ring: fix use after free in ring release
Checks
Commit Message
When using the ring to find out tailq entry, however it had been
freed by rte_memzone_free function. This change prevents that
from happening.
Fixes: 4e32101f9b01 ("ring: support freeing")
Cc: stable@dpdk.org
Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
---
lib/ring/rte_ring.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)
Comments
> -----Original Message-----
> From: Yunjian Wang <wangyunjian@huawei.com>
> Sent: Monday, April 17, 2023 8:12 AM
> To: dev@dpdk.org
> Cc: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>;
> konstantin.v.ananyev@yandex.ru; luyicai@huawei.com; Yunjian Wang
> <wangyunjian@huawei.com>; stable@dpdk.org
> Subject: [dpdk-dev] [PATCH] ring: fix use after free in ring release
>
> When using the ring to find out tailq entry, however it had been freed by
> rte_memzone_free function. This change prevents that from happening.
I am unable to follow the problem you are describing.
After the memzone for the ring is released, the contents of the memzone are not being used. I understand that the variable 'r' is being used, but that should not cause any issues.
>
> Fixes: 4e32101f9b01 ("ring: support freeing")
> Cc: stable@dpdk.org
>
> Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
> ---
> lib/ring/rte_ring.c | 11 +++++------
> 1 file changed, 5 insertions(+), 6 deletions(-)
>
> diff --git a/lib/ring/rte_ring.c b/lib/ring/rte_ring.c index
> 8ed455043d..17d2d7f8a8 100644
> --- a/lib/ring/rte_ring.c
> +++ b/lib/ring/rte_ring.c
> @@ -333,11 +333,6 @@ rte_ring_free(struct rte_ring *r)
> return;
> }
>
> - if (rte_memzone_free(r->memzone) != 0) {
> - RTE_LOG(ERR, RING, "Cannot free memory\n");
> - return;
> - }
Why do we need to free the memzone later?
> -
> ring_list = RTE_TAILQ_CAST(rte_ring_tailq.head, rte_ring_list);
> rte_mcfg_tailq_write_lock();
>
> @@ -349,7 +344,7 @@ rte_ring_free(struct rte_ring *r)
>
> if (te == NULL) {
> rte_mcfg_tailq_write_unlock();
> - return;
> + goto free_memzone;
> }
>
> TAILQ_REMOVE(ring_list, te, next);
> @@ -357,6 +352,10 @@ rte_ring_free(struct rte_ring *r)
> rte_mcfg_tailq_write_unlock();
>
> rte_free(te);
> +
> +free_memzone:
> + if (rte_memzone_free(r->memzone) != 0)
> + RTE_LOG(ERR, RING, "Cannot free memory\n");
> }
>
> /* dump the status of the ring on the console */
> --
> 2.33.0
> -----Original Message-----
> From: Honnappa Nagarahalli [mailto:Honnappa.Nagarahalli@arm.com]
> Sent: Wednesday, April 19, 2023 7:53 AM
> To: wangyunjian <wangyunjian@huawei.com>; dev@dpdk.org
> Cc: konstantin.v.ananyev@yandex.ru; luyicai <luyicai@huawei.com>;
> stable@dpdk.org; nd <nd@arm.com>; Honnappa Nagarahalli
> <Honnappa.Nagarahalli@arm.com>; nd <nd@arm.com>
> Subject: RE: [dpdk-dev] [PATCH] ring: fix use after free in ring release
>
>
>
> > -----Original Message-----
> > From: Yunjian Wang <wangyunjian@huawei.com>
> > Sent: Monday, April 17, 2023 8:12 AM
> > To: dev@dpdk.org
> > Cc: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>;
> > konstantin.v.ananyev@yandex.ru; luyicai@huawei.com; Yunjian Wang
> > <wangyunjian@huawei.com>; stable@dpdk.org
> > Subject: [dpdk-dev] [PATCH] ring: fix use after free in ring release
> >
> > When using the ring to find out tailq entry, however it had been freed
> > by rte_memzone_free function. This change prevents that from happening.
> I am unable to follow the problem you are describing.
> After the memzone for the ring is released, the contents of the memzone are
> not being used. I understand that the variable 'r' is being used, but that should
> not cause any issues.
>
> >
> > Fixes: 4e32101f9b01 ("ring: support freeing")
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
> > ---
> > lib/ring/rte_ring.c | 11 +++++------
> > 1 file changed, 5 insertions(+), 6 deletions(-)
> >
> > diff --git a/lib/ring/rte_ring.c b/lib/ring/rte_ring.c index
> > 8ed455043d..17d2d7f8a8 100644
> > --- a/lib/ring/rte_ring.c
> > +++ b/lib/ring/rte_ring.c
> > @@ -333,11 +333,6 @@ rte_ring_free(struct rte_ring *r)
> > return;
> > }
> >
> > - if (rte_memzone_free(r->memzone) != 0) {
> > - RTE_LOG(ERR, RING, "Cannot free memory\n");
> > - return;
> > - }
> Why do we need to free the memzone later?
After the memzone is freed, it is not removed from the 'rte_ring_tailq'.
If rte_ring_lookup is called at this time, it will cause a use-after-free problem.
Thanks,
Yunjian
>
> > -
> > ring_list = RTE_TAILQ_CAST(rte_ring_tailq.head, rte_ring_list);
> > rte_mcfg_tailq_write_lock();
> >
> > @@ -349,7 +344,7 @@ rte_ring_free(struct rte_ring *r)
> >
> > if (te == NULL) {
> > rte_mcfg_tailq_write_unlock();
> > - return;
> > + goto free_memzone;
> > }
> >
> > TAILQ_REMOVE(ring_list, te, next);
> > @@ -357,6 +352,10 @@ rte_ring_free(struct rte_ring *r)
> > rte_mcfg_tailq_write_unlock();
> >
> > rte_free(te);
> > +
> > +free_memzone:
> > + if (rte_memzone_free(r->memzone) != 0)
> > + RTE_LOG(ERR, RING, "Cannot free memory\n");
> > }
> >
> > /* dump the status of the ring on the console */
> > --
> > 2.33.0
<snip>
> >
> > > -----Original Message-----
> > > From: Yunjian Wang <wangyunjian@huawei.com>
> > > Sent: Monday, April 17, 2023 8:12 AM
> > > To: dev@dpdk.org
> > > Cc: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>;
> > > konstantin.v.ananyev@yandex.ru; luyicai@huawei.com; Yunjian Wang
> > > <wangyunjian@huawei.com>; stable@dpdk.org
> > > Subject: [dpdk-dev] [PATCH] ring: fix use after free in ring release
> > >
> > > When using the ring to find out tailq entry, however it had been
> > > freed by rte_memzone_free function. This change prevents that from
> happening.
> > I am unable to follow the problem you are describing.
> > After the memzone for the ring is released, the contents of the
> > memzone are not being used. I understand that the variable 'r' is
> > being used, but that should not cause any issues.
> >
> > >
> > > Fixes: 4e32101f9b01 ("ring: support freeing")
> > > Cc: stable@dpdk.org
> > >
> > > Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
> > > ---
> > > lib/ring/rte_ring.c | 11 +++++------
> > > 1 file changed, 5 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/lib/ring/rte_ring.c b/lib/ring/rte_ring.c index
> > > 8ed455043d..17d2d7f8a8 100644
> > > --- a/lib/ring/rte_ring.c
> > > +++ b/lib/ring/rte_ring.c
> > > @@ -333,11 +333,6 @@ rte_ring_free(struct rte_ring *r)
> > > return;
> > > }
> > >
> > > - if (rte_memzone_free(r->memzone) != 0) {
> > > - RTE_LOG(ERR, RING, "Cannot free memory\n");
> > > - return;
> > > - }
> > Why do we need to free the memzone later?
>
> After the memzone is freed, it is not removed from the 'rte_ring_tailq'.
> If rte_ring_lookup is called at this time, it will cause a use-after-free problem.
Thanks, understood
>
> Thanks,
> Yunjian
> >
> > > -
> > > ring_list = RTE_TAILQ_CAST(rte_ring_tailq.head, rte_ring_list);
> > > rte_mcfg_tailq_write_lock();
> > >
> > > @@ -349,7 +344,7 @@ rte_ring_free(struct rte_ring *r)
> > >
> > > if (te == NULL) {
> > > rte_mcfg_tailq_write_unlock();
> > > - return;
> > > + goto free_memzone;
We do not need this. If 'te == NULL' is true, then the ring was not found or possibly already freed.
> > > }
> > >
> > > TAILQ_REMOVE(ring_list, te, next); @@ -357,6 +352,10 @@
> > > rte_ring_free(struct rte_ring *r)
We should free the memzone here while holding the lock
> > > rte_mcfg_tailq_write_unlock();
> > >
> > > rte_free(te);
> > > +
> > > +free_memzone:
> > > + if (rte_memzone_free(r->memzone) != 0)
> > > + RTE_LOG(ERR, RING, "Cannot free memory\n");
> > > }
Should be moved up as mentioned above
> > >
> > > /* dump the status of the ring on the console */
> > > --
> > > 2.33.0
> -----Original Message-----
> From: Honnappa Nagarahalli [mailto:Honnappa.Nagarahalli@arm.com]
> Sent: Thursday, April 20, 2023 5:44 AM
> To: wangyunjian <wangyunjian@huawei.com>; dev@dpdk.org
> Cc: konstantin.v.ananyev@yandex.ru; luyicai <luyicai@huawei.com>;
> stable@dpdk.org; nd <nd@arm.com>; nd <nd@arm.com>
> Subject: RE: [dpdk-dev] [PATCH] ring: fix use after free in ring release
>
> <snip>
>
> > >
> > > > -----Original Message-----
> > > > From: Yunjian Wang <wangyunjian@huawei.com>
> > > > Sent: Monday, April 17, 2023 8:12 AM
> > > > To: dev@dpdk.org
> > > > Cc: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>;
> > > > konstantin.v.ananyev@yandex.ru; luyicai@huawei.com; Yunjian Wang
> > > > <wangyunjian@huawei.com>; stable@dpdk.org
> > > > Subject: [dpdk-dev] [PATCH] ring: fix use after free in ring
> > > > release
> > > >
> > > > When using the ring to find out tailq entry, however it had been
> > > > freed by rte_memzone_free function. This change prevents that from
> > happening.
> > > I am unable to follow the problem you are describing.
> > > After the memzone for the ring is released, the contents of the
> > > memzone are not being used. I understand that the variable 'r' is
> > > being used, but that should not cause any issues.
> > >
> > > >
> > > > Fixes: 4e32101f9b01 ("ring: support freeing")
> > > > Cc: stable@dpdk.org
> > > >
> > > > Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
> > > > ---
> > > > lib/ring/rte_ring.c | 11 +++++------
> > > > 1 file changed, 5 insertions(+), 6 deletions(-)
> > > >
> > > > diff --git a/lib/ring/rte_ring.c b/lib/ring/rte_ring.c index
> > > > 8ed455043d..17d2d7f8a8 100644
> > > > --- a/lib/ring/rte_ring.c
> > > > +++ b/lib/ring/rte_ring.c
> > > > @@ -333,11 +333,6 @@ rte_ring_free(struct rte_ring *r)
> > > > return;
> > > > }
> > > >
> > > > - if (rte_memzone_free(r->memzone) != 0) {
> > > > - RTE_LOG(ERR, RING, "Cannot free memory\n");
> > > > - return;
> > > > - }
> > > Why do we need to free the memzone later?
> >
> > After the memzone is freed, it is not removed from the 'rte_ring_tailq'.
> > If rte_ring_lookup is called at this time, it will cause a use-after-free problem.
> Thanks, understood
>
> >
> > Thanks,
> > Yunjian
> > >
> > > > -
> > > > ring_list = RTE_TAILQ_CAST(rte_ring_tailq.head, rte_ring_list);
> > > > rte_mcfg_tailq_write_lock();
> > > >
> > > > @@ -349,7 +344,7 @@ rte_ring_free(struct rte_ring *r)
> > > >
> > > > if (te == NULL) {
> > > > rte_mcfg_tailq_write_unlock();
> > > > - return;
> > > > + goto free_memzone;
> We do not need this. If 'te == NULL' is true, then the ring was not found or
> possibly already freed.
OK
>
> > > > }
> > > >
> > > > TAILQ_REMOVE(ring_list, te, next); @@ -357,6 +352,10 @@
> > > > rte_ring_free(struct rte_ring *r)
> We should free the memzone here while holding the lock
OK, You are right. I fix it on your suggestions.
https://patchwork.dpdk.org/project/dpdk/patch/c23b1135e1b0676ef7d82969b39a21df992d418f.1681972694.git.wangyunjian@huawei.com/
Thanks,
Yunjian
>
> > > > rte_mcfg_tailq_write_unlock();
> > > >
> > > > rte_free(te);
> > > > +
> > > > +free_memzone:
> > > > + if (rte_memzone_free(r->memzone) != 0)
> > > > + RTE_LOG(ERR, RING, "Cannot free memory\n");
> > > > }
> Should be moved up as mentioned above
>
> > > >
> > > > /* dump the status of the ring on the console */
> > > > --
> > > > 2.33.0
@@ -333,11 +333,6 @@ rte_ring_free(struct rte_ring *r)
return;
}
- if (rte_memzone_free(r->memzone) != 0) {
- RTE_LOG(ERR, RING, "Cannot free memory\n");
- return;
- }
-
ring_list = RTE_TAILQ_CAST(rte_ring_tailq.head, rte_ring_list);
rte_mcfg_tailq_write_lock();
@@ -349,7 +344,7 @@ rte_ring_free(struct rte_ring *r)
if (te == NULL) {
rte_mcfg_tailq_write_unlock();
- return;
+ goto free_memzone;
}
TAILQ_REMOVE(ring_list, te, next);
@@ -357,6 +352,10 @@ rte_ring_free(struct rte_ring *r)
rte_mcfg_tailq_write_unlock();
rte_free(te);
+
+free_memzone:
+ if (rte_memzone_free(r->memzone) != 0)
+ RTE_LOG(ERR, RING, "Cannot free memory\n");
}
/* dump the status of the ring on the console */