From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Date: Fri, 18 Oct 2013 07:34:33 -0700 > On Fri, Oct 18, 2013 at 04:04:42PM +0200, Willy Tarreau wrote: >> Greg, David, >> >> one of our customers faced a panic in latest 2.6.32 when both somaxconn >> and the listen backlog are large on an IPv6 socket. It was also reported >> by one haproxy user on the latest RHEL6 kernel a few months ago. We found >> that the same bug affects 3.0 up to and including 3.0.100. >> >> Eric had already spotted that bug and fixed it in 3.2 with the following >> patch : >> >> commit c16a98ed91597b40b22b540c6517103497ef8e74 >> Author: Eric Dumazet <eric.dumazet@xxxxxxxxx> >> Date: Wed Nov 23 15:49:31 2011 -0500 >> >> ipv6: tcp: fix panic in SYN processing >> >> commit 72a3effaf633bc ([NET]: Size listen hash tables using backlog >> hint) added a bug allowing inet6_synq_hash() to return an out of bound >> array index, because of u16 overflow. >> >> Bug can happen if system admins set net.core.somaxconn & >> net.ipv4.tcp_max_syn_backlog sysctls to values greater than 65536 >> >> Signed-off-by: Eric Dumazet <eric.dumazet@xxxxxxxxx> >> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> >> >> In practice, the bug extends to lower values as well (32768 and above), >> because reqsk_queue_alloc() can round the number of entries to double of >> the backlog by doing roundup_pow_of_two(backlog+1), resulting in >> inet6_csk_search_req() calling inet6_synq_hash() with too large an integer. >> >> Could we please apply it to 3.0 before it finishes its life ? > > Unless David objects, I can queue this up just in time for the last > 3.0.stable. > > David? No objections. -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html