diff mbox series

net/vmw_vsock: fix NULL pointer dereference

Message ID trinity-c2d6cede-bfb1-44e2-85af-1fbc7f541715-1612535117028@3c-app-gmx-bap12 (mailing list archive)
State Accepted
Delegated to: Netdev Maintainers
Headers show
Series net/vmw_vsock: fix NULL pointer dereference | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Guessed tree name to be net-next
netdev/subject_prefix warning Target tree name not specified in the subject
netdev/cc_maintainers warning 5 maintainers not CCed: kuba@kernel.org andraprs@amazon.com davem@davemloft.net colin.king@canonical.com jhansen@vmware.com
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 8 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/header_inline success Link
netdev/stable success Stable not CCed

Commit Message

Norbert Slusarek Feb. 5, 2021, 2:25 p.m. UTC
From: Norbert Slusarek <nslusarek@gmx.net>
Date: Fri, 5 Feb 2021 13:12:06 +0100
Subject: [PATCH] net/vmw_vsock: fix NULL pointer dereference

In vsock_stream_connect(), a thread will enter schedule_timeout().
While being scheduled out, another thread can enter vsock_stream_connect()
as well and set vsk->transport to NULL. In case a signal was sent, the
first thread can leave schedule_timeout() and vsock_transport_cancel_pkt()
will be called right after. Inside vsock_transport_cancel_pkt(), a null
dereference will happen on transport->cancel_pkt.

Fixes: c0cfa2d8a788 ("vsock: add multi-transports support")
Reported-by: Norbert Slusarek <nslusarek@gmx.net>
Signed-off-by: Norbert Slusarek <nslusarek@gmx.net>
---
 net/vmw_vsock/af_vsock.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--
2.30.0

Comments

Jakub Kicinski Feb. 7, 2021, 12:57 a.m. UTC | #1
On Fri, 5 Feb 2021 18:13:35 +0100 Stefano Garzarella wrote:
> On Fri, Feb 05, 2021 at 03:25:17PM +0100, Norbert Slusarek wrote:
> >From: Norbert Slusarek <nslusarek@gmx.net>
> >Date: Fri, 5 Feb 2021 13:12:06 +0100
> >Subject: [PATCH] net/vmw_vsock: fix NULL pointer dereference
> >
> >In vsock_stream_connect(), a thread will enter schedule_timeout().
> >While being scheduled out, another thread can enter vsock_stream_connect()
> >as well and set vsk->transport to NULL. In case a signal was sent, the
> >first thread can leave schedule_timeout() and vsock_transport_cancel_pkt()
> >will be called right after. Inside vsock_transport_cancel_pkt(), a null
> >dereference will happen on transport->cancel_pkt.
> >
> >Fixes: c0cfa2d8a788 ("vsock: add multi-transports support")
> >Reported-by: Norbert Slusarek <nslusarek@gmx.net>
> >Signed-off-by: Norbert Slusarek <nslusarek@gmx.net>
> >---
> > net/vmw_vsock/af_vsock.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> >diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
> >index 6894f21dc147..cb81cfb47a78 100644
> >--- a/net/vmw_vsock/af_vsock.c
> >+++ b/net/vmw_vsock/af_vsock.c
> >@@ -1233,7 +1233,7 @@ static int vsock_transport_cancel_pkt(struct vsock_sock *vsk)
> > {
> > 	const struct vsock_transport *transport = vsk->transport;
> >
> >-	if (!transport->cancel_pkt)
> >+	if (!transport || !transport->cancel_pkt)
> > 		return -EOPNOTSUPP;
> >
> > 	return transport->cancel_pkt(vsk);
> >--
> >2.30.0
> >  
> 
> I can't see this patch on https://patchwork.kernel.org/project/netdevbpf/list/
> 
> Maybe because you forgot to CC the netdev maintainers.
> Please next time use scripts/get_maintainer.pl
> 
> Anyway the patch LGTM, so
> 
> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

Applied, thanks!
diff mbox series

Patch

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 6894f21dc147..cb81cfb47a78 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1233,7 +1233,7 @@  static int vsock_transport_cancel_pkt(struct vsock_sock *vsk)
 {
 	const struct vsock_transport *transport = vsk->transport;

-	if (!transport->cancel_pkt)
+	if (!transport || !transport->cancel_pkt)
 		return -EOPNOTSUPP;

 	return transport->cancel_pkt(vsk);