On 7/5/20 10:08 PM, Linus Lüssing wrote:
On Sun, Jul 05, 2020 at 09:33:13PM +0300, Nikolay Aleksandrov wrote:
On 05/07/2020 21:22, Linus Lüssing wrote:
Commit e57f61858b7c ("net: bridge: mcast: fix stale nsrcs pointer in
igmp3/mld2 report handling") introduced a small bug which would potentially
lead to accepting an MLD2 Report with a broken IPv6 header payload length
field.
The check needs to take into account the 2 bytes for the "Number of
Sources" field in the "Multicast Address Record" before reading it.
And not the size of a pointer to this field.
Fixes: e57f61858b7c ("net: bridge: mcast: fix stale nsrcs pointer in igmp3/mld2 report handling")
Signed-off-by: Linus Lüssing <linus.luessing@xxxxxxxxx>
---
net/bridge/br_multicast.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
I'd rather be more concerned with it rejecting a valid report due to wrong size. The ptr
size would always be bigger. :)
Thanks!
Acked-by: Nikolay Aleksandrov <nikolay@xxxxxxxxxxxxxxxxxxx>
Aiy, you're right, it's the other way round. I'll update the
commit message and send a v2 in a minute, with your Acked-by
included.
By the way, I can't verify at the moment, but I think we can drop that whole
hunk altogether since skb_header_pointer() is used and it will simply return
an error if there isn't enough data for nsrcs.
