Re: [syzbot] [wpan?] general protection fault in nl802154_trigger_scan

[Simon Horman]

On Fri, Mar 03, 2023 at 06:30:49AM -0800, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    f3a2439f20d9 Merge tag 'rproc-v6.3' of git://git.kernel.or..
> git tree:       upstream
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=12df1a7f480000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=81f5afa0c201c8de
> dashboard link: https://syzkaller.appspot.com/bug?extid=bd85b31816913a32e473
> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1597f254c80000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15053e40c80000
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/0719d575f3ac/disk-f3a2439f.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/4176aabb67b5/vmlinux-f3a2439f.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/2b0e3c0ab205/bzImage-f3a2439f.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+bd85b31816913a32e473@xxxxxxxxxxxxxxxxxxxxxxxxx
> 
> general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
> KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
> CPU: 1 PID: 5076 Comm: syz-executor386 Not tainted 6.2.0-syzkaller-12485-gf3a2439f20d9 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023
> RIP: 0010:nla_get_u8 include/net/netlink.h:1658 [inline]
> RIP: 0010:nl802154_trigger_scan+0x132/0xc90 net/ieee802154/nl802154.c:1415
> Code: 48 c1 ea 03 80 3c 02 00 0f 85 3f 0a 00 00 48 8b ad f8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7d 04 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 d0 07 00 00
> RSP: 0018:ffffc90003397568 EFLAGS: 00010247
> RAX: dffffc0000000000 RBX: ffffc900033975d8 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: ffffffff89cec1a1 RDI: 0000000000000004
> RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000001
> R10: 0000000000000000 R11: 0000000000000000 R12: ffff888146fb4c90
> R13: ffff888146f82000 R14: ffff888146f820a0 R15: ffffc900033975f8
> FS:  0000555556c9b300(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000055be8d9c04f0 CR3: 0000000023513000 CR4: 00000000003506e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  <TASK>
>  genl_family_rcv_msg_doit.isra.0+0x1e6/0x2d0 net/netlink/genetlink.c:968
>  genl_family_rcv_msg net/netlink/genetlink.c:1048 [inline]
>  genl_rcv_msg+0x4ff/0x7e0 net/netlink/genetlink.c:1065
>  netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2574
>  genl_rcv+0x28/0x40 net/netlink/genetlink.c:1076
>  netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
>  netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1365
>  netlink_sendmsg+0x925/0xe30 net/netlink/af_netlink.c:1942
>  sock_sendmsg_nosec net/socket.c:722 [inline]
>  sock_sendmsg+0xde/0x190 net/socket.c:745
>  ____sys_sendmsg+0x71c/0x900 net/socket.c:2504
>  ___sys_sendmsg+0x110/0x1b0 net/socket.c:2558
>  __sys_sendmsg+0xf7/0x1c0 net/socket.c:2587
>  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>  do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
>  entry_SYSCALL_64_after_hwframe+0x63/0xcd
> RIP: 0033:0x7f416cc9ee69
> Code: 28 c3 e8 5a 14 00 00 66 2e 0f 1f 84 00 00 00 00 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 c0 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007fff243fe498 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
> RAX: ffffffffffffffda RBX: 00007f416cd17380 RCX: 00007f416cc9ee69
> RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000003
> RBP: 0000000000000001 R08: 0000000000000000 R09: 001d00000000000c
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
> R13: 0000000000000003 R14: 00007fff243fe4b7 R15: 00007fff243fe4ba
>  </TASK>
> Modules linked in:
> ---[ end trace 0000000000000000 ]---
> RIP: 0010:nla_get_u8 include/net/netlink.h:1658 [inline]
> RIP: 0010:nl802154_trigger_scan+0x132/0xc90 net/ieee802154/nl802154.c:1415
> Code: 48 c1 ea 03 80 3c 02 00 0f 85 3f 0a 00 00 48 8b ad f8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7d 04 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 d0 07 00 00
> RSP: 0018:ffffc90003397568 EFLAGS: 00010247
> RAX: dffffc0000000000 RBX: ffffc900033975d8 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: ffffffff89cec1a1 RDI: 0000000000000004
> RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000001
> R10: 0000000000000000 R11: 0000000000000000 R12: ffff888146fb4c90
> R13: ffff888146f82000 R14: ffff888146f820a0 R15: ffffc900033975f8
> FS:  0000555556c9b300(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000055be8d9c04f0 CR3: 0000000023513000 CR4: 00000000003506e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> ----------------
> Code disassembly (best guess):
>    0:	48 c1 ea 03          	shr    $0x3,%rdx
>    4:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
>    8:	0f 85 3f 0a 00 00    	jne    0xa4d
>    e:	48 8b ad f8 00 00 00 	mov    0xf8(%rbp),%rbp
>   15:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
>   1c:	fc ff df
>   1f:	48 8d 7d 04          	lea    0x4(%rbp),%rdi
>   23:	48 89 fa             	mov    %rdi,%rdx
>   26:	48 c1 ea 03          	shr    $0x3,%rdx
> * 2a:	0f b6 04 02          	movzbl (%rdx,%rax,1),%eax <-- trapping instruction
>   2e:	48 89 fa             	mov    %rdi,%rdx
>   31:	83 e2 07             	and    $0x7,%edx
>   34:	38 d0                	cmp    %dl,%al
>   36:	7f 08                	jg     0x40
>   38:	84 c0                	test   %al,%al
>   3a:	0f 85 d0 07 00 00    	jne    0x810

I believe this is fixed here:

- [PATCH net] ieee802154: Prevent user from crashing the host
  https://lore.kernel.org/netdev/20230301154450.547716-1-miquel.raynal@xxxxxxxxxxx/

- pull-request: ieee802154 for net 2023-03-02
  https://lore.kernel.org/netdev/20230302153032.1312755-1-stefan@xxxxxxxxxxxxxxxxxx/