* [PATCH v2] sctp: socket.c validate sprstat_policy
@ 2018-10-27 20:53 Tomas Bortoli
2018-10-28 4:17 ` Xin Long
0 siblings, 1 reply; 3+ messages in thread
From: Tomas Bortoli @ 2018-10-27 20:53 UTC (permalink / raw)
To: vyasevich, nhorman, marcelo.leitner
Cc: davem, linux-sctp, netdev, linux-kernel, Tomas Bortoli
It is possible to perform out-of-bound reads on
sctp_getsockopt_pr_streamstatus() and on
sctp_getsockopt_pr_assocstatus() by passing from userspace a
sprstat_policy that overflows the abandoned_sent/abandoned_unsent
fixed length arrays. The over-read data are directly copied/leaked
to userspace.
Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com>
Reported-by: syzbot+5da0d0a72a9e7d791748@syzkaller.appspotmail.com
---
net/sctp/socket.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index fc0386e8ff23..14dce5d95817 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -7083,7 +7083,9 @@ static int sctp_getsockopt_pr_assocstatus(struct sock *sk, int len,
}
policy = params.sprstat_policy;
- if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)))
+ if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)) ||
+ __SCTP_PR_INDEX(policy) > SCTP_PR_INDEX(MAX) ||
+ __SCTP_PR_INDEX(policy) < 0)
goto out;
asoc = sctp_id2assoc(sk, params.sprstat_assoc_id);
@@ -7142,7 +7144,9 @@ static int sctp_getsockopt_pr_streamstatus(struct sock *sk, int len,
}
policy = params.sprstat_policy;
- if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)))
+ if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)) ||
+ __SCTP_PR_INDEX(policy) > SCTP_PR_INDEX(MAX) ||
+ __SCTP_PR_INDEX(policy) < 0)
goto out;
asoc = sctp_id2assoc(sk, params.sprstat_assoc_id);
--
2.11.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2] sctp: socket.c validate sprstat_policy
2018-10-27 20:53 [PATCH v2] sctp: socket.c validate sprstat_policy Tomas Bortoli
@ 2018-10-28 4:17 ` Xin Long
2018-10-28 8:42 ` Tomas Bortoli
0 siblings, 1 reply; 3+ messages in thread
From: Xin Long @ 2018-10-28 4:17 UTC (permalink / raw)
To: tomasbortoli
Cc: Vlad Yasevich, Neil Horman, Marcelo Ricardo Leitner, davem,
linux-sctp, network dev, LKML
On Sun, Oct 28, 2018 at 5:54 AM Tomas Bortoli <tomasbortoli@gmail.com> wrote:
>
> It is possible to perform out-of-bound reads on
> sctp_getsockopt_pr_streamstatus() and on
> sctp_getsockopt_pr_assocstatus() by passing from userspace a
> sprstat_policy that overflows the abandoned_sent/abandoned_unsent
> fixed length arrays. The over-read data are directly copied/leaked
> to userspace.
>
> Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com>
> Reported-by: syzbot+5da0d0a72a9e7d791748@syzkaller.appspotmail.com
> ---
> net/sctp/socket.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> index fc0386e8ff23..14dce5d95817 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -7083,7 +7083,9 @@ static int sctp_getsockopt_pr_assocstatus(struct sock *sk, int len,
> }
>
> policy = params.sprstat_policy;
> - if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)))
> + if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)) ||
> + __SCTP_PR_INDEX(policy) > SCTP_PR_INDEX(MAX) ||
> + __SCTP_PR_INDEX(policy) < 0)
> goto out;
>
> asoc = sctp_id2assoc(sk, params.sprstat_assoc_id);
> @@ -7142,7 +7144,9 @@ static int sctp_getsockopt_pr_streamstatus(struct sock *sk, int len,
> }
>
> policy = params.sprstat_policy;
> - if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)))
> + if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)) ||
> + __SCTP_PR_INDEX(policy) > SCTP_PR_INDEX(MAX) ||
> + __SCTP_PR_INDEX(policy) < 0)
> goto out;
This is not the correct fix.
See https://lkml.org/lkml/2018/10/27/136
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2] sctp: socket.c validate sprstat_policy
2018-10-28 4:17 ` Xin Long
@ 2018-10-28 8:42 ` Tomas Bortoli
0 siblings, 0 replies; 3+ messages in thread
From: Tomas Bortoli @ 2018-10-28 8:42 UTC (permalink / raw)
To: Xin Long
Cc: Vlad Yasevich, Neil Horman, Marcelo Ricardo Leitner, davem,
linux-sctp, network dev, LKML
On 10/28/18 5:17 AM, Xin Long wrote:
> On Sun, Oct 28, 2018 at 5:54 AM Tomas Bortoli <tomasbortoli@gmail.com> wrote:
>>
>> It is possible to perform out-of-bound reads on
>> sctp_getsockopt_pr_streamstatus() and on
>> sctp_getsockopt_pr_assocstatus() by passing from userspace a
>> sprstat_policy that overflows the abandoned_sent/abandoned_unsent
>> fixed length arrays. The over-read data are directly copied/leaked
>> to userspace.
>>
>> Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com>
>> Reported-by: syzbot+5da0d0a72a9e7d791748@syzkaller.appspotmail.com
>> ---
>> net/sctp/socket.c | 8 ++++++--
>> 1 file changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
>> index fc0386e8ff23..14dce5d95817 100644
>> --- a/net/sctp/socket.c
>> +++ b/net/sctp/socket.c
>> @@ -7083,7 +7083,9 @@ static int sctp_getsockopt_pr_assocstatus(struct sock *sk, int len,
>> }
>>
>> policy = params.sprstat_policy;
>> - if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)))
>> + if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)) ||
>> + __SCTP_PR_INDEX(policy) > SCTP_PR_INDEX(MAX) ||
>> + __SCTP_PR_INDEX(policy) < 0)
>> goto out;
>>
>> asoc = sctp_id2assoc(sk, params.sprstat_assoc_id);
>> @@ -7142,7 +7144,9 @@ static int sctp_getsockopt_pr_streamstatus(struct sock *sk, int len,
>> }
>>
>> policy = params.sprstat_policy;
>> - if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)))
>> + if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)) ||
>> + __SCTP_PR_INDEX(policy) > SCTP_PR_INDEX(MAX) ||
>> + __SCTP_PR_INDEX(policy) < 0)
>> goto out;
> This is not the correct fix.
> See https://lkml.org/lkml/2018/10/27/136
>
Ack, good to know ty!
^ permalink raw reply [flat|nested] 3+ messages in thread
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