It returned always NULL, thus it was never possible to get the filter.

Example:
$ ip link add foo type dummy
$ ip link add bar type dummy
$ tc qdisc add dev foo clsact
$ tc filter add dev foo protocol all pref 1 ingress handle 1234 \
	matchall action mirred ingress mirror dev bar

Before the patch:
$ tc filter get dev foo protocol all pref 1 ingress handle 1234 matchall
Error: Specified filter handle not found.
We have an error talking to the kernel

After:
$ tc filter get dev foo protocol all pref 1 ingress handle 1234 matchall
filter ingress protocol all pref 1 matchall chain 0 handle 0x4d2
  not_in_hw
        action order 1: mirred (Ingress Mirror to device bar) pipe
        index 1 ref 1 bind 1

CC: Yotam Gigi <yotamg@mellanox.com>
CC: Jiri Pirko <jiri@mellanox.com>
Fixes: fd62d9f5 ("net/sched: matchall: Fix configuration race")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Configuration check to accept source route IP options should be made on
the incoming netdevice when the skb->dev is an l3mdev master. The route
lookup for the source route next hop also needs the incoming netdev.

v2->v3:
- Simplify by passing the original netdevice down the stack (per David
  Ahern).
Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Cc: Martin Habets <mhabets@solarflare.com>
Signed-off-by: Bert Kenward <bkenward@solarflare.com>
Acked-by: Martin Habets <mhabets@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

 When tcp_sk_init() failed in inet_ctl_sock_create(),
 'net->ipv4.tcp_congestion_control' will be left
 uninitialized, but tcp_sk_exit() hasn't check for
 that.

 This patch add checking on 'net->ipv4.tcp_congestion_control'
 in tcp_sk_exit() to prevent NULL-ptr dereference.

Fixes: 6670e152 ("tcp: Namespace-ify sysctl_tcp_default_congestion_control")
Signed-off-by: Dust Li <dust.li@linux.alibaba.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Xin Long says:

====================
tipc: a batch of uninit-value fixes for netlink_compat

These issues were all reported by syzbot, and exist since very beginning.
See the details on each patch.
====================
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Syzbot found a crash:

  BUG: KMSAN: uninit-value in tipc_nl_compat_name_table_dump+0x54f/0xcd0 net/tipc/netlink_compat.c:872
  Call Trace:
    tipc_nl_compat_name_table_dump+0x54f/0xcd0 net/tipc/netlink_compat.c:872
    __tipc_nl_compat_dumpit+0x59e/0xda0 net/tipc/netlink_compat.c:215
    tipc_nl_compat_dumpit+0x63a/0x820 net/tipc/netlink_compat.c:280
    tipc_nl_compat_handle net/tipc/netlink_compat.c:1226 [inline]
    tipc_nl_compat_recv+0x1b5f/0x2750 net/tipc/netlink_compat.c:1265
    genl_family_rcv_msg net/netlink/genetlink.c:601 [inline]
    genl_rcv_msg+0x185f/0x1a60 net/netlink/genetlink.c:626
    netlink_rcv_skb+0x431/0x620 net/netlink/af_netlink.c:2477
    genl_rcv+0x63/0x80 net/netlink/genetlink.c:637
    netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
    netlink_unicast+0xf3e/0x1020 net/netlink/af_netlink.c:1336
    netlink_sendmsg+0x127f/0x1300 net/netlink/af_netlink.c:1917
    sock_sendmsg_nosec net/socket.c:622 [inline]
    sock_sendmsg net/socket.c:632 [inline]

  Uninit was created at:
    __alloc_skb+0x309/0xa20 net/core/skbuff.c:208
    alloc_skb include/linux/skbuff.h:1012 [inline]
    netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline]
    netlink_sendmsg+0xb82/0x1300 net/netlink/af_netlink.c:1892
    sock_sendmsg_nosec net/socket.c:622 [inline]
    sock_sendmsg net/socket.c:632 [inline]

It was supposed to be fixed on commit 974cb0e3 ("tipc: fix uninit-value
in tipc_nl_compat_name_table_dump") by checking TLV_GET_DATA_LEN(msg->req)
in cmd->header()/tipc_nl_compat_name_table_dump_header(), which is called
ahead of tipc_nl_compat_name_table_dump().

However, tipc_nl_compat_dumpit() doesn't handle the error returned from cmd
header function. It means even when the check added in that fix fails, it
won't stop calling tipc_nl_compat_name_table_dump(), and the issue will be
triggered again.

So this patch is to add the process for the err returned from cmd header
function in tipc_nl_compat_dumpit().

Reported-by: syzbot+3ce8520484b0d4e260a5@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

A similar issue as fixed by Patch "tipc: check bearer name with right
length in tipc_nl_compat_bearer_enable" was also found by syzbot in
tipc_nl_compat_link_set().

The length to check with should be 'TLV_GET_DATA_LEN(msg->req) -
offsetof(struct tipc_link_config, name)'.

Reported-by: syzbot+de00a87b8644a582ae79@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Syzbot reported the following crash:

BUG: KMSAN: uninit-value in memchr+0xce/0x110 lib/string.c:961
  memchr+0xce/0x110 lib/string.c:961
  string_is_valid net/tipc/netlink_compat.c:176 [inline]
  tipc_nl_compat_bearer_enable+0x2c4/0x910 net/tipc/netlink_compat.c:401
  __tipc_nl_compat_doit net/tipc/netlink_compat.c:321 [inline]
  tipc_nl_compat_doit+0x3aa/0xaf0 net/tipc/netlink_compat.c:354
  tipc_nl_compat_handle net/tipc/netlink_compat.c:1162 [inline]
  tipc_nl_compat_recv+0x1ae7/0x2750 net/tipc/netlink_compat.c:1265
  genl_family_rcv_msg net/netlink/genetlink.c:601 [inline]
  genl_rcv_msg+0x185f/0x1a60 net/netlink/genetlink.c:626
  netlink_rcv_skb+0x431/0x620 net/netlink/af_netlink.c:2477
  genl_rcv+0x63/0x80 net/netlink/genetlink.c:637
  netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
  netlink_unicast+0xf3e/0x1020 net/netlink/af_netlink.c:1336
  netlink_sendmsg+0x127f/0x1300 net/netlink/af_netlink.c:1917
  sock_sendmsg_nosec net/socket.c:622 [inline]
  sock_sendmsg net/socket.c:632 [inline]

Uninit was created at:
  __alloc_skb+0x309/0xa20 net/core/skbuff.c:208
  alloc_skb include/linux/skbuff.h:1012 [inline]
  netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline]
  netlink_sendmsg+0xb82/0x1300 net/netlink/af_netlink.c:1892
  sock_sendmsg_nosec net/socket.c:622 [inline]
  sock_sendmsg net/socket.c:632 [inline]

It was triggered when the bearer name size < TIPC_MAX_BEARER_NAME,
it would check with a wrong len/TLV_GET_DATA_LEN(msg->req), which
also includes priority and disc_domain length.

This patch is to fix it by checking it with a right length:
'TLV_GET_DATA_LEN(msg->req) - offsetof(struct tipc_bearer_config, name)'.

Reported-by: syzbot+8b707430713eb46e1e45@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Aaro Koskinen says:

====================
net: stmmac: fix handling of oversized frames

I accidentally had MTU size mismatch (9000 vs. 1500) in my network,
and I noticed I could kill a system using stmmac & 1500 MTU simply
by pinging it with "ping -s 2000 ...".

While testing a fix I encountered also some other issues that need fixing.

I have tested these only with enhanced descriptors, so the normal
descriptor changes need a careful review.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This is log is harmful as it can trigger multiple times per packet. Delete
it.
Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Packets without the last descriptor set should be dropped early. If we
receive a frame larger than the DMA buffer, the HW will continue using the
next descriptor. Driver mistakes these as individual frames, and sometimes
a truncated frame (without the LD set) may look like a valid packet.

This fixes a strange issue where the system replies to 4098-byte ping
although the MTU/DMA buffer size is set to 4096, and yet at the same
time it's logging an oversized packet.
Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If we have error bits set, the discard_frame status will get overwritten
by checksum bit checks, which might set the status back to good one.
Fix by checking the COE status only if the frame is good.
Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, if we drop a packet, we exit from NAPI loop before the budget
is consumed. In some situations this will make the RX processing stall
e.g. when flood pinging the system with oversized packets, as the
errorneous packets are not dropped efficiently.

If we drop a packet, we should just continue to the next one as long as
the budget allows.
Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ratelimit RX error logs.
Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We always program the maximum DMA buffer size into the receive descriptor,
although the allocated size may be less. E.g. with the default MTU size
we allocate only 1536 bytes. If somebody sends us a bigger frame, then
memory may get corrupted.

Fix by using exact buffer sizes.
Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

It was reported that re-introducing ASPM, in combination with RX
interrupt coalescing, results in significantly increased packet
latency, see [0]. Disabling ASPM or RX interrupt coalescing fixes
the issue. Therefore change the driver's default to disable RX
interrupt coalescing. Users still have the option to enable RX
coalescing via ethtool.

[0] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=925496

Fixes: a99790bf ("r8169: Reinstate ASPM Support")
Reported-by: Mike Crowe <mac@mcrowe.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Daniel Borkmann says:

====================
pull-request: bpf 2019-03-29

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) Bug fix in BTF deduplication that was mishandling an equivalence
   comparison, from Andrii.

2) libbpf Makefile fixes to properly link against libelf for the shared
   object and to actually export AF_XDP's xsk.h header, from Björn.

3) Fix use after free in bpf inode eviction, from Daniel.

4) Fix a bug in skb creation out of cpumap redirect, from Jesper.

5) Remove an unnecessary and triggerable WARN_ONCE() in max number
   of call stack frames checking in verifier, from Paul.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Saeed Mahameed says:

====================
Mellanox, mlx5 fixes 2019-03-29

This series introduces some fixes to mlx5 driver.

Please pull and let me know if there is any problem.

For -stable v4.11
('net/mlx5: Decrease default mr cache size')

For -stable v4.12
('net/mlx5e: Add a lock on tir list')

For -stable v4.13
('net/mlx5e: Fix error handling when refreshing TIRs')

For -stable v4.18
('net/mlx5e: Update xon formula')

For -stable v4.19
('net: mlx5: Add a missing check on idr_find, free buf')
('net/mlx5e: Update xoff formula')

net-next merge Note:
When merged with net-next the following simple conflict will appear,

drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.c

++<<<<<<< HEAD (net)
 + *   max_mtu: netdev's max_mtu
++=======
+  *    @mtu: device's MTU
++>>>>>>> net-next

To resolve: just replace the line in net-next
*    @mtu: device's MTU
to
*    @max_mtu: netdev's max_mtu
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit 4d31c4fa.

Accidently applied this to the wrong tree.
Signed-off-by: David S. Miller <davem@davemloft.net>

Change t4fw_version.h to update latest firmware version
number to 1.23.3.0.
Signed-off-by: Vishal Kulkarni <vishal@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

NULL or ZERO_SIZE_PTR will be returned for zero sized memory
request, and derefencing them will lead to a segfault

so it is unnecessory to call vzalloc for zero sized memory
request and not call functions which maybe derefence the
NULL allocated memory

this also fixes a possible memory leak if phy_ethtool_get_stats
returns error, memory should be freed before exit
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Reviewed-by: Wang Li <wangli39@baidu.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

Only decrypt_internal() performs zero copy on rx, all paths
which don't hit decrypt_internal() must set zc to false,
otherwise tls_sw_recvmsg() may return 0 causing the application
to believe that that connection got closed.

Currently this happens with device offload when new record
is first read from.

Fixes: d069b780 ("tls: Fix tls_device receive")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reported-by: David Beckett <david.beckett@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

After queue stopped, the wakeup mechanism may wake it up again
when ring buffer usage is lower than a threshold. This may cause
send path panic on NULL pointer when we stopped all tx queues in
netvsc_detach and start removing the netvsc device.

This patch fix it by adding a tx_disable flag to prevent unwanted
queue wakeup.

Fixes: 7b2ee50c ("hv_netvsc: common detach logic")
Reported-by: Mohammed Gamal <mgamal@redhat.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Bond expects ethernet hwaddr for its slave, but it can be longer than 6
bytes - infiniband interface for example.

 # cat /sys/devices/<skipped>/net/ib0/address
 80:00:02:08:fe:80:00:00:00:00:00:00:7c:fe:90:03:00:be:5d:e1

 # cat /sys/devices/<skipped>/net/ib0/bonding_slave/perm_hwaddr
 80:00:02:08:fe:80

So print full hwaddr in sysfs "bonding_slave/perm_hwaddr" as well.
Signed-off-by: Konstantin Khorenko <khorenko@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The driver allocates an encap context based on the tunnel properties,
and reuse that context for all flows using the same tunnel properties.
Commit df2ef3bf ("net/mlx5e: Add GRE protocol offloading")
introduced another tunnel protocol other than the single VXLAN
previously supported. A flow that uses a tunnel with the same tunnel
properties but with a different tunnel type (GRE vs VXLAN for example)
would mistakenly reuse the previous alocated context, causing the
traffic to be sent with the wrong encapsulation. Fix that by
considering the tunnel type for encap contexts.

Fixes: df2ef3bf ("net/mlx5e: Add GRE protocol offloading")
Signed-off-by: Eli Britstein <elibr@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Set xon = xoff - netdev's max_mtu.
netdev's max_mtu will give enough time for the pause frame to
arrive at the sender.

Fixes: 0696d608 ("net/mlx5e: Receive buffer configuration")
Signed-off-by: Huy Nguyen <huyn@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Set minimum speed in xoff threshold formula to 40Gbps

Fixes: 0696d608 ("net/mlx5e: Receive buffer configuration")
Signed-off-by: Huy Nguyen <huyn@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Make sure the struct mlx5_flow_destination is zero before
filling in the field.

Fixes: 8da202b2 ("net/mlx5: E-Switch, Add support for VEPA in legacy mode.")
Signed-off-by: Huy Nguyen <huyn@mellanox.com>
Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Traditionally, the PF (Physical Function) which resides on vport 0 was
the E-switch manager. Since the ECPF (Embedded CPU Physical Function),
which resides on vport 0xfffe, was introduced as the E-Switch manager,
the assumption that the E-switch manager is on vport 0 is incorrect.

Since the eswitch code already uses the actual vport value, all we
need is to always set other_vport=1.
Signed-off-by: Omri Kahalon <omrik@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

The esw offloads structures share a union with the legacy mode structs.
Reset the offloads struct to zero in init to protect from null
assumptions made by the legacy mode code.
Signed-off-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

The capacity of FDB offloading and NIC offloading table are
different, and when allocating the pedit actions, we should
use the correct namespace type.

Fixes: c500c86b ("net/mlx5e: support for two independent packet edit actions")
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

The esw fdb table has a union of legacy and offloads members.
So if we were in a certain esw mode we could set some memebers and not
set null which is fine as on destroy path and don't care.
But then moving from legacy to switchdev a second time, the cleanup flow
of legacy mode checks if a struct member was in use if it's not null so
we need to make sure to reset the code to null when we init legacy mode.

Fixes: 8da202b2 ("net/mlx5: E-Switch, Add support for VEPA in legacy mode.")
Signed-off-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Huy Nguyen <huyn@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Allow configuration of legacy link-modes even when extended link-modes
are supported. This requires reading of legacy advertisement even when
extended link-modes are supported. Since legacy and extended
advertisement are mutually excluded, wait for empty reply from extended
advertisement before reading legacy advertisement.

Fixes: 6a897372 ("net/mlx5: ethtool, Add ethtool support for 50Gbps per lane link modes")
Signed-off-by: Aya Levin <ayal@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Ethtool option set_link_ksettings allows setting of legacy link-modes
or extended link-modes. Refine the decision of which type of link-modes
is set.

Fixes: 6a897372 ("net/mlx5: ethtool, Add ethtool support for 50Gbps per lane link modes")
Signed-off-by: Aya Levin <ayal@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Refresh tirs is looping over a global list of tirs while netdevs are
adding and removing tirs from that list. That is why a lock is
required.

Fixes: 724b2aa1 ("net/mlx5e: TIRs management refactoring")
Signed-off-by: Yuval Avnery <yuvalav@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

idr_find() can return a NULL value to 'flow' which is used without a
check. The patch adds a check to avoid potential NULL pointer dereference.

In case of mlx5_fpga_sbu_conn_sendmsg() failure, free buf allocated
using kzalloc.

Fixes: ab412e1d ("net/mlx5: Accel, add TLS rx offload routines")
Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

For some protocols we are not allowing IP header rewrite offload, since
the HW is not capable to properly adjust the l4 checksum. However, TTL
& HOPLIMIT modification can be done for all IP protocols, because they
are not part of the pseudo header taken into account for checksum.

Fixes: 73867881 ("drivers: net: use flow action infrastructure")
Signed-off-by: Dmytro Linkin <dmitrolin@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Previously, a false positive would be caught if the TIRs list is
empty, since the err value was initialized to -ENOMEM, and was only
updated if a TIR is refreshed. This is resolved by initializing the
err value to zero.

Fixes: b676f653 ("net/mlx5e: Refactor refresh TIRs")
Signed-off-by: Gavi Teitz <gavi@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Delete initialization of high order entries in mr cache to decrease initial
memory footprint. When required, the administrator can populate the
entries with memory keys via the /sys interface.

This approach is very helpful to significantly reduce the per HW function
memory footprint in virtualization environments such as SRIOV.

Fixes: 9603b61d ("mlx5: Move pci device handling from mlx5_ib to mlx5_core")
Signed-off-by: Artemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reported-by: Shalom Toledo <shalomt@mellanox.com>
Acked-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

We want to avoid leaking pointer info from xdp_frame (that is placed in
top of frame) like commit 6dfb970d ("xdp: avoid leaking info stored in
frame data on page reuse"), and followup commit 97e19cce ("bpf:
reserve xdp_frame size in xdp headroom") that reserve this headroom.

These changes also affected how cpumap constructed SKBs, as xdpf->headroom
size changed, the skb data starting point were in-effect shifted with 32
bytes (sizeof xdp_frame). This was still okay, as the cpumap frame_size
calculation also included xdpf->headroom which were reduced by same amount.

A bug was introduced in commit 77ea5f4c ("bpf/cpumap: make sure
frame_size for build_skb is aligned if headroom isn't"), where the
xdpf->headroom became part of the SKB_DATA_ALIGN rounding up. This
round-up to find the frame_size is in principle still correct as it does
not exceed the 2048 bytes frame_size (which is max for ixgbe and i40e),
but the 32 bytes offset of pkt_data_start puts this over the 2048 bytes
limit. This cause skb_shared_info to spill into next frame. It is a little
hard to trigger, as the SKB need to use above 15 skb_shinfo->frags[] as
far as I calculate. This does happen in practise for TCP streams when
skb_try_coalesce() kicks in.

KASAN can be used to detect these wrong memory accesses, I've seen:
 BUG: KASAN: use-after-free in skb_try_coalesce+0x3cb/0x760
 BUG: KASAN: wild-memory-access in skb_release_data+0xe2/0x250

Driver veth also construct a SKB from xdp_frame in this way, but is not
affected, as it doesn't reserve/deduct the room (used by xdp_frame) from
the SKB headroom. Instead is clears the pointers via xdp_scrub_frame(),
and allows SKB to use this area.

The fix in this patch is to do like veth and instead allow SKB to (re)use
the area occupied by xdp_frame, by clearing via xdp_scrub_frame().  (This
does kill the idea of the SKB being able to access (mem) info from this
area, but I guess it was a bad idea anyhow, and it was already killed by
the veth changes.)

Fixes: 77ea5f4c ("bpf/cpumap: make sure frame_size for build_skb is aligned if headroom isn't")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>