This is a note to let you know that I've just added the patch titled
tipc: Change nla_policy for bearer-related names to NLA_NUL_STRING
to the 6.6-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:
tipc-change-nla_policy-for-bearer-related-names-to-n.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 5ec281b57cc8f3e7f865f30fe9454b5b496014b9
Author: Shigeru Yoshida <syoshida@xxxxxxxxxx>
Date: Mon Oct 30 16:55:40 2023 +0900
tipc: Change nla_policy for bearer-related names to NLA_NUL_STRING
[ Upstream commit 19b3f72a41a8751e26bffc093bb7e1cef29ad579 ]
syzbot reported the following uninit-value access issue [1]:
=====================================================
BUG: KMSAN: uninit-value in strlen lib/string.c:418 [inline]
BUG: KMSAN: uninit-value in strstr+0xb8/0x2f0 lib/string.c:756
strlen lib/string.c:418 [inline]
strstr+0xb8/0x2f0 lib/string.c:756
tipc_nl_node_reset_link_stats+0x3ea/0xb50 net/tipc/node.c:2595
genl_family_rcv_msg_doit net/netlink/genetlink.c:971 [inline]
genl_family_rcv_msg net/netlink/genetlink.c:1051 [inline]
genl_rcv_msg+0x11ec/0x1290 net/netlink/genetlink.c:1066
netlink_rcv_skb+0x371/0x650 net/netlink/af_netlink.c:2545
genl_rcv+0x40/0x60 net/netlink/genetlink.c:1075
netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]
netlink_unicast+0xf47/0x1250 net/netlink/af_netlink.c:1368
netlink_sendmsg+0x1238/0x13d0 net/netlink/af_netlink.c:1910
sock_sendmsg_nosec net/socket.c:730 [inline]
sock_sendmsg net/socket.c:753 [inline]
____sys_sendmsg+0x9c2/0xd60 net/socket.c:2541
___sys_sendmsg+0x28d/0x3c0 net/socket.c:2595
__sys_sendmsg net/socket.c:2624 [inline]
__do_sys_sendmsg net/socket.c:2633 [inline]
__se_sys_sendmsg net/socket.c:2631 [inline]
__x64_sys_sendmsg+0x307/0x490 net/socket.c:2631
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Uninit was created at:
slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767
slab_alloc_node mm/slub.c:3478 [inline]
kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523
kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:559
__alloc_skb+0x318/0x740 net/core/skbuff.c:650
alloc_skb include/linux/skbuff.h:1286 [inline]
netlink_alloc_large_skb net/netlink/af_netlink.c:1214 [inline]
netlink_sendmsg+0xb34/0x13d0 net/netlink/af_netlink.c:1885
sock_sendmsg_nosec net/socket.c:730 [inline]
sock_sendmsg net/socket.c:753 [inline]
____sys_sendmsg+0x9c2/0xd60 net/socket.c:2541
___sys_sendmsg+0x28d/0x3c0 net/socket.c:2595
__sys_sendmsg net/socket.c:2624 [inline]
__do_sys_sendmsg net/socket.c:2633 [inline]
__se_sys_sendmsg net/socket.c:2631 [inline]
__x64_sys_sendmsg+0x307/0x490 net/socket.c:2631
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
TIPC bearer-related names including link names must be null-terminated
strings. If a link name which is not null-terminated is passed through
netlink, strstr() and similar functions can cause buffer overrun. This
causes the above issue.
This patch changes the nla_policy for bearer-related names from NLA_STRING
to NLA_NUL_STRING. This resolves the issue by ensuring that only
null-terminated strings are accepted as bearer-related names.
syzbot reported similar uninit-value issue related to bearer names [2]. The
root cause of this issue is that a non-null-terminated bearer name was
passed. This patch also resolved this issue.
Fixes: 7be57fc69184 ("tipc: add link get/dump to new netlink api")
Fixes: 0655f6a8635b ("tipc: add bearer disable/enable to new netlink api")
Reported-and-tested-by: syzbot+5138ca807af9d2b42574@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=5138ca807af9d2b42574 [1]
Reported-and-tested-by: syzbot+9425c47dccbcb4c17d51@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=9425c47dccbcb4c17d51 [2]
Signed-off-by: Shigeru Yoshida <syoshida@xxxxxxxxxx>
Reviewed-by: Jiri Pirko <jiri@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20231030075540.3784537-1-syoshida@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/tipc/netlink.c b/net/tipc/netlink.c
index e8fd257c0e688..1a9a5bdaccf4f 100644
--- a/net/tipc/netlink.c
+++ b/net/tipc/netlink.c
@@ -88,7 +88,7 @@ const struct nla_policy tipc_nl_net_policy[TIPC_NLA_NET_MAX + 1] = {
const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = {
[TIPC_NLA_LINK_UNSPEC] = { .type = NLA_UNSPEC },
- [TIPC_NLA_LINK_NAME] = { .type = NLA_STRING,
+ [TIPC_NLA_LINK_NAME] = { .type = NLA_NUL_STRING,
.len = TIPC_MAX_LINK_NAME },
[TIPC_NLA_LINK_MTU] = { .type = NLA_U32 },
[TIPC_NLA_LINK_BROADCAST] = { .type = NLA_FLAG },
@@ -125,7 +125,7 @@ const struct nla_policy tipc_nl_prop_policy[TIPC_NLA_PROP_MAX + 1] = {
const struct nla_policy tipc_nl_bearer_policy[TIPC_NLA_BEARER_MAX + 1] = {
[TIPC_NLA_BEARER_UNSPEC] = { .type = NLA_UNSPEC },
- [TIPC_NLA_BEARER_NAME] = { .type = NLA_STRING,
+ [TIPC_NLA_BEARER_NAME] = { .type = NLA_NUL_STRING,
.len = TIPC_MAX_BEARER_NAME },
[TIPC_NLA_BEARER_PROP] = { .type = NLA_NESTED },
[TIPC_NLA_BEARER_DOMAIN] = { .type = NLA_U32 }
