From: David S. Miller Date: Thu, 25 Jun 2020 19:52:41 +0000 (-0700) Subject: Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=f4926d513b4c753c3e831dc619466c82ba192fed;p=linux.git Merge git://git./pub/scm/linux/kernel/git/pablo/nf Pablo Neira Ayuso says: ==================== Netfilter fixes for net The following patchset contains Netfilter fixes for net, they are: 1) Unaligned atomic access in ipset, from Russell King. 2) Missing module description, from Rob Gill. 3) Patches to fix a module unload causing NULL pointer dereference in xtables, from David Wilder. For the record, I posting here his cover letter explaining the problem: A crash happened on ppc64le when running ltp network tests triggered by "rmmod iptable_mangle". See previous discussion in this thread: https://lists.openwall.net/netdev/2020/06/03/161 . In the crash I found in iptable_mangle_hook() that state->net->ipv4.iptable_mangle=NULL causing a NULL pointer dereference. net->ipv4.iptable_mangle is set to NULL in +iptable_mangle_net_exit() and called when ip_mangle modules is unloaded. A rmmod task was found running in the crash dump. A 2nd crash showed the same problem when running "rmmod iptable_filter" (net->ipv4.iptable_filter=NULL). To fix this I added .pre_exit hook in all iptable_foo.c. The pre_exit will un-register the underlying hook and exit would do the table freeing. The netns core does an unconditional +synchronize_rcu after the pre_exit hooks insuring no packets are in flight that have picked up the pointer before completing the un-register. These patches include changes for both iptables and ip6tables. We tested this fix with ltp running iptables01.sh and iptables01.sh -6 a loop for 72 hours. 4) Add a selftest for conntrack helper assignment, from Florian Westphal. ==================== Signed-off-by: David S. Miller --- f4926d513b4c753c3e831dc619466c82ba192fed