This is a note to let you know that I've just added the patch titled net: fib: fib6_add: fix potential NULL pointer dereference to the 3.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-fib-fib6_add-fix-potential-null-pointer-dereference.patch and it can be found in the queue-3.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From af64a37e20ffe1306299bcd2a513dbf467b6cf93 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann <dborkman@xxxxxxxxxx> Date: Sat, 7 Sep 2013 15:13:20 +0200 Subject: net: fib: fib6_add: fix potential NULL pointer dereference From: Daniel Borkmann <dborkman@xxxxxxxxxx> [ Upstream commit ae7b4e1f213aa659aedf9c6ecad0bf5f0476e1e2 ] When the kernel is compiled with CONFIG_IPV6_SUBTREES, and we return with an error in fn = fib6_add_1(), then error codes are encoded into the return pointer e.g. ERR_PTR(-ENOENT). In such an error case, we write the error code into err and jump to out, hence enter the if(err) condition. Now, if CONFIG_IPV6_SUBTREES is enabled, we check for: if (pn != fn && pn->leaf == rt) ... if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) ... Since pn is NULL and fn is f.e. ERR_PTR(-ENOENT), then pn != fn evaluates to true and causes a NULL-pointer dereference on further checks on pn. Fix it, by setting both NULL in error case, so that pn != fn already evaluates to false and no further dereference takes place. This was first correctly implemented in 4a287eba2 ("IPv6 routing, NLM_F_* flag support: REPLACE and EXCL flags support, warn about missing CREATE flag"), but the bug got later on introduced by 188c517a0 ("ipv6: return errno pointers consistently for fib6_add_1()"). Signed-off-by: Daniel Borkmann <dborkman@xxxxxxxxxx> Cc: Lin Ming <mlin@xxxxxxxxxxxxx> Cc: Matti Vaittinen <matti.vaittinen@xxxxxxx> Cc: Hannes Frederic Sowa <hannes@xxxxxxxxxxxxxxxxxxx> Acked-by: Hannes Frederic Sowa <hannes@xxxxxxxxxxxxxxxxxxx> Acked-by: Matti Vaittinen <matti.vaittinen@xxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv6/ip6_fib.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -825,9 +825,9 @@ int fib6_add(struct fib6_node *root, str fn = fib6_add_1(root, &rt->rt6i_dst.addr, sizeof(struct in6_addr), rt->rt6i_dst.plen, offsetof(struct rt6_info, rt6i_dst), allow_create, replace_required); - if (IS_ERR(fn)) { err = PTR_ERR(fn); + fn = NULL; goto out; } Patches currently in stable-queue which might be from dborkman@xxxxxxxxxx are queue-3.10/net-sctp-rfc4443-do-not-report-icmp-redirects-to-user-space.patch queue-3.10/net-sctp-fix-ipv6-ipsec-encryption-bug-in-sctp_v6_xmit.patch queue-3.10/net-sctp-fix-bug-in-sctp_poll-for-sock_select_err_queue.patch queue-3.10/net-fib-fib6_add-fix-potential-null-pointer-dereference.patch queue-3.10/net-flow_dissector-fix-thoff-for-ipproto_ah.patch queue-3.10/net-sctp-fix-smatch-warning-in-sctp_send_asconf_del_ip.patch -- 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