From a7869e5f9174f246b662b2db6390bc128a351388 Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Sat, 4 Jan 2020 10:48:36 +0800 Subject: tipc: eliminate KMSAN: uninit-value in __tipc_nl_compat_dumpit error syzbot found the following crash on: ===================================================== BUG: KMSAN: uninit-value in __nlmsg_parse include/net/netlink.h:661 [inline] BUG: KMSAN: uninit-value in nlmsg_parse_deprecated include/net/netlink.h:706 [inline] BUG: KMSAN: uninit-value in __tipc_nl_compat_dumpit+0x553/0x11e0 net/tipc/netlink_compat.c:215 CPU: 0 PID: 12425 Comm: syz-executor062 Not tainted 5.5.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x220 lib/dump_stack.c:118 kmsan_report+0x128/0x220 mm/kmsan/kmsan_report.c:108 __msan_warning+0x57/0xa0 mm/kmsan/kmsan_instr.c:245 __nlmsg_parse include/net/netlink.h:661 [inline] nlmsg_parse_deprecated include/net/netlink.h:706 [inline] __tipc_nl_compat_dumpit+0x553/0x11e0 net/tipc/netlink_compat.c:215 tipc_nl_compat_dumpit+0x761/0x910 net/tipc/netlink_compat.c:308 tipc_nl_compat_handle net/tipc/netlink_compat.c:1252 [inline] tipc_nl_compat_recv+0x12e9/0x2870 net/tipc/netlink_compat.c:1311 genl_family_rcv_msg_doit net/netlink/genetlink.c:672 [inline] genl_family_rcv_msg net/netlink/genetlink.c:717 [inline] genl_rcv_msg+0x1dd0/0x23a0 net/netlink/genetlink.c:734 netlink_rcv_skb+0x431/0x620 net/netlink/af_netlink.c:2477 genl_rcv+0x63/0x80 net/netlink/genetlink.c:745 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0xfa0/0x1100 net/netlink/af_netlink.c:1328 netlink_sendmsg+0x11f0/0x1480 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:639 [inline] sock_sendmsg net/socket.c:659 [inline] ____sys_sendmsg+0x1362/0x13f0 net/socket.c:2330 ___sys_sendmsg net/socket.c:2384 [inline] __sys_sendmsg+0x4f0/0x5e0 net/socket.c:2417 __do_sys_sendmsg net/socket.c:2426 [inline] __se_sys_sendmsg+0x97/0xb0 net/socket.c:2424 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2424 do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x444179 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 1b d8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffd2d6409c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000444179 RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000003 RBP: 00000000006ce018 R08: 0000000000000000 R09: 00000000004002e0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401e20 R13: 0000000000401eb0 R14: 0000000000000000 R15: 0000000000000000 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:149 [inline] kmsan_internal_poison_shadow+0x5c/0x110 mm/kmsan/kmsan.c:132 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:86 slab_alloc_node mm/slub.c:2774 [inline] __kmalloc_node_track_caller+0xe47/0x11f0 mm/slub.c:4382 __kmalloc_reserve net/core/skbuff.c:141 [inline] __alloc_skb+0x309/0xa50 net/core/skbuff.c:209 alloc_skb include/linux/skbuff.h:1049 [inline] nlmsg_new include/net/netlink.h:888 [inline] tipc_nl_compat_dumpit+0x6e4/0x910 net/tipc/netlink_compat.c:301 tipc_nl_compat_handle net/tipc/netlink_compat.c:1252 [inline] tipc_nl_compat_recv+0x12e9/0x2870 net/tipc/netlink_compat.c:1311 genl_family_rcv_msg_doit net/netlink/genetlink.c:672 [inline] genl_family_rcv_msg net/netlink/genetlink.c:717 [inline] genl_rcv_msg+0x1dd0/0x23a0 net/netlink/genetlink.c:734 netlink_rcv_skb+0x431/0x620 net/netlink/af_netlink.c:2477 genl_rcv+0x63/0x80 net/netlink/genetlink.c:745 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0xfa0/0x1100 net/netlink/af_netlink.c:1328 netlink_sendmsg+0x11f0/0x1480 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:639 [inline] sock_sendmsg net/socket.c:659 [inline] ____sys_sendmsg+0x1362/0x13f0 net/socket.c:2330 ___sys_sendmsg net/socket.c:2384 [inline] __sys_sendmsg+0x4f0/0x5e0 net/socket.c:2417 __do_sys_sendmsg net/socket.c:2426 [inline] __se_sys_sendmsg+0x97/0xb0 net/socket.c:2424 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2424 do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x44/0xa9 ===================================================== The complaint above occurred because the memory region pointed by attrbuf variable was not initialized. To eliminate this warning, we use kcalloc() rather than kmalloc_array() to allocate memory for attrbuf. Reported-by: syzbot+b1fd2bf2c89d8407e15f@syzkaller.appspotmail.com Signed-off-by: Ying Xue Signed-off-by: David S. Miller --- net/tipc/netlink_compat.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/tipc/netlink_compat.c') diff --git a/net/tipc/netlink_compat.c b/net/tipc/netlink_compat.c index 0254bb7e418b..217516357ef2 100644 --- a/net/tipc/netlink_compat.c +++ b/net/tipc/netlink_compat.c @@ -204,8 +204,8 @@ static int __tipc_nl_compat_dumpit(struct tipc_nl_compat_cmd_dump *cmd, return -ENOMEM; } - attrbuf = kmalloc_array(tipc_genl_family.maxattr + 1, - sizeof(struct nlattr *), GFP_KERNEL); + attrbuf = kcalloc(tipc_genl_family.maxattr + 1, + sizeof(struct nlattr *), GFP_KERNEL); if (!attrbuf) { err = -ENOMEM; goto err_out; -- cgit v1.2.3