Messages in this thread Patch in this message | | | Date | Wed, 17 May 2006 00:00:09 -0700 | From | Chris Wright <> | Subject | [PATCH 09/22] [PATCH] Netfilter: do_add_counters race, possible oops or info leak (CVE-2006-0039) |
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-stable review patch. If anyone has any objections, please let us know. ------------------
Solar Designer found a race condition in do_add_counters(). The beginning of paddc is supposed to be the same as tmp which was sanity-checked above, but it might not be the same in reality. In case the integer overflow and/or the race condition are triggered, paddc->num_counters might not match the allocation size for paddc. If the check below (t->private->number != paddc->num_counters) nevertheless passes (perhaps this requires the race condition to be triggered), IPT_ENTRY_ITERATE() would read kernel memory beyond the allocation size, potentially causing an oops or leaking sensitive data (e.g., passwords from host system or from another VPS) via counter increments. This requires CAP_NET_ADMIN.
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=191698
Cc: Solar Designer <solar@openwall.com> Cc: Kirill Korotaev <dev@sw.ru> Cc: Patrick McHardy <kaber@trash.net> (chrisw: rebase of Solar's patch to 2.6.16.16) Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> ---
net/ipv4/netfilter/arp_tables.c | 2 +- net/ipv4/netfilter/ip_tables.c | 2 +- net/ipv6/netfilter/ip6_tables.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-)
--- linux-2.6.16.16.orig/net/ipv4/netfilter/arp_tables.c +++ linux-2.6.16.16/net/ipv4/netfilter/arp_tables.c @@ -941,7 +941,7 @@ static int do_add_counters(void __user * write_lock_bh(&t->lock); private = t->private; - if (private->number != paddc->num_counters) { + if (private->number != tmp.num_counters) { ret = -EINVAL; goto unlock_up_free; } --- linux-2.6.16.16.orig/net/ipv4/netfilter/ip_tables.c +++ linux-2.6.16.16/net/ipv4/netfilter/ip_tables.c @@ -1063,7 +1063,7 @@ do_add_counters(void __user *user, unsig write_lock_bh(&t->lock); private = t->private; - if (private->number != paddc->num_counters) { + if (private->number != tmp.num_counters) { ret = -EINVAL; goto unlock_up_free; } --- linux-2.6.16.16.orig/net/ipv6/netfilter/ip6_tables.c +++ linux-2.6.16.16/net/ipv6/netfilter/ip6_tables.c @@ -1120,7 +1120,7 @@ do_add_counters(void __user *user, unsig write_lock_bh(&t->lock); private = t->private; - if (private->number != paddc->num_counters) { + if (private->number != tmp.num_counters) { ret = -EINVAL; goto unlock_up_free; } -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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