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* [Qemu-devel] [PATCH for-4.0] migration/ram.c: Fix use-after-free in multifd_recv_unfill_packet()
@ 2019-04-09 15:18 Peter Maydell
  2019-04-09 15:18 ` Peter Maydell
                   ` (2 more replies)
  0 siblings, 3 replies; 8+ messages in thread
From: Peter Maydell @ 2019-04-09 15:18 UTC (permalink / raw)
  To: qemu-devel; +Cc: Juan Quintela, Dr. David Alan Gilbert

Coverity points out (CID 1400442) that in this code:

    if (packet->pages_alloc > p->pages->allocated) {
        multifd_pages_clear(p->pages);
        multifd_pages_init(packet->pages_alloc);
    }

we free p->pages in multifd_pages_clear() but continue to
use it in the following code. We also leak memory, because
multifd_pages_init() returns the pointer to a new MultiFDPages_t
struct but we are ignoring its return value.

Fix both of these bugs by adding the missing assignment of
the newly created struct to p->pages.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
I don't know anything about the multifd code, but this seems like
the obvious fix based on looking at what the clear and init
functions are doing. I have only run 'make check' on this,
so review and testing definitely in order. I think we should
really put this into 4.0, which means ideally I'd like to
commit it to master today or tomorrow, though...
---
 migration/ram.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/migration/ram.c b/migration/ram.c
index f68beeeeffc..1ca9ba77b6a 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -851,7 +851,7 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
      */
     if (packet->pages_alloc > p->pages->allocated) {
         multifd_pages_clear(p->pages);
-        multifd_pages_init(packet->pages_alloc);
+        p->pages = multifd_pages_init(packet->pages_alloc);
     }
 
     p->pages->used = be32_to_cpu(packet->pages_used);
-- 
2.20.1

^ permalink raw reply related	[flat|nested] 8+ messages in thread

* [Qemu-devel] [PATCH for-4.0] migration/ram.c: Fix use-after-free in multifd_recv_unfill_packet()
  2019-04-09 15:18 [Qemu-devel] [PATCH for-4.0] migration/ram.c: Fix use-after-free in multifd_recv_unfill_packet() Peter Maydell
@ 2019-04-09 15:18 ` Peter Maydell
  2019-04-09 15:46 ` Juan Quintela
  2019-04-09 18:49 ` Philippe Mathieu-Daudé
  2 siblings, 0 replies; 8+ messages in thread
From: Peter Maydell @ 2019-04-09 15:18 UTC (permalink / raw)
  To: qemu-devel; +Cc: Dr. David Alan Gilbert, Juan Quintela

Coverity points out (CID 1400442) that in this code:

    if (packet->pages_alloc > p->pages->allocated) {
        multifd_pages_clear(p->pages);
        multifd_pages_init(packet->pages_alloc);
    }

we free p->pages in multifd_pages_clear() but continue to
use it in the following code. We also leak memory, because
multifd_pages_init() returns the pointer to a new MultiFDPages_t
struct but we are ignoring its return value.

Fix both of these bugs by adding the missing assignment of
the newly created struct to p->pages.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
I don't know anything about the multifd code, but this seems like
the obvious fix based on looking at what the clear and init
functions are doing. I have only run 'make check' on this,
so review and testing definitely in order. I think we should
really put this into 4.0, which means ideally I'd like to
commit it to master today or tomorrow, though...
---
 migration/ram.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/migration/ram.c b/migration/ram.c
index f68beeeeffc..1ca9ba77b6a 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -851,7 +851,7 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
      */
     if (packet->pages_alloc > p->pages->allocated) {
         multifd_pages_clear(p->pages);
-        multifd_pages_init(packet->pages_alloc);
+        p->pages = multifd_pages_init(packet->pages_alloc);
     }
 
     p->pages->used = be32_to_cpu(packet->pages_used);
-- 
2.20.1



^ permalink raw reply related	[flat|nested] 8+ messages in thread

* Re: [Qemu-devel] [PATCH for-4.0] migration/ram.c: Fix use-after-free in multifd_recv_unfill_packet()
  2019-04-09 15:18 [Qemu-devel] [PATCH for-4.0] migration/ram.c: Fix use-after-free in multifd_recv_unfill_packet() Peter Maydell
  2019-04-09 15:18 ` Peter Maydell
@ 2019-04-09 15:46 ` Juan Quintela
  2019-04-09 15:46   ` Juan Quintela
  2019-04-09 19:47   ` Peter Maydell
  2019-04-09 18:49 ` Philippe Mathieu-Daudé
  2 siblings, 2 replies; 8+ messages in thread
From: Juan Quintela @ 2019-04-09 15:46 UTC (permalink / raw)
  To: Peter Maydell; +Cc: qemu-devel, Dr. David Alan Gilbert

Peter Maydell <peter.maydell@linaro.org> wrote:
> Coverity points out (CID 1400442) that in this code:
>
>     if (packet->pages_alloc > p->pages->allocated) {
>         multifd_pages_clear(p->pages);
>         multifd_pages_init(packet->pages_alloc);
>     }
>
> we free p->pages in multifd_pages_clear() but continue to
> use it in the following code. We also leak memory, because
> multifd_pages_init() returns the pointer to a new MultiFDPages_t
> struct but we are ignoring its return value.
>
> Fix both of these bugs by adding the missing assignment of
> the newly created struct to p->pages.
>
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---

ouch,

good catch.

Reviewed-by: Juan Quintela <quintela@redhat.com>



> I don't know anything about the multifd code, but this seems like
> the obvious fix based on looking at what the clear and init
> functions are doing. I have only run 'make check' on this,
> so review and testing definitely in order. I think we should
> really put this into 4.0, which means ideally I'd like to
> commit it to master today or tomorrow, though...
> ---
>  migration/ram.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/migration/ram.c b/migration/ram.c
> index f68beeeeffc..1ca9ba77b6a 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -851,7 +851,7 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
>       */
>      if (packet->pages_alloc > p->pages->allocated) {
>          multifd_pages_clear(p->pages);
> -        multifd_pages_init(packet->pages_alloc);
> +        p->pages = multifd_pages_init(packet->pages_alloc);
>      }
>  
>      p->pages->used = be32_to_cpu(packet->pages_used);

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [Qemu-devel] [PATCH for-4.0] migration/ram.c: Fix use-after-free in multifd_recv_unfill_packet()
  2019-04-09 15:46 ` Juan Quintela
@ 2019-04-09 15:46   ` Juan Quintela
  2019-04-09 19:47   ` Peter Maydell
  1 sibling, 0 replies; 8+ messages in thread
From: Juan Quintela @ 2019-04-09 15:46 UTC (permalink / raw)
  To: Peter Maydell; +Cc: qemu-devel, Dr. David Alan Gilbert

Peter Maydell <peter.maydell@linaro.org> wrote:
> Coverity points out (CID 1400442) that in this code:
>
>     if (packet->pages_alloc > p->pages->allocated) {
>         multifd_pages_clear(p->pages);
>         multifd_pages_init(packet->pages_alloc);
>     }
>
> we free p->pages in multifd_pages_clear() but continue to
> use it in the following code. We also leak memory, because
> multifd_pages_init() returns the pointer to a new MultiFDPages_t
> struct but we are ignoring its return value.
>
> Fix both of these bugs by adding the missing assignment of
> the newly created struct to p->pages.
>
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---

ouch,

good catch.

Reviewed-by: Juan Quintela <quintela@redhat.com>



> I don't know anything about the multifd code, but this seems like
> the obvious fix based on looking at what the clear and init
> functions are doing. I have only run 'make check' on this,
> so review and testing definitely in order. I think we should
> really put this into 4.0, which means ideally I'd like to
> commit it to master today or tomorrow, though...
> ---
>  migration/ram.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/migration/ram.c b/migration/ram.c
> index f68beeeeffc..1ca9ba77b6a 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -851,7 +851,7 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
>       */
>      if (packet->pages_alloc > p->pages->allocated) {
>          multifd_pages_clear(p->pages);
> -        multifd_pages_init(packet->pages_alloc);
> +        p->pages = multifd_pages_init(packet->pages_alloc);
>      }
>  
>      p->pages->used = be32_to_cpu(packet->pages_used);


^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [Qemu-devel] [PATCH for-4.0] migration/ram.c: Fix use-after-free in multifd_recv_unfill_packet()
  2019-04-09 15:18 [Qemu-devel] [PATCH for-4.0] migration/ram.c: Fix use-after-free in multifd_recv_unfill_packet() Peter Maydell
  2019-04-09 15:18 ` Peter Maydell
  2019-04-09 15:46 ` Juan Quintela
@ 2019-04-09 18:49 ` Philippe Mathieu-Daudé
  2019-04-09 18:49   ` Philippe Mathieu-Daudé
  2 siblings, 1 reply; 8+ messages in thread
From: Philippe Mathieu-Daudé @ 2019-04-09 18:49 UTC (permalink / raw)
  To: Peter Maydell, qemu-devel; +Cc: Dr. David Alan Gilbert, Juan Quintela

On 4/9/19 5:18 PM, Peter Maydell wrote:
> Coverity points out (CID 1400442) that in this code:
> 
>     if (packet->pages_alloc > p->pages->allocated) {
>         multifd_pages_clear(p->pages);
>         multifd_pages_init(packet->pages_alloc);
>     }
> 
> we free p->pages in multifd_pages_clear() but continue to
> use it in the following code. We also leak memory, because
> multifd_pages_init() returns the pointer to a new MultiFDPages_t
> struct but we are ignoring its return value.
> 
> Fix both of these bugs by adding the missing assignment of
> the newly created struct to p->pages.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> ---
> I don't know anything about the multifd code, but this seems like
> the obvious fix based on looking at what the clear and init
> functions are doing. I have only run 'make check' on this,
> so review and testing definitely in order. I think we should
> really put this into 4.0, which means ideally I'd like to
> commit it to master today or tomorrow, though...
> ---
>  migration/ram.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/migration/ram.c b/migration/ram.c
> index f68beeeeffc..1ca9ba77b6a 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -851,7 +851,7 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
>       */
>      if (packet->pages_alloc > p->pages->allocated) {
>          multifd_pages_clear(p->pages);
> -        multifd_pages_init(packet->pages_alloc);
> +        p->pages = multifd_pages_init(packet->pages_alloc);
>      }
>  
>      p->pages->used = be32_to_cpu(packet->pages_used);
> 

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [Qemu-devel] [PATCH for-4.0] migration/ram.c: Fix use-after-free in multifd_recv_unfill_packet()
  2019-04-09 18:49 ` Philippe Mathieu-Daudé
@ 2019-04-09 18:49   ` Philippe Mathieu-Daudé
  0 siblings, 0 replies; 8+ messages in thread
From: Philippe Mathieu-Daudé @ 2019-04-09 18:49 UTC (permalink / raw)
  To: Peter Maydell, qemu-devel; +Cc: Dr. David Alan Gilbert, Juan Quintela

On 4/9/19 5:18 PM, Peter Maydell wrote:
> Coverity points out (CID 1400442) that in this code:
> 
>     if (packet->pages_alloc > p->pages->allocated) {
>         multifd_pages_clear(p->pages);
>         multifd_pages_init(packet->pages_alloc);
>     }
> 
> we free p->pages in multifd_pages_clear() but continue to
> use it in the following code. We also leak memory, because
> multifd_pages_init() returns the pointer to a new MultiFDPages_t
> struct but we are ignoring its return value.
> 
> Fix both of these bugs by adding the missing assignment of
> the newly created struct to p->pages.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> ---
> I don't know anything about the multifd code, but this seems like
> the obvious fix based on looking at what the clear and init
> functions are doing. I have only run 'make check' on this,
> so review and testing definitely in order. I think we should
> really put this into 4.0, which means ideally I'd like to
> commit it to master today or tomorrow, though...
> ---
>  migration/ram.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/migration/ram.c b/migration/ram.c
> index f68beeeeffc..1ca9ba77b6a 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -851,7 +851,7 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
>       */
>      if (packet->pages_alloc > p->pages->allocated) {
>          multifd_pages_clear(p->pages);
> -        multifd_pages_init(packet->pages_alloc);
> +        p->pages = multifd_pages_init(packet->pages_alloc);
>      }
>  
>      p->pages->used = be32_to_cpu(packet->pages_used);
> 


^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [Qemu-devel] [PATCH for-4.0] migration/ram.c: Fix use-after-free in multifd_recv_unfill_packet()
  2019-04-09 15:46 ` Juan Quintela
  2019-04-09 15:46   ` Juan Quintela
@ 2019-04-09 19:47   ` Peter Maydell
  2019-04-09 19:47     ` Peter Maydell
  1 sibling, 1 reply; 8+ messages in thread
From: Peter Maydell @ 2019-04-09 19:47 UTC (permalink / raw)
  To: Juan Quintela; +Cc: QEMU Developers, Dr. David Alan Gilbert

On Tue, 9 Apr 2019 at 22:42, Juan Quintela <quintela@redhat.com> wrote:
>
> Peter Maydell <peter.maydell@linaro.org> wrote:
> > Coverity points out (CID 1400442) that in this code:
> >
> >     if (packet->pages_alloc > p->pages->allocated) {
> >         multifd_pages_clear(p->pages);
> >         multifd_pages_init(packet->pages_alloc);
> >     }
> >
> > we free p->pages in multifd_pages_clear() but continue to
> > use it in the following code. We also leak memory, because
> > multifd_pages_init() returns the pointer to a new MultiFDPages_t
> > struct but we are ignoring its return value.
> >
> > Fix both of these bugs by adding the missing assignment of
> > the newly created struct to p->pages.
> >
> > Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> > ---
>
> ouch,
>
> good catch.
>
> Reviewed-by: Juan Quintela <quintela@redhat.com>

Thanks for the quick review. Applied to master for rc3.

-- PMM

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [Qemu-devel] [PATCH for-4.0] migration/ram.c: Fix use-after-free in multifd_recv_unfill_packet()
  2019-04-09 19:47   ` Peter Maydell
@ 2019-04-09 19:47     ` Peter Maydell
  0 siblings, 0 replies; 8+ messages in thread
From: Peter Maydell @ 2019-04-09 19:47 UTC (permalink / raw)
  To: Juan Quintela; +Cc: QEMU Developers, Dr. David Alan Gilbert

On Tue, 9 Apr 2019 at 22:42, Juan Quintela <quintela@redhat.com> wrote:
>
> Peter Maydell <peter.maydell@linaro.org> wrote:
> > Coverity points out (CID 1400442) that in this code:
> >
> >     if (packet->pages_alloc > p->pages->allocated) {
> >         multifd_pages_clear(p->pages);
> >         multifd_pages_init(packet->pages_alloc);
> >     }
> >
> > we free p->pages in multifd_pages_clear() but continue to
> > use it in the following code. We also leak memory, because
> > multifd_pages_init() returns the pointer to a new MultiFDPages_t
> > struct but we are ignoring its return value.
> >
> > Fix both of these bugs by adding the missing assignment of
> > the newly created struct to p->pages.
> >
> > Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> > ---
>
> ouch,
>
> good catch.
>
> Reviewed-by: Juan Quintela <quintela@redhat.com>

Thanks for the quick review. Applied to master for rc3.

-- PMM


^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2019-04-09 19:48 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-04-09 15:18 [Qemu-devel] [PATCH for-4.0] migration/ram.c: Fix use-after-free in multifd_recv_unfill_packet() Peter Maydell
2019-04-09 15:18 ` Peter Maydell
2019-04-09 15:46 ` Juan Quintela
2019-04-09 15:46   ` Juan Quintela
2019-04-09 19:47   ` Peter Maydell
2019-04-09 19:47     ` Peter Maydell
2019-04-09 18:49 ` Philippe Mathieu-Daudé
2019-04-09 18:49   ` Philippe Mathieu-Daudé

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