Messages in this thread | | | Date | Thu, 05 Oct 2023 01:39:09 +0900 (JST) | Subject | Re: [PATCH] tipc: Fix uninit-value access in tipc_nl_node_reset_link_stats() | From | Shigeru Yoshida <> |
| |
On Tue, 03 Oct 2023 10:58:54 +0200, Paolo Abeni wrote: > On Sun, 2023-09-24 at 15:03 +0900, Shigeru Yoshida wrote: >> syzbot reported the following uninit-value access issue: >> >> ===================================================== >> 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 >> >> 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 fixes this issue by returning -EINVAL if a non-null-terminated >> link name is passed. >> >> Fixes: ae36342b50a9 ("tipc: add link stat reset to new netlink api") >> Reported-and-tested-by: syzbot+5138ca807af9d2b42574@syzkaller.appspotmail.com >> Closes: https://syzkaller.appspot.com/bug?extid=5138ca807af9d2b42574 >> Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> >> --- >> net/tipc/node.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/net/tipc/node.c b/net/tipc/node.c >> index 3105abe97bb9..f167bdafc034 100644 >> --- a/net/tipc/node.c >> +++ b/net/tipc/node.c >> @@ -2586,6 +2586,10 @@ int tipc_nl_node_reset_link_stats(struct sk_buff *skb, struct genl_info *info) >> >> link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]); >> >> + if (link_name[strnlen(link_name, >> + nla_len(attrs[TIPC_NLA_LINK_NAME]))] != '\0') >> + return -EINVAL; > > I have the same comment as for the other tipc patch, please use > nla_strscpy instead, thanks!
Thank you for your comment. I'll send a v2 patch using nla_strscpy() and check if other usage of TIPC_NLA_LINK_NAME have the same issue.
Thanks, Shigeru
> > Paolo >
| |