linux-kernel - [syzbot] [net?] BUG: unable to handle kernel paging request in nsim_drv_port

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Message-ID: <681f2922.050a0220.f2294.0005.GAE@google.com>
Date: Sat, 10 May 2025 03:23:30 -0700
From: syzbot <syzbot+1e4a7dc1542addfca0a5@...kaller.appspotmail.com>
To: andrew+netdev@...n.ch, davem@...emloft.net, edumazet@...gle.com, 
	kuba@...nel.org, linux-kernel@...r.kernel.org, netdev@...r.kernel.org, 
	pabeni@...hat.com, syzkaller-bugs@...glegroups.com
Subject: [syzbot] [net?] BUG: unable to handle kernel paging request in nsim_drv_port_add

Hello,

syzbot found the following issue on:

HEAD commit:    9c69f8884904 Merge tag 'bcachefs-2025-05-08' of git://evil..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12b5d8f4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=6b353fce507849ee
dashboard link: https://syzkaller.appspot.com/bug?extid=1e4a7dc1542addfca0a5
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6f122d34f751/disk-9c69f888.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d2f2b90345ca/vmlinux-9c69f888.xz
kernel image: https://storage.googleapis.com/syzbot-assets/90cead75be18/bzImage-9c69f888.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1e4a7dc1542addfca0a5@...kaller.appspotmail.com

BUG: unable to handle page fault for address: fffffffffffffee8
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD e184067 P4D e184067 PUD e186067 PMD 0 
Oops: Oops: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 19500 Comm: syz.0.2769 Tainted: G     U              6.15.0-rc5-syzkaller-00136-g9c69f8884904 #0 PREEMPT(full) 
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:580 [inline]
RIP: 0010:__mutex_lock+0x159/0xb90 kernel/locking/mutex.c:746
Code: 00 8b 35 9a 09 48 0f 85 f6 75 29 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 60 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 93 07 00 00 <48> 3b 5b 60 0f 85 e0 01 00 00 bf 01 00 00 00 e8 43 0d 1e f6 48 8d
RSP: 0018:ffffc9000407fa50 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: fffffffffffffe88 RCX: 1ffffffff35654bc
RDX: 1fffffffffffffdd RSI: 0000000000000000 RDI: fffffffffffffee8
RBP: ffffc9000407fb90 R08: ffffffff870eaaa4 R09: 0000000000000000
R10: ffffc9000407fba8 R11: 0000000000000000 R12: dffffc0000000000
R13: ffffc9000407fad0 R14: 0000000000000000 R15: 1ffff9200080ff54
FS:  00007ff6196956c0(0000) GS:ffff8881249ec000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffee8 CR3: 000000005fcee000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 nsim_drv_port_add+0x54/0x1a0 drivers/net/netdevsim/dev.c:1710
 new_port_store+0x129/0x170 drivers/net/netdevsim/bus.c:79
 dev_attr_store+0x55/0x80 drivers/base/core.c:2440
 sysfs_kf_write+0xef/0x150 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x351/0x510 fs/kernfs/file.c:334
 new_sync_write fs/read_write.c:591 [inline]
 vfs_write+0x5ba/0x1180 fs/read_write.c:684
 ksys_write+0x12a/0x240 fs/read_write.c:736
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff61878e969
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:00007ff619695038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ff6189b5fa0 RCX: 00007ff61878e969
RDX: 0000000000000001 RSI: 0000200000000500 RDI: 0000000000000003
RBP: 00007ff618810ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff6189b5fa0 R15: 00007ffde1b77968
 </TASK>
Modules linked in:
CR2: fffffffffffffee8
---[ end trace 0000000000000000 ]---
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:580 [inline]
RIP: 0010:__mutex_lock+0x159/0xb90 kernel/locking/mutex.c:746
Code: 00 8b 35 9a 09 48 0f 85 f6 75 29 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 60 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 93 07 00 00 <48> 3b 5b 60 0f 85 e0 01 00 00 bf 01 00 00 00 e8 43 0d 1e f6 48 8d
RSP: 0018:ffffc9000407fa50 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: fffffffffffffe88 RCX: 1ffffffff35654bc
RDX: 1fffffffffffffdd RSI: 0000000000000000 RDI: fffffffffffffee8
RBP: ffffc9000407fb90 R08: ffffffff870eaaa4 R09: 0000000000000000
R10: ffffc9000407fba8 R11: 0000000000000000 R12: dffffc0000000000
R13: ffffc9000407fad0 R14: 0000000000000000 R15: 1ffff9200080ff54
FS:  00007ff6196956c0(0000) GS:ffff8881249ec000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffee8 CR3: 000000005fcee000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	8b 35 9a 09 48 0f    	mov    0xf48099a(%rip),%esi        # 0xf4809a0
   6:	85 f6                	test   %esi,%esi
   8:	75 29                	jne    0x33
   a:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  11:	fc ff df
  14:	48 8d 7b 60          	lea    0x60(%rbx),%rdi
  18:	48 89 fa             	mov    %rdi,%rdx
  1b:	48 c1 ea 03          	shr    $0x3,%rdx
  1f:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
  23:	0f 85 93 07 00 00    	jne    0x7bc
* 29:	48 3b 5b 60          	cmp    0x60(%rbx),%rbx <-- trapping instruction
  2d:	0f 85 e0 01 00 00    	jne    0x213
  33:	bf 01 00 00 00       	mov    $0x1,%edi
  38:	e8 43 0d 1e f6       	call   0xf61e0d80
  3d:	48                   	rex.W
  3e:	8d                   	.byte 0x8d


---
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