[v5.15] Internal error in fault_in_writeable

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c79648372d02 Linux 5.15.189
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=103be5a2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=9e47345638b85bd0
dashboard link: https://syzkaller.appspot.com/bug?extid=6ea090b57a4a81675d17
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7ab49562317a/disk-c7964837.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e847ec1e38d3/vmlinux-c7964837.xz
kernel image: https://storage.googleapis.com/syzbot-assets/263158c6371c/Image-c7964837.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6ea090...@syzkaller.appspotmail.com

Internal error: Oops - BTI: 0000000036000001 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 4241 Comm: syz.2.26 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 42400405 (nZcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=jc)
pc : fault_in_writeable+0x254/0x324 mm/gup.c:1721
lr : fault_in_writeable+0x234/0x324 mm/gup.c:1721
sp : ffff8000200a79b0
x29: ffff8000200a79c0 x28: 0000002100000000 x27: 0000000021002000
x26: 0000000021000000 x25: 0000000021000000 x24: 00000000fffffff2
x23: 1fffe0001baed6d0 x22: ffff0000dd76b680 x21: 0000000000000000
x20: 0000000021000000 x19: dfff800000000000 x18: 0000000000000000
x17: 0000000000000002 x16: ffff800008733858 x15: 00000000ffffffef
x14: 0000000000ff0100 x13: 1ffff0000282e06b x12: 0000000000ff0100
x11: 0000000000000000 x10: 0000000000000002 x9 : 0000ffffffffffff
x8 : 0000000021000000 x7 : ffff800008750ed4 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000001
x2 : 0000000000000008 x1 : 0000000000000001 x0 : 0000000000000000
Call trace:
fault_in_writeable+0x254/0x324 mm/gup.c:1721
search_ioctl+0x348/0x4d8 fs/btrfs/ioctl.c:2278
btrfs_ioctl_tree_search_v2+0x244/0x4f8 fs/btrfs/ioctl.c:2362
btrfs_ioctl+0x2c4/0xb38 fs/btrfs/ioctl.c:4975
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:860
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Code: d503229f 2a1503f8 2a1503e0 38000915 (2a1803e1)
---[ end trace 7848d8a39ac127da ]---
----------------
Code disassembly (best guess):
0: d503229f csdb
4: 2a1503f8 mov w24, w21
8: 2a1503e0 mov w0, w21
c: 38000915 sttrb w21, [x8]
* 10: 2a1803e1 mov w1, w24 <-- trapping instruction


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: c79648372d02 Linux 5.15.189
git tree: linux-5.15.y

console output: https://syzkaller.appspot.com/x/log.txt?x=11b77a34580000

kernel config: https://syzkaller.appspot.com/x/.config?x=9e47345638b85bd0
dashboard link: https://syzkaller.appspot.com/bug?extid=6ea090b57a4a81675d17
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
userspace arch: arm64

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=149ab862580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15b77a34580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7ab49562317a/disk-c7964837.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e847ec1e38d3/vmlinux-c7964837.xz
kernel image: https://storage.googleapis.com/syzbot-assets/263158c6371c/Image-c7964837.gz.xz

mounted in repro: https://storage.googleapis.com/syzbot-assets/8732153bc1f0/mount_0.gz
fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=109ab862580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6ea090...@syzkaller.appspotmail.com

BTRFS info (device loop0): using sha256 (sha256-ce) checksum algorithm
BTRFS info (device loop0): using free space tree
BTRFS info (device loop0): has skinny extents
BTRFS info (device loop0): enabling ssd optimizations

Internal error: Oops - BTI: 0000000036000001 [#1] PREEMPT SMP
Modules linked in:

CPU: 0 PID: 4230 Comm: syz.0.17 Not tainted 5.15.189-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 42400405 (nZcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=jc)
pc : fault_in_writeable+0x254/0x324 mm/gup.c:1721
lr : fault_in_writeable+0x234/0x324 mm/gup.c:1721

sp : ffff80001fdb79b0
x29: ffff80001fdb79c0 x28: 0000002100000000 x27: 0000000021001000

x26: 0000000021000000 x25: 0000000021000000 x24: 00000000fffffff2

x23: 1fffe0001ae22a38 x22: ffff0000d71151c0 x21: 0000000000000000

x20: 0000000021000000 x19: dfff800000000000 x18: 0000000000000000

x17: ffff800008921238 x16: ffff800008733858 x15: ffff800009f19ca8
x14: ffff800009f24dfc x13: 1ffff0000282e06b x12: 0000000000ff0100
x11: 0000000000000000 x10: 0000000000000000 x9 : 0000ffffffffffff

x8 : 0000000021000000 x7 : ffff800008750ed4 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000001
x2 : 0000000000000008 x1 : 0000000000000001 x0 : 0000000000000000
Call trace:
fault_in_writeable+0x254/0x324 mm/gup.c:1721
search_ioctl+0x348/0x4d8 fs/btrfs/ioctl.c:2278
btrfs_ioctl_tree_search_v2+0x244/0x4f8 fs/btrfs/ioctl.c:2362
btrfs_ioctl+0x2c4/0xb38 fs/btrfs/ioctl.c:4975
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:860
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Code: d503229f 2a1503f8 2a1503e0 38000915 (2a1803e1)

---[ end trace 80402b989d2680bc ]---

----------------
Code disassembly (best guess):
0: d503229f csdb
4: 2a1503f8 mov w24, w21
8: 2a1503e0 mov w0, w21
c: 38000915 sttrb w21, [x8]
* 10: 2a1803e1 mov w1, w24 <-- trapping instruction


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