* general protection fault in fdb_find_rcu
@ 2018-12-30 4:01 syzbot
2018-12-30 11:34 ` Nikolay Aleksandrov
0 siblings, 1 reply; 5+ messages in thread
From: syzbot @ 2018-12-30 4:01 UTC (permalink / raw)
To: bridge, davem, linux-kernel, netdev, nikolay, roopa,
syzkaller-bugs
Hello,
syzbot found the following crash on:
HEAD commit: 90cadbbf341d Merge git://git.kernel.org/pub/scm/linux/kern..
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1745c69b400000
kernel config: https://syzkaller.appspot.com/x/.config?x=9d41c8529d7e7362
dashboard link: https://syzkaller.appspot.com/bug?extid=017b1f61c82a1c3e7efd
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15babaab400000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14c6142d400000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+017b1f61c82a1c3e7efd@syzkaller.appspotmail.com
IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
8021q: adding VLAN 0 to HW filter on device team0
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 7824 Comm: syz-executor809 Not tainted 4.20.0-rc7+ #360
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:fdb_find_rcu+0x194/0xc90 include/linux/string.h:352
Code: 40 84 c6 0f 85 23 09 00 00 84 c9 0f 95 c2 0f 9e c0 84 c2 0f 85 13 09
00 00 48 b9 00 00 00 00 00 fc ff df 4c 89 e0 48 c1 e8 03 <0f> b6 14 08 49
8d 44 24 05 48 89 c6 48 c1 ee 03 0f b6 0c 0e 4c 89
RSP: 0018:ffff8881b932f0b8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 1ffff11037265e01 RDI: ffff8881b932f1a8
RBP: ffff8881b932f310 R08: ffff8881bcc84400 R09: ffffed103b5a5b77
R10: ffffed103b5a5b77 R11: ffff8881dad2dbbb R12: 0000000000000000
R13: 0000000000000001 R14: ffff8881b9e68f40 R15: ffff8881b932f2e8
FS: 0000000001e8e880(0000) GS:ffff8881dad00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000180 CR3: 00000001bec05000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
br_fdb_find_rcu net/bridge/br_fdb.c:152 [inline]
br_fdb_get+0xac/0x230 net/bridge/br_fdb.c:788
rtnl_fdb_get+0x8a0/0x13b0 net/core/rtnetlink.c:4166
rtnetlink_rcv_msg+0x46a/0xc20 net/core/rtnetlink.c:5125
netlink_rcv_skb+0x16c/0x430 net/netlink/af_netlink.c:2477
rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5143
netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
netlink_unicast+0x59f/0x750 net/netlink/af_netlink.c:1336
netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1917
sock_sendmsg_nosec net/socket.c:621 [inline]
sock_sendmsg+0xd5/0x120 net/socket.c:631
___sys_sendmsg+0x7fd/0x930 net/socket.c:2116
__sys_sendmsg+0x11d/0x280 net/socket.c:2154
__do_sys_sendmsg net/socket.c:2163 [inline]
__se_sys_sendmsg net/socket.c:2161 [inline]
__x64_sys_sendmsg+0x78/0xb0 net/socket.c:2161
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x441679
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 2b 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff99382768 EFLAGS: 00000213 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441679
RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000003
RBP: 00000000006cd018 R08: 0000000000000100 R09: 0000000000000100
R10: 0000000000000020 R11: 0000000000000213 R12: 0000000000402430
R13: 00000000004024c0 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace d6d5286333ca98b5 ]---
RIP: 0010:fdb_find_rcu+0x194/0xc90 include/linux/string.h:352
Code: 40 84 c6 0f 85 23 09 00 00 84 c9 0f 95 c2 0f 9e c0 84 c2 0f 85 13 09
00 00 48 b9 00 00 00 00 00 fc ff df 4c 89 e0 48 c1 e8 03 <0f> b6 14 08 49
8d 44 24 05 48 89 c6 48 c1 ee 03 0f b6 0c 0e 4c 89
RSP: 0018:ffff8881b932f0b8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 1ffff11037265e01 RDI: ffff8881b932f1a8
RBP: ffff8881b932f310 R08: ffff8881bcc84400 R09: ffffed103b5a5b77
R10: ffffed103b5a5b77 R11: ffff8881dad2dbbb R12: 0000000000000000
R13: 0000000000000001 R14: ffff8881b9e68f40 R15: ffff8881b932f2e8
FS: 0000000001e8e880(0000) GS:ffff8881dad00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000180 CR3: 00000001bec05000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
---
This bug 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 syzkaller@googlegroups.com.
syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: general protection fault in fdb_find_rcu
2018-12-30 4:01 general protection fault in fdb_find_rcu syzbot
@ 2018-12-30 11:34 ` Nikolay Aleksandrov
2018-12-30 12:33 ` [PATCH net] net: rtnetlink: address is mandatory for rtnl_fdb_get Nikolay Aleksandrov
0 siblings, 1 reply; 5+ messages in thread
From: Nikolay Aleksandrov @ 2018-12-30 11:34 UTC (permalink / raw)
To: syzbot, bridge, davem, linux-kernel, netdev, roopa,
syzkaller-bugs
On 30/12/2018 06:01, syzbot wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: 90cadbbf341d Merge git://git.kernel.org/pub/scm/linux/kern..
> git tree: net-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=1745c69b400000
> kernel config: https://syzkaller.appspot.com/x/.config?x=9d41c8529d7e7362
> dashboard link: https://syzkaller.appspot.com/bug?extid=017b1f61c82a1c3e7efd
> compiler: gcc (GCC) 8.0.1 20180413 (experimental)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15babaab400000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14c6142d400000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+017b1f61c82a1c3e7efd@syzkaller.appspotmail.com
>
Ah yes, good catch. We've missed this obvious bug during the review.
A patch is on its way, just need to run a few tests.
Cheers,
Nik
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH net] net: rtnetlink: address is mandatory for rtnl_fdb_get
2018-12-30 11:34 ` Nikolay Aleksandrov
@ 2018-12-30 12:33 ` Nikolay Aleksandrov
2018-12-30 19:10 ` Roopa Prabhu
2018-12-30 19:36 ` David Miller
0 siblings, 2 replies; 5+ messages in thread
From: Nikolay Aleksandrov @ 2018-12-30 12:33 UTC (permalink / raw)
To: netdev; +Cc: bridge, davem, Nikolay Aleksandrov, Roopa Prabhu, David Ahern
We must have an address to lookup otherwise we'll derefence a null
pointer in the ndo_fdb_get callbacks.
CC: Roopa Prabhu <roopa@cumulusnetworks.com>
CC: David Ahern <dsa@cumulusnetworks.com>
Reported-by: syzbot+017b1f61c82a1c3e7efd@syzkaller.appspotmail.com
Fixes: 5b2f94b27622 ("net: rtnetlink: support for fdb get")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
---
net/core/rtnetlink.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 48f61885fd6f..5ea1bed08ede 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -4104,6 +4104,11 @@ static int rtnl_fdb_get(struct sk_buff *in_skb, struct nlmsghdr *nlh,
if (err < 0)
return err;
+ if (!addr) {
+ NL_SET_ERR_MSG(extack, "Missing lookup address for fdb get request");
+ return -EINVAL;
+ }
+
if (brport_idx) {
dev = __dev_get_by_index(net, brport_idx);
if (!dev) {
--
2.19.2
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH net] net: rtnetlink: address is mandatory for rtnl_fdb_get
2018-12-30 12:33 ` [PATCH net] net: rtnetlink: address is mandatory for rtnl_fdb_get Nikolay Aleksandrov
@ 2018-12-30 19:10 ` Roopa Prabhu
2018-12-30 19:36 ` David Miller
1 sibling, 0 replies; 5+ messages in thread
From: Roopa Prabhu @ 2018-12-30 19:10 UTC (permalink / raw)
To: Nikolay Aleksandrov; +Cc: netdev, bridge, David Miller, David Ahern
On Sun, Dec 30, 2018 at 4:33 AM Nikolay Aleksandrov
<nikolay@cumulusnetworks.com> wrote:
>
> We must have an address to lookup otherwise we'll derefence a null
> pointer in the ndo_fdb_get callbacks.
>
> CC: Roopa Prabhu <roopa@cumulusnetworks.com>
> CC: David Ahern <dsa@cumulusnetworks.com>
> Reported-by: syzbot+017b1f61c82a1c3e7efd@syzkaller.appspotmail.com
> Fixes: 5b2f94b27622 ("net: rtnetlink: support for fdb get")
> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Thanks Nikolay!.
> ---
> net/core/rtnetlink.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
> index 48f61885fd6f..5ea1bed08ede 100644
> --- a/net/core/rtnetlink.c
> +++ b/net/core/rtnetlink.c
> @@ -4104,6 +4104,11 @@ static int rtnl_fdb_get(struct sk_buff *in_skb, struct nlmsghdr *nlh,
> if (err < 0)
> return err;
>
> + if (!addr) {
> + NL_SET_ERR_MSG(extack, "Missing lookup address for fdb get request");
> + return -EINVAL;
> + }
> +
> if (brport_idx) {
> dev = __dev_get_by_index(net, brport_idx);
> if (!dev) {
> --
> 2.19.2
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH net] net: rtnetlink: address is mandatory for rtnl_fdb_get
2018-12-30 12:33 ` [PATCH net] net: rtnetlink: address is mandatory for rtnl_fdb_get Nikolay Aleksandrov
2018-12-30 19:10 ` Roopa Prabhu
@ 2018-12-30 19:36 ` David Miller
1 sibling, 0 replies; 5+ messages in thread
From: David Miller @ 2018-12-30 19:36 UTC (permalink / raw)
To: nikolay; +Cc: netdev, bridge, roopa, dsa
From: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Date: Sun, 30 Dec 2018 14:33:20 +0200
> We must have an address to lookup otherwise we'll derefence a null
> pointer in the ndo_fdb_get callbacks.
>
> CC: Roopa Prabhu <roopa@cumulusnetworks.com>
> CC: David Ahern <dsa@cumulusnetworks.com>
> Reported-by: syzbot+017b1f61c82a1c3e7efd@syzkaller.appspotmail.com
> Fixes: 5b2f94b27622 ("net: rtnetlink: support for fdb get")
> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Applied, thanks.
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2018-12-30 20:29 UTC | newest]
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2018-12-30 4:01 general protection fault in fdb_find_rcu syzbot
2018-12-30 11:34 ` Nikolay Aleksandrov
2018-12-30 12:33 ` [PATCH net] net: rtnetlink: address is mandatory for rtnl_fdb_get Nikolay Aleksandrov
2018-12-30 19:10 ` Roopa Prabhu
2018-12-30 19:36 ` David Miller
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