BUG: corrupted list in team_nl_cmd_options_set

[syzbot]

Hello,

syzbot hit the following crash on upstream commit
b284d4d5a6785f8cd07eda2646a95782373cd01e (Tue Apr 10 19:25:30 2018 +0000)
Merge tag 'ceph-for-4.17-rc1' of git://github.com/ceph/ceph-client
syzbot dashboard link:
https://syzkaller.appspot.com/bug?extid=4d4af685432dc0e56c91

C reproducer: https://syzkaller.appspot.com/x/repro.c?id=6161158629228544
syzkaller reproducer:
https://syzkaller.appspot.com/x/repro.syz?id=5600380654190592
Raw console output:
https://syzkaller.appspot.com/x/log.txt?id=4627738266697728
Kernel config:
https://syzkaller.appspot.com/x/.config?id=-1223000601505858474
compiler: gcc (GCC) 8.0.1 20180301 (experimental)

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+4d4af6...@syzkaller.appspotmail.com
It will help syzbot understand when the bug is fixed. See footer for
details.
If you forward the report, please keep this part and the footer.

8021q: adding VLAN 0 to HW filter on device team0
netlink: 'syzkaller556835': attribute type 3 has an invalid length.
netlink: 'syzkaller556835': attribute type 3 has an invalid length.
list_add double add: new=0000000004f859c0, prev=00000000c9745291,
next=0000000004f859c0.
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:31!
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 4466 Comm: syzkaller556835 Not tainted 4.16.0+ #17
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:__list_add_valid+0xaa/0xb0 lib/list_debug.c:29
RSP: 0018:ffff8801b04bf248 EFLAGS: 00010286
RAX: 0000000000000058 RBX: ffff8801c8fc7a90 RCX: 0000000000000000
RDX: 0000000000000058 RSI: ffffffff815fbf41 RDI: ffffed0036097e3f
RBP: ffff8801b04bf260 R08: ffff8801b0b2a700 R09: ffffed003b604f90
R10: ffffed003b604f90 R11: ffff8801db027c87 R12: ffff8801c8fc7a90
R13: ffff8801c8fc7a90 R14: dffffc0000000000 R15: 0000000000000000
FS: 0000000000b98880(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000043fc30 CR3: 00000001afe8e000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__list_add include/linux/list.h:60 [inline]
list_add include/linux/list.h:79 [inline]
team_nl_cmd_options_set+0x9ff/0x12b0 drivers/net/team/team.c:2571
genl_family_rcv_msg+0x889/0x1120 net/netlink/genetlink.c:599
genl_rcv_msg+0xc6/0x170 net/netlink/genetlink.c:624
netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2448
genl_rcv+0x28/0x40 net/netlink/genetlink.c:635
netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
netlink_unicast+0x58b/0x740 net/netlink/af_netlink.c:1336
netlink_sendmsg+0x9f0/0xfa0 net/netlink/af_netlink.c:1901
sock_sendmsg_nosec net/socket.c:629 [inline]
sock_sendmsg+0xd5/0x120 net/socket.c:639
___sys_sendmsg+0x805/0x940 net/socket.c:2117
__sys_sendmsg+0x115/0x270 net/socket.c:2155
SYSC_sendmsg net/socket.c:2164 [inline]
SyS_sendmsg+0x29/0x30 net/socket.c:2162
do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4458b9
RSP: 002b:00007ffd1d4a7278 EFLAGS: 00000213 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000000001b RCX: 00000000004458b9
RDX: 0000000000000010 RSI: 0000000020000d00 RDI: 0000000000000004
RBP: 00000000004a74ed R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000213 R12: 00007ffd1d4a7348
R13: 0000000000402a60 R14: 0000000000000000 R15: 0000000000000000
Code: 75 e8 eb a9 48 89 f7 48 89 75 e8 e8 d1 85 7b fe 48 8b 75 e8 eb bb 48
89 f2 48 89 d9 4c 89 e6 48 c7 c7 a0 84 d8 87 e8 ea 67 28 fe <0f> 0b 0f 1f
40 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 e5 41
RIP: __list_add_valid+0xaa/0xb0 lib/list_debug.c:29 RSP: ffff8801b04bf248
---[ end trace b4f71d7dd7ca6d10 ]---


---
This bug is generated by a dumb bot. It may contain errors.
See https://goo.gl/tpsmEJ for details.
Direct all questions to syzk...@googlegroups.com.

syzbot will keep track of this bug report.
If you forgot to add the Reported-by tag, once the fix for this bug is
merged
into any tree, please reply to this email with:
#syz fix: exact-commit-title
If you want to test a patch for this bug, please reply with:
#syz test: git://repo/address.git branch
and provide the patch inline or as an attachment.
To mark this as a duplicate of another syzbot report, please reply with:
#syz dup: exact-subject-of-another-report
If it's a one-off invalid bug report, please reply with:
#syz invalid
Note: if the crash happens again, it will cause creation of a new bug
report.
Note: all commands must start from beginning of the line in the email body.

[Paolo Abeni]

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git master

---
diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c
index a6c6ce19eeee..acbe84967834 100644
--- a/drivers/net/team/team.c
+++ b/drivers/net/team/team.c
@@ -261,6 +261,17 @@ static void __team_option_inst_mark_removed_port(struct team *team,
}
}

+static bool __team_option_inst_tmp_find(const struct list_head *opts,
+ const struct team_option_inst *needle)
+{
+ struct team_option_inst *opt_inst;
+
+ list_for_each_entry(opt_inst, opts, tmp_list)
+ if (opt_inst == needle)
+ return true;
+ return false;
+}
+
static int __team_options_register(struct team *team,
const struct team_option *option,
size_t option_count)
@@ -2568,6 +2579,14 @@ static int team_nl_cmd_options_set(struct sk_buff *skb, struct genl_info *info)
if (err)
goto team_put;
opt_inst->changed = true;
+
+ /* dumb/evil user-space can send us duplicate opt,
+ * keep only the last one
+ */
+ if (__team_option_inst_tmp_find(&opt_inst_list,
+ opt_inst))
+ continue;
+
list_add(&opt_inst->tmp_list, &opt_inst_list);
}
if (!opt_found) {

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger
crash:

Reported-and-tested-by:
syzbot+4d4af6...@syzkaller.appspotmail.com

Note: the tag will also help syzbot to understand when the bug is fixed.

Tested on net commit
2290482379278e0254e6edfdb681d88359143fd1 (Mon Apr 9 07:03:14 2018 +0000)
net: dsa: mv88e6xxx: Fix receive time stamp race condition.

compiler: gcc (GCC) 8.0.1 20180413 (experimental)
Patch: https://syzkaller.appspot.com/x/patch.diff?id=5879265430077440
Kernel config:
https://syzkaller.appspot.com/x/.config?id=-5947642240294114534


---
There is no WARRANTY for the result, to the extent permitted by applicable
law.
Except when otherwise stated in writing syzbot provides the result "AS IS"
without warranty of any kind, either expressed or implied, but not limited
to,
the implied warranties of merchantability and fittness for a particular
purpose.
The entire risk as to the quality of the result is with you. Should the
result
prove defective, you assume the cost of all necessary servicing, repair or
correction.