fault in write_all_supers

From: syzbot
Date: Tue Sep 10 2024 - 18:11:36 EST

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Hello,

syzbot found the following issue on:

HEAD commit: b831f83e40a2 Merge tag 'bpf-6.11-rc7' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1197909f980000
kernel config: https://syzkaller.appspot.com/x/.config?x=660f6eb11f9c7dc5
dashboard link: https://syzkaller.appspot.com/bug?extid=56360f93efa90ff15870
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=14ccaffb980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=107d03c7980000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-b831f83e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ab02bf22935d/vmlinux-b831f83e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c1101078451d/bzImage-b831f83e.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/6d79e1e6aae6/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+56360f93efa90ff15870@xxxxxxxxxxxxxxxxxxxxxxxxx

BTRFS info (device loop0 state MCS): disabling free space tree
BTRFS info (device loop0 state MCS): clearing compat-ro feature flag for FREE_SPACE_TREE (0x1)
BTRFS info (device loop0 state MCS): clearing compat-ro feature flag for FREE_SPACE_TREE_VALID (0x2)
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
CPU: 0 UID: 0 PID: 5101 Comm: syz-executor285 Not tainted 6.11.0-rc6-syzkaller-00183-gb831f83e40a2 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:backup_super_roots fs/btrfs/disk-io.c:1691 [inline]
RIP: 0010:write_all_supers+0x97a/0x40f0 fs/btrfs/disk-io.c:4041
Code: 00 00 00 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 8a 34 00 00 44 88 33 48 8b 5c 24 10 48 83 c3 18 49 89 df 49 c1 ef 03 <43> 80 3c 2f 00 74 08 48 89 df e8 17 b6 4b fe 48 89 5c 24 10 48 8b
RSP: 0018:ffffc90002d3f040 EFLAGS: 00010206
RAX: 0000000000000000 RBX: 0000000000000018 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff888035eeaa80
RBP: ffffc90002d3f3f0 R08: ffff88803d48806b R09: 1ffff11007a9100d
R10: dffffc0000000000 R11: ffffed1007a9100e R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000003
FS: 0000555594a77380(0000) GS:ffff88801fe00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056349cf20668 CR3: 000000003f9f4000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
btrfs_commit_transaction+0x1eae/0x3740 fs/btrfs/transaction.c:2530
btrfs_delete_free_space_tree+0x383/0x730 fs/btrfs/free-space-tree.c:1312
btrfs_start_pre_rw_mount+0xf28/0x1300 fs/btrfs/disk-io.c:3012
btrfs_remount_rw fs/btrfs/super.c:1309 [inline]
btrfs_reconfigure+0xae6/0x2d40 fs/btrfs/super.c:1534
btrfs_reconfigure_for_mount fs/btrfs/super.c:2020 [inline]
btrfs_get_tree_subvol fs/btrfs/super.c:2079 [inline]
btrfs_get_tree+0x918/0x1920 fs/btrfs/super.c:2115
vfs_get_tree+0x90/0x2b0 fs/super.c:1800
do_new_mount+0x2be/0xb40 fs/namespace.c:3472
do_mount fs/namespace.c:3812 [inline]
__do_sys_mount fs/namespace.c:4020 [inline]
__se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3997
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb7b8916e99
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007ffe5c5484c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007fb7b8916e99
RDX: 0000000020000280 RSI: 0000000020000180 RDI: 0000000020000100
RBP: 00007fb7b89905f0 R08: 0000000000000000 R09: 0000555594a784c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe5c5484f0
R13: 00007ffe5c548718 R14: 431bde82d7b634db R15: 00007fb7b896003b
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:backup_super_roots fs/btrfs/disk-io.c:1691 [inline]
RIP: 0010:write_all_supers+0x97a/0x40f0 fs/btrfs/disk-io.c:4041
Code: 00 00 00 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 8a 34 00 00 44 88 33 48 8b 5c 24 10 48 83 c3 18 49 89 df 49 c1 ef 03 <43> 80 3c 2f 00 74 08 48 89 df e8 17 b6 4b fe 48 89 5c 24 10 48 8b
RSP: 0018:ffffc90002d3f040 EFLAGS: 00010206
RAX: 0000000000000000 RBX: 0000000000000018 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff888035eeaa80
RBP: ffffc90002d3f3f0 R08: ffff88803d48806b R09: 1ffff11007a9100d
R10: dffffc0000000000 R11: ffffed1007a9100e R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000003
FS: 0000555594a77380(0000) GS:ffff88801fe00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f731263196e CR3: 000000003f9f4000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 00 48 89 add %cl,-0x77(%rax)
5: d8 48 c1 fmuls -0x3f(%rax)
8: e8 03 42 0f b6 call 0xb60f4210
d: 04 28 add $0x28,%al
f: 84 c0 test %al,%al
11: 0f 85 8a 34 00 00 jne 0x34a1
17: 44 88 33 mov %r14b,(%rbx)
1a: 48 8b 5c 24 10 mov 0x10(%rsp),%rbx
1f: 48 83 c3 18 add $0x18,%rbx
23: 49 89 df mov %rbx,%r15
26: 49 c1 ef 03 shr $0x3,%r15
* 2a: 43 80 3c 2f 00 cmpb $0x0,(%r15,%r13,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 48 89 df mov %rbx,%rdi
34: e8 17 b6 4b fe call 0xfe4bb650
39: 48 89 5c 24 10 mov %rbx,0x10(%rsp)
3e: 48 rex.W
3f: 8b .byte 0x8b

---
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Next message: John Stultz: "[RESEND x2][PATCH v12 0/7] Preparatory changes for Proxy Execution v12"
Previous message: Rosen Penev: "[PATCHv2 net-next] net: gianfar: fix NVMEM mac address"
Next in thread: Lizhi Xu: "Re: [syzbot] [btrfs?] general protection fault in write_all_supers"
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