* [PATCH net] sctp: walk the list of asoc safely
@ 2019-02-01 14:15 Greg Kroah-Hartman
2019-02-01 14:20 ` Marcelo Ricardo Leitner
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Greg Kroah-Hartman @ 2019-02-01 14:15 UTC (permalink / raw)
To: Vlad Yasevich, Neil Horman, Marcelo Ricardo Leitner, linux-sctp, netdev
In sctp_sendmesg(), when walking the list of endpoint associations, the
association can be dropped from the list, making the list corrupt.
Properly handle this by using list_for_each_entry_safe()
Fixes: 4910280503f3 ("sctp: add support for snd flag SCTP_SENDALL process in sendmsg")
Reported-by: Secunia Research <vuln@secunia.com>
Tested-by: Secunia Research <vuln@secunia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index f93c3cf9e567..65d6d04546ae 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -2027,7 +2027,7 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
struct sctp_endpoint *ep = sctp_sk(sk)->ep;
struct sctp_transport *transport = NULL;
struct sctp_sndrcvinfo _sinfo, *sinfo;
- struct sctp_association *asoc;
+ struct sctp_association *asoc, *tmp;
struct sctp_cmsgs cmsgs;
union sctp_addr *daddr;
bool new = false;
@@ -2053,7 +2053,7 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
/* SCTP_SENDALL process */
if ((sflags & SCTP_SENDALL) && sctp_style(sk, UDP)) {
- list_for_each_entry(asoc, &ep->asocs, asocs) {
+ list_for_each_entry_safe(asoc, tmp, &ep->asocs, asocs) {
err = sctp_sendmsg_check_sflags(asoc, sflags, msg,
msg_len);
if (err == 0)
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH net] sctp: walk the list of asoc safely
2019-02-01 14:15 [PATCH net] sctp: walk the list of asoc safely Greg Kroah-Hartman
@ 2019-02-01 14:20 ` Marcelo Ricardo Leitner
2019-02-01 14:43 ` Greg Kroah-Hartman
2019-02-01 15:55 ` Neil Horman
2019-02-01 19:04 ` David Miller
2 siblings, 1 reply; 6+ messages in thread
From: Marcelo Ricardo Leitner @ 2019-02-01 14:20 UTC (permalink / raw)
To: Greg Kroah-Hartman; +Cc: Vlad Yasevich, Neil Horman, linux-sctp, netdev, vuln
On Fri, Feb 01, 2019 at 03:15:22PM +0100, Greg Kroah-Hartman wrote:
> In sctp_sendmesg(), when walking the list of endpoint associations, the
> association can be dropped from the list, making the list corrupt.
> Properly handle this by using list_for_each_entry_safe()
>
> Fixes: 4910280503f3 ("sctp: add support for snd flag SCTP_SENDALL process in sendmsg")
> Reported-by: Secunia Research <vuln@secunia.com>
> Tested-by: Secunia Research <vuln@secunia.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>
> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> index f93c3cf9e567..65d6d04546ae 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -2027,7 +2027,7 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
> struct sctp_endpoint *ep = sctp_sk(sk)->ep;
> struct sctp_transport *transport = NULL;
> struct sctp_sndrcvinfo _sinfo, *sinfo;
> - struct sctp_association *asoc;
> + struct sctp_association *asoc, *tmp;
> struct sctp_cmsgs cmsgs;
> union sctp_addr *daddr;
> bool new = false;
> @@ -2053,7 +2053,7 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
Extending the context here by 1 line:
lock_sock(sk);
>
> /* SCTP_SENDALL process */
> if ((sflags & SCTP_SENDALL) && sctp_style(sk, UDP)) {
> - list_for_each_entry(asoc, &ep->asocs, asocs) {
> + list_for_each_entry_safe(asoc, tmp, &ep->asocs, asocs) {
With the socket being locked by here, how can an asoc be removed
while the list is being traversed? The socket lock should be
protecting from it.
> err = sctp_sendmsg_check_sflags(asoc, sflags, msg,
> msg_len);
> if (err == 0)
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH net] sctp: walk the list of asoc safely
2019-02-01 14:20 ` Marcelo Ricardo Leitner
@ 2019-02-01 14:43 ` Greg Kroah-Hartman
2019-02-01 14:58 ` Marcelo Ricardo Leitner
0 siblings, 1 reply; 6+ messages in thread
From: Greg Kroah-Hartman @ 2019-02-01 14:43 UTC (permalink / raw)
To: Marcelo Ricardo Leitner
Cc: Vlad Yasevich, Neil Horman, linux-sctp, netdev, vuln
On Fri, Feb 01, 2019 at 12:20:37PM -0200, Marcelo Ricardo Leitner wrote:
> On Fri, Feb 01, 2019 at 03:15:22PM +0100, Greg Kroah-Hartman wrote:
> > In sctp_sendmesg(), when walking the list of endpoint associations, the
> > association can be dropped from the list, making the list corrupt.
> > Properly handle this by using list_for_each_entry_safe()
> >
> > Fixes: 4910280503f3 ("sctp: add support for snd flag SCTP_SENDALL process in sendmsg")
> > Reported-by: Secunia Research <vuln@secunia.com>
> > Tested-by: Secunia Research <vuln@secunia.com>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> >
> > diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> > index f93c3cf9e567..65d6d04546ae 100644
> > --- a/net/sctp/socket.c
> > +++ b/net/sctp/socket.c
> > @@ -2027,7 +2027,7 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
> > struct sctp_endpoint *ep = sctp_sk(sk)->ep;
> > struct sctp_transport *transport = NULL;
> > struct sctp_sndrcvinfo _sinfo, *sinfo;
> > - struct sctp_association *asoc;
> > + struct sctp_association *asoc, *tmp;
> > struct sctp_cmsgs cmsgs;
> > union sctp_addr *daddr;
> > bool new = false;
> > @@ -2053,7 +2053,7 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
>
> Extending the context here by 1 line:
> lock_sock(sk);
> >
> > /* SCTP_SENDALL process */
> > if ((sflags & SCTP_SENDALL) && sctp_style(sk, UDP)) {
> > - list_for_each_entry(asoc, &ep->asocs, asocs) {
> > + list_for_each_entry_safe(asoc, tmp, &ep->asocs, asocs) {
>
> With the socket being locked by here, how can an asoc be removed
> while the list is being traversed? The socket lock should be
> protecting from it.
What about when the SCTP_ABORT flag is set with SCTP_SENDALL at the same
time?
:(
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH net] sctp: walk the list of asoc safely
2019-02-01 14:43 ` Greg Kroah-Hartman
@ 2019-02-01 14:58 ` Marcelo Ricardo Leitner
0 siblings, 0 replies; 6+ messages in thread
From: Marcelo Ricardo Leitner @ 2019-02-01 14:58 UTC (permalink / raw)
To: Greg Kroah-Hartman; +Cc: Vlad Yasevich, Neil Horman, linux-sctp, netdev, vuln
On Fri, Feb 01, 2019 at 03:43:59PM +0100, Greg Kroah-Hartman wrote:
> On Fri, Feb 01, 2019 at 12:20:37PM -0200, Marcelo Ricardo Leitner wrote:
> > On Fri, Feb 01, 2019 at 03:15:22PM +0100, Greg Kroah-Hartman wrote:
> > > In sctp_sendmesg(), when walking the list of endpoint associations, the
> > > association can be dropped from the list, making the list corrupt.
> > > Properly handle this by using list_for_each_entry_safe()
> > >
> > > Fixes: 4910280503f3 ("sctp: add support for snd flag SCTP_SENDALL process in sendmsg")
> > > Reported-by: Secunia Research <vuln@secunia.com>
> > > Tested-by: Secunia Research <vuln@secunia.com>
> > > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > >
> > > diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> > > index f93c3cf9e567..65d6d04546ae 100644
> > > --- a/net/sctp/socket.c
> > > +++ b/net/sctp/socket.c
> > > @@ -2027,7 +2027,7 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
> > > struct sctp_endpoint *ep = sctp_sk(sk)->ep;
> > > struct sctp_transport *transport = NULL;
> > > struct sctp_sndrcvinfo _sinfo, *sinfo;
> > > - struct sctp_association *asoc;
> > > + struct sctp_association *asoc, *tmp;
> > > struct sctp_cmsgs cmsgs;
> > > union sctp_addr *daddr;
> > > bool new = false;
> > > @@ -2053,7 +2053,7 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
> >
> > Extending the context here by 1 line:
> > lock_sock(sk);
> > >
> > > /* SCTP_SENDALL process */
> > > if ((sflags & SCTP_SENDALL) && sctp_style(sk, UDP)) {
> > > - list_for_each_entry(asoc, &ep->asocs, asocs) {
> > > + list_for_each_entry_safe(asoc, tmp, &ep->asocs, asocs) {
> >
> > With the socket being locked by here, how can an asoc be removed
> > while the list is being traversed? The socket lock should be
> > protecting from it.
>
> What about when the SCTP_ABORT flag is set with SCTP_SENDALL at the same
> time?
>
> :(
Good point! Thanks.
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH net] sctp: walk the list of asoc safely
2019-02-01 14:15 [PATCH net] sctp: walk the list of asoc safely Greg Kroah-Hartman
2019-02-01 14:20 ` Marcelo Ricardo Leitner
@ 2019-02-01 15:55 ` Neil Horman
2019-02-01 19:04 ` David Miller
2 siblings, 0 replies; 6+ messages in thread
From: Neil Horman @ 2019-02-01 15:55 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Vlad Yasevich, Marcelo Ricardo Leitner, linux-sctp, netdev
On Fri, Feb 01, 2019 at 03:15:22PM +0100, Greg Kroah-Hartman wrote:
> In sctp_sendmesg(), when walking the list of endpoint associations, the
> association can be dropped from the list, making the list corrupt.
> Properly handle this by using list_for_each_entry_safe()
>
> Fixes: 4910280503f3 ("sctp: add support for snd flag SCTP_SENDALL process in sendmsg")
> Reported-by: Secunia Research <vuln@secunia.com>
> Tested-by: Secunia Research <vuln@secunia.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>
> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> index f93c3cf9e567..65d6d04546ae 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -2027,7 +2027,7 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
> struct sctp_endpoint *ep = sctp_sk(sk)->ep;
> struct sctp_transport *transport = NULL;
> struct sctp_sndrcvinfo _sinfo, *sinfo;
> - struct sctp_association *asoc;
> + struct sctp_association *asoc, *tmp;
> struct sctp_cmsgs cmsgs;
> union sctp_addr *daddr;
> bool new = false;
> @@ -2053,7 +2053,7 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
>
> /* SCTP_SENDALL process */
> if ((sflags & SCTP_SENDALL) && sctp_style(sk, UDP)) {
> - list_for_each_entry(asoc, &ep->asocs, asocs) {
> + list_for_each_entry_safe(asoc, tmp, &ep->asocs, asocs) {
> err = sctp_sendmsg_check_sflags(asoc, sflags, msg,
> msg_len);
> if (err == 0)
>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH net] sctp: walk the list of asoc safely
2019-02-01 14:15 [PATCH net] sctp: walk the list of asoc safely Greg Kroah-Hartman
2019-02-01 14:20 ` Marcelo Ricardo Leitner
2019-02-01 15:55 ` Neil Horman
@ 2019-02-01 19:04 ` David Miller
2 siblings, 0 replies; 6+ messages in thread
From: David Miller @ 2019-02-01 19:04 UTC (permalink / raw)
To: gregkh; +Cc: vyasevich, nhorman, marcelo.leitner, linux-sctp, netdev
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Fri, 1 Feb 2019 15:15:22 +0100
> In sctp_sendmesg(), when walking the list of endpoint associations, the
> association can be dropped from the list, making the list corrupt.
> Properly handle this by using list_for_each_entry_safe()
>
> Fixes: 4910280503f3 ("sctp: add support for snd flag SCTP_SENDALL process in sendmsg")
> Reported-by: Secunia Research <vuln@secunia.com>
> Tested-by: Secunia Research <vuln@secunia.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Applied and queued up for -stable.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2019-02-01 19:04 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-02-01 14:15 [PATCH net] sctp: walk the list of asoc safely Greg Kroah-Hartman
2019-02-01 14:20 ` Marcelo Ricardo Leitner
2019-02-01 14:43 ` Greg Kroah-Hartman
2019-02-01 14:58 ` Marcelo Ricardo Leitner
2019-02-01 15:55 ` Neil Horman
2019-02-01 19:04 ` David Miller
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).