[v5.15] Internal error in fscrypt_ioctl_set_policy

[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=12b73ea2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=9e47345638b85bd0
dashboard link: https://syzkaller.appspot.com/bug?extid=d7c1b7aef2b6ac48365e
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+d7c1b7...@syzkaller.appspotmail.com

EXT4-fs (loop1): mounted filesystem without journal. Opts: ,errors=continue. Quota mode: none.
Internal error: Oops - BTI: 0000000036000001 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 4466 Comm: syz.1.126 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 : fscrypt_ioctl_set_policy+0x188/0x5b8 fs/crypto/policy.c:445
lr : fscrypt_ioctl_set_policy+0x164/0x5b8 fs/crypto/policy.c:445
sp : ffff800020117780
x29: ffff800020117860 x28: ffff0000e9c302a0 x27: 0000000000000000
x26: ffff700004022ef4 x25: ffff0000dc232280 x24: 00000000fffffff2
x23: ffff0000cb56d1e4 x22: ffff0000cb56d1c0 x21: 0000000000000000
x20: 0000000000000000 x19: 1fffe000196ada3c x18: 0000000000000000
x17: 0000000000000002 x16: ffff800008a3b6bc x15: 00000000c0c0583b
x14: 0000000000ff0100 x13: 1ffff0000282e06b x12: 0000000000ff0100
x11: 0000000000000000 x10: 0000000000000002 x9 : 0000000000000000
x8 : 0000ffffffffffff x7 : ffff800008750ed4 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000001
x2 : 0000000000000008 x1 : 0000000000000001 x0 : 0000000000000000
Call trace:
fscrypt_ioctl_set_policy+0x188/0x5b8 fs/crypto/policy.c:445
__ext4_ioctl fs/ext4/ioctl.c:1144 [inline]
ext4_ioctl+0x10bc/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 2a1f03f8 2a1f03e0 38400934 (2a1803e1)
---[ end trace 35b8c44d0bc83466 ]---
----------------
Code disassembly (best guess):
0: d503229f csdb
4: 2a1f03f8 mov w24, wzr
8: 2a1f03e0 mov w0, wzr
c: 38400934 ldtrb w20, [x9]
* 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=16ffc9a2580000

kernel config: https://syzkaller.appspot.com/x/.config?x=9e47345638b85bd0
dashboard link: https://syzkaller.appspot.com/bug?extid=d7c1b7aef2b6ac48365e
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=10a899a2580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14a899a2580000

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/aafd9498e90c/mount_0.gz
fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=172899a2580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d7c1b7...@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 128
EXT4-fs (loop0): mounted filesystem without journal. Opts: ,errors=continue. Quota mode: none.

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

CPU: 1 PID: 4225 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 : fscrypt_ioctl_set_policy+0x188/0x5b8 fs/crypto/policy.c:445
lr : fscrypt_ioctl_set_policy+0x164/0x5b8 fs/crypto/policy.c:445

sp : ffff80001f7b7780
x29: ffff80001f7b7860 x28: ffff0000e29eb478 x27: 0000000000000000
x26: ffff700003ef6ef4 x25: ffff0000d012a780 x24: 00000000fffffff2
x23: ffff0000d5da0024 x22: ffff0000d5da0000 x21: 0000000000000000
x20: 0000000000000000 x19: 1fffe0001abb4004 x18: 0000000000000000
x17: 0000000000000000 x16: ffff800008a3b6bc x15: 00000000c0c0583b

x14: 0000000000ff0100 x13: 1ffff0000282e06b x12: 0000000000ff0100

x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000

x8 : 0000ffffffffffff x7 : ffff800008750ed4 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000001
x2 : 0000000000000008 x1 : 0000000000000001 x0 : 0000000000000000
Call trace:
fscrypt_ioctl_set_policy+0x188/0x5b8 fs/crypto/policy.c:445
__ext4_ioctl fs/ext4/ioctl.c:1144 [inline]
ext4_ioctl+0x10bc/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 2a1f03f8 2a1f03e0 38400934 (2a1803e1)

---[ end trace f972b3ecc2e0dbe1 ]---

----------------
Code disassembly (best guess):
0: d503229f csdb
4: 2a1f03f8 mov w24, wzr
8: 2a1f03e0 mov w0, wzr
c: 38400934 ldtrb w20, [x9]
* 10: 2a1803e1 mov w1, w24 <-- trapping instruction


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