[v5.15] Internal error in fsverity_ioctl_measure

[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=1215e9a2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=9e47345638b85bd0
dashboard link: https://syzkaller.appspot.com/bug?extid=f6fb2bed5efddfc57f66
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+f6fb2b...@syzkaller.appspotmail.com

EXT4-fs (loop1): mounted filesystem without journal. Opts: ,errors=continue. Quota mode: none.
fs-verity: sha512 using implementation "sha512-ce"
Internal error: Oops - BTI: 0000000036000001 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 4396 Comm: syz.1.82 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 : fsverity_ioctl_measure+0x1b4/0x564 fs/verity/measure.c:42
lr : fsverity_ioctl_measure+0x190/0x564 fs/verity/measure.c:42
sp : ffff8000203677e0
x29: ffff800020367860 x28: ffff800014448ec0 x27: 1ffff0000406cf00
x26: dfff800000000000 x25: 0000000000000200 x24: 0000000000000000
x23: 00000000fffffff2 x22: ffff0000cd8eb6a4 x21: ffff0000cd8eb680
x20: 0000000000000000 x19: ffff0000cce5c000 x18: 0000000000000000
x17: 0000000000000002 x16: ffff800008a41fdc x15: 00000000c0c0583b
x14: 0000000000ff0100 x13: 1ffff0000282e06b x12: 0000000000ff0100
x11: 0000000000000000 x10: 0000000000000002 x9 : 0000ffffffffffff
x8 : 0000000000000002 x7 : ffff800008750ed4 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000001
x2 : 0000000000000008 x1 : 0000000000000001 x0 : 0000000000000000
Call trace:
fsverity_ioctl_measure+0x1b4/0x564 fs/verity/measure.c:42
__ext4_ioctl fs/ext4/ioctl.c:1264 [inline]
ext4_ioctl+0x10d0/0x3614 fs/ext4/ioctl.c:1282
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 2a1f03f7 2a1f03e0 78400958 (2a1703e1)
---[ end trace cdd5c677a61a236b ]---
----------------
Code disassembly (best guess):
0: d503229f csdb
4: 2a1f03f7 mov w23, wzr
8: 2a1f03e0 mov w0, wzr
c: 78400958 ldtrh w24, [x10]
* 10: 2a1703e1 mov w1, w23 <-- 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=1623ac34580000

kernel config: https://syzkaller.appspot.com/x/.config?x=9e47345638b85bd0
dashboard link: https://syzkaller.appspot.com/bug?extid=f6fb2bed5efddfc57f66
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=105acda2580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1082f5a2580000

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/736b8df40e5a/mount_0.gz
fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=179acda2580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f6fb2b...@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 2048
EXT4-fs (loop0): mounted filesystem without journal. Opts: ,errors=continue. Quota mode: none.

fs-verity: sha512 using implementation "sha512-ce"
Internal error: Oops - BTI: 0000000036000001 [#1] PREEMPT SMP
Modules linked in:

CPU: 0 PID: 4209 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 : fsverity_ioctl_measure+0x1b4/0x564 fs/verity/measure.c:42
lr : fsverity_ioctl_measure+0x190/0x564 fs/verity/measure.c:42

sp : ffff80001fc677e0
x29: ffff80001fc67860 x28: ffff800014448ec0 x27: 1ffff00003f8cf00

x26: dfff800000000000 x25: 0000000000000200 x24: 0000000000000000

x23: 00000000fffffff2 x22: ffff0000ccc69b64 x21: ffff0000ccc69b40
x20: 0000000000000000 x19: ffff0000dd7d9000 x18: 0000000000000000
x17: 0000000000000000 x16: ffff800008a41fdc x15: 00000000c0c0583b

x14: 0000000000ff0100 x13: 1ffff0000282e06b x12: 0000000000ff0100
x11: 0000000000000000 x10: 0000000000000002 x9 : 0000ffffffffffff
x8 : 0000000000000002 x7 : ffff800008750ed4 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000001
x2 : 0000000000000008 x1 : 0000000000000001 x0 : 0000000000000000
Call trace:
fsverity_ioctl_measure+0x1b4/0x564 fs/verity/measure.c:42
__ext4_ioctl fs/ext4/ioctl.c:1264 [inline]
ext4_ioctl+0x10d0/0x3614 fs/ext4/ioctl.c:1282
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 2a1f03f7 2a1f03e0 78400958 (2a1703e1)

---[ end trace e711ce646d396779 ]---

----------------
Code disassembly (best guess):
0: d503229f csdb
4: 2a1f03f7 mov w23, wzr
8: 2a1f03e0 mov w0, wzr
c: 78400958 ldtrh w24, [x10]
* 10: 2a1703e1 mov w1, w23 <-- trapping instruction


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