CVE-2023-52845

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> tipc: Change nla_policy for bearer-related names to NLA_NUL_STRING<br /> <br /> syzbot reported the following uninit-value access issue [1]:<br /> <br /> =====================================================<br /> BUG: KMSAN: uninit-value in strlen lib/string.c:418 [inline]<br /> BUG: KMSAN: uninit-value in strstr+0xb8/0x2f0 lib/string.c:756<br /> strlen lib/string.c:418 [inline]<br /> strstr+0xb8/0x2f0 lib/string.c:756<br /> tipc_nl_node_reset_link_stats+0x3ea/0xb50 net/tipc/node.c:2595<br /> genl_family_rcv_msg_doit net/netlink/genetlink.c:971 [inline]<br /> genl_family_rcv_msg net/netlink/genetlink.c:1051 [inline]<br /> genl_rcv_msg+0x11ec/0x1290 net/netlink/genetlink.c:1066<br /> netlink_rcv_skb+0x371/0x650 net/netlink/af_netlink.c:2545<br /> genl_rcv+0x40/0x60 net/netlink/genetlink.c:1075<br /> netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]<br /> netlink_unicast+0xf47/0x1250 net/netlink/af_netlink.c:1368<br /> netlink_sendmsg+0x1238/0x13d0 net/netlink/af_netlink.c:1910<br /> sock_sendmsg_nosec net/socket.c:730 [inline]<br /> sock_sendmsg net/socket.c:753 [inline]<br /> ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2541<br /> ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2595<br /> __sys_sendmsg net/socket.c:2624 [inline]<br /> __do_sys_sendmsg net/socket.c:2633 [inline]<br /> __se_sys_sendmsg net/socket.c:2631 [inline]<br /> __x64_sys_sendmsg+0x307/0x490 net/socket.c:2631<br /> do_syscall_x64 arch/x86/entry/common.c:50 [inline]<br /> do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80<br /> entry_SYSCALL_64_after_hwframe+0x63/0xcd<br /> <br /> Uninit was created at:<br /> slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767<br /> slab_alloc_node mm/slub.c:3478 [inline]<br /> kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523<br /> kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:559<br /> __alloc_skb+0x318/0x740 net/core/skbuff.c:650<br /> alloc_skb include/linux/skbuff.h:1286 [inline]<br /> netlink_alloc_large_skb net/netlink/af_netlink.c:1214 [inline]<br /> netlink_sendmsg+0xb34/0x13d0 net/netlink/af_netlink.c:1885<br /> sock_sendmsg_nosec net/socket.c:730 [inline]<br /> sock_sendmsg net/socket.c:753 [inline]<br /> ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2541<br /> ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2595<br /> __sys_sendmsg net/socket.c:2624 [inline]<br /> __do_sys_sendmsg net/socket.c:2633 [inline]<br /> __se_sys_sendmsg net/socket.c:2631 [inline]<br /> __x64_sys_sendmsg+0x307/0x490 net/socket.c:2631<br /> do_syscall_x64 arch/x86/entry/common.c:50 [inline]<br /> do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80<br /> entry_SYSCALL_64_after_hwframe+0x63/0xcd<br /> <br /> TIPC bearer-related names including link names must be null-terminated<br /> strings. If a link name which is not null-terminated is passed through<br /> netlink, strstr() and similar functions can cause buffer overrun. This<br /> causes the above issue.<br /> <br /> This patch changes the nla_policy for bearer-related names from NLA_STRING<br /> to NLA_NUL_STRING. This resolves the issue by ensuring that only<br /> null-terminated strings are accepted as bearer-related names.<br /> <br /> syzbot reported similar uninit-value issue related to bearer names [2]. The<br /> root cause of this issue is that a non-null-terminated bearer name was<br /> passed. This patch also resolved this issue.