user/sven/linux.git/net/ipv4/devinet.c, branch v5.5

inet: protect against too small mtu values.

2019-12-07T19:55:11Z

syzbot was once again able to crash a host by setting a very small mtu on loopback device. Let's make inetdev_valid_mtu() available in include/net/ip.h, and use it in ip_setup_cork(), so that we protect both ip_append_page() and __ip_append_data() Also add a READ_ONCE() when the device mtu is read. Pairs this lockless read with one WRITE_ONCE() in __dev_set_mtu(), even if other code paths might write over this field. Add a big comment in include/linux/netdevice.h about dev->mtu needing READ_ONCE()/WRITE_ONCE() annotations. Hopefully we will add the missing ones in followup patches. [1] refcount_t: saturated; leaking memory. WARNING: CPU: 0 PID: 9464 at lib/refcount.c:22 refcount_warn_saturate+0x138/0x1f0 lib/refcount.c:22 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 9464 Comm: syz-executor850 Not tainted 5.4.0-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+0x197/0x210 lib/dump_stack.c:118 panic+0x2e3/0x75c kernel/panic.c:221 __warn.cold+0x2f/0x3e kernel/panic.c:582 report_bug+0x289/0x300 lib/bug.c:195 fixup_bug arch/x86/kernel/traps.c:174 [inline] fixup_bug arch/x86/kernel/traps.c:169 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027 RIP: 0010:refcount_warn_saturate+0x138/0x1f0 lib/refcount.c:22 Code: 06 31 ff 89 de e8 c8 f5 e6 fd 84 db 0f 85 6f ff ff ff e8 7b f4 e6 fd 48 c7 c7 e0 71 4f 88 c6 05 56 a6 a4 06 01 e8 c7 a8 b7 fd <0f> 0b e9 50 ff ff ff e8 5c f4 e6 fd 0f b6 1d 3d a6 a4 06 31 ff 89 RSP: 0018:ffff88809689f550 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff815e4336 RDI: ffffed1012d13e9c RBP: ffff88809689f560 R08: ffff88809c50a3c0 R09: fffffbfff15d31b1 R10: fffffbfff15d31b0 R11: ffffffff8ae98d87 R12: 0000000000000001 R13: 0000000000040100 R14: ffff888099041104 R15: ffff888218d96e40 refcount_add include/linux/refcount.h:193 [inline] skb_set_owner_w+0x2b6/0x410 net/core/sock.c:1999 sock_wmalloc+0xf1/0x120 net/core/sock.c:2096 ip_append_page+0x7ef/0x1190 net/ipv4/ip_output.c:1383 udp_sendpage+0x1c7/0x480 net/ipv4/udp.c:1276 inet_sendpage+0xdb/0x150 net/ipv4/af_inet.c:821 kernel_sendpage+0x92/0xf0 net/socket.c:3794 sock_sendpage+0x8b/0xc0 net/socket.c:936 pipe_to_sendpage+0x2da/0x3c0 fs/splice.c:458 splice_from_pipe_feed fs/splice.c:512 [inline] __splice_from_pipe+0x3ee/0x7c0 fs/splice.c:636 splice_from_pipe+0x108/0x170 fs/splice.c:671 generic_splice_sendpage+0x3c/0x50 fs/splice.c:842 do_splice_from fs/splice.c:861 [inline] direct_splice_actor+0x123/0x190 fs/splice.c:1035 splice_direct_to_actor+0x3b4/0xa30 fs/splice.c:990 do_splice_direct+0x1da/0x2a0 fs/splice.c:1078 do_sendfile+0x597/0xd00 fs/read_write.c:1464 __do_sys_sendfile64 fs/read_write.c:1525 [inline] __se_sys_sendfile64 fs/read_write.c:1511 [inline] __x64_sys_sendfile64+0x1dd/0x220 fs/read_write.c:1511 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x441409 Code: e8 ac e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 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 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fffb64c4f78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441409 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000005 RBP: 0000000000073b8a R08: 0000000000000010 R09: 0000000000000010 R10: 0000000000010001 R11: 0000000000000246 R12: 0000000000402180 R13: 0000000000402210 R14: 0000000000000000 R15: 0000000000000000 Kernel Offset: disabled Rebooting in 86400 seconds.. Fixes: 1470ddf7f8ce ("inet: Remove explicit write references to sk/inet in ip_append_data") Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2019-07-09T02:48:57Z

Two cases of overlapping changes, nothing fancy. Signed-off-by: David S. Miller

ipv4: don't set IPv6 only flags to IPv4 addresses

2019-07-01T18:31:38Z

Avoid the situation where an IPV6 only flag is applied to an IPv4 address: # ip addr add 192.0.2.1/24 dev dummy0 nodad home mngtmpaddr noprefixroute # ip -4 addr show dev dummy0 2: dummy0: mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 inet 192.0.2.1/24 scope global noprefixroute dummy0 valid_lft forever preferred_lft forever Or worse, by sending a malicious netlink command: # ip -4 addr show dev dummy0 2: dummy0: mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 inet 192.0.2.1/24 scope global nodad optimistic dadfailed home tentative mngtmpaddr noprefixroute stable-privacy dummy0 valid_lft forever preferred_lft forever Signed-off-by: Matteo Croce Reviewed-by: David Ahern Signed-off-by: David S. Miller

net: ipv4: fix infinite loop on secondary addr promotion

2019-06-27T16:54:34Z

secondary address promotion causes infinite loop -- it arranges for ifa->ifa_next to point back to itself. Problem is that 'prev_prom' and 'last_prim' might point at the same entry, so 'last_sec' pointer must be obtained after prev_prom->next update. Fixes: 2638eb8b50cf ("net: ipv4: provide __rcu annotation for ifa_list") Reported-by: Ran Rozenstein Reported-by: Tariq Toukan Signed-off-by: Florian Westphal Signed-off-by: David S. Miller

ipv4: fix confirm_addr_indev() when enable route_localnet

2019-06-24T16:02:47Z

When arp_ignore=3, the NIC won't reply for scope host addresses, but if enable route_locanet, we need to reply ip address with head 127 and scope RT_SCOPE_HOST. Fixes: d0daebc3d622 ("ipv4: Add interface option to enable routing of 127.0.0.0/8") Signed-off-by: Shijie Luo Signed-off-by: Zhiqiang Liu Signed-off-by: David S. Miller

ipv4: fix inet_select_addr() when enable route_localnet

2019-06-24T16:01:42Z

Suppose we have two interfaces eth0 and eth1 in two hosts, follow the same steps in the two hosts: # sysctl -w net.ipv4.conf.eth1.route_localnet=1 # sysctl -w net.ipv4.conf.eth1.arp_announce=2 # ip route del 127.0.0.0/8 dev lo table local and then set ip to eth1 in host1 like: # ifconfig eth1 127.25.3.4/24 set ip to eth2 in host2 and ping host1: # ifconfig eth1 127.25.3.14/24 # ping -I eth1 127.25.3.4 Well, host2 cannot connect to host1. When set a ip address with head 127, the scope of the address defaults to RT_SCOPE_HOST. In this situation, host2 will use arp_solicit() to send a arp request for the mac address of host1 with ip address 127.25.3.14. When arp_announce=2, inet_select_addr() cannot select a correct saddr with condition ifa->ifa_scope > scope, because ifa_scope is RT_SCOPE_HOST and scope is RT_SCOPE_LINK. Then, inet_select_addr() will go to no_in_dev to lookup all interfaces to find a primary ip and finally get the primary ip of eth0. Here I add a localnet_scope defaults to RT_SCOPE_HOST, and when route_localnet is enabled, this value changes to RT_SCOPE_LINK to make inet_select_addr() find a correct primary ip as saddr of arp request. Fixes: d0daebc3d622 ("ipv4: Add interface option to enable routing of 127.0.0.0/8") Signed-off-by: Shijie Luo Signed-off-by: Zhiqiang Liu Signed-off-by: David S. Miller

net: ipv4: remove erroneous advancement of list pointer

2019-06-17T23:27:42Z

Causes crash when lifetime expires on an adress as garbage is dereferenced soon after. This used to look like this: for (ifap = &ifa->ifa_dev->ifa_list; *ifap != NULL; ifap = &(*ifap)->ifa_next) { if (*ifap == ifa) ... but this was changed to: struct in_ifaddr *tmp; ifap = &ifa->ifa_dev->ifa_list; tmp = rtnl_dereference(*ifap); while (tmp) { tmp = rtnl_dereference(tmp->ifa_next); // Bogus if (rtnl_dereference(*ifap) == ifa) { ... ifap = &tmp->ifa_next; // Can be NULL tmp = rtnl_dereference(*ifap); // Dereference } } Remove the bogus assigment/list entry skip. Fixes: 2638eb8b50cf ("net: ipv4: provide __rcu annotation for ifa_list") Signed-off-by: Florian Westphal Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2019-06-07T18:00:14Z

Some ISDN files that got removed in net-next had some changes done in mainline, take the removals. Signed-off-by: David S. Miller

net: ipv4: fix rcu lockdep splat due to wrong annotation

2019-06-04T21:24:10Z

syzbot triggered following splat when strict netlink validation is enabled: net/ipv4/devinet.c:1766 suspicious rcu_dereference_check() usage! This occurs because we hold RTNL mutex, but no rcu read lock. The second call site holds both, so just switch to the _rtnl variant. Reported-by: syzbot+bad6e32808a3a97b1515@syzkaller.appspotmail.com Fixes: 2638eb8b50cf ("net: ipv4: provide __rcu annotation for ifa_list") Signed-off-by: Florian Westphal Signed-off-by: David S. Miller

net: ipv4: provide __rcu annotation for ifa_list

2019-06-03T01:08:36Z

ifa_list is protected by rcu, yet code doesn't reflect this. Add the __rcu annotations and fix up all places that are now reported by sparse. I've done this in the same commit to not add intermediate patches that result in new warnings. Reported-by: Eric Dumazet Signed-off-by: Florian Westphal Signed-off-by: David S. Miller