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Commit | Line | Data |
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9e4b7051 GKH |
1 | From 2ac695d1d602ce00b12170242f58c3d3a8e36d04 Mon Sep 17 00:00:00 2001 |
2 | From: Xin Long <lucien.xin@gmail.com> | |
3 | Date: Sun, 31 Mar 2019 22:50:10 +0800 | |
4 | Subject: tipc: handle the err returned from cmd header function | |
5 | ||
6 | From: Xin Long <lucien.xin@gmail.com> | |
7 | ||
8 | commit 2ac695d1d602ce00b12170242f58c3d3a8e36d04 upstream. | |
9 | ||
10 | Syzbot found a crash: | |
11 | ||
12 | BUG: KMSAN: uninit-value in tipc_nl_compat_name_table_dump+0x54f/0xcd0 net/tipc/netlink_compat.c:872 | |
13 | Call Trace: | |
14 | tipc_nl_compat_name_table_dump+0x54f/0xcd0 net/tipc/netlink_compat.c:872 | |
15 | __tipc_nl_compat_dumpit+0x59e/0xda0 net/tipc/netlink_compat.c:215 | |
16 | tipc_nl_compat_dumpit+0x63a/0x820 net/tipc/netlink_compat.c:280 | |
17 | tipc_nl_compat_handle net/tipc/netlink_compat.c:1226 [inline] | |
18 | tipc_nl_compat_recv+0x1b5f/0x2750 net/tipc/netlink_compat.c:1265 | |
19 | genl_family_rcv_msg net/netlink/genetlink.c:601 [inline] | |
20 | genl_rcv_msg+0x185f/0x1a60 net/netlink/genetlink.c:626 | |
21 | netlink_rcv_skb+0x431/0x620 net/netlink/af_netlink.c:2477 | |
22 | genl_rcv+0x63/0x80 net/netlink/genetlink.c:637 | |
23 | netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] | |
24 | netlink_unicast+0xf3e/0x1020 net/netlink/af_netlink.c:1336 | |
25 | netlink_sendmsg+0x127f/0x1300 net/netlink/af_netlink.c:1917 | |
26 | sock_sendmsg_nosec net/socket.c:622 [inline] | |
27 | sock_sendmsg net/socket.c:632 [inline] | |
28 | ||
29 | Uninit was created at: | |
30 | __alloc_skb+0x309/0xa20 net/core/skbuff.c:208 | |
31 | alloc_skb include/linux/skbuff.h:1012 [inline] | |
32 | netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline] | |
33 | netlink_sendmsg+0xb82/0x1300 net/netlink/af_netlink.c:1892 | |
34 | sock_sendmsg_nosec net/socket.c:622 [inline] | |
35 | sock_sendmsg net/socket.c:632 [inline] | |
36 | ||
37 | It was supposed to be fixed on commit 974cb0e3e7c9 ("tipc: fix uninit-value | |
38 | in tipc_nl_compat_name_table_dump") by checking TLV_GET_DATA_LEN(msg->req) | |
39 | in cmd->header()/tipc_nl_compat_name_table_dump_header(), which is called | |
40 | ahead of tipc_nl_compat_name_table_dump(). | |
41 | ||
42 | However, tipc_nl_compat_dumpit() doesn't handle the error returned from cmd | |
43 | header function. It means even when the check added in that fix fails, it | |
44 | won't stop calling tipc_nl_compat_name_table_dump(), and the issue will be | |
45 | triggered again. | |
46 | ||
47 | So this patch is to add the process for the err returned from cmd header | |
48 | function in tipc_nl_compat_dumpit(). | |
49 | ||
50 | Reported-by: syzbot+3ce8520484b0d4e260a5@syzkaller.appspotmail.com | |
51 | Signed-off-by: Xin Long <lucien.xin@gmail.com> | |
52 | Signed-off-by: David S. Miller <davem@davemloft.net> | |
53 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
54 | ||
55 | --- | |
56 | net/tipc/netlink_compat.c | 10 ++++++++-- | |
57 | 1 file changed, 8 insertions(+), 2 deletions(-) | |
58 | ||
59 | --- a/net/tipc/netlink_compat.c | |
60 | +++ b/net/tipc/netlink_compat.c | |
61 | @@ -262,8 +262,14 @@ static int tipc_nl_compat_dumpit(struct | |
62 | if (msg->rep_type) | |
63 | tipc_tlv_init(msg->rep, msg->rep_type); | |
64 | ||
65 | - if (cmd->header) | |
66 | - (*cmd->header)(msg); | |
67 | + if (cmd->header) { | |
68 | + err = (*cmd->header)(msg); | |
69 | + if (err) { | |
70 | + kfree_skb(msg->rep); | |
71 | + msg->rep = NULL; | |
72 | + return err; | |
73 | + } | |
74 | + } | |
75 | ||
76 | arg = nlmsg_new(0, GFP_KERNEL); | |
77 | if (!arg) { |