syzbot


Internal error in __rseq_handle_notify_resume

Status: upstream: reported C repro on 2025/08/12 10:10
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+b435439693ca168abb6f@syzkaller.appspotmail.com
First crash: 7d02h, last: 1d09h
Bug presence (2)
Date Name Commit Repro Result
2025/08/16 linux-5.15.y (ToT) c79648372d02 C [report] Internal error in __rseq_handle_notify_resume
2025/08/16 upstream (ToT) dfd4b508c8c6 C Didn't crash

Sample crash report:
Internal error: Oops - BTI: 0000000036000001 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 4264 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 : clear_rseq_cs kernel/rseq.c:-1 [inline]
pc : rseq_ip_fixup kernel/rseq.c:276 [inline]
pc : __rseq_handle_notify_resume+0x89c/0x1604 kernel/rseq.c:314
lr : __uaccess_mask_ptr arch/arm64/include/asm/uaccess.h:244 [inline]
lr : clear_rseq_cs kernel/rseq.c:242 [inline]
lr : rseq_ip_fixup kernel/rseq.c:276 [inline]
lr : __rseq_handle_notify_resume+0x87c/0x1604 kernel/rseq.c:314
sp : ffff8000204c7ac0
x29: ffff8000204c7b80 x28: ffff700004098f60 x27: dfff800000000000
x26: 0000ffffab1dff28 x25: 00000000fffffff2 x24: 0000002000004800
x23: 0000000020000048 x22: 0000000000000001 x21: ffff0000d18136a4

x20: ffff0000d1813680 x19: 1fffe0001a3026d4 x18: 0000000000000000

x17: 0000000000000000 x16: ffff800008658704 x15: 0000000000000000
x14: 0000000000000000 x13: 1ffff0000282e06b x12: 0000000000ff0100
x11: 0000000020000048 x10: 0000ffffffffffff x9 : 0000000020000048
x8 : 0000000000000000 x7 : ffff800008750ed4 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000001
x2 : 0000000000000008 x1 : 0000000000000001 x0 : 0000000000000000
Call trace:
 clear_rseq_cs kernel/rseq.c:242 [inline]
 rseq_ip_fixup kernel/rseq.c:276 [inline]
 __rseq_handle_notify_resume+0x89c/0x1604 kernel/rseq.c:314
 rseq_handle_notify_resume include/linux/sched.h:2202 [inline]
 tracehook_notify_resume include/linux/tracehook.h:201 [inline]
 do_notify_resume+0x21f8/0x3128 arch/arm64/kernel/signal.c:949
 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:133 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:138 [inline]
 el0_svc+0xf0/0x1e0 arch/arm64/kernel/entry-common.c:609
 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: 9a9f02eb d503229f aa1f03e8 f8000968 (14000105) 
---[ end trace af8d6d5235b80817 ]---
----------------
Code disassembly (best guess):
   0:	9a9f02eb 	csel	x11, x23, xzr, eq	// eq = none
   4:	d503229f 	csdb
   8:	aa1f03e8 	mov	x8, xzr
   c:	f8000968 	sttr	x8, [x11]
* 10:	14000105 	b	0x424 <-- trapping instruction

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/16 01:59 linux-5.15.y c79648372d02 1804e95e .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 Internal error in __rseq_handle_notify_resume
2025/08/15 23:06 linux-5.15.y c79648372d02 1804e95e .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 Internal error in __rseq_handle_notify_resume
2025/08/18 03:13 linux-5.15.y c79648372d02 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 Internal error in __rseq_handle_notify_resume
2025/08/16 02:22 linux-5.15.y c79648372d02 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 Internal error in __rseq_handle_notify_resume
2025/08/16 02:21 linux-5.15.y c79648372d02 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 Internal error in __rseq_handle_notify_resume
2025/08/12 10:11 linux-5.15.y c79648372d02 c06e8995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 Internal error in __rseq_handle_notify_resume
2025/08/12 10:09 linux-5.15.y c79648372d02 c06e8995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 Internal error in __rseq_handle_notify_resume
* Struck through repros no longer work on HEAD.