netdev - RE: [PATCH v4 net] tipc: fix null-ptr-deref when acquiring remote ip of ethernet bearer

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID:
 <GV1P189MB19882E69E2C71A79B6A7EB58C673A@GV1P189MB1988.EURP189.PROD.OUTLOOK.COM>
Date: Tue, 17 Jun 2025 06:12:36 +0000
From: Tung Quang Nguyen <tung.quang.nguyen@....tech>
To: Haixia Qu <hxqu@...lstonenet.com>, Jon Maloy <jmaloy@...hat.com>, "David
 S. Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, Jakub
 Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>, Simon Horman
	<horms@...nel.org>
CC: "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	"tipc-discussion@...ts.sourceforge.net"
	<tipc-discussion@...ts.sourceforge.net>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>
Subject: RE: [PATCH v4 net] tipc: fix null-ptr-deref when acquiring remote ip
 of ethernet bearer

>Subject: [PATCH v4 net] tipc: fix null-ptr-deref when acquiring remote ip of
>ethernet bearer
>
>The reproduction steps:
>1. create a tun interface
>2. enable l2 bearer
>3. TIPC_NL_UDP_GET_REMOTEIP with media name set to tun
>
>tipc: Started in network mode
>tipc: Node identity 8af312d38a21, cluster identity 4711
>tipc: Enabled bearer <eth:syz_tun>, priority 1
>Oops: general protection fault
>KASAN: null-ptr-deref in range
>CPU: 1 UID: 1000 PID: 559 Comm: poc Not tainted 6.16.0-rc1+ #117 PREEMPT
>Hardware name: QEMU Ubuntu 24.04 PC
>RIP: 0010:tipc_udp_nl_dump_remoteip+0x4a4/0x8f0
>
>the ub was in fact a struct dev.
>
>when bid != 0 && skip_cnt != 0, bearer_list[bid] may be NULL or other media
>when other thread changes it.
>
>fix this by checking media_id.
>
>Fixes: 832629ca5c313 ("tipc: add UDP remoteip dump to netlink API")
>Signed-off-by: Haixia Qu <hxqu@...lstonenet.com>
>---
>v4:
>  - make commit message more descriptive
>v3:
>https://patchwork.kernel.org/project/netdevbpf/patch/20250616042901.12978
>-1-hxqu@...lstonenet.com/
>  - add Fixes tag in commit message
>  - add target tree net
>---
> net/tipc/udp_media.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
>diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c index
>108a4cc2e001..258d6aa4f21a 100644
>--- a/net/tipc/udp_media.c
>+++ b/net/tipc/udp_media.c
>@@ -489,7 +489,7 @@ int tipc_udp_nl_dump_remoteip(struct sk_buff *skb,
>struct netlink_callback *cb)
>
> 		rtnl_lock();
> 		b = tipc_bearer_find(net, bname);
>-		if (!b) {
>+		if (!b || b->bcast_addr.media_id != TIPC_MEDIA_TYPE_UDP) {
> 			rtnl_unlock();
> 			return -EINVAL;
> 		}
>@@ -500,7 +500,7 @@ int tipc_udp_nl_dump_remoteip(struct sk_buff *skb,
>struct netlink_callback *cb)
>
> 		rtnl_lock();
> 		b = rtnl_dereference(tn->bearer_list[bid]);
>-		if (!b) {
>+		if (!b || b->bcast_addr.media_id != TIPC_MEDIA_TYPE_UDP) {
> 			rtnl_unlock();
> 			return -EINVAL;
> 		}
>--
>2.43.0
>
Reviewed-by: Tung Nguyen <tung.quang.nguyen@....tech>