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* [RFC PATCH] net/tls: Fix skb memory leak when running kTLS traffic
@ 2022-01-02  8:12 Gal Pressman
  2022-01-07 18:51 ` Jakub Kicinski
  0 siblings, 1 reply; 6+ messages in thread
From: Gal Pressman @ 2022-01-02  8:12 UTC (permalink / raw)
  To: Eric Dumazet, Jakub Kicinski, David S. Miller
  Cc: netdev, Tariq Toukan, Saeed Mahameed, Gal Pressman

The cited Fixes commit introduced a memory leak when running kTLS
traffic (with/without hardware offloads).
I'm running nginx on the server side and wrk on the client side and get
the following:

  unreferenced object 0xffff8881935e9b80 (size 224):
  comm "softirq", pid 0, jiffies 4294903611 (age 43.204s)
  hex dump (first 32 bytes):
    80 9b d0 36 81 88 ff ff 00 00 00 00 00 00 00 00  ...6............
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000efe2a999>] build_skb+0x1f/0x170
    [<00000000ef521785>] mlx5e_skb_from_cqe_mpwrq_linear+0x2bc/0x610 [mlx5_core]
    [<00000000945d0ffe>] mlx5e_handle_rx_cqe_mpwrq+0x264/0x9e0 [mlx5_core]
    [<00000000cb675b06>] mlx5e_poll_rx_cq+0x3ad/0x17a0 [mlx5_core]
    [<0000000018aac6a9>] mlx5e_napi_poll+0x28c/0x1b60 [mlx5_core]
    [<000000001f3369d1>] __napi_poll+0x9f/0x560
    [<00000000cfa11f72>] net_rx_action+0x357/0xa60
    [<000000008653b8d7>] __do_softirq+0x282/0x94e
    [<00000000644923c6>] __irq_exit_rcu+0x11f/0x170
    [<00000000d4085f8f>] irq_exit_rcu+0xa/0x20
    [<00000000d412fef4>] common_interrupt+0x7d/0xa0
    [<00000000bfb0cebc>] asm_common_interrupt+0x1e/0x40
    [<00000000d80d0890>] default_idle+0x53/0x70
    [<00000000f2b9780e>] default_idle_call+0x8c/0xd0
    [<00000000c7659e15>] do_idle+0x394/0x450

I'm not familiar with these areas of the code, but I've added this
sk_defer_free_flush() to tls_sw_recvmsg() based on a hunch and it
resolved the issue.

Eric, do you think this is the correct fix? Maybe we're missing a call
to sk_defer_free_flush() in other places as well?

Thanks!

Fixes: f35f821935d8 ("tcp: defer skb freeing after socket lock is released")
Signed-off-by: Gal Pressman <gal@nvidia.com>
---
 net/tls/tls_sw.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 3f271e29812f..95e774f1b91f 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -1990,6 +1990,7 @@ int tls_sw_recvmsg(struct sock *sk,
 
 end:
 	release_sock(sk);
+	sk_defer_free_flush(sk);
 	if (psock)
 		sk_psock_put(sk, psock);
 	return copied ? : err;
-- 
2.25.1


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

* Re: [RFC PATCH] net/tls: Fix skb memory leak when running kTLS traffic
  2022-01-02  8:12 [RFC PATCH] net/tls: Fix skb memory leak when running kTLS traffic Gal Pressman
@ 2022-01-07 18:51 ` Jakub Kicinski
  2022-01-07 19:12   ` Eric Dumazet
  0 siblings, 1 reply; 6+ messages in thread
From: Jakub Kicinski @ 2022-01-07 18:51 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Gal Pressman, David S. Miller, netdev, Tariq Toukan, Saeed Mahameed

On Sun, 2 Jan 2022 10:12:53 +0200 Gal Pressman wrote:
> The cited Fixes commit introduced a memory leak when running kTLS
> traffic (with/without hardware offloads).
> I'm running nginx on the server side and wrk on the client side and get
> the following:
> 
>   unreferenced object 0xffff8881935e9b80 (size 224):
>   comm "softirq", pid 0, jiffies 4294903611 (age 43.204s)
>   hex dump (first 32 bytes):
>     80 9b d0 36 81 88 ff ff 00 00 00 00 00 00 00 00  ...6............
>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>   backtrace:
>     [<00000000efe2a999>] build_skb+0x1f/0x170
>     [<00000000ef521785>] mlx5e_skb_from_cqe_mpwrq_linear+0x2bc/0x610 [mlx5_core]
>     [<00000000945d0ffe>] mlx5e_handle_rx_cqe_mpwrq+0x264/0x9e0 [mlx5_core]
>     [<00000000cb675b06>] mlx5e_poll_rx_cq+0x3ad/0x17a0 [mlx5_core]
>     [<0000000018aac6a9>] mlx5e_napi_poll+0x28c/0x1b60 [mlx5_core]
>     [<000000001f3369d1>] __napi_poll+0x9f/0x560
>     [<00000000cfa11f72>] net_rx_action+0x357/0xa60
>     [<000000008653b8d7>] __do_softirq+0x282/0x94e
>     [<00000000644923c6>] __irq_exit_rcu+0x11f/0x170
>     [<00000000d4085f8f>] irq_exit_rcu+0xa/0x20
>     [<00000000d412fef4>] common_interrupt+0x7d/0xa0
>     [<00000000bfb0cebc>] asm_common_interrupt+0x1e/0x40
>     [<00000000d80d0890>] default_idle+0x53/0x70
>     [<00000000f2b9780e>] default_idle_call+0x8c/0xd0
>     [<00000000c7659e15>] do_idle+0x394/0x450
> 
> I'm not familiar with these areas of the code, but I've added this
> sk_defer_free_flush() to tls_sw_recvmsg() based on a hunch and it
> resolved the issue.
> 
> Eric, do you think this is the correct fix? Maybe we're missing a call
> to sk_defer_free_flush() in other places as well?

Any thoughts, Eric? Since the merge window is coming soon should 
we purge the defer free queue when socket is destroyed at least?
All the .read_sock callers will otherwise risk the leaks, it seems.

> Fixes: f35f821935d8 ("tcp: defer skb freeing after socket lock is released")
> Signed-off-by: Gal Pressman <gal@nvidia.com>
> ---
>  net/tls/tls_sw.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
> index 3f271e29812f..95e774f1b91f 100644
> --- a/net/tls/tls_sw.c
> +++ b/net/tls/tls_sw.c
> @@ -1990,6 +1990,7 @@ int tls_sw_recvmsg(struct sock *sk,
>  
>  end:
>  	release_sock(sk);
> +	sk_defer_free_flush(sk);
>  	if (psock)
>  		sk_psock_put(sk, psock);
>  	return copied ? : err;


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

* Re: [RFC PATCH] net/tls: Fix skb memory leak when running kTLS traffic
  2022-01-07 18:51 ` Jakub Kicinski
@ 2022-01-07 19:12   ` Eric Dumazet
  2022-01-08  2:44     ` Jakub Kicinski
  0 siblings, 1 reply; 6+ messages in thread
From: Eric Dumazet @ 2022-01-07 19:12 UTC (permalink / raw)
  To: Jakub Kicinski
  Cc: Gal Pressman, David S. Miller, netdev, Tariq Toukan, Saeed Mahameed

On Fri, Jan 7, 2022 at 10:51 AM Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Sun, 2 Jan 2022 10:12:53 +0200 Gal Pressman wrote:
> > The cited Fixes commit introduced a memory leak when running kTLS
> > traffic (with/without hardware offloads).
> > I'm running nginx on the server side and wrk on the client side and get
> > the following:
> >
> >   unreferenced object 0xffff8881935e9b80 (size 224):
> >   comm "softirq", pid 0, jiffies 4294903611 (age 43.204s)
> >   hex dump (first 32 bytes):
> >     80 9b d0 36 81 88 ff ff 00 00 00 00 00 00 00 00  ...6............
> >     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
> >   backtrace:
> >     [<00000000efe2a999>] build_skb+0x1f/0x170
> >     [<00000000ef521785>] mlx5e_skb_from_cqe_mpwrq_linear+0x2bc/0x610 [mlx5_core]
> >     [<00000000945d0ffe>] mlx5e_handle_rx_cqe_mpwrq+0x264/0x9e0 [mlx5_core]
> >     [<00000000cb675b06>] mlx5e_poll_rx_cq+0x3ad/0x17a0 [mlx5_core]
> >     [<0000000018aac6a9>] mlx5e_napi_poll+0x28c/0x1b60 [mlx5_core]
> >     [<000000001f3369d1>] __napi_poll+0x9f/0x560
> >     [<00000000cfa11f72>] net_rx_action+0x357/0xa60
> >     [<000000008653b8d7>] __do_softirq+0x282/0x94e
> >     [<00000000644923c6>] __irq_exit_rcu+0x11f/0x170
> >     [<00000000d4085f8f>] irq_exit_rcu+0xa/0x20
> >     [<00000000d412fef4>] common_interrupt+0x7d/0xa0
> >     [<00000000bfb0cebc>] asm_common_interrupt+0x1e/0x40
> >     [<00000000d80d0890>] default_idle+0x53/0x70
> >     [<00000000f2b9780e>] default_idle_call+0x8c/0xd0
> >     [<00000000c7659e15>] do_idle+0x394/0x450
> >
> > I'm not familiar with these areas of the code, but I've added this
> > sk_defer_free_flush() to tls_sw_recvmsg() based on a hunch and it
> > resolved the issue.
> >
> > Eric, do you think this is the correct fix? Maybe we're missing a call
> > to sk_defer_free_flush() in other places as well?
>
> Any thoughts, Eric? Since the merge window is coming soon should
> we purge the defer free queue when socket is destroyed at least?
> All the .read_sock callers will otherwise risk the leaks, it seems.

It seems I missed this patch.

We might merge it, and eventually add another

WARN_ON_ONCE(!llist_empty(sk->defer_list))
sk_defer_free_flush(sk);

at socket destroy as you suggested ?

Reviewed-by: Eric Dumazet <edumazet@google.com>

>
> > Fixes: f35f821935d8 ("tcp: defer skb freeing after socket lock is released")
> > Signed-off-by: Gal Pressman <gal@nvidia.com>
> > ---
> >  net/tls/tls_sw.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
> > index 3f271e29812f..95e774f1b91f 100644
> > --- a/net/tls/tls_sw.c
> > +++ b/net/tls/tls_sw.c
> > @@ -1990,6 +1990,7 @@ int tls_sw_recvmsg(struct sock *sk,
> >
> >  end:
> >       release_sock(sk);
> > +     sk_defer_free_flush(sk);
> >       if (psock)
> >               sk_psock_put(sk, psock);
> >       return copied ? : err;
>

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

* Re: [RFC PATCH] net/tls: Fix skb memory leak when running kTLS traffic
  2022-01-07 19:12   ` Eric Dumazet
@ 2022-01-08  2:44     ` Jakub Kicinski
  2022-01-09 11:49       ` Gal Pressman
  0 siblings, 1 reply; 6+ messages in thread
From: Jakub Kicinski @ 2022-01-08  2:44 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Gal Pressman, David S. Miller, netdev, Tariq Toukan, Saeed Mahameed

On Fri, 7 Jan 2022 11:12:28 -0800 Eric Dumazet wrote:
> On Fri, Jan 7, 2022 at 10:51 AM Jakub Kicinski <kuba@kernel.org> wrote:
> >
> > On Sun, 2 Jan 2022 10:12:53 +0200 Gal Pressman wrote:  
> > > The cited Fixes commit introduced a memory leak when running kTLS
> > > traffic (with/without hardware offloads).
> > > I'm running nginx on the server side and wrk on the client side and get
> > > the following:
> > >
> > >   unreferenced object 0xffff8881935e9b80 (size 224):
> > >   comm "softirq", pid 0, jiffies 4294903611 (age 43.204s)
> > >   hex dump (first 32 bytes):
> > >     80 9b d0 36 81 88 ff ff 00 00 00 00 00 00 00 00  ...6............
> > >     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
> > >   backtrace:
> > >     [<00000000efe2a999>] build_skb+0x1f/0x170
> > >     [<00000000ef521785>] mlx5e_skb_from_cqe_mpwrq_linear+0x2bc/0x610 [mlx5_core]
> > >     [<00000000945d0ffe>] mlx5e_handle_rx_cqe_mpwrq+0x264/0x9e0 [mlx5_core]
> > >     [<00000000cb675b06>] mlx5e_poll_rx_cq+0x3ad/0x17a0 [mlx5_core]
> > >     [<0000000018aac6a9>] mlx5e_napi_poll+0x28c/0x1b60 [mlx5_core]
> > >     [<000000001f3369d1>] __napi_poll+0x9f/0x560
> > >     [<00000000cfa11f72>] net_rx_action+0x357/0xa60
> > >     [<000000008653b8d7>] __do_softirq+0x282/0x94e
> > >     [<00000000644923c6>] __irq_exit_rcu+0x11f/0x170
> > >     [<00000000d4085f8f>] irq_exit_rcu+0xa/0x20
> > >     [<00000000d412fef4>] common_interrupt+0x7d/0xa0
> > >     [<00000000bfb0cebc>] asm_common_interrupt+0x1e/0x40
> > >     [<00000000d80d0890>] default_idle+0x53/0x70
> > >     [<00000000f2b9780e>] default_idle_call+0x8c/0xd0
> > >     [<00000000c7659e15>] do_idle+0x394/0x450
> > >
> > > I'm not familiar with these areas of the code, but I've added this
> > > sk_defer_free_flush() to tls_sw_recvmsg() based on a hunch and it
> > > resolved the issue.
> > >
> > > Eric, do you think this is the correct fix? Maybe we're missing a call
> > > to sk_defer_free_flush() in other places as well?  
> >
> > Any thoughts, Eric? Since the merge window is coming soon should
> > we purge the defer free queue when socket is destroyed at least?
> > All the .read_sock callers will otherwise risk the leaks, it seems.  
> 
> It seems I missed this patch.
> 
> We might merge it, and eventually add another
> 
> WARN_ON_ONCE(!llist_empty(sk->defer_list))
> sk_defer_free_flush(sk);
> 
> at socket destroy as you suggested ?
> 
> Reviewed-by: Eric Dumazet <edumazet@google.com>

Thanks, applied!

Gal please follow up as suggested, for TLS similar treatment to what
you have done here will be necessary in the splice_read handler.

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

* Re: [RFC PATCH] net/tls: Fix skb memory leak when running kTLS traffic
  2022-01-08  2:44     ` Jakub Kicinski
@ 2022-01-09 11:49       ` Gal Pressman
  2022-01-09 21:16         ` Jakub Kicinski
  0 siblings, 1 reply; 6+ messages in thread
From: Gal Pressman @ 2022-01-09 11:49 UTC (permalink / raw)
  To: Jakub Kicinski, Eric Dumazet
  Cc: David S. Miller, netdev, Tariq Toukan, Saeed Mahameed


On 08/01/2022 04:44, Jakub Kicinski wrote:
> On Fri, 7 Jan 2022 11:12:28 -0800 Eric Dumazet wrote:
>> On Fri, Jan 7, 2022 at 10:51 AM Jakub Kicinski <kuba@kernel.org> wrote:
>>> On Sun, 2 Jan 2022 10:12:53 +0200 Gal Pressman wrote:  
>>>> The cited Fixes commit introduced a memory leak when running kTLS
>>>> traffic (with/without hardware offloads).
>>>> I'm running nginx on the server side and wrk on the client side and get
>>>> the following:
>>>>
>>>>   unreferenced object 0xffff8881935e9b80 (size 224):
>>>>   comm "softirq", pid 0, jiffies 4294903611 (age 43.204s)
>>>>   hex dump (first 32 bytes):
>>>>     80 9b d0 36 81 88 ff ff 00 00 00 00 00 00 00 00  ...6............
>>>>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>>>>   backtrace:
>>>>     [<00000000efe2a999>] build_skb+0x1f/0x170
>>>>     [<00000000ef521785>] mlx5e_skb_from_cqe_mpwrq_linear+0x2bc/0x610 [mlx5_core]
>>>>     [<00000000945d0ffe>] mlx5e_handle_rx_cqe_mpwrq+0x264/0x9e0 [mlx5_core]
>>>>     [<00000000cb675b06>] mlx5e_poll_rx_cq+0x3ad/0x17a0 [mlx5_core]
>>>>     [<0000000018aac6a9>] mlx5e_napi_poll+0x28c/0x1b60 [mlx5_core]
>>>>     [<000000001f3369d1>] __napi_poll+0x9f/0x560
>>>>     [<00000000cfa11f72>] net_rx_action+0x357/0xa60
>>>>     [<000000008653b8d7>] __do_softirq+0x282/0x94e
>>>>     [<00000000644923c6>] __irq_exit_rcu+0x11f/0x170
>>>>     [<00000000d4085f8f>] irq_exit_rcu+0xa/0x20
>>>>     [<00000000d412fef4>] common_interrupt+0x7d/0xa0
>>>>     [<00000000bfb0cebc>] asm_common_interrupt+0x1e/0x40
>>>>     [<00000000d80d0890>] default_idle+0x53/0x70
>>>>     [<00000000f2b9780e>] default_idle_call+0x8c/0xd0
>>>>     [<00000000c7659e15>] do_idle+0x394/0x450
>>>>
>>>> I'm not familiar with these areas of the code, but I've added this
>>>> sk_defer_free_flush() to tls_sw_recvmsg() based on a hunch and it
>>>> resolved the issue.
>>>>
>>>> Eric, do you think this is the correct fix? Maybe we're missing a call
>>>> to sk_defer_free_flush() in other places as well?  
>>> Any thoughts, Eric? Since the merge window is coming soon should
>>> we purge the defer free queue when socket is destroyed at least?
>>> All the .read_sock callers will otherwise risk the leaks, it seems.  
>> It seems I missed this patch.
>>
>> We might merge it, and eventually add another
>>
>> WARN_ON_ONCE(!llist_empty(sk->defer_list))
>> sk_defer_free_flush(sk);
>>
>> at socket destroy as you suggested ?
>>
>> Reviewed-by: Eric Dumazet <edumazet@google.com>
> Thanks, applied!
>
> Gal please follow up as suggested, for TLS similar treatment to what
> you have done here will be necessary in the splice_read handler.


Thanks Eric and Jakub!

So you want one patch that adds a sk_defer_free_flush() call in
tls_sw_splice_read(), and a second one that adds the WARN_ON_ONCE to
sk_free()?


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

* Re: [RFC PATCH] net/tls: Fix skb memory leak when running kTLS traffic
  2022-01-09 11:49       ` Gal Pressman
@ 2022-01-09 21:16         ` Jakub Kicinski
  0 siblings, 0 replies; 6+ messages in thread
From: Jakub Kicinski @ 2022-01-09 21:16 UTC (permalink / raw)
  To: Gal Pressman
  Cc: Eric Dumazet, David S. Miller, netdev, Tariq Toukan, Saeed Mahameed

On Sun, 9 Jan 2022 13:49:42 +0200 Gal Pressman wrote:
> So you want one patch that adds a sk_defer_free_flush() call in
> tls_sw_splice_read(), and a second one that adds the WARN_ON_ONCE to
> sk_free()?

Two separate patches is probably the best way to go.

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

end of thread, other threads:[~2022-01-09 21:16 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-01-02  8:12 [RFC PATCH] net/tls: Fix skb memory leak when running kTLS traffic Gal Pressman
2022-01-07 18:51 ` Jakub Kicinski
2022-01-07 19:12   ` Eric Dumazet
2022-01-08  2:44     ` Jakub Kicinski
2022-01-09 11:49       ` Gal Pressman
2022-01-09 21:16         ` Jakub Kicinski

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