4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet edumazet@google.com
[ Upstream commit 644c7eebbfd59e72982d11ec6cc7d39af12450ae ]
It seems that rtnl_group_changelink() can call do_setlink while a prior call to validate_linkmsg(dev = NULL, ...) could not validate IFLA_ADDRESS / IFLA_BROADCAST
Make sure do_setlink() calls validate_linkmsg() instead of letting its callers having this responsibility.
With help from Dmitry Vyukov, thanks a lot !
BUG: KMSAN: uninit-value in is_valid_ether_addr include/linux/etherdevice.h:199 [inline] BUG: KMSAN: uninit-value in eth_prepare_mac_addr_change net/ethernet/eth.c:275 [inline] BUG: KMSAN: uninit-value in eth_mac_addr+0x203/0x2b0 net/ethernet/eth.c:308 CPU: 1 PID: 8695 Comm: syz-executor3 Not tainted 4.17.0-rc5+ #103 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+0x185/0x1d0 lib/dump_stack.c:113 kmsan_report+0x149/0x260 mm/kmsan/kmsan.c:1084 __msan_warning_32+0x6e/0xc0 mm/kmsan/kmsan_instr.c:686 is_valid_ether_addr include/linux/etherdevice.h:199 [inline] eth_prepare_mac_addr_change net/ethernet/eth.c:275 [inline] eth_mac_addr+0x203/0x2b0 net/ethernet/eth.c:308 dev_set_mac_address+0x261/0x530 net/core/dev.c:7157 do_setlink+0xbc3/0x5fc0 net/core/rtnetlink.c:2317 rtnl_group_changelink net/core/rtnetlink.c:2824 [inline] rtnl_newlink+0x1fe9/0x37a0 net/core/rtnetlink.c:2976 rtnetlink_rcv_msg+0xa32/0x1560 net/core/rtnetlink.c:4646 netlink_rcv_skb+0x378/0x600 net/netlink/af_netlink.c:2448 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4664 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x1678/0x1750 net/netlink/af_netlink.c:1336 netlink_sendmsg+0x104f/0x1350 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg net/socket.c:639 [inline] ___sys_sendmsg+0xec0/0x1310 net/socket.c:2117 __sys_sendmsg net/socket.c:2155 [inline] __do_sys_sendmsg net/socket.c:2164 [inline] __se_sys_sendmsg net/socket.c:2162 [inline] __x64_sys_sendmsg+0x331/0x460 net/socket.c:2162 do_syscall_64+0x152/0x230 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x455a09 RSP: 002b:00007fc07480ec68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fc07480f6d4 RCX: 0000000000455a09 RDX: 0000000000000000 RSI: 00000000200003c0 RDI: 0000000000000014 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000005d0 R14: 00000000006fdc20 R15: 0000000000000000
Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279 [inline] kmsan_save_stack mm/kmsan/kmsan.c:294 [inline] kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:685 kmsan_memcpy_origins+0x11d/0x170 mm/kmsan/kmsan.c:527 __msan_memcpy+0x109/0x160 mm/kmsan/kmsan_instr.c:478 do_setlink+0xb84/0x5fc0 net/core/rtnetlink.c:2315 rtnl_group_changelink net/core/rtnetlink.c:2824 [inline] rtnl_newlink+0x1fe9/0x37a0 net/core/rtnetlink.c:2976 rtnetlink_rcv_msg+0xa32/0x1560 net/core/rtnetlink.c:4646 netlink_rcv_skb+0x378/0x600 net/netlink/af_netlink.c:2448 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4664 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x1678/0x1750 net/netlink/af_netlink.c:1336 netlink_sendmsg+0x104f/0x1350 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg net/socket.c:639 [inline] ___sys_sendmsg+0xec0/0x1310 net/socket.c:2117 __sys_sendmsg net/socket.c:2155 [inline] __do_sys_sendmsg net/socket.c:2164 [inline] __se_sys_sendmsg net/socket.c:2162 [inline] __x64_sys_sendmsg+0x331/0x460 net/socket.c:2162 do_syscall_64+0x152/0x230 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279 [inline] kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:189 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:315 kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan.c:322 slab_post_alloc_hook mm/slab.h:446 [inline] slab_alloc_node mm/slub.c:2753 [inline] __kmalloc_node_track_caller+0xb32/0x11b0 mm/slub.c:4395 __kmalloc_reserve net/core/skbuff.c:138 [inline] __alloc_skb+0x2cb/0x9e0 net/core/skbuff.c:206 alloc_skb include/linux/skbuff.h:988 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline] netlink_sendmsg+0x76e/0x1350 net/netlink/af_netlink.c:1876 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg net/socket.c:639 [inline] ___sys_sendmsg+0xec0/0x1310 net/socket.c:2117 __sys_sendmsg net/socket.c:2155 [inline] __do_sys_sendmsg net/socket.c:2164 [inline] __se_sys_sendmsg net/socket.c:2162 [inline] __x64_sys_sendmsg+0x331/0x460 net/socket.c:2162 do_syscall_64+0x152/0x230 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes: e7ed828f10bd ("netlink: support setting devgroup parameters") Signed-off-by: Eric Dumazet edumazet@google.com Reported-by: syzbot syzkaller@googlegroups.com Cc: Dmitry Vyukov dvyukov@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/core/rtnetlink.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1914,6 +1914,10 @@ static int do_setlink(const struct sk_bu const struct net_device_ops *ops = dev->netdev_ops; int err;
+ err = validate_linkmsg(dev, tb); + if (err < 0) + return err; + if (tb[IFLA_NET_NS_PID] || tb[IFLA_NET_NS_FD]) { struct net *net = rtnl_link_get_net(dev_net(dev), tb); if (IS_ERR(net)) { @@ -2234,10 +2238,6 @@ static int rtnl_setlink(struct sk_buff * goto errout; }
- err = validate_linkmsg(dev, tb); - if (err < 0) - goto errout; - err = do_setlink(skb, dev, ifm, tb, ifname, 0); errout: return err;