CVE-2023-52845 in Linux
Sumário
de VulDB • 28/05/2026
No kernel do Linux, a seguinte vulnerabilidade foi resolvida:
tipc: Alterar nla_policy para nomes relacionados ao bearer para NLA_NUL_STRING
O syzbot relatou o seguinte problema de acesso a valor não inicializado [1]:
===================================================== BUG: KMSAN: uninit-value em strlen lib/string.c:418 [inline]
BUG: KMSAN: uninit-value em 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
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.
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