Subject: WARNING in ieee80211_check_rate_mask

From: syzbot <[email-masked]>
Date: Tue, 06 Oct 2020 01:08:24 -0700

Hello,

syzbot found the following issue on:

HEAD commit:    c2568c8c Merge branch 'net-Constify-struct-genl_small_ops'
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=16e2fb4d900000
kernel config:  https://syzkaller.appspot.com/x/.config?x=1e6c5266df853ae
dashboard link: https://syzkaller.appspot.com/bug?extid=be0e03ca215b06199629
compiler:       gcc (GCC) 10.1.0-syz 20200507
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1790e83b900000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=111a5bc7900000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]

netlink: 20 bytes leftover after parsing attributes in process `syz-executor823'.
------------[ cut here ]------------
WARNING: CPU: 1 PID: 6878 at net/mac80211/rate.c:281 ieee80211_check_rate_mask+0x1af/0x220 net/mac80211/rate.c:281
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 6878 Comm: syz-executor823 Not tainted 5.9.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x198/0x1fd lib/dump_stack.c:118
 panic+0x382/0x7fb kernel/panic.c:231
 __warn.cold+0x20/0x4b kernel/panic.c:600
 report_bug+0x1bd/0x210 lib/bug.c:198
 handle_bug+0x38/0x90 arch/x86/kernel/traps.c:234
 exc_invalid_op+0x14/0x40 arch/x86/kernel/traps.c:254
 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536
RIP: 0010:ieee80211_check_rate_mask+0x1af/0x220 net/mac80211/rate.c:281
Code: 45 85 ff 0f 84 86 0c 00 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f e9 bf 8c a1 f9 e8 ba 8c a1 f9 0f 0b eb e4 e8 b1 8c a1 f9 <0f> 0b eb db e8 e8 4f e3 f9 e9 f6 fe ff ff 48 89 ef e8 db 4f e3 f9
RSP: 0018:ffffc900055274b0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff88808a7d0c00 RCX: ffffffff87d4fa14
RDX: ffff888091b2e000 RSI: ffffffff87d4faff RDI: 0000000000000005
RBP: 0000000000000000 R08: ffff88808a7d1e58 R09: ffff888091b2e900
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 00000000ffffffff R14: ffff88808a7d0c00 R15: 0000000000000000
 ieee80211_change_bss+0x53c/0xc20 net/mac80211/cfg.c:2314
 rdev_change_bss net/wireless/rdev-ops.h:394 [inline]
 nl80211_set_bss+0x76c/0xc70 net/wireless/nl80211.c:7009
 genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:739
 genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
 genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:800
 netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2489
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:671
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2353
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2407
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2440
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4419c9
Code: e8 dc 05 03 00 48 83 c4 18 c3 0f 1f 80 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 0f 83 7b 0d fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffdbf57fbe8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004419c9
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000004
RBP: 000000306e616c77 R08: 0000000000000000 R09: 0000002000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000032
R13: 0000000000000000 R14: 000000000000000c R15: 0000000000000004
Kernel Offset: disabled
Rebooting in 86400 seconds..

---
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 [email-masked].

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches