3.2.97-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Ben Hutchings <[email protected]> commit 1137b5e2529a8f5ca8ee709288ecba3e68044df2 upstream. This is a fix for CVE-2017-16939 suitable for older stable branches. The upstream fix is commit 1137b5e2529a8f5ca8ee709288ecba3e68044df2, from which the following explanation is taken: An independent security researcher, Mohamed Ghannam, has reported this vulnerability to Beyond Security's SecuriTeam Secure Disclosure program. The xfrm_dump_policy_done function expects xfrm_dump_policy to have been called at least once or it will crash. This can be triggered if a dump fails because the target socket's receive buffer is full. It was not possible to define a 'start' callback for netlink dumps until Linux 4.5, so instead add a check for the initialisation flag in the 'done' callback. Signed-off-by: Ben Hutchings <[email protected]> --- --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -1530,7 +1530,8 @@ static int xfrm_dump_policy_done(struct { struct xfrm_policy_walk *walk = (struct xfrm_policy_walk *) &cb->args[1]; - xfrm_policy_walk_done(walk); + if (cb->args[0]) + xfrm_policy_walk_done(walk); return 0; }
