| Message ID | 20200731082833.16568-1-juergh@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | [SRU,B/linux] tap: fix use-after-free | expand |
On 31/07/2020 09:28, Juerg Haefliger wrote: > From: "Michael S. Tsirkin" <mst@redhat.com> > > BugLink: https://bugs.launchpad.net/bugs/1889735 > > Lockless access to __ptr_ring_full is only legal if ring is > never resized, otherwise it might cause use-after free errors. > Simply drop the lockless test, we'll drop the packet > a bit later when produce fails. > > Fixes: 362899b8 ("macvtap: switch to use skb array") > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > Signed-off-by: David S. Miller <davem@davemloft.net> > > (backported from commit 88fae87327a2261cf8db078f6ce4e5a3e55b30b1) > [juergh: __ptr_ring_full() -> __skb_array_full() due to lack of commit > 5990a30510ed ("tun/tap: use ptr_ring instead of skb_array").] > Signed-off-by: Juerg Haefliger <juergh@canonical.com> > --- > drivers/net/tap.c | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/drivers/net/tap.c b/drivers/net/tap.c > index afbe5bec2c33..f8b44d395c2f 100644 > --- a/drivers/net/tap.c > +++ b/drivers/net/tap.c > @@ -330,9 +330,6 @@ rx_handler_result_t tap_handle_frame(struct sk_buff **pskb) > if (!q) > return RX_HANDLER_PASS; > > - if (__skb_array_full(&q->skb_array)) > - goto drop; > - > skb_push(skb, ETH_HLEN); > > /* Apply the forward feature mask so that we perform segmentation > Backport looks good to me. Thanks Juerg. Acked-by: Colin Ian King <colin.king@canonical.com>
On 31.07.20 10:28, Juerg Haefliger wrote: > From: "Michael S. Tsirkin" <mst@redhat.com> > > BugLink: https://bugs.launchpad.net/bugs/1889735 > > Lockless access to __ptr_ring_full is only legal if ring is > never resized, otherwise it might cause use-after free errors. > Simply drop the lockless test, we'll drop the packet > a bit later when produce fails. > > Fixes: 362899b8 ("macvtap: switch to use skb array") > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > Signed-off-by: David S. Miller <davem@davemloft.net> > > (backported from commit 88fae87327a2261cf8db078f6ce4e5a3e55b30b1) > [juergh: __ptr_ring_full() -> __skb_array_full() due to lack of commit > 5990a30510ed ("tun/tap: use ptr_ring instead of skb_array").] > Signed-off-by: Juerg Haefliger <juergh@canonical.com> Acked-by: Stefan Bader <stefan.bader@canonical.com> > --- You seem to have tried using the form of regression potential that was asked by the sru team. Though I am not quite understanding the impact. Not sure how anyone from sru team would cope. Maybe "some network packets going missing" would be better. The testcase should be defined before a kernel with this is hitting proposed. -Stefan > drivers/net/tap.c | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/drivers/net/tap.c b/drivers/net/tap.c > index afbe5bec2c33..f8b44d395c2f 100644 > --- a/drivers/net/tap.c > +++ b/drivers/net/tap.c > @@ -330,9 +330,6 @@ rx_handler_result_t tap_handle_frame(struct sk_buff **pskb) > if (!q) > return RX_HANDLER_PASS; > > - if (__skb_array_full(&q->skb_array)) > - goto drop; > - > skb_push(skb, ETH_HLEN); > > /* Apply the forward feature mask so that we perform segmentation >
On 2020-07-31 10:28:33 , Juerg Haefliger wrote: > From: "Michael S. Tsirkin" <mst@redhat.com> > > BugLink: https://bugs.launchpad.net/bugs/1889735 > > Lockless access to __ptr_ring_full is only legal if ring is > never resized, otherwise it might cause use-after free errors. > Simply drop the lockless test, we'll drop the packet > a bit later when produce fails. > > Fixes: 362899b8 ("macvtap: switch to use skb array") > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > Signed-off-by: David S. Miller <davem@davemloft.net> > > (backported from commit 88fae87327a2261cf8db078f6ce4e5a3e55b30b1) > [juergh: __ptr_ring_full() -> __skb_array_full() due to lack of commit > 5990a30510ed ("tun/tap: use ptr_ring instead of skb_array").] > Signed-off-by: Juerg Haefliger <juergh@canonical.com> > --- > drivers/net/tap.c | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/drivers/net/tap.c b/drivers/net/tap.c > index afbe5bec2c33..f8b44d395c2f 100644 > --- a/drivers/net/tap.c > +++ b/drivers/net/tap.c > @@ -330,9 +330,6 @@ rx_handler_result_t tap_handle_frame(struct sk_buff **pskb) > if (!q) > return RX_HANDLER_PASS; > > - if (__skb_array_full(&q->skb_array)) > - goto drop; > - > skb_push(skb, ETH_HLEN); > > /* Apply the forward feature mask so that we perform segmentation > -- > 2.25.1 > > > -- > kernel-team mailing list > kernel-team@lists.ubuntu.com > https://lists.ubuntu.com/mailman/listinfo/kernel-team
diff --git a/drivers/net/tap.c b/drivers/net/tap.c index afbe5bec2c33..f8b44d395c2f 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -330,9 +330,6 @@ rx_handler_result_t tap_handle_frame(struct sk_buff **pskb) if (!q) return RX_HANDLER_PASS; - if (__skb_array_full(&q->skb_array)) - goto drop; - skb_push(skb, ETH_HLEN); /* Apply the forward feature mask so that we perform segmentation