Re: [syzbot] [net?] [s390?] general protection fault in __smc_diag_dump (3)

[syzbot <syzbot+271fed3ed6f24600c364@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
general protection fault in __smc_diag_dump

Oops: general protection fault, probably for non-canonical address 0xdffffc0000002c03: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: probably user-memory-access in range [0x0000000000016018-0x000000000001601f]
CPU: 1 UID: 0 PID: 6134 Comm: syz.0.50 Not tainted 6.12.0-rc6-syzkaller-g80fb25341631 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:smc_diag_msg_common_fill net/smc/smc_diag.c:44 [inline]
RIP: 0010:__smc_diag_dump.constprop.0+0x3e2/0x2500 net/smc/smc_diag.c:89
Code: 4c 8b b3 58 05 00 00 4d 85 f6 0f 84 f6 02 00 00 e8 83 62 d1 f6 49 8d 7e 18 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 86 1c 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b
RSP: 0018:ffffc90002f8f160 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffff88802861e780 RCX: ffffffff88ff0104
RDX: 0000000000002c03 RSI: ffffffff8abb41ed RDI: 0000000000016018
RBP: ffff88807446e5e0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000001 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88807ca98000 R14: 0000000000016000 R15: 0000000000000002
FS:  00007f91ea7fe6c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f91ea7ddd58 CR3: 000000007a980000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 smc_diag_dump_proto+0x26d/0x420 net/smc/smc_diag.c:217
 smc_diag_dump+0x27/0x90 net/smc/smc_diag.c:234
 netlink_dump+0x552/0xcc0 net/netlink/af_netlink.c:2326
 __netlink_dump_start+0x6d9/0x980 net/netlink/af_netlink.c:2441
 netlink_dump_start include/linux/netlink.h:339 [inline]
 smc_diag_handler_dump+0x1fb/0x240 net/smc/smc_diag.c:251
 __sock_diag_cmd net/core/sock_diag.c:249 [inline]
 sock_diag_rcv_msg+0x437/0x790 net/core/sock_diag.c:287
 netlink_rcv_skb+0x165/0x410 net/netlink/af_netlink.c:2551
 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
 netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1357
 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:729 [inline]
 __sock_sendmsg net/socket.c:744 [inline]
 ____sys_sendmsg+0x9ae/0xb40 net/socket.c:2607
 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2661
 __sys_sendmsg+0x117/0x1f0 net/socket.c:2690
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f91eb57dff9
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:00007f91ea7fe038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f91eb735f80 RCX: 00007f91eb57dff9
RDX: 000000000400c000 RSI: 0000000020000140 RDI: 0000000000000003
RBP: 00007f91eb5f0296 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f91eb735f80 R15: 00007fff7cd545b8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:smc_diag_msg_common_fill net/smc/smc_diag.c:44 [inline]
RIP: 0010:__smc_diag_dump.constprop.0+0x3e2/0x2500 net/smc/smc_diag.c:89
Code: 4c 8b b3 58 05 00 00 4d 85 f6 0f 84 f6 02 00 00 e8 83 62 d1 f6 49 8d 7e 18 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 86 1c 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b
RSP: 0018:ffffc90002f8f160 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffff88802861e780 RCX: ffffffff88ff0104
RDX: 0000000000002c03 RSI: ffffffff8abb41ed RDI: 0000000000016018
RBP: ffff88807446e5e0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000001 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88807ca98000 R14: 0000000000016000 R15: 0000000000000002
FS:  00007f91ea7fe6c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f91ea7ddd58 CR3: 000000007a980000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	4c 8b b3 58 05 00 00 	mov    0x558(%rbx),%r14
   7:	4d 85 f6             	test   %r14,%r14
   a:	0f 84 f6 02 00 00    	je     0x306
  10:	e8 83 62 d1 f6       	call   0xf6d16298
  15:	49 8d 7e 18          	lea    0x18(%r14),%rdi
  19:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  20:	fc ff df
  23:	48 89 fa             	mov    %rdi,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 86 1c 00 00    	jne    0x1cba
  34:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  3b:	fc ff df
  3e:	4d                   	rex.WRB
  3f:	8b                   	.byte 0x8b


Tested on:

commit:         80fb2534 Merge tag 'pwm/for-6.12-rc7-fixes' of git://g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1438fd5f980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=3f17c54526422c3
dashboard link: https://syzkaller.appspot.com/bug?extid=271fed3ed6f24600c364
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

Note: no patches were applied.