* kernel BUG in fou_build_udp
@ 2023-04-14 3:35 Palash Oswal
2023-04-15 19:44 ` Kuniyuki Iwashima
0 siblings, 1 reply; 4+ messages in thread
From: Palash Oswal @ 2023-04-14 3:35 UTC (permalink / raw)
To: David S. Miller, David Ahern, Eric Dumazet, Jakub Kicinski,
Paolo Abeni, netdev, LKML, syzkaller-bugs
Hello,
I found the following issue using syzkaller with enriched corpus on:
HEAD commit : 0bcc4025550403ae28d2984bddacafbca0a2f112
git tree: linux
C Reproducer : https://gist.github.com/oswalpalash/2a4bdb639c605ec80dbeec220e09603c
Kernel .config :
https://gist.github.com/oswalpalash/d9580b0bfce202b37445fa5fd426e41f
syz-repro :
r0 = socket$inet6(0xa, 0x2, 0x0)
r1 = socket$nl_route(0x10, 0x3, 0x0)
r2 = socket(0x10, 0x803, 0x0)
sendmsg$nl_route(r2, &(0x7f0000000380)={0x0, 0x0,
&(0x7f0000000340)={0x0, 0x14}}, 0x0)
getsockname$packet(r2, &(0x7f0000000100)={0x11, 0x0, <r3=>0x0, 0x1,
0x0, 0x6, @broadcast}, &(0x7f00000000c0)=0x14)
sendmsg$nl_route(r1, &(0x7f0000000080)={0x0, 0x0,
&(0x7f0000000500)={&(0x7f0000000180)=@newlink={0x60, 0x10, 0x439, 0x0,
0x0, {0x0, 0x0, 0x0, 0x0, 0x9801}, [@IFLA_LINKINFO={0x40, 0x12, 0x0,
0x1, @sit={{0x8}, {0x34, 0x2, 0x0, 0x1, [@IFLA_IPTUN_LINK={0x8, 0x1,
r3}, @IFLA_IPTUN_ENCAP_TYPE={0x6, 0xf, 0x2},
@IFLA_IPTUN_ENCAP_SPORT={0x6, 0x11, 0x4e21},
@IFLA_IPTUN_ENCAP_SPORT={0x6, 0x11, 0x4e24}, @IFLA_IPTUN_LOCAL={0x8,
0x2, @dev={0xac, 0x14, 0x14, 0x16}}, @IFLA_IPTUN_ENCAP_FLAGS={0x6,
0x10, 0xfff}]}}}]}, 0x60}}, 0x20048894)
sendmmsg$inet(r0, &(0x7f00000017c0)=[{{&(0x7f0000000040)={0x2, 0x4e20,
@multicast1}, 0x10, 0x0, 0x0, &(0x7f0000000000)=[@ip_pktinfo={{0x1c,
0x0, 0x8, {r3, @empty, @remote}}}], 0x20}}], 0x1, 0x0)
Console log:
skbuff: skb_under_panic: text:ffffffff88a09da0 len:48 put:8
head:ffff88801e4be680 data:ffff88801e4be67c tail:0x2c end:0x140
dev:sit1
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:150!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 10068 Comm: syz-executor.3 Not tainted
6.3.0-rc6-pasta-00035-g0bcc40255504 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:skb_panic+0x152/0x1d0
Code: 0f b6 04 01 84 c0 74 04 3c 03 7e 20 8b 4b 70 41 56 45 89 e8 48
c7 c7 80 b3 5b 8b 41 57 56 48 89 ee 52 4c 89 e2 e8 ae 15 6c f9 <0f> 0b
4c 89 4c 24 10 48 89 54 24 08 48 89 34 24 e8 69 1f d8 f9 4c
RSP: 0018:ffffc900029bead0 EFLAGS: 00010282
RAX: 0000000000000084 RBX: ffff88801d1c3d00 RCX: ffffc9000d863000
RDX: 0000000000000000 RSI: ffffffff816695cc RDI: 0000000000000005
RBP: ffffffff8b5bc1e0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000400 R11: 0000000000000000 R12: ffffffff88a09da0
R13: 0000000000000008 R14: ffff8880306b8000 R15: 0000000000000140
FS: 00007f1dae5ed700(0000) GS:ffff888063a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564f403b7d10 CR3: 0000000117f1c000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
skb_push+0xc8/0xe0
fou_build_udp+0x30/0x370
gue_build_header+0xfb/0x150
ip_tunnel_xmit+0x66e/0x3150
sit_tunnel_xmit__.isra.0+0xe7/0x150
sit_tunnel_xmit+0xf7e/0x28e0
dev_hard_start_xmit+0x187/0x700
__dev_queue_xmit+0x2ce4/0x3c40
neigh_connected_output+0x3c2/0x550
ip_finish_output2+0x78a/0x22e0
__ip_finish_output+0x396/0x650
ip_finish_output+0x31/0x280
ip_mc_output+0x21f/0x710
ip_send_skb+0xd8/0x260
udp_send_skb+0x73a/0x1480
udp_sendmsg+0x1bb2/0x2840
udpv6_sendmsg+0x1710/0x2c20
inet6_sendmsg+0x9d/0xe0
sock_sendmsg+0xde/0x190
____sys_sendmsg+0x334/0x900
___sys_sendmsg+0x110/0x1b0
__sys_sendmmsg+0x18f/0x460
__x64_sys_sendmmsg+0x9d/0x100
do_syscall_64+0x39/0xb0
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f1dad88eacd
Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 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:00007f1dae5ecbf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f1dad9bbf80 RCX: 00007f1dad88eacd
RDX: 0000000000000001 RSI: 00000000200017c0 RDI: 0000000000000003
RBP: 00007f1dad8fcb05 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff4922802f R14: 00007fff492281d0 R15: 00007f1dae5ecd80
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:skb_panic+0x152/0x1d0
Code: 0f b6 04 01 84 c0 74 04 3c 03 7e 20 8b 4b 70 41 56 45 89 e8 48
c7 c7 80 b3 5b 8b 41 57 56 48 89 ee 52 4c 89 e2 e8 ae 15 6c f9 <0f> 0b
4c 89 4c 24 10 48 89 54 24 08 48 89 34 24 e8 69 1f d8 f9 4c
RSP: 0018:ffffc900029bead0 EFLAGS: 00010282
RAX: 0000000000000084 RBX: ffff88801d1c3d00 RCX: ffffc9000d863000
RDX: 0000000000000000 RSI: ffffffff816695cc RDI: 0000000000000005
RBP: ffffffff8b5bc1e0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000400 R11: 0000000000000000 R12: ffffffff88a09da0
R13: 0000000000000008 R14: ffff8880306b8000 R15: 0000000000000140
FS: 00007f1dae5ed700(0000) GS:ffff888063a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564f403b7d10 CR3: 0000000117f1c000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: kernel BUG in fou_build_udp
2023-04-14 3:35 kernel BUG in fou_build_udp Palash Oswal
@ 2023-04-15 19:44 ` Kuniyuki Iwashima
2023-04-17 9:00 ` Eric Dumazet
0 siblings, 1 reply; 4+ messages in thread
From: Kuniyuki Iwashima @ 2023-04-15 19:44 UTC (permalink / raw)
To: oswalpalash
Cc: davem, dsahern, edumazet, kuba, linux-kernel, netdev, pabeni,
syzkaller-bugs, kuniyu
Hi,
Thanks for reporting the issue.
From: Palash Oswal <oswalpalash@gmail.com>
Date: Thu, 13 Apr 2023 20:35:52 -0700
> Hello,
> I found the following issue using syzkaller with enriched corpus on:
> HEAD commit : 0bcc4025550403ae28d2984bddacafbca0a2f112
> git tree: linux
>
> C Reproducer : https://gist.github.com/oswalpalash/2a4bdb639c605ec80dbeec220e09603c
> Kernel .config :
> https://gist.github.com/oswalpalash/d9580b0bfce202b37445fa5fd426e41f
> syz-repro :
> r0 = socket$inet6(0xa, 0x2, 0x0)
> r1 = socket$nl_route(0x10, 0x3, 0x0)
> r2 = socket(0x10, 0x803, 0x0)
> sendmsg$nl_route(r2, &(0x7f0000000380)={0x0, 0x0,
> &(0x7f0000000340)={0x0, 0x14}}, 0x0)
> getsockname$packet(r2, &(0x7f0000000100)={0x11, 0x0, <r3=>0x0, 0x1,
> 0x0, 0x6, @broadcast}, &(0x7f00000000c0)=0x14)
> sendmsg$nl_route(r1, &(0x7f0000000080)={0x0, 0x0,
> &(0x7f0000000500)={&(0x7f0000000180)=@newlink={0x60, 0x10, 0x439, 0x0,
> 0x0, {0x0, 0x0, 0x0, 0x0, 0x9801}, [@IFLA_LINKINFO={0x40, 0x12, 0x0,
> 0x1, @sit={{0x8}, {0x34, 0x2, 0x0, 0x1, [@IFLA_IPTUN_LINK={0x8, 0x1,
> r3}, @IFLA_IPTUN_ENCAP_TYPE={0x6, 0xf, 0x2},
> @IFLA_IPTUN_ENCAP_SPORT={0x6, 0x11, 0x4e21},
> @IFLA_IPTUN_ENCAP_SPORT={0x6, 0x11, 0x4e24}, @IFLA_IPTUN_LOCAL={0x8,
> 0x2, @dev={0xac, 0x14, 0x14, 0x16}}, @IFLA_IPTUN_ENCAP_FLAGS={0x6,
> 0x10, 0xfff}]}}}]}, 0x60}}, 0x20048894)
> sendmmsg$inet(r0, &(0x7f00000017c0)=[{{&(0x7f0000000040)={0x2, 0x4e20,
> @multicast1}, 0x10, 0x0, 0x0, &(0x7f0000000000)=[@ip_pktinfo={{0x1c,
> 0x0, 0x8, {r3, @empty, @remote}}}], 0x20}}], 0x1, 0x0)
>
>
> Console log:
>
> skbuff: skb_under_panic: text:ffffffff88a09da0 len:48 put:8
> head:ffff88801e4be680 data:ffff88801e4be67c tail:0x2c end:0x140
> dev:sit1
> ------------[ cut here ]------------
> kernel BUG at net/core/skbuff.c:150!
> invalid opcode: 0000 [#1] PREEMPT SMP KASAN
> CPU: 0 PID: 10068 Comm: syz-executor.3 Not tainted
> 6.3.0-rc6-pasta-00035-g0bcc40255504 #1
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> 1.13.0-1ubuntu1.1 04/01/2014
> RIP: 0010:skb_panic+0x152/0x1d0
> Code: 0f b6 04 01 84 c0 74 04 3c 03 7e 20 8b 4b 70 41 56 45 89 e8 48
> c7 c7 80 b3 5b 8b 41 57 56 48 89 ee 52 4c 89 e2 e8 ae 15 6c f9 <0f> 0b
> 4c 89 4c 24 10 48 89 54 24 08 48 89 34 24 e8 69 1f d8 f9 4c
> RSP: 0018:ffffc900029bead0 EFLAGS: 00010282
> RAX: 0000000000000084 RBX: ffff88801d1c3d00 RCX: ffffc9000d863000
> RDX: 0000000000000000 RSI: ffffffff816695cc RDI: 0000000000000005
> RBP: ffffffff8b5bc1e0 R08: 0000000000000005 R09: 0000000000000000
> R10: 0000000000000400 R11: 0000000000000000 R12: ffffffff88a09da0
> R13: 0000000000000008 R14: ffff8880306b8000 R15: 0000000000000140
> FS: 00007f1dae5ed700(0000) GS:ffff888063a00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000564f403b7d10 CR3: 0000000117f1c000 CR4: 00000000000006f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> <TASK>
> skb_push+0xc8/0xe0
> fou_build_udp+0x30/0x370
It seems we need skb_cow_head() before skb_push().
I'll take a deeper look on the repro.
---8<---
diff --git a/net/ipv4/fou_core.c b/net/ipv4/fou_core.c
index cafec9b4eee0..24c751f1dbc4 100644
--- a/net/ipv4/fou_core.c
+++ b/net/ipv4/fou_core.c
@@ -1013,10 +1013,15 @@ EXPORT_SYMBOL(__gue_build_header);
#ifdef CONFIG_NET_FOU_IP_TUNNELS
-static void fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
- struct flowi4 *fl4, u8 *protocol, __be16 sport)
+static int fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
+ struct flowi4 *fl4, u8 *protocol, __be16 sport)
{
struct udphdr *uh;
+ int err;
+
+ err = skb_cow_head(skb, sizeof(*uh));
+ if (err)
+ return err;
skb_push(skb, sizeof(struct udphdr));
skb_reset_transport_header(skb);
@@ -1030,6 +1035,8 @@ static void fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
fl4->saddr, fl4->daddr, skb->len);
*protocol = IPPROTO_UDP;
+
+ return 0;
}
static int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
@@ -1044,9 +1051,7 @@ static int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
if (err)
return err;
- fou_build_udp(skb, e, fl4, protocol, sport);
-
- return 0;
+ return fou_build_udp(skb, e, fl4, protocol, sport);
}
static int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
@@ -1061,9 +1066,7 @@ static int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
if (err)
return err;
- fou_build_udp(skb, e, fl4, protocol, sport);
-
- return 0;
+ return fou_build_udp(skb, e, fl4, protocol, sport);
}
static int gue_err_proto_handler(int proto, struct sk_buff *skb, u32 info)
---8<---
Thanks,
Kuniyuki
> gue_build_header+0xfb/0x150
> ip_tunnel_xmit+0x66e/0x3150
> sit_tunnel_xmit__.isra.0+0xe7/0x150
> sit_tunnel_xmit+0xf7e/0x28e0
> dev_hard_start_xmit+0x187/0x700
> __dev_queue_xmit+0x2ce4/0x3c40
> neigh_connected_output+0x3c2/0x550
> ip_finish_output2+0x78a/0x22e0
> __ip_finish_output+0x396/0x650
> ip_finish_output+0x31/0x280
> ip_mc_output+0x21f/0x710
> ip_send_skb+0xd8/0x260
> udp_send_skb+0x73a/0x1480
> udp_sendmsg+0x1bb2/0x2840
> udpv6_sendmsg+0x1710/0x2c20
> inet6_sendmsg+0x9d/0xe0
> sock_sendmsg+0xde/0x190
> ____sys_sendmsg+0x334/0x900
> ___sys_sendmsg+0x110/0x1b0
> __sys_sendmmsg+0x18f/0x460
> __x64_sys_sendmmsg+0x9d/0x100
> do_syscall_64+0x39/0xb0
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
> RIP: 0033:0x7f1dad88eacd
> Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 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:00007f1dae5ecbf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
> RAX: ffffffffffffffda RBX: 00007f1dad9bbf80 RCX: 00007f1dad88eacd
> RDX: 0000000000000001 RSI: 00000000200017c0 RDI: 0000000000000003
> RBP: 00007f1dad8fcb05 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007fff4922802f R14: 00007fff492281d0 R15: 00007f1dae5ecd80
> </TASK>
> Modules linked in:
> ---[ end trace 0000000000000000 ]---
> RIP: 0010:skb_panic+0x152/0x1d0
> Code: 0f b6 04 01 84 c0 74 04 3c 03 7e 20 8b 4b 70 41 56 45 89 e8 48
> c7 c7 80 b3 5b 8b 41 57 56 48 89 ee 52 4c 89 e2 e8 ae 15 6c f9 <0f> 0b
> 4c 89 4c 24 10 48 89 54 24 08 48 89 34 24 e8 69 1f d8 f9 4c
> RSP: 0018:ffffc900029bead0 EFLAGS: 00010282
> RAX: 0000000000000084 RBX: ffff88801d1c3d00 RCX: ffffc9000d863000
> RDX: 0000000000000000 RSI: ffffffff816695cc RDI: 0000000000000005
> RBP: ffffffff8b5bc1e0 R08: 0000000000000005 R09: 0000000000000000
> R10: 0000000000000400 R11: 0000000000000000 R12: ffffffff88a09da0
> R13: 0000000000000008 R14: ffff8880306b8000 R15: 0000000000000140
> FS: 00007f1dae5ed700(0000) GS:ffff888063a00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000564f403b7d10 CR3: 0000000117f1c000 CR4: 00000000000006f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: kernel BUG in fou_build_udp
2023-04-15 19:44 ` Kuniyuki Iwashima
@ 2023-04-17 9:00 ` Eric Dumazet
2023-04-17 15:26 ` Kuniyuki Iwashima
0 siblings, 1 reply; 4+ messages in thread
From: Eric Dumazet @ 2023-04-17 9:00 UTC (permalink / raw)
To: Kuniyuki Iwashima
Cc: oswalpalash, davem, dsahern, kuba, linux-kernel, netdev, pabeni,
syzkaller-bugs
On Sat, Apr 15, 2023 at 9:44 PM Kuniyuki Iwashima <kuniyu@amazon.com> wrote:
>
> Hi,
>
> Thanks for reporting the issue.
>
> From: Palash Oswal <oswalpalash@gmail.com>
> Date: Thu, 13 Apr 2023 20:35:52 -0700
> > Hello,
> > I found the following issue using syzkaller with enriched corpus on:
> > HEAD commit : 0bcc4025550403ae28d2984bddacafbca0a2f112
> > git tree: linux
> >
> > C Reproducer : https://gist.github.com/oswalpalash/2a4bdb639c605ec80dbeec220e09603c
> > Kernel .config :
> > https://gist.github.com/oswalpalash/d9580b0bfce202b37445fa5fd426e41f
> > syz-repro :
> > r0 = socket$inet6(0xa, 0x2, 0x0)
> > r1 = socket$nl_route(0x10, 0x3, 0x0)
> > r2 = socket(0x10, 0x803, 0x0)
> > sendmsg$nl_route(r2, &(0x7f0000000380)={0x0, 0x0,
> > &(0x7f0000000340)={0x0, 0x14}}, 0x0)
> > getsockname$packet(r2, &(0x7f0000000100)={0x11, 0x0, <r3=>0x0, 0x1,
> > 0x0, 0x6, @broadcast}, &(0x7f00000000c0)=0x14)
> > sendmsg$nl_route(r1, &(0x7f0000000080)={0x0, 0x0,
> > &(0x7f0000000500)={&(0x7f0000000180)=@newlink={0x60, 0x10, 0x439, 0x0,
> > 0x0, {0x0, 0x0, 0x0, 0x0, 0x9801}, [@IFLA_LINKINFO={0x40, 0x12, 0x0,
> > 0x1, @sit={{0x8}, {0x34, 0x2, 0x0, 0x1, [@IFLA_IPTUN_LINK={0x8, 0x1,
> > r3}, @IFLA_IPTUN_ENCAP_TYPE={0x6, 0xf, 0x2},
> > @IFLA_IPTUN_ENCAP_SPORT={0x6, 0x11, 0x4e21},
> > @IFLA_IPTUN_ENCAP_SPORT={0x6, 0x11, 0x4e24}, @IFLA_IPTUN_LOCAL={0x8,
> > 0x2, @dev={0xac, 0x14, 0x14, 0x16}}, @IFLA_IPTUN_ENCAP_FLAGS={0x6,
> > 0x10, 0xfff}]}}}]}, 0x60}}, 0x20048894)
> > sendmmsg$inet(r0, &(0x7f00000017c0)=[{{&(0x7f0000000040)={0x2, 0x4e20,
> > @multicast1}, 0x10, 0x0, 0x0, &(0x7f0000000000)=[@ip_pktinfo={{0x1c,
> > 0x0, 0x8, {r3, @empty, @remote}}}], 0x20}}], 0x1, 0x0)
> >
> >
> > Console log:
> >
> > skbuff: skb_under_panic: text:ffffffff88a09da0 len:48 put:8
> > head:ffff88801e4be680 data:ffff88801e4be67c tail:0x2c end:0x140
> > dev:sit1
> > ------------[ cut here ]------------
> > kernel BUG at net/core/skbuff.c:150!
> > invalid opcode: 0000 [#1] PREEMPT SMP KASAN
> > CPU: 0 PID: 10068 Comm: syz-executor.3 Not tainted
> > 6.3.0-rc6-pasta-00035-g0bcc40255504 #1
> > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> > 1.13.0-1ubuntu1.1 04/01/2014
> > RIP: 0010:skb_panic+0x152/0x1d0
> > Code: 0f b6 04 01 84 c0 74 04 3c 03 7e 20 8b 4b 70 41 56 45 89 e8 48
> > c7 c7 80 b3 5b 8b 41 57 56 48 89 ee 52 4c 89 e2 e8 ae 15 6c f9 <0f> 0b
> > 4c 89 4c 24 10 48 89 54 24 08 48 89 34 24 e8 69 1f d8 f9 4c
> > RSP: 0018:ffffc900029bead0 EFLAGS: 00010282
> > RAX: 0000000000000084 RBX: ffff88801d1c3d00 RCX: ffffc9000d863000
> > RDX: 0000000000000000 RSI: ffffffff816695cc RDI: 0000000000000005
> > RBP: ffffffff8b5bc1e0 R08: 0000000000000005 R09: 0000000000000000
> > R10: 0000000000000400 R11: 0000000000000000 R12: ffffffff88a09da0
> > R13: 0000000000000008 R14: ffff8880306b8000 R15: 0000000000000140
> > FS: 00007f1dae5ed700(0000) GS:ffff888063a00000(0000) knlGS:0000000000000000
> > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > CR2: 0000564f403b7d10 CR3: 0000000117f1c000 CR4: 00000000000006f0
> > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> > Call Trace:
> > <TASK>
> > skb_push+0xc8/0xe0
> > fou_build_udp+0x30/0x370
>
> It seems we need skb_cow_head() before skb_push().
> I'll take a deeper look on the repro.
Not sure about that.
The issue looks to be a lack of dev->needed_headroom update as we do
in other tunnels.
>
> ---8<---
> diff --git a/net/ipv4/fou_core.c b/net/ipv4/fou_core.c
> index cafec9b4eee0..24c751f1dbc4 100644
> --- a/net/ipv4/fou_core.c
> +++ b/net/ipv4/fou_core.c
> @@ -1013,10 +1013,15 @@ EXPORT_SYMBOL(__gue_build_header);
>
> #ifdef CONFIG_NET_FOU_IP_TUNNELS
>
> -static void fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
> - struct flowi4 *fl4, u8 *protocol, __be16 sport)
> +static int fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
> + struct flowi4 *fl4, u8 *protocol, __be16 sport)
> {
> struct udphdr *uh;
> + int err;
> +
> + err = skb_cow_head(skb, sizeof(*uh));
> + if (err)
> + return err;
>
> skb_push(skb, sizeof(struct udphdr));
> skb_reset_transport_header(skb);
> @@ -1030,6 +1035,8 @@ static void fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
> fl4->saddr, fl4->daddr, skb->len);
>
> *protocol = IPPROTO_UDP;
> +
> + return 0;
> }
>
> static int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
> @@ -1044,9 +1051,7 @@ static int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
> if (err)
> return err;
>
> - fou_build_udp(skb, e, fl4, protocol, sport);
> -
> - return 0;
> + return fou_build_udp(skb, e, fl4, protocol, sport);
> }
>
> static int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
> @@ -1061,9 +1066,7 @@ static int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
> if (err)
> return err;
>
> - fou_build_udp(skb, e, fl4, protocol, sport);
> -
> - return 0;
> + return fou_build_udp(skb, e, fl4, protocol, sport);
> }
>
> static int gue_err_proto_handler(int proto, struct sk_buff *skb, u32 info)
> ---8<---
>
> Thanks,
> Kuniyuki
>
>
> > gue_build_header+0xfb/0x150
> > ip_tunnel_xmit+0x66e/0x3150
> > sit_tunnel_xmit__.isra.0+0xe7/0x150
> > sit_tunnel_xmit+0xf7e/0x28e0
> > dev_hard_start_xmit+0x187/0x700
> > __dev_queue_xmit+0x2ce4/0x3c40
> > neigh_connected_output+0x3c2/0x550
> > ip_finish_output2+0x78a/0x22e0
> > __ip_finish_output+0x396/0x650
> > ip_finish_output+0x31/0x280
> > ip_mc_output+0x21f/0x710
> > ip_send_skb+0xd8/0x260
> > udp_send_skb+0x73a/0x1480
> > udp_sendmsg+0x1bb2/0x2840
> > udpv6_sendmsg+0x1710/0x2c20
> > inet6_sendmsg+0x9d/0xe0
> > sock_sendmsg+0xde/0x190
> > ____sys_sendmsg+0x334/0x900
> > ___sys_sendmsg+0x110/0x1b0
> > __sys_sendmmsg+0x18f/0x460
> > __x64_sys_sendmmsg+0x9d/0x100
> > do_syscall_64+0x39/0xb0
> > entry_SYSCALL_64_after_hwframe+0x63/0xcd
> > RIP: 0033:0x7f1dad88eacd
> > Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 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:00007f1dae5ecbf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
> > RAX: ffffffffffffffda RBX: 00007f1dad9bbf80 RCX: 00007f1dad88eacd
> > RDX: 0000000000000001 RSI: 00000000200017c0 RDI: 0000000000000003
> > RBP: 00007f1dad8fcb05 R08: 0000000000000000 R09: 0000000000000000
> > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> > R13: 00007fff4922802f R14: 00007fff492281d0 R15: 00007f1dae5ecd80
> > </TASK>
> > Modules linked in:
> > ---[ end trace 0000000000000000 ]---
> > RIP: 0010:skb_panic+0x152/0x1d0
> > Code: 0f b6 04 01 84 c0 74 04 3c 03 7e 20 8b 4b 70 41 56 45 89 e8 48
> > c7 c7 80 b3 5b 8b 41 57 56 48 89 ee 52 4c 89 e2 e8 ae 15 6c f9 <0f> 0b
> > 4c 89 4c 24 10 48 89 54 24 08 48 89 34 24 e8 69 1f d8 f9 4c
> > RSP: 0018:ffffc900029bead0 EFLAGS: 00010282
> > RAX: 0000000000000084 RBX: ffff88801d1c3d00 RCX: ffffc9000d863000
> > RDX: 0000000000000000 RSI: ffffffff816695cc RDI: 0000000000000005
> > RBP: ffffffff8b5bc1e0 R08: 0000000000000005 R09: 0000000000000000
> > R10: 0000000000000400 R11: 0000000000000000 R12: ffffffff88a09da0
> > R13: 0000000000000008 R14: ffff8880306b8000 R15: 0000000000000140
> > FS: 00007f1dae5ed700(0000) GS:ffff888063a00000(0000) knlGS:0000000000000000
> > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > CR2: 0000564f403b7d10 CR3: 0000000117f1c000 CR4: 00000000000006f0
> > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: kernel BUG in fou_build_udp
2023-04-17 9:00 ` Eric Dumazet
@ 2023-04-17 15:26 ` Kuniyuki Iwashima
0 siblings, 0 replies; 4+ messages in thread
From: Kuniyuki Iwashima @ 2023-04-17 15:26 UTC (permalink / raw)
To: edumazet
Cc: davem, dsahern, kuba, kuniyu, linux-kernel, netdev, oswalpalash,
pabeni, syzkaller-bugs
From: Eric Dumazet <edumazet@google.com>
Date: Mon, 17 Apr 2023 11:00:20 +0200
> On Sat, Apr 15, 2023 at 9:44 PM Kuniyuki Iwashima <kuniyu@amazon.com> wrote:
> >
> > Hi,
> >
> > Thanks for reporting the issue.
> >
> > From: Palash Oswal <oswalpalash@gmail.com>
> > Date: Thu, 13 Apr 2023 20:35:52 -0700
> > > Hello,
> > > I found the following issue using syzkaller with enriched corpus on:
> > > HEAD commit : 0bcc4025550403ae28d2984bddacafbca0a2f112
> > > git tree: linux
> > >
> > > C Reproducer : https://gist.github.com/oswalpalash/2a4bdb639c605ec80dbeec220e09603c
> > > Kernel .config :
> > > https://gist.github.com/oswalpalash/d9580b0bfce202b37445fa5fd426e41f
> > > syz-repro :
> > > r0 = socket$inet6(0xa, 0x2, 0x0)
> > > r1 = socket$nl_route(0x10, 0x3, 0x0)
> > > r2 = socket(0x10, 0x803, 0x0)
> > > sendmsg$nl_route(r2, &(0x7f0000000380)={0x0, 0x0,
> > > &(0x7f0000000340)={0x0, 0x14}}, 0x0)
> > > getsockname$packet(r2, &(0x7f0000000100)={0x11, 0x0, <r3=>0x0, 0x1,
> > > 0x0, 0x6, @broadcast}, &(0x7f00000000c0)=0x14)
> > > sendmsg$nl_route(r1, &(0x7f0000000080)={0x0, 0x0,
> > > &(0x7f0000000500)={&(0x7f0000000180)=@newlink={0x60, 0x10, 0x439, 0x0,
> > > 0x0, {0x0, 0x0, 0x0, 0x0, 0x9801}, [@IFLA_LINKINFO={0x40, 0x12, 0x0,
> > > 0x1, @sit={{0x8}, {0x34, 0x2, 0x0, 0x1, [@IFLA_IPTUN_LINK={0x8, 0x1,
> > > r3}, @IFLA_IPTUN_ENCAP_TYPE={0x6, 0xf, 0x2},
> > > @IFLA_IPTUN_ENCAP_SPORT={0x6, 0x11, 0x4e21},
> > > @IFLA_IPTUN_ENCAP_SPORT={0x6, 0x11, 0x4e24}, @IFLA_IPTUN_LOCAL={0x8,
> > > 0x2, @dev={0xac, 0x14, 0x14, 0x16}}, @IFLA_IPTUN_ENCAP_FLAGS={0x6,
> > > 0x10, 0xfff}]}}}]}, 0x60}}, 0x20048894)
> > > sendmmsg$inet(r0, &(0x7f00000017c0)=[{{&(0x7f0000000040)={0x2, 0x4e20,
> > > @multicast1}, 0x10, 0x0, 0x0, &(0x7f0000000000)=[@ip_pktinfo={{0x1c,
> > > 0x0, 0x8, {r3, @empty, @remote}}}], 0x20}}], 0x1, 0x0)
> > >
> > >
> > > Console log:
> > >
> > > skbuff: skb_under_panic: text:ffffffff88a09da0 len:48 put:8
> > > head:ffff88801e4be680 data:ffff88801e4be67c tail:0x2c end:0x140
> > > dev:sit1
> > > ------------[ cut here ]------------
> > > kernel BUG at net/core/skbuff.c:150!
> > > invalid opcode: 0000 [#1] PREEMPT SMP KASAN
> > > CPU: 0 PID: 10068 Comm: syz-executor.3 Not tainted
> > > 6.3.0-rc6-pasta-00035-g0bcc40255504 #1
> > > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> > > 1.13.0-1ubuntu1.1 04/01/2014
> > > RIP: 0010:skb_panic+0x152/0x1d0
> > > Code: 0f b6 04 01 84 c0 74 04 3c 03 7e 20 8b 4b 70 41 56 45 89 e8 48
> > > c7 c7 80 b3 5b 8b 41 57 56 48 89 ee 52 4c 89 e2 e8 ae 15 6c f9 <0f> 0b
> > > 4c 89 4c 24 10 48 89 54 24 08 48 89 34 24 e8 69 1f d8 f9 4c
> > > RSP: 0018:ffffc900029bead0 EFLAGS: 00010282
> > > RAX: 0000000000000084 RBX: ffff88801d1c3d00 RCX: ffffc9000d863000
> > > RDX: 0000000000000000 RSI: ffffffff816695cc RDI: 0000000000000005
> > > RBP: ffffffff8b5bc1e0 R08: 0000000000000005 R09: 0000000000000000
> > > R10: 0000000000000400 R11: 0000000000000000 R12: ffffffff88a09da0
> > > R13: 0000000000000008 R14: ffff8880306b8000 R15: 0000000000000140
> > > FS: 00007f1dae5ed700(0000) GS:ffff888063a00000(0000) knlGS:0000000000000000
> > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > > CR2: 0000564f403b7d10 CR3: 0000000117f1c000 CR4: 00000000000006f0
> > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> > > Call Trace:
> > > <TASK>
> > > skb_push+0xc8/0xe0
> > > fou_build_udp+0x30/0x370
> >
> > It seems we need skb_cow_head() before skb_push().
> > I'll take a deeper look on the repro.
>
> Not sure about that.
>
> The issue looks to be a lack of dev->needed_headroom update as we do
> in other tunnels.
I'll check around it as well.
Thank you!
>
> >
> > ---8<---
> > diff --git a/net/ipv4/fou_core.c b/net/ipv4/fou_core.c
> > index cafec9b4eee0..24c751f1dbc4 100644
> > --- a/net/ipv4/fou_core.c
> > +++ b/net/ipv4/fou_core.c
> > @@ -1013,10 +1013,15 @@ EXPORT_SYMBOL(__gue_build_header);
> >
> > #ifdef CONFIG_NET_FOU_IP_TUNNELS
> >
> > -static void fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
> > - struct flowi4 *fl4, u8 *protocol, __be16 sport)
> > +static int fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
> > + struct flowi4 *fl4, u8 *protocol, __be16 sport)
> > {
> > struct udphdr *uh;
> > + int err;
> > +
> > + err = skb_cow_head(skb, sizeof(*uh));
> > + if (err)
> > + return err;
> >
> > skb_push(skb, sizeof(struct udphdr));
> > skb_reset_transport_header(skb);
> > @@ -1030,6 +1035,8 @@ static void fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
> > fl4->saddr, fl4->daddr, skb->len);
> >
> > *protocol = IPPROTO_UDP;
> > +
> > + return 0;
> > }
> >
> > static int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
> > @@ -1044,9 +1051,7 @@ static int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
> > if (err)
> > return err;
> >
> > - fou_build_udp(skb, e, fl4, protocol, sport);
> > -
> > - return 0;
> > + return fou_build_udp(skb, e, fl4, protocol, sport);
> > }
> >
> > static int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
> > @@ -1061,9 +1066,7 @@ static int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
> > if (err)
> > return err;
> >
> > - fou_build_udp(skb, e, fl4, protocol, sport);
> > -
> > - return 0;
> > + return fou_build_udp(skb, e, fl4, protocol, sport);
> > }
> >
> > static int gue_err_proto_handler(int proto, struct sk_buff *skb, u32 info)
> > ---8<---
> >
> > Thanks,
> > Kuniyuki
> >
> >
> > > gue_build_header+0xfb/0x150
> > > ip_tunnel_xmit+0x66e/0x3150
> > > sit_tunnel_xmit__.isra.0+0xe7/0x150
> > > sit_tunnel_xmit+0xf7e/0x28e0
> > > dev_hard_start_xmit+0x187/0x700
> > > __dev_queue_xmit+0x2ce4/0x3c40
> > > neigh_connected_output+0x3c2/0x550
> > > ip_finish_output2+0x78a/0x22e0
> > > __ip_finish_output+0x396/0x650
> > > ip_finish_output+0x31/0x280
> > > ip_mc_output+0x21f/0x710
> > > ip_send_skb+0xd8/0x260
> > > udp_send_skb+0x73a/0x1480
> > > udp_sendmsg+0x1bb2/0x2840
> > > udpv6_sendmsg+0x1710/0x2c20
> > > inet6_sendmsg+0x9d/0xe0
> > > sock_sendmsg+0xde/0x190
> > > ____sys_sendmsg+0x334/0x900
> > > ___sys_sendmsg+0x110/0x1b0
> > > __sys_sendmmsg+0x18f/0x460
> > > __x64_sys_sendmmsg+0x9d/0x100
> > > do_syscall_64+0x39/0xb0
> > > entry_SYSCALL_64_after_hwframe+0x63/0xcd
> > > RIP: 0033:0x7f1dad88eacd
> > > Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 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:00007f1dae5ecbf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
> > > RAX: ffffffffffffffda RBX: 00007f1dad9bbf80 RCX: 00007f1dad88eacd
> > > RDX: 0000000000000001 RSI: 00000000200017c0 RDI: 0000000000000003
> > > RBP: 00007f1dad8fcb05 R08: 0000000000000000 R09: 0000000000000000
> > > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> > > R13: 00007fff4922802f R14: 00007fff492281d0 R15: 00007f1dae5ecd80
> > > </TASK>
> > > Modules linked in:
> > > ---[ end trace 0000000000000000 ]---
> > > RIP: 0010:skb_panic+0x152/0x1d0
> > > Code: 0f b6 04 01 84 c0 74 04 3c 03 7e 20 8b 4b 70 41 56 45 89 e8 48
> > > c7 c7 80 b3 5b 8b 41 57 56 48 89 ee 52 4c 89 e2 e8 ae 15 6c f9 <0f> 0b
> > > 4c 89 4c 24 10 48 89 54 24 08 48 89 34 24 e8 69 1f d8 f9 4c
> > > RSP: 0018:ffffc900029bead0 EFLAGS: 00010282
> > > RAX: 0000000000000084 RBX: ffff88801d1c3d00 RCX: ffffc9000d863000
> > > RDX: 0000000000000000 RSI: ffffffff816695cc RDI: 0000000000000005
> > > RBP: ffffffff8b5bc1e0 R08: 0000000000000005 R09: 0000000000000000
> > > R10: 0000000000000400 R11: 0000000000000000 R12: ffffffff88a09da0
> > > R13: 0000000000000008 R14: ffff8880306b8000 R15: 0000000000000140
> > > FS: 00007f1dae5ed700(0000) GS:ffff888063a00000(0000) knlGS:0000000000000000
> > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > > CR2: 0000564f403b7d10 CR3: 0000000117f1c000 CR4: 00000000000006f0
> > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2023-04-17 15:28 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-04-14 3:35 kernel BUG in fou_build_udp Palash Oswal
2023-04-15 19:44 ` Kuniyuki Iwashima
2023-04-17 9:00 ` Eric Dumazet
2023-04-17 15:26 ` Kuniyuki Iwashima
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