Subject: [syzbot] general protection fault in smc_tx_sendmsg

From: syzbot <[email-masked]>
Date: Sun, 20 Jun 2021 16:22:16 -0700

Hello,

syzbot found the following issue on:

HEAD commit:    0c337952 Merge tag 'wireless-drivers-next-2021-06-16' of g..
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1621de10300000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a6380da8984033f1
dashboard link: https://syzkaller.appspot.com/bug?extid=5dda108b672b54141857
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=121d2d20300000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=100bd768300000

The issue was bisected to:

commit f9006acc8dfe59e25aa75729728ac57a8d84fc32
Author: Florian Westphal <[email-masked]>
Date:   Wed Apr 21 07:51:08 2021 +0000

    netfilter: arp_tables: pass table pointer via nf_hook_ops

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=12600fffd00000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=11600fffd00000
console output: https://syzkaller.appspot.com/x/log.txt?x=16600fffd00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]
Fixes: f9006acc8dfe ("netfilter: arp_tables: pass table pointer via nf_hook_ops")

general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 1 PID: 8455 Comm: syz-executor893 Not tainted 5.13.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:smc_tx_sendmsg+0x204/0x1ba0 net/smc/smc_tx.c:157
Code: 48 c1 ea 03 80 3c 02 00 0f 85 8b 17 00 00 49 8b 9d 08 05 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 20 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e 8f 17 00 00 48 63 5b 20 4c 8b
RSP: 0018:ffffc9000164f800 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffffffff889cd6ae RDI: 0000000000000020
RBP: ffff88801cf58000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff889cd6a1 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88801cf58000 R14: ffffc9000164fd90 R15: ffff88801cf58060
FS:  0000000000ebf300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd43ca1328 CR3: 000000002acf2000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 smc_sendmsg+0x274/0x5b0 net/smc/af_smc.c:2037
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:674
 ____sys_sendmsg+0x331/0x810 net/socket.c:2350
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2404
 __sys_sendmmsg+0x195/0x470 net/socket.c:2490
 __do_sys_sendmmsg net/socket.c:2519 [inline]
 __se_sys_sendmmsg net/socket.c:2516 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2516
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x43ee89
Code: 28 c3 e8 2a 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:00007ffc82b20a58 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000000400488 RCX: 000000000043ee89
RDX: 0000000000000001 RSI: 0000000020003d80 RDI: 0000000000000003
RBP: 0000000000402e70 R08: 0000000000000000 R09: 0000000000400488
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402f00
R13: 0000000000000000 R14: 00000000004ac018 R15: 0000000000400488
Modules linked in:
---[ end trace 459b28282ae53115 ]---
RIP: 0010:smc_tx_sendmsg+0x204/0x1ba0 net/smc/smc_tx.c:157
Code: 48 c1 ea 03 80 3c 02 00 0f 85 8b 17 00 00 49 8b 9d 08 05 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 20 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e 8f 17 00 00 48 63 5b 20 4c 8b
RSP: 0018:ffffc9000164f800 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffffffff889cd6ae RDI: 0000000000000020
RBP: ffff88801cf58000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff889cd6a1 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88801cf58000 R14: ffffc9000164fd90 R15: ffff88801cf58060
FS:  0000000000ebf300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b7501be298 CR3: 000000002acf2000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

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