From 6f07e5f06c8712acc423485f657799fc8e11e56c Mon Sep 17 00:00:00 2001 From: Xin Long Date: Sun, 31 Mar 2019 22:50:08 +0800 Subject: tipc: check bearer name with right length in tipc_nl_compat_bearer_enable Syzbot reported the following crash: BUG: KMSAN: uninit-value in memchr+0xce/0x110 lib/string.c:961 memchr+0xce/0x110 lib/string.c:961 string_is_valid net/tipc/netlink_compat.c:176 [inline] tipc_nl_compat_bearer_enable+0x2c4/0x910 net/tipc/netlink_compat.c:401 __tipc_nl_compat_doit net/tipc/netlink_compat.c:321 [inline] tipc_nl_compat_doit+0x3aa/0xaf0 net/tipc/netlink_compat.c:354 tipc_nl_compat_handle net/tipc/netlink_compat.c:1162 [inline] tipc_nl_compat_recv+0x1ae7/0x2750 net/tipc/netlink_compat.c:1265 genl_family_rcv_msg net/netlink/genetlink.c:601 [inline] genl_rcv_msg+0x185f/0x1a60 net/netlink/genetlink.c:626 netlink_rcv_skb+0x431/0x620 net/netlink/af_netlink.c:2477 genl_rcv+0x63/0x80 net/netlink/genetlink.c:637 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0xf3e/0x1020 net/netlink/af_netlink.c:1336 netlink_sendmsg+0x127f/0x1300 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg net/socket.c:632 [inline] Uninit was created at: __alloc_skb+0x309/0xa20 net/core/skbuff.c:208 alloc_skb include/linux/skbuff.h:1012 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline] netlink_sendmsg+0xb82/0x1300 net/netlink/af_netlink.c:1892 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg net/socket.c:632 [inline] It was triggered when the bearer name size < TIPC_MAX_BEARER_NAME, it would check with a wrong len/TLV_GET_DATA_LEN(msg->req), which also includes priority and disc_domain length. This patch is to fix it by checking it with a right length: 'TLV_GET_DATA_LEN(msg->req) - offsetof(struct tipc_bearer_config, name)'. Reported-by: syzbot+8b707430713eb46e1e45@syzkaller.appspotmail.com Signed-off-by: Xin Long Signed-off-by: David S. Miller --- net/tipc/netlink_compat.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'net/tipc') diff --git a/net/tipc/netlink_compat.c b/net/tipc/netlink_compat.c index 4ad3586da8f0..5f8e53cca222 100644 --- a/net/tipc/netlink_compat.c +++ b/net/tipc/netlink_compat.c @@ -397,7 +397,12 @@ static int tipc_nl_compat_bearer_enable(struct tipc_nl_compat_cmd_doit *cmd, if (!bearer) return -EMSGSIZE; - len = min_t(int, TLV_GET_DATA_LEN(msg->req), TIPC_MAX_BEARER_NAME); + len = TLV_GET_DATA_LEN(msg->req); + len -= offsetof(struct tipc_bearer_config, name); + if (len <= 0) + return -EINVAL; + + len = min_t(int, len, TIPC_MAX_BEARER_NAME); if (!string_is_valid(b->name, len)) return -EINVAL; -- cgit v1.2.3 From 8c63bf9ab4be8b83bd8c34aacfd2f1d2c8901c8a Mon Sep 17 00:00:00 2001 From: Xin Long Date: Sun, 31 Mar 2019 22:50:09 +0800 Subject: tipc: check link name with right length in tipc_nl_compat_link_set A similar issue as fixed by Patch "tipc: check bearer name with right length in tipc_nl_compat_bearer_enable" was also found by syzbot in tipc_nl_compat_link_set(). The length to check with should be 'TLV_GET_DATA_LEN(msg->req) - offsetof(struct tipc_link_config, name)'. Reported-by: syzbot+de00a87b8644a582ae79@syzkaller.appspotmail.com Signed-off-by: Xin Long Signed-off-by: David S. Miller --- net/tipc/netlink_compat.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'net/tipc') diff --git a/net/tipc/netlink_compat.c b/net/tipc/netlink_compat.c index 5f8e53cca222..0bfd03d67fdd 100644 --- a/net/tipc/netlink_compat.c +++ b/net/tipc/netlink_compat.c @@ -771,7 +771,12 @@ static int tipc_nl_compat_link_set(struct tipc_nl_compat_cmd_doit *cmd, lc = (struct tipc_link_config *)TLV_DATA(msg->req); - len = min_t(int, TLV_GET_DATA_LEN(msg->req), TIPC_MAX_LINK_NAME); + len = TLV_GET_DATA_LEN(msg->req); + len -= offsetof(struct tipc_link_config, name); + if (len <= 0) + return -EINVAL; + + len = min_t(int, len, TIPC_MAX_LINK_NAME); if (!string_is_valid(lc->name, len)) return -EINVAL; -- cgit v1.2.3 From 2ac695d1d602ce00b12170242f58c3d3a8e36d04 Mon Sep 17 00:00:00 2001 From: Xin Long Date: Sun, 31 Mar 2019 22:50:10 +0800 Subject: tipc: handle the err returned from cmd header function Syzbot found a crash: BUG: KMSAN: uninit-value in tipc_nl_compat_name_table_dump+0x54f/0xcd0 net/tipc/netlink_compat.c:872 Call Trace: tipc_nl_compat_name_table_dump+0x54f/0xcd0 net/tipc/netlink_compat.c:872 __tipc_nl_compat_dumpit+0x59e/0xda0 net/tipc/netlink_compat.c:215 tipc_nl_compat_dumpit+0x63a/0x820 net/tipc/netlink_compat.c:280 tipc_nl_compat_handle net/tipc/netlink_compat.c:1226 [inline] tipc_nl_compat_recv+0x1b5f/0x2750 net/tipc/netlink_compat.c:1265 genl_family_rcv_msg net/netlink/genetlink.c:601 [inline] genl_rcv_msg+0x185f/0x1a60 net/netlink/genetlink.c:626 netlink_rcv_skb+0x431/0x620 net/netlink/af_netlink.c:2477 genl_rcv+0x63/0x80 net/netlink/genetlink.c:637 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0xf3e/0x1020 net/netlink/af_netlink.c:1336 netlink_sendmsg+0x127f/0x1300 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg net/socket.c:632 [inline] Uninit was created at: __alloc_skb+0x309/0xa20 net/core/skbuff.c:208 alloc_skb include/linux/skbuff.h:1012 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline] netlink_sendmsg+0xb82/0x1300 net/netlink/af_netlink.c:1892 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg net/socket.c:632 [inline] It was supposed to be fixed on commit 974cb0e3e7c9 ("tipc: fix uninit-value in tipc_nl_compat_name_table_dump") by checking TLV_GET_DATA_LEN(msg->req) in cmd->header()/tipc_nl_compat_name_table_dump_header(), which is called ahead of tipc_nl_compat_name_table_dump(). However, tipc_nl_compat_dumpit() doesn't handle the error returned from cmd header function. It means even when the check added in that fix fails, it won't stop calling tipc_nl_compat_name_table_dump(), and the issue will be triggered again. So this patch is to add the process for the err returned from cmd header function in tipc_nl_compat_dumpit(). Reported-by: syzbot+3ce8520484b0d4e260a5@syzkaller.appspotmail.com Signed-off-by: Xin Long Signed-off-by: David S. Miller --- net/tipc/netlink_compat.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/netlink_compat.c b/net/tipc/netlink_compat.c index 0bfd03d67fdd..340a6e7c43a7 100644 --- a/net/tipc/netlink_compat.c +++ b/net/tipc/netlink_compat.c @@ -267,8 +267,14 @@ static int tipc_nl_compat_dumpit(struct tipc_nl_compat_cmd_dump *cmd, if (msg->rep_type) tipc_tlv_init(msg->rep, msg->rep_type); - if (cmd->header) - (*cmd->header)(msg); + if (cmd->header) { + err = (*cmd->header)(msg); + if (err) { + kfree_skb(msg->rep); + msg->rep = NULL; + return err; + } + } arg = nlmsg_new(0, GFP_KERNEL); if (!arg) { -- cgit v1.2.3