[v6.1] BUG: unable to handle kernel paging request in btrfs_root_node

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 7ec6f9fa3d97 Linux 6.1.114
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=175a5230580000
kernel config: https://syzkaller.appspot.com/x/.config?x=344cdb747ab79921
dashboard link: https://syzkaller.appspot.com/bug?extid=83f9d214f99a8c47f5a3
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e7551ab2b38b/disk-7ec6f9fa.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/99ca69a69b01/vmlinux-7ec6f9fa.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0d62742f11c2/Image-7ec6f9fa.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+83f9d2...@syzkaller.appspotmail.com

BTRFS info (device loop2): enabling ssd optimizations
Unable to handle kernel paging request at virtual address dfff800000000003
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
Mem abort info:
ESR = 0x0000000096000006
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x06: level 2 translation fault
Data abort info:
ISV = 0, ISS = 0x00000006
CM = 0, WnR = 0
[dfff800000000003] address between user and kernel address ranges
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 6507 Comm: syz.2.323 Not tainted 6.1.114-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : btrfs_root_node+0xe0/0x3c8 fs/btrfs/ctree.c:148
lr : rcu_read_lock include/linux/rcupdate.h:792 [inline]
lr : btrfs_root_node+0x88/0x3c8 fs/btrfs/ctree.c:147
sp : ffff8000235471d0
x29: ffff8000235471d0 x28: dfff800000000000 x27: ffff8000127d4a20
x26: 0000000000000001 x25: ffff8000127d5140 x24: 0000000000000003
x23: ffff8000127d5180 x22: ffff80001833c000 x21: 0000000000000001
x20: ffff80001833c000 x19: 0000000000000018 x18: 1fffe000367a3376
x17: ffff8000159cd000 x16: ffff800012290d3c x15: ffff800008ad5000
x14: 1ffff00002b3a0b0 x13: dfff800000000000 x12: 0000000000040000
x11: 000000000003ffff x10: ffff80002249f000 x9 : ffff80000a0a1344
x8 : 0000000000040000 x7 : ffff80000a0b4da4 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000002
x2 : 0000000000000008 x1 : ffff8000128c83e0 x0 : 0000000000000001
Call trace:
rcu_read_lock include/linux/rcupdate.h:792 [inline]
btrfs_root_node+0xe0/0x3c8 fs/btrfs/ctree.c:147
btrfs_read_lock_root_node+0x6c/0x350 fs/btrfs/locking.c:277
btrfs_build_ref_tree+0xe8/0x1220 fs/btrfs/ref-verify.c:994
open_ctree+0x1d48/0x2340 fs/btrfs/disk-io.c:3810
btrfs_fill_super+0x1b4/0x2c8 fs/btrfs/super.c:1469
btrfs_mount_root+0x6f8/0x7f8 fs/btrfs/super.c:1835
legacy_get_tree+0xd4/0x16c fs/fs_context.c:632
vfs_get_tree+0x90/0x274 fs/super.c:1573
fc_mount fs/namespace.c:1043 [inline]
vfs_kern_mount+0xdc/0x178 fs/namespace.c:1073
btrfs_mount+0x330/0x9c8 fs/btrfs/super.c:1895
legacy_get_tree+0xd4/0x16c fs/fs_context.c:632
vfs_get_tree+0x90/0x274 fs/super.c:1573
do_new_mount+0x278/0x8fc fs/namespace.c:3056
path_mount+0x590/0xe5c fs/namespace.c:3386
do_mount fs/namespace.c:3399 [inline]
__do_sys_mount fs/namespace.c:3607 [inline]
__se_sys_mount fs/namespace.c:3584 [inline]
__arm64_sys_mount+0x45c/0x594 fs/namespace.c:3584
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
Code: 52806321 aa1703e2 390d82da 9789cacb (387c6b08)
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
0: 52806321 mov w1, #0x319 // #793
4: aa1703e2 mov x2, x23
8: 390d82da strb w26, [x22, #864]
c: 9789cacb bl 0xfffffffffe272b38
* 10: 387c6b08 ldrb w8, [x24, x28] <-- trapping instruction


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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 7ec6f9fa3d97 Linux 6.1.114
git tree: linux-6.1.y

console output: https://syzkaller.appspot.com/x/log.txt?x=124e2940580000

kernel config: https://syzkaller.appspot.com/x/.config?x=344cdb747ab79921
dashboard link: https://syzkaller.appspot.com/bug?extid=83f9d214f99a8c47f5a3
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12c9cca7980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1429ea87980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e7551ab2b38b/disk-7ec6f9fa.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/99ca69a69b01/vmlinux-7ec6f9fa.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0d62742f11c2/Image-7ec6f9fa.gz.xz

mounted in repro: https://storage.googleapis.com/syzbot-assets/4fa7539f0c52/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+83f9d2...@syzkaller.appspotmail.com

BTRFS info (device loop0): enabling ssd optimizations

Unable to handle kernel paging request at virtual address dfff800000000003
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
Mem abort info:
ESR = 0x0000000096000006
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x06: level 2 translation fault
Data abort info:
ISV = 0, ISS = 0x00000006
CM = 0, WnR = 0
[dfff800000000003] address between user and kernel address ranges
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:

CPU: 0 PID: 4290 Comm: syz-executor333 Not tainted 6.1.114-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024

pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)

pc : btrfs_root_node+0xe0/0x3c8 fs/btrfs/ctree.c:148
lr : rcu_read_lock include/linux/rcupdate.h:792 [inline]
lr : btrfs_root_node+0x88/0x3c8 fs/btrfs/ctree.c:147

sp : ffff800020fa71d0
x29: ffff800020fa71d0 x28: dfff800000000000 x27: ffff8000127d4a20

x26: 0000000000000001 x25: ffff8000127d5140 x24: 0000000000000003
x23: ffff8000127d5180 x22: ffff80001833c000 x21: 0000000000000001

x20: ffff80001833c000 x19: 0000000000000018 x18: 1fffe0003679f176
x17: 0000000000000000 x16: ffff800012290d3c x15: ffff800008ad5000
x14: 1ffff00002b3a0b0 x13: dfff800000000000 x12: 00000000829d4c0d
x11: 0000000000ff0100 x10: 0000000000000000 x9 : ffff80000a0a1344
x8 : ffff0000d9311bc0 x7 : ffff80000a0b4da4 x6 : 0000000000000000

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