linux-stable.git/net/core/rtnetlink.c, branch v4.18.2

rtnetlink: add rtnl_link_state check in rtnl_configure_link

2018-07-22T17:52:37+00:00

rtnl_configure_link sets dev->rtnl_link_state to
RTNL_LINK_INITIALIZED and unconditionally calls
__dev_notify_flags to notify user-space of dev flags.

current call sequence for rtnl_configure_link
rtnetlink_newlink
    rtnl_link_ops->newlink
    rtnl_configure_link (unconditionally notifies userspace of
                         default and new dev flags)

If a newlink handler wants to call rtnl_configure_link
early, we will end up with duplicate notifications to
user-space.

This patch fixes rtnl_configure_link to check rtnl_link_state
and call __dev_notify_flags with gchanges = 0 if already
RTNL_LINK_INITIALIZED.

Later in the series, this patch will help the following sequence
where a driver implementing newlink can call rtnl_configure_link
to initialize the link early.

makes the following call sequence work:
rtnetlink_newlink
    rtnl_link_ops->newlink (vxlan) -> rtnl_configure_link (initializes
                                                link and notifies
                                                user-space of default
                                                dev flags)
    rtnl_configure_link (updates dev flags if requested by user ifm
                         and notifies user-space of new dev flags)

Signed-off-by: Roopa Prabhu 
Signed-off-by: David S. Miller

rtnetlink: validate attributes in do_setlink()

2018-06-05T16:45:29+00:00

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 
Reported-by: syzbot 
Cc: Dmitry Vyukov 
Signed-off-by: David S. Miller

rtnetlink: Fix null-ptr-deref in rtnl_newlink

2018-06-01T14:39:24+00:00

In rtnl_newlink(), NULL check is performed on m_ops however member of
ops is accessed. Fixed by accessing member of m_ops instead of ops.

[  345.432629] BUG: KASAN: null-ptr-deref in rtnl_newlink+0x400/0x1110
[  345.432629] Read of size 4 at addr 0000000000000088 by task ip/986
[  345.432629]
[  345.432629] CPU: 1 PID: 986 Comm: ip Not tainted 4.17.0-rc6+ #9
[  345.432629] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[  345.432629] Call Trace:
[  345.432629]  dump_stack+0xc6/0x150
[  345.432629]  ? dump_stack_print_info.cold.0+0x1b/0x1b
[  345.432629]  ? kasan_report+0xb4/0x410
[  345.432629]  kasan_report.cold.4+0x8f/0x91
[  345.432629]  ? rtnl_newlink+0x400/0x1110
[  345.432629]  rtnl_newlink+0x400/0x1110
[...]

Fixes: ccf8dbcd062a ("rtnetlink: Remove VLA usage")
Signed-off-by: Prashant Bhole 
Tested-by: Ido Schimmel 
Signed-off-by: David S. Miller

rtnetlink: Remove VLA usage

2018-06-01T02:48:46+00:00

In the quest to remove all stack VLA usage from the kernel[1], this
allocates the maximum size expected for all possible types and adds
sanity-checks at both registration and usage to make sure nothing gets
out of sync. This matches the proposed VLA solution for nfnetlink[2]. The
values chosen here were based on finding assignments for .maxtype and
.slave_maxtype and manually counting the enums:

slave_maxtype (max 33):
	IFLA_BRPORT_MAX     33
	IFLA_BOND_SLAVE_MAX  9

maxtype (max 45):
	IFLA_BOND_MAX       28
	IFLA_BR_MAX         45
	__IFLA_CAIF_HSI_MAX  8
	IFLA_CAIF_MAX        4
	IFLA_CAN_MAX        16
	IFLA_GENEVE_MAX     12
	IFLA_GRE_MAX        25
	IFLA_GTP_MAX         5
	IFLA_HSR_MAX         7
	IFLA_IPOIB_MAX       4
	IFLA_IPTUN_MAX      21
	IFLA_IPVLAN_MAX      3
	IFLA_MACSEC_MAX     15
	IFLA_MACVLAN_MAX     7
	IFLA_PPP_MAX         2
	__IFLA_RMNET_MAX     4
	IFLA_VLAN_MAX        6
	IFLA_VRF_MAX         2
	IFLA_VTI_MAX         7
	IFLA_VXLAN_MAX      28
	VETH_INFO_MAX        2
	VXCAN_INFO_MAX       2

This additionally changes maxtype and slave_maxtype fields to unsigned,
since they're only ever using positive values.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com
[2] https://patchwork.kernel.org/patch/10439647/

Signed-off-by: Kees Cook 
Signed-off-by: David S. Miller

net: Handle null dst in rtnl_put_cacheinfo

2018-04-18T03:41:15+00:00

Need to keep expires time for IPv6 routes in a dump of FIB entries.
Update rtnl_put_cacheinfo to allow dst to be NULL in which case
rta_cacheinfo will only contain non-dst data.

Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

net: Do not take net_rwsem in __rtnl_link_unregister()

2018-04-01T02:24:58+00:00

This function calls call_netdevice_notifier(), which also
may take net_rwsem. So, we can't use net_rwsem here.

This patch makes callers of this functions take pernet_ops_rwsem,
like register_netdevice_notifier() does. This will protect
the modifications of net_namespace_list, and allows notifiers
to take it (they won't have to care about context).

Since __rtnl_link_unregister() is used on module load
and unload (which are not frequent operations), this looks
for me better, than make all call_netdevice_notifier()
always executing in "protected net_namespace_list" context.

Also, this fixes the problem we had a deal in 328fbe747ad4
"Close race between {un, }register_netdevice_notifier and ...",
and guarantees __rtnl_link_unregister() does not skip
exitting net.

Signed-off-by: Kirill Tkhai 
Signed-off-by: David S. Miller

net: Introduce net_rwsem to protect net_namespace_list

2018-03-29T17:47:53+00:00

rtnl_lock() is used everywhere, and contention is very high.
When someone wants to iterate over alive net namespaces,
he/she has no a possibility to do that without exclusive lock.
But the exclusive rtnl_lock() in such places is overkill,
and it just increases the contention. Yes, there is already
for_each_net_rcu() in kernel, but it requires rcu_read_lock(),
and this can't be sleepable. Also, sometimes it may be need
really prevent net_namespace_list growth, so for_each_net_rcu()
is not fit there.

This patch introduces new rw_semaphore, which will be used
instead of rtnl_mutex to protect net_namespace_list. It is
sleepable and allows not-exclusive iterations over net
namespaces list. It allows to stop using rtnl_lock()
in several places (what is made in next patches) and makes
less the time, we keep rtnl_mutex. Here we just add new lock,
while the explanation of we can remove rtnl_lock() there are
in next patches.

Fine grained locks generally are better, then one big lock,
so let's do that with net_namespace_list, while the situation
allows that.

Signed-off-by: Kirill Tkhai 
Signed-off-by: David S. Miller

net: Add more comments

2018-03-27T17:18:09+00:00

This adds comments to different places to improve
readability.

Signed-off-by: Kirill Tkhai 
Signed-off-by: David S. Miller

net: Rename net_sem to pernet_ops_rwsem

2018-03-27T17:18:09+00:00

net_sem is some undefined area name, so it will be better
to make the area more defined.

Rename it to pernet_ops_rwsem for better readability and
better intelligibility.

Signed-off-by: Kirill Tkhai 
Signed-off-by: David S. Miller

net: Drop pernet_operations::async

2018-03-27T17:18:09+00:00

Synchronous pernet_operations are not allowed anymore.
All are asynchronous. So, drop the structure member.

Signed-off-by: Kirill Tkhai 
Signed-off-by: David S. Miller