The current ila_xlat_nl_cmd_get_mapping will call genlmsg_reply even if
not ila_map found with user provided parameters. Then an empty netlink
message will be sent and cause a WARNING like below.
WARNING: CPU: 1 PID: 7709 at include/linux/skbuff.h:2524 __dev_queue_xmit+0x241b/0x3b60 net/core/dev.c:4171
Modules linked in:
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:skb_assert_len include/linux/skbuff.h:2524 [inline]
RIP: 0010:__dev_queue_xmit+0x241b/0x3b60 net/core/dev.c:4171
RSP: 0018:ffffc9000f90f228 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000040000 RSI: ffffffff816968a8 RDI: fffff52001f21e37
RBP: ffff8881077f2d3a R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff8881077f2c90 R15: ffff8881077f2c80
FS: 00007fb8be338700(0000) GS:ffff888135c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c00ca8a000 CR3: 0000000105e17000 CR4: 0000000000150ee0
Call Trace:
<TASK>
dev_queue_xmit include/linux/netdevice.h:3008 [inline]
__netlink_deliver_tap_skb net/netlink/af_netlink.c:307 [inline]
__netlink_deliver_tap net/netlink/af_netlink.c:325 [inline]
netlink_deliver_tap+0x9e4/0xc40 net/netlink/af_netlink.c:338
__netlink_sendskb net/netlink/af_netlink.c:1263 [inline]
netlink_sendskb net/netlink/af_netlink.c:1272 [inline]
netlink_unicast+0x6ac/0x7f0 net/netlink/af_netlink.c:1360
nlmsg_unicast include/net/netlink.h:1067 [inline]
genlmsg_unicast include/net/genetlink.h:372 [inline]
genlmsg_reply include/net/genetlink.h:382 [inline]
ila_xlat_nl_cmd_get_mapping+0x589/0x950 net/ipv6/ila/ila_xlat.c:493
genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:756
genl_family_rcv_msg net/netlink/genetlink.c:833 [inline]
genl_rcv_msg+0x441/0x780 net/netlink/genetlink.c:850
netlink_rcv_skb+0x153/0x400 net/netlink/af_netlink.c:2540
genl_rcv+0x24/0x40 net/netlink/genetlink.c:861
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921
sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:734
____sys_sendmsg+0x6eb/0x810 net/socket.c:2482
___sys_sendmsg+0x110/0x1b0 net/socket.c:2536
__sys_sendmsg+0xf3/0x1c0 net/socket.c:2565
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fb8bd68f359
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb8be338168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fb8bd7bbf80 RCX: 00007fb8bd68f359
RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000005
RBP: 00007fb8bd6da498 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc22fb52af R14: 00007fb8be338300 R15: 0000000000022000
Do nullptr check and assign -EINVAL ret if no ila_map found.
Signed-off-by: Lin Ma <[email protected]>
---
net/ipv6/ila/ila_xlat.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/ipv6/ila/ila_xlat.c b/net/ipv6/ila/ila_xlat.c
index 67e8c9440977..63b8fe1b8255 100644
--- a/net/ipv6/ila/ila_xlat.c
+++ b/net/ipv6/ila/ila_xlat.c
@@ -483,6 +483,8 @@ int ila_xlat_nl_cmd_get_mapping(struct sk_buff *skb, struct genl_info *info)
info->snd_portid,
info->snd_seq, 0, msg,
info->genlhdr->cmd);
+ } else {
+ ret = -EINVAL;
}
rcu_read_unlock();
--
2.34.1
Wed, May 22, 2024 at 05:15:37AM CEST, [email protected] wrote:
>The current ila_xlat_nl_cmd_get_mapping will call genlmsg_reply even if
>not ila_map found with user provided parameters. Then an empty netlink
>message will be sent and cause a WARNING like below.
>
>WARNING: CPU: 1 PID: 7709 at include/linux/skbuff.h:2524 __dev_queue_xmit+0x241b/0x3b60 net/core/dev.c:4171
>Modules linked in:
>Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
>RIP: 0010:skb_assert_len include/linux/skbuff.h:2524 [inline]
>RIP: 0010:__dev_queue_xmit+0x241b/0x3b60 net/core/dev.c:4171
>RSP: 0018:ffffc9000f90f228 EFLAGS: 00010282
>RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
>RDX: 0000000000040000 RSI: ffffffff816968a8 RDI: fffff52001f21e37
>RBP: ffff8881077f2d3a R08: 0000000000000005 R09: 0000000000000000
>R10: 0000000080000000 R11: 0000000000000000 R12: dffffc0000000000
>R13: 0000000000000000 R14: ffff8881077f2c90 R15: ffff8881077f2c80
>FS: 00007fb8be338700(0000) GS:ffff888135c00000(0000) knlGS:0000000000000000
>CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>CR2: 000000c00ca8a000 CR3: 0000000105e17000 CR4: 0000000000150ee0
>Call Trace:
> <TASK>
> dev_queue_xmit include/linux/netdevice.h:3008 [inline]
> __netlink_deliver_tap_skb net/netlink/af_netlink.c:307 [inline]
> __netlink_deliver_tap net/netlink/af_netlink.c:325 [inline]
> netlink_deliver_tap+0x9e4/0xc40 net/netlink/af_netlink.c:338
> __netlink_sendskb net/netlink/af_netlink.c:1263 [inline]
> netlink_sendskb net/netlink/af_netlink.c:1272 [inline]
> netlink_unicast+0x6ac/0x7f0 net/netlink/af_netlink.c:1360
> nlmsg_unicast include/net/netlink.h:1067 [inline]
> genlmsg_unicast include/net/genetlink.h:372 [inline]
> genlmsg_reply include/net/genetlink.h:382 [inline]
> ila_xlat_nl_cmd_get_mapping+0x589/0x950 net/ipv6/ila/ila_xlat.c:493
> genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:756
> genl_family_rcv_msg net/netlink/genetlink.c:833 [inline]
> genl_rcv_msg+0x441/0x780 net/netlink/genetlink.c:850
> netlink_rcv_skb+0x153/0x400 net/netlink/af_netlink.c:2540
> genl_rcv+0x24/0x40 net/netlink/genetlink.c:861
> netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
> netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
> netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921
> sock_sendmsg_nosec net/socket.c:714 [inline]
> sock_sendmsg+0xcf/0x120 net/socket.c:734
> ____sys_sendmsg+0x6eb/0x810 net/socket.c:2482
> ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536
> __sys_sendmsg+0xf3/0x1c0 net/socket.c:2565
> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>RIP: 0033:0x7fb8bd68f359
>Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
>RSP: 002b:00007fb8be338168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
>RAX: ffffffffffffffda RBX: 00007fb8bd7bbf80 RCX: 00007fb8bd68f359
>RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000005
>RBP: 00007fb8bd6da498 R08: 0000000000000000 R09: 0000000000000000
>R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
>R13: 00007ffc22fb52af R14: 00007fb8be338300 R15: 0000000000022000
>
>Do nullptr check and assign -EINVAL ret if no ila_map found.
>
>Signed-off-by: Lin Ma <[email protected]>
You should aim -net tree and add appropriate Fixes tag here.
>---
> net/ipv6/ila/ila_xlat.c | 2 ++
> 1 file changed, 2 insertions(+)
>
>diff --git a/net/ipv6/ila/ila_xlat.c b/net/ipv6/ila/ila_xlat.c
>index 67e8c9440977..63b8fe1b8255 100644
>--- a/net/ipv6/ila/ila_xlat.c
>+++ b/net/ipv6/ila/ila_xlat.c
>@@ -483,6 +483,8 @@ int ila_xlat_nl_cmd_get_mapping(struct sk_buff *skb, struct genl_info *info)
> info->snd_portid,
> info->snd_seq, 0, msg,
> info->genlhdr->cmd);
>+ } else {
>+ ret = -EINVAL;
> }
>
> rcu_read_unlock();
>--
>2.34.1
>
>
On Wed, May 22, 2024 at 11:15:37AM +0800, Lin Ma wrote:
> The current ila_xlat_nl_cmd_get_mapping will call genlmsg_reply even if
> not ila_map found with user provided parameters. Then an empty netlink
> message will be sent and cause a WARNING like below.
>
> WARNING: CPU: 1 PID: 7709 at include/linux/skbuff.h:2524 __dev_queue_xmit+0x241b/0x3b60 net/core/dev.c:4171
> Modules linked in:
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
> RIP: 0010:skb_assert_len include/linux/skbuff.h:2524 [inline]
> RIP: 0010:__dev_queue_xmit+0x241b/0x3b60 net/core/dev.c:4171
> RSP: 0018:ffffc9000f90f228 EFLAGS: 00010282
> RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
> RDX: 0000000000040000 RSI: ffffffff816968a8 RDI: fffff52001f21e37
> RBP: ffff8881077f2d3a R08: 0000000000000005 R09: 0000000000000000
> R10: 0000000080000000 R11: 0000000000000000 R12: dffffc0000000000
> R13: 0000000000000000 R14: ffff8881077f2c90 R15: ffff8881077f2c80
> FS: 00007fb8be338700(0000) GS:ffff888135c00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000000c00ca8a000 CR3: 0000000105e17000 CR4: 0000000000150ee0
> Call Trace:
> <TASK>
> dev_queue_xmit include/linux/netdevice.h:3008 [inline]
> __netlink_deliver_tap_skb net/netlink/af_netlink.c:307 [inline]
> __netlink_deliver_tap net/netlink/af_netlink.c:325 [inline]
> netlink_deliver_tap+0x9e4/0xc40 net/netlink/af_netlink.c:338
> __netlink_sendskb net/netlink/af_netlink.c:1263 [inline]
> netlink_sendskb net/netlink/af_netlink.c:1272 [inline]
> netlink_unicast+0x6ac/0x7f0 net/netlink/af_netlink.c:1360
> nlmsg_unicast include/net/netlink.h:1067 [inline]
> genlmsg_unicast include/net/genetlink.h:372 [inline]
> genlmsg_reply include/net/genetlink.h:382 [inline]
> ila_xlat_nl_cmd_get_mapping+0x589/0x950 net/ipv6/ila/ila_xlat.c:493
> genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:756
> genl_family_rcv_msg net/netlink/genetlink.c:833 [inline]
> genl_rcv_msg+0x441/0x780 net/netlink/genetlink.c:850
> netlink_rcv_skb+0x153/0x400 net/netlink/af_netlink.c:2540
> genl_rcv+0x24/0x40 net/netlink/genetlink.c:861
> netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
> netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
> netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921
> sock_sendmsg_nosec net/socket.c:714 [inline]
> sock_sendmsg+0xcf/0x120 net/socket.c:734
> ____sys_sendmsg+0x6eb/0x810 net/socket.c:2482
> ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536
> __sys_sendmsg+0xf3/0x1c0 net/socket.c:2565
> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
> RIP: 0033:0x7fb8bd68f359
> Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007fb8be338168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
> RAX: ffffffffffffffda RBX: 00007fb8bd7bbf80 RCX: 00007fb8bd68f359
> RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000005
> RBP: 00007fb8bd6da498 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007ffc22fb52af R14: 00007fb8be338300 R15: 0000000000022000
>
> Do nullptr check and assign -EINVAL ret if no ila_map found.
>
> Signed-off-by: Lin Ma <[email protected]>
> ---
> net/ipv6/ila/ila_xlat.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/net/ipv6/ila/ila_xlat.c b/net/ipv6/ila/ila_xlat.c
> index 67e8c9440977..63b8fe1b8255 100644
> --- a/net/ipv6/ila/ila_xlat.c
> +++ b/net/ipv6/ila/ila_xlat.c
Hi Lin Ma,
The lines immediately above those covered by this patch are as follows:
ret = -ESRCH;
ila = ila_lookup_by_params(&xp, ilan);
if (ila) {
ret = ila_dump_info(ila,
> @@ -483,6 +483,8 @@ int ila_xlat_nl_cmd_get_mapping(struct sk_buff *skb, struct genl_info *info)
> info->snd_portid,
> info->snd_seq, 0, msg,
> info->genlhdr->cmd);
> + } else {
> + ret = -EINVAL;
> }
>
> rcu_read_unlock();
And the lines following, up to the end of the function, are:
if (ret < 0)
goto out_free;
return genlmsg_reply(msg, info);
out_free:
nlmsg_free(msg);
return ret;
By my reading, without your patch, if ila is not found (NULL)
then ret will be -ESRCH, and genlmsg_reply will not be called.
I feel that I am missing something here.
Hi Simon.
>
> Hi Lin Ma,
>
> The lines immediately above those covered by this patch are as follows:
>
> ret = -ESRCH;
> ila = ila_lookup_by_params(&xp, ilan);
> if (ila) {
> ret = ila_dump_info(ila,
>
> > @@ -483,6 +483,8 @@ int ila_xlat_nl_cmd_get_mapping(struct sk_buff *skb, struct genl_info *info)
> > info->snd_portid,
> > info->snd_seq, 0, msg,
> > info->genlhdr->cmd);
> > + } else {
> > + ret = -EINVAL;
> > }
> >
> > rcu_read_unlock();
>
> And the lines following, up to the end of the function, are:
>
> if (ret < 0)
> goto out_free;
>
> return genlmsg_reply(msg, info);
>
> out_free:
> nlmsg_free(msg);
> return ret;
>
> By my reading, without your patch, if ila is not found (NULL)
> then ret will be -ESRCH, and genlmsg_reply will not be called.
>
> I feel that I am missing something here.
Oh my bad, it seems this bug was already fixed by the
commit 693aa2c0d9b6 ("ila: do not generate empty messages
in ila_xlat_nl_cmd_get_mapping()") last year.
And my dated kernel does not apply that one.
Thanks for reminding me of this false alarm.
Regards
Lin
On Thu, May 23, 2024 at 09:44:15AM +0800, Lin Ma wrote:
> Hi Simon.
>
> >
> > Hi Lin Ma,
> >
> > The lines immediately above those covered by this patch are as follows:
> >
> > ret = -ESRCH;
> > ila = ila_lookup_by_params(&xp, ilan);
> > if (ila) {
> > ret = ila_dump_info(ila,
> >
> > > @@ -483,6 +483,8 @@ int ila_xlat_nl_cmd_get_mapping(struct sk_buff *skb, struct genl_info *info)
> > > info->snd_portid,
> > > info->snd_seq, 0, msg,
> > > info->genlhdr->cmd);
> > > + } else {
> > > + ret = -EINVAL;
> > > }
> > >
> > > rcu_read_unlock();
> >
> > And the lines following, up to the end of the function, are:
> >
> > if (ret < 0)
> > goto out_free;
> >
> > return genlmsg_reply(msg, info);
> >
> > out_free:
> > nlmsg_free(msg);
> > return ret;
> >
> > By my reading, without your patch, if ila is not found (NULL)
> > then ret will be -ESRCH, and genlmsg_reply will not be called.
> >
> > I feel that I am missing something here.
>
> Oh my bad, it seems this bug was already fixed by the
> commit 693aa2c0d9b6 ("ila: do not generate empty messages
> in ila_xlat_nl_cmd_get_mapping()") last year.
> And my dated kernel does not apply that one.
>
> Thanks for reminding me of this false alarm.
Thanks for checking.
I think we can retire this patch.