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* [PATCH bpf 0/4] bpf, sockmap: Fix some issues with using apply_bytes
@ 2022-11-16 11:29 Pengcheng Yang
  2022-11-16 11:29 ` [PATCH bpf 2/4] bpf, sockmap: Fix missing BPF_F_INGRESS flag when " Pengcheng Yang
                   ` (4 more replies)
  0 siblings, 5 replies; 6+ messages in thread
From: Pengcheng Yang @ 2022-11-16 11:29 UTC (permalink / raw)
  To: John Fastabend, Jakub Sitnicki, bpf, netdev; +Cc: Pengcheng Yang

Patch 0001~0003 fixes three issues with using apply_bytes when redirecting.
Patch 0004 adds ingress tests for txmsg with apply_bytes in selftests.

Pengcheng Yang (4):
  bpf, sockmap: Fix repeated calls to sock_put() when msg has more_data
  bpf, sockmap: Fix missing BPF_F_INGRESS flag when using apply_bytes
  bpf, sockmap: Fix data loss caused by using apply_bytes on ingress
    redirect
  selftests/bpf: Add ingress tests for txmsg with apply_bytes

 include/linux/skmsg.h                      |  1 +
 net/core/skmsg.c                           |  1 +
 net/ipv4/tcp_bpf.c                         |  9 +++++++--
 net/tls/tls_sw.c                           |  1 +
 tools/testing/selftests/bpf/test_sockmap.c | 18 ++++++++++++++++++
 5 files changed, 28 insertions(+), 2 deletions(-)

-- 
1.8.3.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH bpf 2/4] bpf, sockmap: Fix missing BPF_F_INGRESS flag when using apply_bytes
  2022-11-16 11:29 [PATCH bpf 0/4] bpf, sockmap: Fix some issues with using apply_bytes Pengcheng Yang
@ 2022-11-16 11:29 ` Pengcheng Yang
  2022-11-16 11:29 ` [PATCH bpf 4/4] selftests/bpf: Add ingress tests for txmsg with apply_bytes Pengcheng Yang
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: Pengcheng Yang @ 2022-11-16 11:29 UTC (permalink / raw)
  To: John Fastabend, Jakub Sitnicki, bpf, netdev; +Cc: Pengcheng Yang

When redirecting, we use sk_msg_to_ingress() to get the BPF_F_INGRESS
flag from the msg->flags. If apply_bytes is used and it is larger than
the current data being processed, sk_psock_msg_verdict() will not be
called when sendmsg() is called again. At this time, the msg->flags is 0,
and we lost the BPF_F_INGRESS flag.

So we need to save the BPF_F_INGRESS flag in sk_psock and assign it to
msg->flags before redirection.

Fixes: 8934ce2fd081 ("bpf: sockmap redirect ingress support")
Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>
---
 include/linux/skmsg.h | 1 +
 net/core/skmsg.c      | 1 +
 net/ipv4/tcp_bpf.c    | 1 +
 net/tls/tls_sw.c      | 1 +
 4 files changed, 4 insertions(+)

diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h
index 48f4b64..e1d463f 100644
--- a/include/linux/skmsg.h
+++ b/include/linux/skmsg.h
@@ -82,6 +82,7 @@ struct sk_psock {
 	u32				apply_bytes;
 	u32				cork_bytes;
 	u32				eval;
+	u32				flags;
 	struct sk_msg			*cork;
 	struct sk_psock_progs		progs;
 #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index 188f855..ab2f8f3 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -888,6 +888,7 @@ int sk_psock_msg_verdict(struct sock *sk, struct sk_psock *psock,
 		if (psock->sk_redir)
 			sock_put(psock->sk_redir);
 		psock->sk_redir = msg->sk_redir;
+		psock->flags = msg->flags;
 		if (!psock->sk_redir) {
 			ret = __SK_DROP;
 			goto out;
diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
index ef5de4f..1390d72 100644
--- a/net/ipv4/tcp_bpf.c
+++ b/net/ipv4/tcp_bpf.c
@@ -323,6 +323,7 @@ static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock,
 		break;
 	case __SK_REDIRECT:
 		sk_redir = psock->sk_redir;
+		msg->flags = psock->flags;
 		sk_msg_apply_bytes(psock, tosend);
 		if (!psock->apply_bytes) {
 			/* Clean up before releasing the sock lock. */
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index fe27241..49e424d 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -838,6 +838,7 @@ static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,
 		break;
 	case __SK_REDIRECT:
 		sk_redir = psock->sk_redir;
+		msg->flags = psock->flags;
 		memcpy(&msg_redir, msg, sizeof(*msg));
 		if (msg->apply_bytes < send)
 			msg->apply_bytes = 0;
-- 
1.8.3.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH bpf 4/4] selftests/bpf: Add ingress tests for txmsg with apply_bytes
  2022-11-16 11:29 [PATCH bpf 0/4] bpf, sockmap: Fix some issues with using apply_bytes Pengcheng Yang
  2022-11-16 11:29 ` [PATCH bpf 2/4] bpf, sockmap: Fix missing BPF_F_INGRESS flag when " Pengcheng Yang
@ 2022-11-16 11:29 ` Pengcheng Yang
  2022-11-21  9:35 ` [PATCH bpf 0/4] bpf, sockmap: Fix some issues with using apply_bytes Jakub Sitnicki
                   ` (2 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: Pengcheng Yang @ 2022-11-16 11:29 UTC (permalink / raw)
  To: John Fastabend, Jakub Sitnicki, bpf, netdev; +Cc: Pengcheng Yang

Currently, the ingress redirect is not covered in "txmsg test apply".

Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>
---
 tools/testing/selftests/bpf/test_sockmap.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/tools/testing/selftests/bpf/test_sockmap.c b/tools/testing/selftests/bpf/test_sockmap.c
index 0fbaccd..9bc0cb4 100644
--- a/tools/testing/selftests/bpf/test_sockmap.c
+++ b/tools/testing/selftests/bpf/test_sockmap.c
@@ -1649,24 +1649,42 @@ static void test_txmsg_apply(int cgrp, struct sockmap_options *opt)
 {
 	txmsg_pass = 1;
 	txmsg_redir = 0;
+	txmsg_ingress = 0;
 	txmsg_apply = 1;
 	txmsg_cork = 0;
 	test_send_one(opt, cgrp);
 
 	txmsg_pass = 0;
 	txmsg_redir = 1;
+	txmsg_ingress = 0;
+	txmsg_apply = 1;
+	txmsg_cork = 0;
+	test_send_one(opt, cgrp);
+
+	txmsg_pass = 0;
+	txmsg_redir = 1;
+	txmsg_ingress = 1;
 	txmsg_apply = 1;
 	txmsg_cork = 0;
 	test_send_one(opt, cgrp);
 
 	txmsg_pass = 1;
 	txmsg_redir = 0;
+	txmsg_ingress = 0;
+	txmsg_apply = 1024;
+	txmsg_cork = 0;
+	test_send_large(opt, cgrp);
+
+	txmsg_pass = 0;
+	txmsg_redir = 1;
+	txmsg_ingress = 0;
 	txmsg_apply = 1024;
 	txmsg_cork = 0;
 	test_send_large(opt, cgrp);
 
 	txmsg_pass = 0;
 	txmsg_redir = 1;
+	txmsg_ingress = 1;
 	txmsg_apply = 1024;
 	txmsg_cork = 0;
 	test_send_large(opt, cgrp);
-- 
1.8.3.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH bpf 0/4] bpf, sockmap: Fix some issues with using apply_bytes
  2022-11-16 11:29 [PATCH bpf 0/4] bpf, sockmap: Fix some issues with using apply_bytes Pengcheng Yang
  2022-11-16 11:29 ` [PATCH bpf 2/4] bpf, sockmap: Fix missing BPF_F_INGRESS flag when " Pengcheng Yang
  2022-11-16 11:29 ` [PATCH bpf 4/4] selftests/bpf: Add ingress tests for txmsg with apply_bytes Pengcheng Yang
@ 2022-11-21  9:35 ` Jakub Sitnicki
  2022-11-21 16:38 ` Daniel Borkmann
       [not found] ` <1668598161-15455-2-git-send-email-yangpc@wangsu.com>
  4 siblings, 0 replies; 6+ messages in thread
From: Jakub Sitnicki @ 2022-11-21  9:35 UTC (permalink / raw)
  To: Pengcheng Yang; +Cc: John Fastabend, bpf, netdev

On Wed, Nov 16, 2022 at 07:29 PM +08, Pengcheng Yang wrote:
> Patch 0001~0003 fixes three issues with using apply_bytes when redirecting.
> Patch 0004 adds ingress tests for txmsg with apply_bytes in selftests.
>
> Pengcheng Yang (4):
>   bpf, sockmap: Fix repeated calls to sock_put() when msg has more_data
>   bpf, sockmap: Fix missing BPF_F_INGRESS flag when using apply_bytes
>   bpf, sockmap: Fix data loss caused by using apply_bytes on ingress
>     redirect
>   selftests/bpf: Add ingress tests for txmsg with apply_bytes
>
>  include/linux/skmsg.h                      |  1 +
>  net/core/skmsg.c                           |  1 +
>  net/ipv4/tcp_bpf.c                         |  9 +++++++--
>  net/tls/tls_sw.c                           |  1 +
>  tools/testing/selftests/bpf/test_sockmap.c | 18 ++++++++++++++++++
>  5 files changed, 28 insertions(+), 2 deletions(-)

Thanks for the patches. I need a bit more time to review them.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH bpf 0/4] bpf, sockmap: Fix some issues with using apply_bytes
  2022-11-16 11:29 [PATCH bpf 0/4] bpf, sockmap: Fix some issues with using apply_bytes Pengcheng Yang
                   ` (2 preceding siblings ...)
  2022-11-21  9:35 ` [PATCH bpf 0/4] bpf, sockmap: Fix some issues with using apply_bytes Jakub Sitnicki
@ 2022-11-21 16:38 ` Daniel Borkmann
       [not found] ` <1668598161-15455-2-git-send-email-yangpc@wangsu.com>
  4 siblings, 0 replies; 6+ messages in thread
From: Daniel Borkmann @ 2022-11-21 16:38 UTC (permalink / raw)
  To: Pengcheng Yang, John Fastabend, Jakub Sitnicki, bpf, netdev

On 11/16/22 12:29 PM, Pengcheng Yang wrote:
> Patch 0001~0003 fixes three issues with using apply_bytes when redirecting.
> Patch 0004 adds ingress tests for txmsg with apply_bytes in selftests.
> 
> Pengcheng Yang (4):
>    bpf, sockmap: Fix repeated calls to sock_put() when msg has more_data
>    bpf, sockmap: Fix missing BPF_F_INGRESS flag when using apply_bytes
>    bpf, sockmap: Fix data loss caused by using apply_bytes on ingress
>      redirect
>    selftests/bpf: Add ingress tests for txmsg with apply_bytes

Patch 1 & 3 didn't make it to the list [0], could you resend your series?

   [0] https://lore.kernel.org/bpf/1668598161-15455-1-git-send-email-yangpc@wangsu.com/

>   include/linux/skmsg.h                      |  1 +
>   net/core/skmsg.c                           |  1 +
>   net/ipv4/tcp_bpf.c                         |  9 +++++++--
>   net/tls/tls_sw.c                           |  1 +
>   tools/testing/selftests/bpf/test_sockmap.c | 18 ++++++++++++++++++
>   5 files changed, 28 insertions(+), 2 deletions(-)
> 


^ permalink raw reply	[flat|nested] 6+ messages in thread

* RE: [PATCH bpf 1/4] bpf, sockmap: Fix repeated calls to sock_put() when msg has more_data
       [not found] ` <1668598161-15455-2-git-send-email-yangpc@wangsu.com>
@ 2022-11-22  2:16   ` John Fastabend
  0 siblings, 0 replies; 6+ messages in thread
From: John Fastabend @ 2022-11-22  2:16 UTC (permalink / raw)
  To: Pengcheng Yang, John Fastabend, Jakub Sitnicki, bpf, netdev
  Cc: Pengcheng Yang

Pengcheng Yang wrote:
> In tcp_bpf_send_verdict() redirection, the eval variable is assigned to
> __SK_REDIRECT after the apply_bytes data is sent, if msg has more_data,
> sock_put() will be called multiple times.
> We should reset the eval variable to __SK_NONE every time more_data
> starts.
> 
> This causes:
> 
> IPv4: Attempt to release TCP socket in state 1 00000000b4c925d7
> ------------[ cut here ]------------
> refcount_t: addition on 0; use-after-free.
> WARNING: CPU: 5 PID: 4482 at lib/refcount.c:25 refcount_warn_saturate+0x7d/0x110
> Modules linked in:
> CPU: 5 PID: 4482 Comm: sockhash_bypass Kdump: loaded Not tainted 6.0.0 #1
> Hardware name: Red Hat KVM, BIOS 1.11.0-2.el7 04/01/2014
> Call Trace:
>  <TASK>
>  __tcp_transmit_skb+0xa1b/0xb90
>  ? __alloc_skb+0x8c/0x1a0
>  ? __kmalloc_node_track_caller+0x184/0x320
>  tcp_write_xmit+0x22a/0x1110
>  __tcp_push_pending_frames+0x32/0xf0
>  do_tcp_sendpages+0x62d/0x640
>  tcp_bpf_push+0xae/0x2c0
>  tcp_bpf_sendmsg_redir+0x260/0x410
>  ? preempt_count_add+0x70/0xa0
>  tcp_bpf_send_verdict+0x386/0x4b0
>  tcp_bpf_sendmsg+0x21b/0x3b0
>  sock_sendmsg+0x58/0x70
>  __sys_sendto+0xfa/0x170
>  ? xfd_validate_state+0x1d/0x80
>  ? switch_fpu_return+0x59/0xe0
>  __x64_sys_sendto+0x24/0x30
>  do_syscall_64+0x37/0x90
>  entry_SYSCALL_64_after_hwframe+0x63/0xcd
> 
> Fixes: cd9733f5d75c ("tcp_bpf: Fix one concurrency problem in the tcp_bpf_send_verdict function")
> Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>

I'll wait for the resend with all the patches but for this one.

Acked-by: John Fastabend <john.fastabend@gmail.com>

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2022-11-22  2:21 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-11-16 11:29 [PATCH bpf 0/4] bpf, sockmap: Fix some issues with using apply_bytes Pengcheng Yang
2022-11-16 11:29 ` [PATCH bpf 2/4] bpf, sockmap: Fix missing BPF_F_INGRESS flag when " Pengcheng Yang
2022-11-16 11:29 ` [PATCH bpf 4/4] selftests/bpf: Add ingress tests for txmsg with apply_bytes Pengcheng Yang
2022-11-21  9:35 ` [PATCH bpf 0/4] bpf, sockmap: Fix some issues with using apply_bytes Jakub Sitnicki
2022-11-21 16:38 ` Daniel Borkmann
     [not found] ` <1668598161-15455-2-git-send-email-yangpc@wangsu.com>
2022-11-22  2:16   ` [PATCH bpf 1/4] bpf, sockmap: Fix repeated calls to sock_put() when msg has more_data John Fastabend

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