[v5.15] Internal error in clear_rseq_cs

[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=1168d5bc580000
kernel config: https://syzkaller.appspot.com/x/.config?x=9e47345638b85bd0
dashboard link: https://syzkaller.appspot.com/bug?extid=10d5584e36b745fe53f5
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+10d558...@syzkaller.appspotmail.com

Internal error: Oops - BTI: 0000000036000001 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 4364 Comm: syz.2.91 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 : clear_rseq_cs+0xf8/0x140 kernel/rseq.c:-1
lr : __uaccess_mask_ptr arch/arm64/include/asm/uaccess.h:244 [inline]
lr : clear_rseq_cs+0xd8/0x140 kernel/rseq.c:242
sp : ffff80001fb97cd0
x29: ffff80001fb97cd0 x28: ffff0000cd330000 x27: 0000002000040800
x26: 1fffe00019a6628d x25: dfff800000000000 x24: 0000000000000000
x23: 0000000000400040 x22: dfff800000000000 x21: 0000002000040800
x20: 0000000020000408 x19: 0000000000000001 x18: 0000000000000000
x17: 0000000000000000 x16: ffff800008659ec8 x15: 0000000000000000
x14: 0000000000000000 x13: 1ffff0000282e06b x12: 0000000000080000
x11: 0000000020000408 x10: 0000ffffffffffff x9 : 0000000020000408
x8 : 0000000000000000 x7 : ffff800008750ed4 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000001
x2 : 0000000000000008 x1 : 0000000000000001 x0 : 00000000fffffff2
Call trace:
clear_rseq_cs+0xf8/0x140 kernel/rseq.c:242
__do_sys_rseq kernel/rseq.c:410 [inline]
__se_sys_rseq kernel/rseq.c:350 [inline]
__arm64_sys_rseq+0x444/0x75c kernel/rseq.c:350
__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: 9a9f028b d503229f aa1f03e8 f8000968 (14000003)
---[ end trace bb59c8c6f424dbe7 ]---
----------------
Code disassembly (best guess):
0: 9a9f028b csel x11, x20, xzr, eq // eq = none
4: d503229f csdb
8: aa1f03e8 mov x8, xzr
c: f8000968 sttr x8, [x11]
* 10: 14000003 b 0x1c <-- trapping instruction


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.