Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most
netlink based interfaces (including recently added ones) are still not
setting it in kernel generated messages. Without the flag, message parsers
not aware of attribute semantics (e.g. wireshark dissector or libmnl's
mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display
the structure of their contents.

Unfortunately we cannot just add the flag everywhere as there may be
userspace applications which check nlattr::nla_type directly rather than
through a helper masking out the flags. Therefore the patch renames
nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start()
as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually
are rewritten to use nla_nest_start().

Except for changes in include/net/netlink.h, the patch was generated using
this semantic patch:

@@ expression E1, E2; @@
-nla_nest_start(E1, E2)
+nla_nest_start_noflag(E1, E2)

@@ expression E1, E2; @@
-nla_nest_start_noflag(E1, E2 | NLA_F_NESTED)
+nla_nest_start(E1, E2)
Signed-off-by: NMichal Kubecek <mkubecek@suse.cz>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To avoid a sparse warning byteswap the be32 sequence number
before it's stored in the atomic value.  While at it drop
unnecessary brackets and use kernel's u64 type.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tls_device_sk_destruct being set on a socket used to indicate
that socket is a kTLS device one.  That is no longer true -
now we use sk_validate_xmit_skb pointer for that purpose.
Remove the export.  tls_device_attach() needs to be moved.

While at it, remove the dead declaration of tls_sk_destruct().
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NDirk van der Merwe <dirk.vandermerwe@netronome.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently when CONFIG_TLS_DEVICE is set each time kTLS
connection is opened and the offload is not successful
(either because the underlying device doesn't support
it or e.g. it's tables are full) a rate limited error
will be printed to the logs.

There is nothing wrong with failing TLS offload.  SW
path will process the packets just fine, drop the
noisy messages.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I forgot to remove one rcu_read_unlock() before a return statement.

Joy of mixing goto and return styles in a function :)

Fixes: 4109a2c3 ("tipc: tipc_udp_recv() cleanup vs rcu verbs")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: Nkbuild test robot <lkp@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

fib6_result is not initialized in bpf_ipv6_fib_lookup and potentially
passses garbage to the fib lookup which triggers a KASAN warning:

[  262.055450] ==================================================================
[  262.057640] BUG: KASAN: user-memory-access in fib6_rule_suppress+0x4b/0xce
[  262.059488] Read of size 8 at addr 00000a20000000b0 by task swapper/1/0
[  262.061238]
[  262.061673] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.1.0-rc5+ #56
[  262.063493] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.1-1 04/01/2014
[  262.065593] Call Trace:
[  262.066277]  <IRQ>
[  262.066848]  dump_stack+0x7e/0xbb
[  262.067764]  kasan_report+0x18b/0x1b5
[  262.069921]  __asan_load8+0x7f/0x81
[  262.070879]  fib6_rule_suppress+0x4b/0xce
[  262.071980]  fib_rules_lookup+0x275/0x2cd
[  262.073090]  fib6_lookup+0x119/0x218
[  262.076457]  bpf_ipv6_fib_lookup+0x39d/0x664
...

Initialize fib6_result to 0.

Fixes: b1d40991 ("ipv6: Rename fib6_multipath_select and pass fib6_result")
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add missing break statement in order to prevent the code from falling
through to cases SIOCGSTAMP_NEW and SIOCGSTAMPNS_NEW.

This bug was found thanks to the ongoing efforts to enable
-Wimplicit-fallthrough.

Fixes: 0768e170 ("net: socket: implement 64-bit timestamps")
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The requirement for mesh link metric refreshing, is that from one
mesh point we be able to send some data frames to other mesh points
which are not currently selected as a primary traffic path, but which
are only 1 hop away. The absence of the primary path to the chosen node
makes it necessary to apply some form of marking on a chosen packet
stream so that the packets can be properly steered to the selected node
for testing, and not by the regular mesh path lookup.
Tested-by: NPradeep Kumar Chitrapu <pradeepc@codeaurora.org>
Signed-off-by: NRajkumar Manoharan <rmanohar@codeaurora.org>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Allows setting of control flags of skb cb - if needed -
when calling ieee80211_subif_start_xmit().
Tested-by: NPradeep Kumar Chitrapu <pradeepc@codeaurora.org>
Signed-off-by: NRajkumar Manoharan <rmanohar@codeaurora.org>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Adding support to allow mesh HWMP to measure link metrics on unexercised
direct mesh path by sending some data frames to other mesh points which
are not currently selected as a primary traffic path but only 1 hop away.
The absence of the primary path to the chosen node makes it necessary to
apply some form of marking on a chosen packet stream so that the packets
can be properly steered to the selected node for testing, and not by the
regular mesh path lookup.
Tested-by: NPradeep Kumar Chitrapu <pradeepc@codeaurora.org>
Signed-off-by: NRajkumar Manoharan <rmanohar@codeaurora.org>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Mac80211 SW crypto handles replacing PTK keys correctly.

Don't trigger needless warnings or workarounds when the driver can only
use the known good SW crypto provided by mac80211.
Signed-off-by: NAlexander Wetzel <alexander@wetzel-home.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

We are copying one entire structure to another of the same type in
nl80211_notify_radar_detection, so it's simpler and safer to do a
struct assignment instead of memcpy().
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Only enable Extended Key ID support for drivers which are not supporting
crypto offload and also do not support A-MPDU.

While any driver using SW crypto from mac80211 is generally able to also
support Extended Key ID these drivers are likely to mix keyIDs in
AMPDUs when rekeying.

According to IEEE 802.11-2016 "9.7.3 A-MPDU contents" this is not
allowed.
Signed-off-by: NAlexander Wetzel <alexander@wetzel-home.de>
[reword comment a bit, move ! into logic expression]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The cfg80211_merge_profile() and ieee802_11_find_bssid_profile() are
a bit cleaner if we just pass the merged_ie pointer instead of a pointer
to the pointer.

This isn't a functional change, it's just a clean up.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This patch introduce a new driver callback drv_sta_set_txpwr. This API will
copy the transmit power value passed from user space and call the driver
callback to set the tx power for the station.
Co-developed-by: NBalaji Pothunoori <bpothuno@codeaurora.org>
Signed-off-by: NAshok Raj Nagarajan <arnagara@codeaurora.org>
Signed-off-by: NBalaji Pothunoori <bpothuno@codeaurora.org>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This patch adds support to set transmit power setting type and transmit
power level attributes to NL80211_CMD_SET_STATION in order to facilitate
adjusting the transmit power level of a station associated to the AP.

The added attributes allow selection of automatic and limited transmit
power level, with the level defined in dBm format.
Co-developed-by: NBalaji Pothunoori <bpothuno@codeaurora.org>
Signed-off-by: NAshok Raj Nagarajan <arnagara@codeaurora.org>
Signed-off-by: NBalaji Pothunoori <bpothuno@codeaurora.org>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

There's no need to allocate than one queue in the iTXQs case
now that we no longer use ndo_select_queue to assign the AC.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
    int stuff;
    struct boo entry[];
};

size = sizeof(struct foo) + count * sizeof(struct boo);
instance = kzalloc(size, GFP_KERNEL)

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL)

Notice that, in this case, variable size_of_regd is not necessary,
hence it is removed.

This code was detected with the help of Coccinelle.
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
    int stuff;
    struct boo entry[];
};

size = sizeof(struct foo) + count * sizeof(struct boo);
instance = kzalloc(size, GFP_KERNEL)

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL)

Notice that, in this case, variable size_of_regd is not necessary,
hence it is removed.

This code was detected with the help of Coccinelle.
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

At Technical University of Munich we use MAC 802.11 TX status frames to
perform several measurements in MAC 802.11 setups.

With ath based drivers this was possible until commit d94a461d
("ath9k: use ieee80211_tx_status_noskb where possible") as the driver
ignored the IEEE80211_TX_CTL_REQ_TX_STATUS flag and always delivered
tx_status frames. Since that commit, this behavior was changed and the
driver now adheres to IEEE80211_TX_CTL_REQ_TX_STATUS.

Due to performance reasons, IEEE80211_TX_CTL_REQ_TX_STATUS is not set for
data frames from interfaces in managed mode. Hence, frames that are sent
from a managed mode interface do never deliver tx_status frames. This
remains true even if a monitor mode interface (the measurement interface)
is added to the same ieee80211 physical device. Thus, there is no
possibility for receiving tx_status frames for frames sent on an interface
in managed mode, if the driver adheres to IEEE80211_TX_CTL_REQ_TX_STATUS.

In order to force delivery of tx_status frames for research and debugging
purposes, implement a debugfs option force_tx_status for ieee80211 physical
devices. When this option is set for a physical device,
IEEE80211_TX_CTL_REQ_TX_STATUS is enabled in all packets sent from that
device. This option can be set via
/sys/kernel/debug/ieee80211/<dev>/force_tx_status. The default is disabled.
Co-developed-by: NCharlie Groh <ga58taw@mytum.de>
Signed-off-by: NCharlie Groh <ga58taw@mytum.de>
Signed-off-by: NJulius Niedworok <julius.n@gmx.net>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The zero check on variable changed is redundant as it must be
between 1 and 3 at the end of the proceeding if statement block.
Remove the redundant check.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

FullMAC STAs have no way to update bss channel after CSA channel switch
completion. As a result, user-space tools may provide inconsistent
channel info. For instance, consider the following two commands:
$ sudo iw dev wlan0 link
$ sudo iw dev wlan0 info
The latter command gets channel info from the hardware, so most probably
its output will be correct. However the former command gets channel info
from scan cache, so its output will contain outdated channel info.
In fact, current bss channel info will not be updated until the
next [re-]connect.

Note that mac80211 STAs have a workaround for this, but it requires
access to internal cfg80211 data, see ieee80211_chswitch_work:

	/* XXX: shouldn't really modify cfg80211-owned data! */
	ifmgd->associated->channel = sdata->csa_chandef.chan;

This patch suggests to convert mac80211 workaround into cfg80211 behavior
and to update current bss channel in cfg80211_ch_switch_notify.
Signed-off-by: NSergey Matyukevich <sergey.matyukevich.os@quantenna.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

A per-group shift was added to reduce the size of the per-rate transmit
duration field to u16 without sacrificing a lot of precision
This patch changes the macros to automatically calculate the best value for
this shift based on the lowest rate within the group.
This simplifies adding more groups and slightly improves accuracy for some of
the existing groups.
Signed-off-by: NFelix Fietkau <nbd@nbd.name>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This is needed for the upcoming driver for MT7615 4x4 802.11ac chipsets
Signed-off-by: NFelix Fietkau <nbd@nbd.name>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When using iTXQ, the network stack does not need the real queue number, since
mac80211 is using its internal queues anyway. In that case we can defer
selecting the queue and remove a redundant station lookup in the tx path to save
some CPU cycles.
Signed-off-by: NFelix Fietkau <nbd@nbd.name>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Add support for Extended Key ID as defined in IEEE 802.11-2016.

 - Implement the nl80211 API for Extended Key ID
 - Extend mac80211 API to allow drivers to support Extended Key ID
 - Enable Extended Key ID by default for drivers only supporting SW
   crypto (e.g. mac80211_hwsim)
 - Allow unicast Tx usage to be supressed (IEEE80211_KEY_FLAG_NO_AUTO_TX)
 - Select the decryption key based on the MPDU keyid
 - Enforce existing assumptions in the code that rekeys don't change the
   cipher
Signed-off-by: NAlexander Wetzel <alexander@wetzel-home.de>
[remove module parameter]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Add support for IEEE 802.11-2016 "Extended Key ID for Individually
Addressed Frames".

Extend cfg80211 and nl80211 to allow pairwise keys to be installed for
Rx only, enable Tx separately and allow Key ID 1 for pairwise keys.
Signed-off-by: NAlexander Wetzel <alexander@wetzel-home.de>
[use NLA_POLICY_RANGE() for NL80211_KEY_MODE]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Optimize/cleanup the delay tailroom checks and adds one missing tailroom
update.
Signed-off-by: NAlexander Wetzel <alexander@wetzel-home.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When using iTXQ, tx sequence number allocation and statistics are run at
dequeue time. Because of that, it is safe to enable NETIF_F_LLTX, which
allows tx handlers to run on multiple CPUs in parallel.
Signed-off-by: NFelix Fietkau <nbd@nbd.name>
Acked-by: NToke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Reduces lock contention on enqueue/dequeue of iTXQ packets
Signed-off-by: NFelix Fietkau <nbd@nbd.name>
Acked-by: NToke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Reduces lock contention on enqueue/dequeue of iTXQ packets
Signed-off-by: NFelix Fietkau <nbd@nbd.name>
Acked-by: NToke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The callers of these functions are all within RCU locked sections
Signed-off-by: NFelix Fietkau <nbd@nbd.name>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Since an element is limited to 255 octets, a profile may be split
split to several elements. Support the split as defined in the 11ax
draft 3.
Signed-off-by: NSara Sharon <sara.sharon@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Since an element is limited to 255 octets, a profile may be split
split to several elements. Support the split as defined in the 11ax
draft 3. Detect legacy split and print a net-rate limited warning,
since there is no ROI in supporting this probably non-existent
split.
Signed-off-by: NSara Sharon <sara.sharon@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Subelement profile may specify element IDs it doesn't inherit
from the management frame. Support it.
Signed-off-by: NSara Sharon <sara.sharon@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Subelement profile may specify element IDs it doesn't inherit
from the management frame. Support it.
Signed-off-by: NSara Sharon <sara.sharon@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When creating the IEs for the nontransmitted BSS, the index
element is skipped. However, we need to get DTIM values from
it, so don't skip it.
Signed-off-by: NSara Sharon <sara.sharon@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The minimum encryption key size for LE connections is 56 bits and to
align LE with BR/EDR, enforce 56 bits of minimum encryption key size for
BR/EDR connections as well.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Cc: stable@vger.kernel.org

Before calling __ip_options_compile(), we need to ensure the network
header is a an IPv4 one, and that it is already pulled in skb->head.

RAW sockets going through a tunnel can end up calling ipv4_link_failure()
with total garbage in the skb, or arbitrary lengthes.

syzbot report :

BUG: KASAN: stack-out-of-bounds in memcpy include/linux/string.h:355 [inline]
BUG: KASAN: stack-out-of-bounds in __ip_options_echo+0x294/0x1120 net/ipv4/ip_options.c:123
Write of size 69 at addr ffff888096abf068 by task syz-executor.4/9204

CPU: 0 PID: 9204 Comm: syz-executor.4 Not tainted 5.1.0-rc5+ #77
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+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x123/0x190 mm/kasan/generic.c:191
 memcpy+0x38/0x50 mm/kasan/common.c:133
 memcpy include/linux/string.h:355 [inline]
 __ip_options_echo+0x294/0x1120 net/ipv4/ip_options.c:123
 __icmp_send+0x725/0x1400 net/ipv4/icmp.c:695
 ipv4_link_failure+0x29f/0x550 net/ipv4/route.c:1204
 dst_link_failure include/net/dst.h:427 [inline]
 vti6_xmit net/ipv6/ip6_vti.c:514 [inline]
 vti6_tnl_xmit+0x10d4/0x1c0c net/ipv6/ip6_vti.c:553
 __netdev_start_xmit include/linux/netdevice.h:4414 [inline]
 netdev_start_xmit include/linux/netdevice.h:4423 [inline]
 xmit_one net/core/dev.c:3292 [inline]
 dev_hard_start_xmit+0x1b2/0x980 net/core/dev.c:3308
 __dev_queue_xmit+0x271d/0x3060 net/core/dev.c:3878
 dev_queue_xmit+0x18/0x20 net/core/dev.c:3911
 neigh_direct_output+0x16/0x20 net/core/neighbour.c:1527
 neigh_output include/net/neighbour.h:508 [inline]
 ip_finish_output2+0x949/0x1740 net/ipv4/ip_output.c:229
 ip_finish_output+0x73c/0xd50 net/ipv4/ip_output.c:317
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip_output+0x21f/0x670 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:444 [inline]
 NF_HOOK include/linux/netfilter.h:289 [inline]
 raw_send_hdrinc net/ipv4/raw.c:432 [inline]
 raw_sendmsg+0x1d2b/0x2f20 net/ipv4/raw.c:663
 inet_sendmsg+0x147/0x5d0 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xdd/0x130 net/socket.c:661
 sock_write_iter+0x27c/0x3e0 net/socket.c:988
 call_write_iter include/linux/fs.h:1866 [inline]
 new_sync_write+0x4c7/0x760 fs/read_write.c:474
 __vfs_write+0xe4/0x110 fs/read_write.c:487
 vfs_write+0x20c/0x580 fs/read_write.c:549
 ksys_write+0x14f/0x2d0 fs/read_write.c:599
 __do_sys_write fs/read_write.c:611 [inline]
 __se_sys_write fs/read_write.c:608 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:608
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458c29
Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f293b44bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458c29
RDX: 0000000000000014 RSI: 00000000200002c0 RDI: 0000000000000003
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f293b44c6d4
R13: 00000000004c8623 R14: 00000000004ded68 R15: 00000000ffffffff

The buggy address belongs to the page:
page:ffffea00025aafc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x1fffc0000000000()
raw: 01fffc0000000000 0000000000000000 ffffffff025a0101 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888096abef80: 00 00 00 f2 f2 f2 f2 f2 00 00 00 00 00 00 00 f2
 ffff888096abf000: f2 f2 f2 f2 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888096abf080: 00 00 f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00
                         ^
 ffff888096abf100: 00 00 00 00 f1 f1 f1 f1 00 00 f3 f3 00 00 00 00
 ffff888096abf180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Fixes: ed0de45a ("ipv4: recompile ip options in ipv4_link_failure")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Stephen Suryaputra <ssuryaextr@gmail.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds a limit on the number of skbs that fuzzers can queue
into loopback_queue. 1000 packets for rose loopback seems more than enough.

Then, since we now have multiple cpus in most linux hosts,
we also need to limit the number of skbs rose_loopback_timer()
can dequeue at each round.

rose_loopback_queue() can be drop-monitor friendly, calling
consume_skb() or kfree_skb() appropriately.

Finally, use mod_timer() instead of del_timer() + add_timer()

syzbot report was :

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu:    0-...!: (10499 ticks this GP) idle=536/1/0x4000000000000002 softirq=103291/103291 fqs=34
rcu:     (t=10500 jiffies g=140321 q=323)
rcu: rcu_preempt kthread starved for 10426 jiffies! g140321 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt     I29168    10      2 0x80000000
Call Trace:
 context_switch kernel/sched/core.c:2877 [inline]
 __schedule+0x813/0x1cc0 kernel/sched/core.c:3518
 schedule+0x92/0x180 kernel/sched/core.c:3562
 schedule_timeout+0x4db/0xfd0 kernel/time/timer.c:1803
 rcu_gp_fqs_loop kernel/rcu/tree.c:1971 [inline]
 rcu_gp_kthread+0x962/0x17b0 kernel/rcu/tree.c:2128
 kthread+0x357/0x430 kernel/kthread.c:253
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 0
CPU: 0 PID: 7632 Comm: kworker/0:4 Not tainted 5.1.0-rc5+ #172
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events iterate_cleanup_work
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1be/0x236 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x183/0x1cf kernel/rcu/tree.c:1223
 print_cpu_stall kernel/rcu/tree.c:1360 [inline]
 check_cpu_stall kernel/rcu/tree.c:1434 [inline]
 rcu_pending kernel/rcu/tree.c:3103 [inline]
 rcu_sched_clock_irq.cold+0x500/0xa4a kernel/rcu/tree.c:2544
 update_process_times+0x32/0x80 kernel/time/timer.c:1635
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161
 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x33e/0xde0 kernel/time/hrtimer.c:1451
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline]
 smp_apic_timer_interrupt+0x120/0x570 arch/x86/kernel/apic/apic.c:1060
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x50 kernel/kcov.c:95
Code: 89 25 b4 6e ec 08 41 bc f4 ff ff ff e8 cd 5d ea ff 48 c7 05 9e 6e ec 08 00 00 00 00 e9 a4 e9 ff ff 90 90 90 90 90 90 90 90 90 <55> 48 89 e5 48 8b 75 08 65 48 8b 04 25 00 ee 01 00 65 8b 15 c8 60
RSP: 0018:ffff8880ae807ce0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: ffff88806fd40640 RBX: dffffc0000000000 RCX: ffffffff863fbc56
RDX: 0000000000000100 RSI: ffffffff863fbc1d RDI: ffff88808cf94228
RBP: ffff8880ae807d10 R08: ffff88806fd40640 R09: ffffed1015d00f8b
R10: ffffed1015d00f8a R11: 0000000000000003 R12: ffff88808cf941c0
R13: 00000000fffff034 R14: ffff8882166cd840 R15: 0000000000000000
 rose_loopback_timer+0x30d/0x3f0 net/rose/rose_loopback.c:91
 call_timer_fn+0x190/0x720 kernel/time/timer.c:1325
 expire_timers kernel/time/timer.c:1362 [inline]
 __run_timers kernel/time/timer.c:1681 [inline]
 __run_timers kernel/time/timer.c:1649 [inline]
 run_timer_softirq+0x652/0x1700 kernel/time/timer.c:1694
 __do_softirq+0x266/0x95a kernel/softirq.c:293
 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1027

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>