kernel/linux.git/net/tipc/netlink.c, branch v6.19.11

tipc: Change nla_policy for bearer-related names to NLA_NUL_STRING

2023-11-02T05:26:37+00:00

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 Reviewed-by: Jiri Pirko Link: https://lore.kernel.org/r/20231030075540.3784537-1-syoshida@redhat.com Signed-off-by: Jakub Kicinski

genetlink: start to validate reserved header bytes

2022-08-29T11:47:15+00:00

We had historically not checked that genlmsghdr.reserved is 0 on input which prevents us from using those precious bytes in the future. One use case would be to extend the cmd field, which is currently just 8 bits wide and 256 is not a lot of commands for some core families. To make sure that new families do the right thing by default put the onus of opting out of validation on existing families. Signed-off-by: Jakub Kicinski Acked-by: Paul Moore (NetLabel) Signed-off-by: David S. Miller

tipc: add automatic rekeying for encryption key

2020-09-18T20:58:37+00:00

Rekeying is required for security since a key is less secure when using for a long time. Also, key will be detached when its nonce value (or seqno ...) is exhausted. We now make the rekeying process automatic and configurable by user. Basically, TIPC will at a specific interval generate a new key by using the kernel 'Random Number Generator' cipher, then attach it as the node TX key and securely distribute to others in the cluster as RX keys (- the key exchange). The automatic key switching will then take over, and make the new key active shortly. Afterwards, the traffic from this node will be encrypted with the new session key. The same can happen in peer nodes but not necessarily at the same time. For simplicity, the automatically generated key will be initiated as a per node key. It is not too hard to also support a cluster key rekeying (e.g. a given node will generate a unique cluster key and update to the others in the cluster...), but that doesn't bring much benefit, while a per-node key is even more secure. We also enable user to force a rekeying or change the rekeying interval via netlink, the new 'set key' command option: 'TIPC_NLA_NODE_REKEYING' is added for these purposes as follows: - A value >= 1 will be set as the rekeying interval (in minutes); - A value of 0 will disable the rekeying; - A value of 'TIPC_REKEYING_NOW' (~0) will force an immediate rekeying; The default rekeying interval is (60 * 24) minutes i.e. done every day. There isn't any restriction for the value but user shouldn't set it too small or too large which results in an "ineffective" rekeying (thats ok for testing though). Acked-by: Jon Maloy Signed-off-by: Tuong Lien Signed-off-by: David S. Miller

tipc: introduce encryption master key

2020-09-18T20:58:37+00:00

In addition to the supported cluster & per-node encryption keys for the en/decryption of TIPC messages, we now introduce one option for user to set a cluster key as 'master key', which is simply a symmetric key like the former but has a longer life cycle. It has two purposes: - Authentication of new member nodes in the cluster. New nodes, having no knowledge of current session keys in the cluster will still be able to join the cluster as long as they know the master key. This is because all neighbor discovery (LINK_CONFIG) messages must be encrypted with this key. - Encryption of session encryption keys during automatic exchange and update of those.This is a feature we will introduce in a later commit in this series. We insert the new key into the currently unused slot 0 in the key array and start using it immediately once the user has set it. After joining, a node only knowing the master key should be fully communicable to existing nodes in the cluster, although those nodes may have their own session keys activated (i.e. not the master one). To support this, we define a 'grace period', starting from the time a node itself reports having no RX keys, so the existing nodes will use the master key for encryption instead. The grace period can be extended but will automatically stop after e.g. 5 seconds without a new report. This is also the basis for later key exchanging feature as the new node will be impossible to decrypt anything without the support from master key. For user to set a master key, we define a new netlink flag - 'TIPC_NLA_NODE_KEY_MASTER', so it can be added to the current 'set key' netlink command to specify the setting key to be a master key. Above all, the traditional cluster/per-node key mechanism is guaranteed to work when user comes not to use this master key option. This is also compatible to legacy nodes without the feature supported. Even this master key can be updated without any interruption of cluster connectivity but is so is needed, this has to be coordinated and set by the user. Acked-by: Jon Maloy Signed-off-by: Tuong Lien Signed-off-by: David S. Miller

tipc: add support for broadcast rcv stats dumping

2020-05-26T22:16:52+00:00

This commit enables dumping the statistics of a broadcast-receiver link like the traditional 'broadcast-link' one (which is for broadcast- sender). The link dumping can be triggered via netlink (e.g. the iproute2/tipc tool) by the link flag - 'TIPC_NLA_LINK_BROADCAST' as the indicator. The name of a broadcast-receiver link of a specific peer will be in the format: 'broadcast-link:'. For example: Link Window:50 packets RX packets:7841 fragments:2408/440 bundles:0/0 TX packets:0 fragments:0/0 bundles:0/0 RX naks:0 defs:124 dups:0 TX naks:21 acks:0 retrans:0 Congestion link:0 Send queue max:0 avg:0 In addition, the broadcast-receiver link statistics can be reset in the usual way via netlink by specifying that link name in command. Note: the 'tipc_link_name_ext()' is removed because the link name can now be retrieved simply via the 'l->name'. Acked-by: Ying Xue Acked-by: Jon Maloy Signed-off-by: Tuong Lien Signed-off-by: David S. Miller

tipc: add missing attribute validation for MTU property

2020-03-03T21:28:49+00:00

Add missing attribute validation for TIPC_NLA_PROP_MTU to the netlink policy. Fixes: 901271e0403a ("tipc: implement configuration of UDP media MTU") Signed-off-by: Jakub Kicinski Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller

tipc: make legacy address flag readable over netlink

2019-12-21T05:18:42+00:00

To enable iproute2/tipc to generate backwards compatible printouts and validate command parameters for nodes using a node address, it needs to be able to read the legacy address flag from the kernel. The legacy address flag records the way in which the node identity was originally specified. The legacy address flag is requested by the netlink message TIPC_NL_ADDR_LEGACY_GET. If the flag is set the attribute TIPC_NLA_NET_ADDR_LEGACY is set in the return message. Signed-off-by: John Rutherford Acked-by: Jon Maloy Signed-off-by: David S. Miller

tipc: add support for AEAD key setting via netlink

2019-11-08T22:01:59+00:00

This commit adds two netlink commands to TIPC in order for user to be able to set or remove AEAD keys: - TIPC_NL_KEY_SET - TIPC_NL_KEY_FLUSH When the 'KEY_SET' is given along with the key data, the key will be initiated and attached to TIPC crypto. On the other hand, the 'KEY_FLUSH' command will remove all existing keys if any. Acked-by: Ying Xue Acked-by: Jon Maloy Signed-off-by: Tuong Lien Signed-off-by: David S. Miller

net: tipc: allocate attrs locally instead of using genl_family_attrbuf in compat_dumpit()

2019-10-06T13:44:47+00:00

As this is the last user of genl_family_attrbuf, convert to allocate attrs locally and do it in a similar way this is done in compat_doit(). Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller

net: tipc: have genetlink code to parse the attrs during dumpit

2019-10-06T13:44:47+00:00

Benefit from the fact that the generic netlink code can parse the attrs for dumpit op and avoid need to parse it in the op callback. Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller