[ Upstream commit 04c20a9356f283da623903e81e7c6d5df7e4dc3c ]
As documented in skbuff.h, devices with NETIF_F_IPV6_CSUM capability
can only checksum TCP and UDP over IPv6 if the IP header does not
contains extension.
This is enforced for UDP packets emitted from user-space to an IPv6
address as they go through ip6_make_skb(), which calls
__ip6_append_data() where a check is done on the header size before
setting CHECKSUM_PARTIAL.
But the introduction of UDP encapsulation with fou6 added a code-path
where it is possible to get an skb with a partial UDP checksum and an
IPv6 header with extension:
* fou6 adds a UDP header with a partial checksum if the inner packet
does not contains a valid checksum.
* ip6_tunnel adds an IPv6 header with a destination option extension
header if encap_limit is non-zero (the default value is 4).
The thread linked below describes in more details how to reproduce the
problem with GRE-in-UDP tunnel.
Add a check on the network header size in skb_csum_hwoffload_help() to
make sure no IPv6 packet with extension header is handed to a network
device with NETIF_F_IPV6_CSUM capability.
Link: https://lore.kernel.org/netdev/26548921.1r3eYUQgxm@benoit.monin/T/#u
Fixes: aa3463d65e7b ("fou: Add encap ops for IPv6 tunnels")
Signed-off-by: Benoît Monin <benoit.monin@gmx.fr>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/5fbeecfc311ea182aa1d1c771725ab8b4cac515e.1729778144.git.benoit.monin@gmx.fr
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 62fafcd63139920eb25b3fbf154177ce3e6f3232 ]
NETIF_F_IP|IPV6_CSUM feature flag indicates UDP and TCP csum offload
while NETIF_F_HW_CSUM feature flag indicates ip generic csum offload
for HW, which includes not only for TCP/UDP csum, but also for other
protocols' csum like GRE's.
However, in skb_csum_hwoffload_help() it only checks features against
NETIF_F_CSUM_MASK(NETIF_F_HW|IP|IPV6_CSUM). So if it's a non TCP/UDP
packet and the features doesn't support NETIF_F_HW_CSUM, but supports
NETIF_F_IP|IPV6_CSUM only, it would still return 0 and leave the HW
to do csum.
This patch is to support ip generic csum processing by checking
NETIF_F_HW_CSUM for all protocols, and check (NETIF_F_IP_CSUM |
NETIF_F_IPV6_CSUM) only for TCP and UDP.
Note that we're using skb->csum_offset to check if it's a TCP/UDP
proctol, this might be fragile. However, as Alex said, for now we
only have a few L4 protocols that are requesting Tx csum offload,
we'd better fix this until a new protocol comes with a same csum
offset.
v1->v2:
- not extend skb->csum_not_inet, but use skb->csum_offset to tell
if it's an UDP/TCP csum packet.
v2->v3:
- add a note in the changelog, as Willem suggested.
Suggested-by: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 04c20a9356f2 ("net: skip offload for NETIF_F_IPV6_CSUM if ipv6 header contains extension")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ab9a9a9e9647392a19e7a885b08000e89c86b535 ]
One path takes care of SKB_GSO_DODGY, assuming
skb->len is bigger than hdr_len.
virtio_net_hdr_to_skb() does not fully dissect TCP headers,
it only make sure it is at least 20 bytes.
It is possible for an user to provide a malicious 'GSO' packet,
total length of 80 bytes.
- 20 bytes of IPv4 header
- 60 bytes TCP header
- a small gso_size like 8
virtio_net_hdr_to_skb() would declare this packet as a normal
GSO packet, because it would see 40 bytes of payload,
bigger than gso_size.
We need to make detect this case to not underflow
qdisc_skb_cb(skb)->pkt_len.
Fixes: 1def9238d4aa ("net_sched: more precise pkt_len computation")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cd42ba1c8ac9deb9032add6adf491110e7442040 ]
This came while reviewing commit c4e86b4363ac ("net: add two more
call_rcu_hurry()").
Paolo asked if adding one synchronize_rcu() would help.
While synchronize_rcu() does not help, making sure to call
rcu_barrier() before msleep(wait) is definitely helping
to make sure lazy call_rcu() are completed.
Instead of waiting ~100 seconds in my tests, the ref_tracker
splats occurs one time only, and netdev_wait_allrefs_any()
latency is reduced to the strict minimum.
Ideally we should audit our call_rcu() users to make sure
no refcount (or cascading call_rcu()) is held too long,
because rcu_barrier() is quite expensive.
Fixes: 0e4be9e57e8c ("net: use exponential backoff in netdev_wait_allrefs")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/all/28bbf698-befb-42f6-b561-851c67f464aa@kernel.org/T/#m76d73ed6b03cd930778ac4d20a777f22a08d6824
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b5f0de6df6dce8d641ef58ef7012f3304dffb9a1 ]
One of the worst offenders of "fake flexible arrays" is struct sockaddr,
as it is the classic example of why GCC and Clang have been traditionally
forced to treat all trailing arrays as fake flexible arrays: in the
distant misty past, sa_data became too small, and code started just
treating it as a flexible array, even though it was fixed-size. The
special case by the compiler is specifically that sizeof(sa->sa_data)
and FORTIFY_SOURCE (which uses __builtin_object_size(sa->sa_data, 1))
do not agree (14 and -1 respectively), which makes FORTIFY_SOURCE treat
it as a flexible array.
However, the coming -fstrict-flex-arrays compiler flag will remove
these special cases so that FORTIFY_SOURCE can gain coverage over all
the trailing arrays in the kernel that are _not_ supposed to be treated
as a flexible array. To deal with this change, convert sa_data to a true
flexible array. To keep the structure size the same, move sa_data into
a union with a newly introduced sa_data_min with the original size. The
result is that FORTIFY_SOURCE can continue to have no idea how large
sa_data may actually be, but anything using sizeof(sa->sa_data) must
switch to sizeof(sa->sa_data_min).
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: David Ahern <dsahern@kernel.org>
Cc: Dylan Yudaken <dylany@fb.com>
Cc: Yajun Deng <yajun.deng@linux.dev>
Cc: Petr Machata <petrm@nvidia.com>
Cc: Hangbin Liu <liuhangbin@gmail.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: syzbot <syzkaller@googlegroups.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221018095503.never.671-kees@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: a7d6027790ac ("arp: Prevent overflow in arp_req_get().")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 24ab059d2ebd62fdccc43794796f6ffbabe49ebc ]
Some drivers might misbehave if TSO packets get too big.
GVE for instance uses a 16bit field in its TX descriptor,
and will do bad things if a packet is bigger than 2^16 bytes.
Linux TCP stack honors dev->gso_max_size, but there are
other ways for too big packets to reach an ndo_start_xmit()
handler : virtio_net, af_packet, GRO...
Add a generic check in gso_features_check() and fallback
to GSO when needed.
gso_max_size was added in the blamed commit.
Fixes: 82cc1a7a5687 ("[NET]: Add per-connection option to set max TSO frame size")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20231219125331.4127498-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1d155dfdf50efc2b0793bce93c06d1a5b23d0877 ]
In bug report [0] a warning in r8169 driver was reported that was
caused by an invalid GSO SKB (gso_type was 0). See [1] for a discussion
about this issue. Still the origin of the invalid GSO SKB isn't clear.
It shouldn't be a network drivers task to check for invalid GSO SKB's.
Also, even if issue [0] can be fixed, we can't be sure that a
similar issue doesn't pop up again at another place.
Therefore let gso_features_check() check for such invalid GSO SKB's.
[0] https://bugzilla.kernel.org/show_bug.cgi?id=209423
[1] https://www.spinics.net/lists/netdev/msg690794.html
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/97c78d21-7f0b-d843-df17-3589f224d2cf@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 24ab059d2ebd ("net: check dev->gso_max_size in gso_features_check()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
