kernel/git/stable/linux.git/net/ipv4/devinet.c, branch linux-3.16.y

inet: protect against too small mtu values.

2020-02-11T20:03:57+00:00

commit 501a90c945103e8627406763dac418f20f3837b2 upstream. 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 Signed-off-by: Greg Kroah-Hartman [bwh: Backported to 3.16: - Use ACCESS_ONCE() instead of {READ,WRITE}_ONCE() - Keep using literal 68 instead of IPV4_MIN_MTU - Adjust context] Signed-off-by: Ben Hutchings

ipv4: Don't do expensive useless work during inetdev destroy.

2016-03-29T14:53:41+00:00

commit fbd40ea0180a2d328c5adc61414dc8bab9335ce2 upstream. When an inetdev is destroyed, every address assigned to the interface is removed. And in this scenerio we do two pointless things which can be very expensive if the number of assigned interfaces is large: 1) Address promotion. We are deleting all addresses, so there is no point in doing this. 2) A full nf conntrack table purge for every address. We only need to do this once, as is already caught by the existing masq_dev_notifier so masq_inet_event() can skip this. Reported-by: Solar Designer Signed-off-by: David S. Miller Tested-by: Cyrill Gorcunov Cc: Moritz Muehlenhoff [ luis: backported to 3.16: - file rename: nf_nat_masquerade_ipv4.c -> ipt_MASQUERADE.c ] Signed-off-by: Luis Henriques

rtnl: RTM_GETNETCONF: fix wrong return value

2016-03-24T10:00:46+00:00

commit a97eb33ff225f34a8124774b3373fd244f0e83ce upstream. An error response from a RTM_GETNETCONF request can return the positive error value EINVAL in the struct nlmsgerr that can mislead userspace. Signed-off-by: Anton Protopopov Acked-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Luis Henriques

ipv4: minor spelling fix

2014-05-19T01:10:29+00:00

Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller

ipv4: remove inet_addr_hash_lock in devinet.c

2014-05-09T02:56:56+00:00

All the callers hold RTNL lock, so there is no need to use inet_addr_hash_lock to protect the hash list. Cc: David S. Miller Signed-off-by: Cong Wang Signed-off-by: David S. Miller

ipv4: Fix runtime WARNING in rtmsg_ifa()

2014-02-07T04:02:15+00:00

On m68k/ARAnyM: WARNING: CPU: 0 PID: 407 at net/ipv4/devinet.c:1599 0x316a99() Modules linked in: CPU: 0 PID: 407 Comm: ifconfig Not tainted 3.13.0-atari-09263-g0c71d68014d1 #1378 Stack from 10c4fdf0: 10c4fdf0 002ffabb 000243e8 00000000 008ced6c 00024416 00316a99 0000063f 00316a99 00000009 00000000 002501b4 00316a99 0000063f c0a86117 00000080 c0a86117 00ad0c90 00250a5a 00000014 00ad0c90 00000000 00000000 00000001 00b02dd0 00356594 00000000 00356594 c0a86117 eff6c9e4 008ced6c 00000002 008ced60 0024f9b4 00250b52 00ad0c90 00000000 00000000 00252390 00ad0c90 eff6c9e4 0000004f 00000000 00000000 eff6c9e4 8000e25c eff6c9e4 80001020 Call Trace: [<000243e8>] warn_slowpath_common+0x52/0x6c [<00024416>] warn_slowpath_null+0x14/0x1a [<002501b4>] rtmsg_ifa+0xdc/0xf0 [<00250a5a>] __inet_insert_ifa+0xd6/0x1c2 [<0024f9b4>] inet_abc_len+0x0/0x42 [<00250b52>] inet_insert_ifa+0xc/0x12 [<00252390>] devinet_ioctl+0x2ae/0x5d6 Adding some debugging code reveals that net_fill_ifaddr() fails in put_cacheinfo(skb, ifa->ifa_cstamp, ifa->ifa_tstamp, preferred, valid)) nla_put complains: lib/nlattr.c:454: skb_tailroom(skb) = 12, nla_total_size(attrlen) = 20 Apparently commit 5c766d642bcaffd0c2a5b354db2068515b3846cf ("ipv4: introduce address lifetime") forgot to take into account the addition of struct ifa_cacheinfo in inet_nlmsg_size(). Hence add it, like is already done for ipv6. Suggested-by: Cong Wang Signed-off-by: Geert Uytterhoeven Signed-off-by: Cong Wang Signed-off-by: David S. Miller

net/ipv4: queue work on power efficient wq

2014-01-23T05:57:05+00:00

Workqueue used in ipv4 layer have no real dependency of scheduling these on the cpu which scheduled them. On a idle system, it is observed that an idle cpu wakes up many times just to service this work. It would be better if we can schedule it on a cpu which the scheduler believes to be the most appropriate one. This patch replaces normal workqueues with power efficient versions. This doesn't change existing behavior of code unless CONFIG_WQ_POWER_EFFICIENT is enabled. Signed-off-by: Viresh Kumar Signed-off-by: David S. Miller

net: replace macros net_random and net_srandom with direct calls to prandom

2014-01-14T23:15:25+00:00

This patch removes the net_random and net_srandom macros and replaces them with direct calls to the prandom ones. As new commits only seem to use prandom_u32 there is no use to keep them around. This change makes it easier to grep for users of prandom_u32. Signed-off-by: Aruna-Hewapathirane Suggested-by: Hannes Frederic Sowa Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller

ipv4: loopback device: ignore value changes after device is upped

2014-01-07T20:55:17+00:00

When lo is brought up, new ifa is created. Then, devconf and neigh values bitfield should be set so later changes of default values would not affect lo values. Note that the same behaviour is in ipv6. Also note that this is likely not an issue in many distros (for example Fedora 19) because userspace sets address to lo manually before bringing it up. Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller

netconf: rename PROXY_ARP to NEIGH_PROXY

2013-12-22T23:02:43+00:00

Use same field for both IPv4 (proxy_arp) and IPv6 (proxy_ndp) so fix it before API is set to be a common name Signed-off-by: Stephen Hemminger Acked-by: Nicolas Dichtel Signed-off-by: David S. Miller