Messages in this thread | | | Date | Mon, 30 Oct 2023 13:00:18 +0100 | From | Jiri Pirko <> | Subject | Re: [PATCH net v3] tipc: Change nla_policy for bearer-related names to NLA_NUL_STRING |
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Mon, Oct 30, 2023 at 08:55:40AM CET, syoshida@redhat.com wrote: >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@syzkaller.appspotmail.com >Closes: https://syzkaller.appspot.com/bug?extid=5138ca807af9d2b42574 [1] >Reported-and-tested-by: syzbot+9425c47dccbcb4c17d51@syzkaller.appspotmail.com >Closes: https://syzkaller.appspot.com/bug?extid=9425c47dccbcb4c17d51 [2] >Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
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