All of lore.kernel.org
 help / color / mirror / Atom feed
From: syzbot <syzbot+60f8f8d9d0a992e59f1a@syzkaller.appspotmail.com>
To: Liam.Howlett@oracle.com, akpm@linux-foundation.org,
	jannh@google.com,  linux-kernel@vger.kernel.org,
	linux-mm@kvack.org, lorenzo.stoakes@oracle.com,
	 pfalcato@suse.de, syzkaller-bugs@googlegroups.com,
	vbabka@suse.cz
Subject: [syzbot] [mm?] general protection fault in __rt_mutex_slowlock_locked
Date: Tue, 11 Nov 2025 12:25:29 -0800	[thread overview]
Message-ID: <69139bb9.a70a0220.22f260.014b.GAE@google.com> (raw)

Hello,

syzbot found the following issue on:

HEAD commit:    4a0c9b339199 Merge tag 'probes-fixes-v6.18-rc4' of git://g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=136e9114580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=41ad820f608cb833
dashboard link: https://syzkaller.appspot.com/bug?extid=60f8f8d9d0a992e59f1a
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/2f1bc58f2850/disk-4a0c9b33.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d4d546567b38/vmlinux-4a0c9b33.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4618744dea2b/bzImage-4a0c9b33.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+60f8f8d9d0a992e59f1a@syzkaller.appspotmail.com

loop2: detected capacity change from 0 to 32768
Oops: general protection fault, probably for non-canonical address 0xdffffc00e0000153: 0000 [#1] SMP KASAN PTI
KASAN: probably user-memory-access in range [0x0000000700000a98-0x0000000700000a9f]
CPU: 0 UID: 0 PID: 13777 Comm: syz.2.923 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:kasan_byte_accessible+0x12/0x30 mm/kasan/generic.c:210
Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 c3 cc cc cc cc cc 66 66 66 66 66 66 2e
RSP: 0018:ffffc90004b4f2f0 EFLAGS: 00010006
RAX: dffffc0000000000 RBX: ffffffff8ac3ee8e RCX: 8a8d6ce156f8e600
RDX: 0000000000000000 RSI: ffffffff8ac3ee8e RDI: 00000000e0000153
RBP: ffffffff819ba5a3 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100a608c91 R12: 0000000000000000
R13: 0000000700000a98 R14: 0000000700000a98 R15: 0000000000000001
FS:  00007f6cb050e6c0(0000) GS:ffff888126df9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31923ffc CR3: 0000000068aae000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __kasan_check_byte+0x12/0x40 mm/kasan/common.c:579
 kasan_check_byte include/linux/kasan.h:401 [inline]
 lock_acquire+0x8d/0x360 kernel/locking/lockdep.c:5842
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 task_blocks_on_rt_mutex kernel/locking/rtmutex.c:1265 [inline]
 __rt_mutex_slowlock kernel/locking/rtmutex.c:1719 [inline]
 __rt_mutex_slowlock_locked+0x1223/0x25e0 kernel/locking/rtmutex.c:1760
 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800
 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
 rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244
 i_mmap_lock_write include/linux/fs.h:548 [inline]
 vma_link_file mm/vma.c:1781 [inline]
 __mmap_new_vma mm/vma.c:2499 [inline]
 __mmap_region mm/vma.c:2670 [inline]
 mmap_region+0x1bf4/0x20f0 mm/vma.c:2740
 do_mmap+0xc23/0x10c0 mm/mmap.c:558
 vm_mmap_pgoff+0x2a9/0x4d0 mm/util.c:581
 ksys_mmap_pgoff+0x4e9/0x720 mm/mmap.c:604
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6cb22af6c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6cb050e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f6cb2505fa0 RCX: 00007f6cb22af6c9
RDX: 00000000027ffff7 RSI: 0000000000600000 RDI: 0000200000000000
RBP: 00007f6cb2331f91 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000004012011 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6cb2506038 R14: 00007f6cb2505fa0 R15: 00007ffebcf391b8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:kasan_byte_accessible+0x12/0x30 mm/kasan/generic.c:210
Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 c3 cc cc cc cc cc 66 66 66 66 66 66 2e
RSP: 0018:ffffc90004b4f2f0 EFLAGS: 00010006
RAX: dffffc0000000000 RBX: ffffffff8ac3ee8e RCX: 8a8d6ce156f8e600
RDX: 0000000000000000 RSI: ffffffff8ac3ee8e RDI: 00000000e0000153
RBP: ffffffff819ba5a3 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100a608c91 R12: 0000000000000000
R13: 0000000700000a98 R14: 0000000700000a98 R15: 0000000000000001
FS:  00007f6cb050e6c0(0000) GS:ffff888126df9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31923ffc CR3: 0000000068aae000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
   7:	00
   8:	90                   	nop
   9:	90                   	nop
   a:	90                   	nop
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	0f 1f 40 d6          	nopl   -0x2a(%rax)
  1c:	48 c1 ef 03          	shr    $0x3,%rdi
  20:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  27:	fc ff df
* 2a:	0f b6 04 07          	movzbl (%rdi,%rax,1),%eax <-- trapping instruction
  2e:	3c 08                	cmp    $0x8,%al
  30:	0f 92 c0             	setb   %al
  33:	c3                   	ret
  34:	cc                   	int3
  35:	cc                   	int3
  36:	cc                   	int3
  37:	cc                   	int3
  38:	cc                   	int3
  39:	66                   	data16
  3a:	66                   	data16
  3b:	66                   	data16
  3c:	66                   	data16
  3d:	66                   	data16
  3e:	66                   	data16
  3f:	2e                   	cs


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup


                 reply	other threads:[~2025-11-11 20:25 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=69139bb9.a70a0220.22f260.014b.GAE@google.com \
    --to=syzbot+60f8f8d9d0a992e59f1a@syzkaller.appspotmail.com \
    --cc=Liam.Howlett@oracle.com \
    --cc=akpm@linux-foundation.org \
    --cc=jannh@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=lorenzo.stoakes@oracle.com \
    --cc=pfalcato@suse.de \
    --cc=syzkaller-bugs@googlegroups.com \
    --cc=vbabka@suse.cz \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.