[ Upstream commit e28acc9c1ccfcb24c08e020828f69d0a915b06ae ]
Accessing `mr_table->mfc_cache_list` is protected by an RCU lock. In the
following code flow, the RCU read lock is not held, causing the
following error when `RCU_PROVE` is not held. The same problem might
show up in the IPv6 code path.
6.12.0-rc5-kbuilder-01145-gbac17284bdcb #33 Tainted: G E N
-----------------------------
net/ipv4/ipmr_base.c:313 RCU-list traversed in non-reader section!!
rcu_scheduler_active = 2, debug_locks = 1
2 locks held by RetransmitAggre/3519:
#0: ffff88816188c6c0 (nlk_cb_mutex-ROUTE){+.+.}-{3:3}, at: __netlink_dump_start+0x8a/0x290
#1: ffffffff83fcf7a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_dumpit+0x6b/0x90
stack backtrace:
lockdep_rcu_suspicious
mr_table_dump
ipmr_rtm_dumproute
rtnl_dump_all
rtnl_dumpit
netlink_dump
__netlink_dump_start
rtnetlink_rcv_msg
netlink_rcv_skb
netlink_unicast
netlink_sendmsg
This is not a problem per see, since the RTNL lock is held here, so, it
is safe to iterate in the list without the RCU read lock, as suggested
by Eric.
To alleviate the concern, modify the code to use
list_for_each_entry_rcu() with the RTNL-held argument.
The annotation will raise an error only if RTNL or RCU read lock are
missing during iteration, signaling a legitimate problem, otherwise it
will avoid this false positive.
This will solve the IPv6 case as well, since ip6mr_rtm_dumproute() calls
this function as well.
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20241108-ipmr_rcu-v2-1-c718998e209b@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b8469721034300bbb6dec5b4bf32492c95e16a0c ]
The series in the "fixes" tag added the ability to consider L4 attributes
in routing rules.
The dst lookup on the outer packet of encapsulated traffic in the xfrm
code was not adapted to this change, thus routing behavior that relies
on L4 information is not respected.
Pass the ip protocol information when performing dst lookups.
Fixes: a25724b05af0 ("Merge branch 'fib_rules-support-sport-dport-and-proto-match'")
Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
Tested-by: Antony Antony <antony.antony@secunet.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 22600596b6756b166fd052d5facb66287e6f0bad ]
After commit 8d7017fd621d ("blackhole_netdev: use blackhole_netdev to
invalidate dst entries"), blackhole_netdev was introduced to invalidate
dst cache entries on the TX path whenever the cache times out or is
flushed.
When two UDP sockets (sk1 and sk2) send messages to the same destination
simultaneously, they are using the same dst cache. If the dst cache is
invalidated on one path (sk2) while the other (sk1) is still transmitting,
sk1 may try to use the invalid dst entry.
CPU1 CPU2
udp_sendmsg(sk1) udp_sendmsg(sk2)
udp_send_skb()
ip_output()
<--- dst timeout or flushed
dst_dev_put()
ip_finish_output2()
ip_neigh_for_gw()
This results in a scenario where ip_neigh_for_gw() returns -EINVAL because
blackhole_dev lacks an in_dev, which is needed to initialize the neigh in
arp_constructor(). This error is then propagated back to userspace,
breaking the UDP application.
The patch fixes this issue by assigning an in_dev to blackhole_dev for
IPv4, similar to what was done for IPv6 in commit e5f80fcf869a ("ipv6:
give an IPv6 dev to blackhole_netdev"). This ensures that even when the
dst entry is invalidated with blackhole_dev, it will not fail to create
the neigh entry.
As devinet_init() is called ealier than blackhole_netdev_init() in system
booting, it can not assign the in_dev to blackhole_dev in devinet_init().
As Paolo suggested, add a separate late_initcall() in devinet.c to ensure
inet_blackhole_dev_init() is called after blackhole_netdev_init().
Fixes: 8d7017fd621d ("blackhole_netdev: use blackhole_netdev to invalidate dst entries")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/3000792d45ca44e16c785ebe2b092e610e5b3df1.1728499633.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit db53cd3d88dc328dea2e968c9c8d3b4294a8a674 upstream.
Ido reported that the commit referenced in the Fixes tag broke
a gre use case with dummy devices. Add a check to ip_tunnel_init_flow
to see if the oif is an l3mdev port and if so set the oif to 0 to
avoid the oif comparison in fib_lookup_good_nhc.
Fixes: 40867d74c374 ("net: Add l3mdev index to flow struct and avoid oif reset for port devices")
Reported-by: Ido Schimmel <idosch@idosch.org>
Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 05ef7055debc804e8083737402127975e7244fc4 ]
We need to init l3mdev unconditionally, else main routing table is searched
and incorrect result is returned unless strict (iif keyword) matching is
requested.
Next patch adds a selftest for this.
Fixes: 2a8a7c0eaa87 ("netfilter: nft_fib: Fix for rpath check with VRF devices")
Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1761
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1fcc064b305a1aadeff0d4bff961094d27660acd ]
Currently netfilter's rpfilter and fib modules implicitely initialise
->flowic_uid with 0. This is normally the root UID. However, this isn't
the case in user namespaces, where user ID 0 is mapped to a different
kernel UID. By initialising ->flowic_uid with sock_net_uid(), we get
the root UID of the user namespace, thus keeping the same behaviour
whether or not we're running in a user namepspace.
Note, this is similar to commit 8bcfd0925ef1 ("ipv4: add missing
initialization for flowi4_uid"), which fixed the rp_filter sysctl.
Fixes: 622ec2c9d524 ("net: core: add UID to flows, rules, and routes")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Stable-dep-of: 05ef7055debc ("netfilter: fib: check correct rtable in vrf setups")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit acc641ab95b66b813c1ce856c377a2bbe71e7f52 ]
Use the introduced field for correct operation with VRF devices instead
of conditionally overwriting flowic_oif. This is a partial revert of
commit b575b24b8eee3 ("netfilter: Fix rpfilter dropping vrf packets by
mistake"), implementing a simpler solution.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Stable-dep-of: 05ef7055debc ("netfilter: fib: check correct rtable in vrf setups")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 40867d74c374b235e14d839f3a77f26684feefe5 ]
The fundamental premise of VRF and l3mdev core code is binding a socket
to a device (l3mdev or netdev with an L3 domain) to indicate L3 scope.
Legacy code resets flowi_oif to the l3mdev losing any original port
device binding. Ben (among others) has demonstrated use cases where the
original port device binding is important and needs to be retained.
This patch handles that by adding a new entry to the common flow struct
that can indicate the l3mdev index for later rule and table matching
avoiding the need to reset flowi_oif.
In addition to allowing more use cases that require port device binds,
this patch brings a few datapath simplications:
1. l3mdev_fib_rule_match is only called when walking fib rules and
always after l3mdev_update_flow. That allows an optimization to bail
early for non-VRF type uses cases when flowi_l3mdev is not set. Also,
only that index needs to be checked for the FIB table id.
2. l3mdev_update_flow can be called with flowi_oif set to a l3mdev
(e.g., VRF) device. By resetting flowi_oif only for this case the
FLOWI_FLAG_SKIP_NH_OIF flag is not longer needed and can be removed,
removing several checks in the datapath. The flowi_iif path can be
simplified to only be called if the it is not loopback (loopback can
not be assigned to an L3 domain) and the l3mdev index is not already
set.
3. Avoid another device lookup in the output path when the fib lookup
returns a reject failure.
Note: 2 functional tests for local traffic with reject fib rules are
updated to reflect the new direct failure at FIB lookup time for ping
rather than the failure on packet path. The current code fails like this:
HINT: Fails since address on vrf device is out of device scope
COMMAND: ip netns exec ns-A ping -c1 -w1 -I eth1 172.16.3.1
ping: Warning: source address might be selected on device other than: eth1
PING 172.16.3.1 (172.16.3.1) from 172.16.3.1 eth1: 56(84) bytes of data.
--- 172.16.3.1 ping statistics ---
1 packets transmitted, 0 received, 100% packet loss, time 0ms
where the test now directly fails:
HINT: Fails since address on vrf device is out of device scope
COMMAND: ip netns exec ns-A ping -c1 -w1 -I eth1 172.16.3.1
ping: connect: No route to host
Signed-off-by: David Ahern <dsahern@kernel.org>
Tested-by: Ben Greear <greearb@candelatech.com>
Link: https://lore.kernel.org/r/20220314204551.16369-1-dsahern@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 05ef7055debc ("netfilter: fib: check correct rtable in vrf setups")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b41b4cbd9655bcebcce941bef3601db8110335be ]
Fix tcp_enter_recovery() so that if there are no retransmits out then
we zero retrans_stamp when entering fast recovery. This is necessary
to fix two buggy behaviors.
Currently a non-zero retrans_stamp value can persist across multiple
back-to-back loss recovery episodes. This is because we generally only
clears retrans_stamp if we are completely done with loss recoveries,
and get to tcp_try_to_open() and find !tcp_any_retrans_done(sk). This
behavior causes two bugs:
(1) When a loss recovery episode (CA_Loss or CA_Recovery) is followed
immediately by a new CA_Recovery, the retrans_stamp value can persist
and can be a time before this new CA_Recovery episode starts. That
means that timestamp-based undo will be using the wrong retrans_stamp
(a value that is too old) when comparing incoming TS ecr values to
retrans_stamp to see if the current fast recovery episode can be
undone.
(2) If there is a roughly minutes-long sequence of back-to-back fast
recovery episodes, one after another (e.g. in a shallow-buffered or
policed bottleneck), where each fast recovery successfully makes
forward progress and recovers one window of sequence space (but leaves
at least one retransmit in flight at the end of the recovery),
followed by several RTOs, then the ETIMEDOUT check may be using the
wrong retrans_stamp (a value set at the start of the first fast
recovery in the sequence). This can cause a very premature ETIMEDOUT,
killing the connection prematurely.
This commit changes the code to zero retrans_stamp when entering fast
recovery, when this is known to be safe (no retransmits are out in the
network). That ensures that when starting a fast recovery episode, and
it is safe to do so, retrans_stamp is set when we send the fast
retransmit packet. That addresses both bug (1) and bug (2) by ensuring
that (if no retransmits are out when we start a fast recovery) we use
the initial fast retransmit of this fast recovery as the time value
for undo and ETIMEDOUT calculations.
This makes intuitive sense, since the start of a new fast recovery
episode (in a scenario where no lost packets are out in the network)
means that the connection has made forward progress since the last RTO
or fast recovery, and we should thus "restart the clock" used for both
undo and ETIMEDOUT logic.
Note that if when we start fast recovery there *are* retransmits out
in the network, there can still be undesirable (1)/(2) issues. For
example, after this patch we can still have the (1) and (2) problems
in cases like this:
+ round 1: sender sends flight 1
+ round 2: sender receives SACKs and enters fast recovery 1,
retransmits some packets in flight 1 and then sends some new data as
flight 2
+ round 3: sender receives some SACKs for flight 2, notes losses, and
retransmits some packets to fill the holes in flight 2
+ fast recovery has some lost retransmits in flight 1 and continues
for one or more rounds sending retransmits for flight 1 and flight 2
+ fast recovery 1 completes when snd_una reaches high_seq at end of
flight 1
+ there are still holes in the SACK scoreboard in flight 2, so we
enter fast recovery 2, but some retransmits in the flight 2 sequence
range are still in flight (retrans_out > 0), so we can't execute the
new retrans_stamp=0 added here to clear retrans_stamp
It's not yet clear how to fix these remaining (1)/(2) issues in an
efficient way without breaking undo behavior, given that retrans_stamp
is currently used for undo and ETIMEDOUT. Perhaps the optimal (but
expensive) strategy would be to set retrans_stamp to the timestamp of
the earliest outstanding retransmit when entering fast recovery. But
at least this commit makes things better.
Note that this does not change the semantics of retrans_stamp; it
simply makes retrans_stamp accurate in some cases where it was not
before:
(1) Some loss recovery, followed by an immediate entry into a fast
recovery, where there are no retransmits out when entering the fast
recovery.
(2) When a TFO server has a SYNACK retransmit that sets retrans_stamp,
and then the ACK that completes the 3-way handshake has SACK blocks
that trigger a fast recovery. In this case when entering fast recovery
we want to zero out the retrans_stamp from the TFO SYNACK retransmit,
and set the retrans_stamp based on the timestamp of the fast recovery.
We introduce a tcp_retrans_stamp_cleanup() helper, because this
two-line sequence already appears in 3 places and is about to appear
in 2 more as a result of this bug fix patch series. Once this bug fix
patches series in the net branch makes it into the net-next branch
we'll update the 3 other call sites to use the new helper.
This is a long-standing issue. The Fixes tag below is chosen to be the
oldest commit at which the patch will apply cleanly, which is from
Linux v3.5 in 2012.
Fixes: 1fbc340514fc ("tcp: early retransmit: tcp_enter_recovery()")
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241001200517.2756803-3-ncardwell.sw@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e37ab7373696e650d3b6262a5b882aadad69bb9e ]
Fix the TCP loss recovery undo logic in tcp_packet_delayed() so that
it can trigger undo even if TSQ prevents a fast recovery episode from
reaching tcp_retransmit_skb().
Geumhwan Yu <geumhwan.yu@samsung.com> recently reported that after
this commit from 2019:
commit bc9f38c8328e ("tcp: avoid unconditional congestion window undo
on SYN retransmit")
...and before this fix we could have buggy scenarios like the
following:
+ Due to reordering, a TCP connection receives some SACKs and enters a
spurious fast recovery.
+ TSQ prevents all invocations of tcp_retransmit_skb(), because many
skbs are queued in lower layers of the sending machine's network
stack; thus tp->retrans_stamp remains 0.
+ The connection receives a TCP timestamp ECR value echoing a
timestamp before the fast recovery, indicating that the fast
recovery was spurious.
+ The connection fails to undo the spurious fast recovery because
tp->retrans_stamp is 0, and thus tcp_packet_delayed() returns false,
due to the new logic in the 2019 commit: commit bc9f38c8328e ("tcp:
avoid unconditional congestion window undo on SYN retransmit")
This fix tweaks the logic to be more similar to the
tcp_packet_delayed() logic before bc9f38c8328e, except that we take
care not to be fooled by the FLAG_SYN_ACKED code path zeroing out
tp->retrans_stamp (the bug noted and fixed by Yuchung in
bc9f38c8328e).
Note that this returns the high-level behavior of tcp_packet_delayed()
to again match the comment for the function, which says: "Nothing was
retransmitted or returned timestamp is less than timestamp of the
first retransmission." Note that this comment is in the original
2005-04-16 Linux git commit, so this is evidently long-standing
behavior.
Fixes: bc9f38c8328e ("tcp: avoid unconditional congestion window undo on SYN retransmit")
Reported-by: Geumhwan Yu <geumhwan.yu@samsung.com>
Diagnosed-by: Geumhwan Yu <geumhwan.yu@samsung.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241001200517.2756803-2-ncardwell.sw@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0d9e5df4a257afc3a471a82961ace9a22b88295a ]
We found that one close-wait socket was reset by the other side
due to a new connection reusing the same port which is beyond our
expectation, so we have to investigate the underlying reason.
The following experiment is conducted in the test environment. We
limit the port range from 40000 to 40010 and delay the time to close()
after receiving a fin from the active close side, which can help us
easily reproduce like what happened in production.
Here are three connections captured by tcpdump:
127.0.0.1.40002 > 127.0.0.1.9999: Flags [S], seq 2965525191
127.0.0.1.9999 > 127.0.0.1.40002: Flags [S.], seq 2769915070
127.0.0.1.40002 > 127.0.0.1.9999: Flags [.], ack 1
127.0.0.1.40002 > 127.0.0.1.9999: Flags [F.], seq 1, ack 1
// a few seconds later, within 60 seconds
127.0.0.1.40002 > 127.0.0.1.9999: Flags [S], seq 2965590730
127.0.0.1.9999 > 127.0.0.1.40002: Flags [.], ack 2
127.0.0.1.40002 > 127.0.0.1.9999: Flags [R], seq 2965525193
// later, very quickly
127.0.0.1.40002 > 127.0.0.1.9999: Flags [S], seq 2965590730
127.0.0.1.9999 > 127.0.0.1.40002: Flags [S.], seq 3120990805
127.0.0.1.40002 > 127.0.0.1.9999: Flags [.], ack 1
As we can see, the first flow is reset because:
1) client starts a new connection, I mean, the second one
2) client tries to find a suitable port which is a timewait socket
(its state is timewait, substate is fin_wait2)
3) client occupies that timewait port to send a SYN
4) server finds a corresponding close-wait socket in ehash table,
then replies with a challenge ack
5) client sends an RST to terminate this old close-wait socket.
I don't think the port selection algo can choose a FIN_WAIT2 socket
when we turn on tcp_tw_reuse because on the server side there
remain unread data. In some cases, if one side haven't call close() yet,
we should not consider it as expendable and treat it at will.
Even though, sometimes, the server isn't able to call close() as soon
as possible like what we expect, it can not be terminated easily,
especially due to a second unrelated connection happening.
After this patch, we can see the expected failure if we start a
connection when all the ports are occupied in fin_wait2 state:
"Ncat: Cannot assign requested address."
Reported-by: Jade Dong <jadedong@tencent.com>
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20240823001152.31004-1-kerneljasonxing@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8fed54758cd248cd311a2b5c1e180abef1866237 ]
The NETLINK_FIB_LOOKUP netlink family can be used to perform a FIB
lookup according to user provided parameters and communicate the result
back to user space.
However, unlike other users of the FIB lookup API, the upper DSCP bits
and the ECN bits of the DS field are not masked, which can result in the
wrong result being returned.
Solve this by masking the upper DSCP bits and the ECN bits using
IPTOS_RT_MASK.
The structure that communicates the request and the response is not
exported to user space, so it is unlikely that this netlink family is
actually in use [1].
[1] https://lore.kernel.org/netdev/ZpqpB8vJU%2FQ6LSqa@debian/
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e3af3d3c5b26c33a7950e34e137584f6056c4319 ]
dev->ip_ptr could be NULL if we set an invalid MTU.
Even then, if we issue ioctl(SIOCSIFADDR) for a new IPv4 address,
devinet_ioctl() allocates struct in_ifaddr and fails later in
inet_set_ifa() because in_dev is NULL.
Let's move the check earlier.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20240809235406.50187-2-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c4a14f6d9d17ad1e41a36182dd3b8a5fd91efbd7 ]
Regression Description:
Depending on the options specified for the GRE tunnel device, small
packets may be dropped. This occurs because the pskb_network_may_pull
function fails due to the packet's insufficient length.
For example, if only the okey option is specified for the tunnel device,
original (before encapsulation) packets smaller than 28 bytes (including
the IPv4 header) will be dropped. This happens because the required
length is calculated relative to the network header, not the skb->head.
Here is how the required length is computed and checked:
* The pull_len variable is set to 28 bytes, consisting of:
* IPv4 header: 20 bytes
* GRE header with Key field: 8 bytes
* The pskb_network_may_pull function adds the network offset, shifting
the checkable space further to the beginning of the network header and
extending it to the beginning of the packet. As a result, the end of
the checkable space occurs beyond the actual end of the packet.
Instead of ensuring that 28 bytes are present in skb->head, the function
is requesting these 28 bytes starting from the network header. For small
packets, this requested length exceeds the actual packet size, causing
the check to fail and the packets to be dropped.
This issue affects both locally originated and forwarded packets in
DMVPN-like setups.
How to reproduce (for local originated packets):
ip link add dev gre1 type gre ikey 1.9.8.4 okey 1.9.8.4 \
local <your-ip> remote 0.0.0.0
ip link set mtu 1400 dev gre1
ip link set up dev gre1
ip address add 192.168.13.1/24 dev gre1
ip neighbor add 192.168.13.2 lladdr <remote-ip> dev gre1
ping -s 1374 -c 10 192.168.13.2
tcpdump -vni gre1
tcpdump -vni <your-ext-iface> 'ip proto 47'
ip -s -s -d link show dev gre1
Solution:
Use the pskb_may_pull function instead the pskb_network_may_pull.
Fixes: 80d875cfc9d3 ("ipv4: ip_gre: Avoid skb_pull() failure in ipgre_xmit()")
Signed-off-by: Anton Danilov <littlesmilingcloud@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20240924235158.106062-1-littlesmilingcloud@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 18685451fc4e546fc0e718580d32df3c0e5c8272 upstream.
ip_local_out() and other functions can pass skb->sk as function argument.
If the skb is a fragment and reassembly happens before such function call
returns, the sk must not be released.
This affects skb fragments reassembled via netfilter or similar
modules, e.g. openvswitch or ct_act.c, when run as part of tx pipeline.
Eric Dumazet made an initial analysis of this bug. Quoting Eric:
Calling ip_defrag() in output path is also implying skb_orphan(),
which is buggy because output path relies on sk not disappearing.
A relevant old patch about the issue was :
8282f27449bf ("inet: frag: Always orphan skbs inside ip_defrag()")
[..]
net/ipv4/ip_output.c depends on skb->sk being set, and probably to an
inet socket, not an arbitrary one.
If we orphan the packet in ipvlan, then downstream things like FQ
packet scheduler will not work properly.
We need to change ip_defrag() to only use skb_orphan() when really
needed, ie whenever frag_list is going to be used.
Eric suggested to stash sk in fragment queue and made an initial patch.
However there is a problem with this:
If skb is refragmented again right after, ip_do_fragment() will copy
head->sk to the new fragments, and sets up destructor to sock_wfree.
IOW, we have no choice but to fix up sk_wmem accouting to reflect the
fully reassembled skb, else wmem will underflow.
This change moves the orphan down into the core, to last possible moment.
As ip_defrag_offset is aliased with sk_buff->sk member, we must move the
offset into the FRAG_CB, else skb->sk gets clobbered.
This allows to delay the orphaning long enough to learn if the skb has
to be queued or if the skb is completing the reasm queue.
In the former case, things work as before, skb is orphaned. This is
safe because skb gets queued/stolen and won't continue past reasm engine.
In the latter case, we will steal the skb->sk reference, reattach it to
the head skb, and fix up wmem accouting when inet_frag inflates truesize.
Fixes: 7026b1ddb6b8 ("netfilter: Pass socket pointer down through okfn().")
Diagnosed-by: Eric Dumazet <edumazet@google.com>
Reported-by: xingwei lee <xrivendell7@gmail.com>
Reported-by: yue sun <samsun1006219@gmail.com>
Reported-by: syzbot+e5167d7144a62715044c@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240326101845.30836-1-fw@strlen.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 4c8002277167125078e6b9b90137bdf443ebaa08 ]
The grc must be initialize first. There can be a condition where if
fou is NULL, goto out will be executed and grc would be used
uninitialized.
Fixes: 7e4196935069 ("fou: Fix null-ptr-deref in GRO.")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20240906102839.202798-1-usama.anjum@collabora.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 627b94f75b82d13d1530b59155a545fd99d807db ]
All gro_complete() handlers are called from napi_gro_complete()
while rcu_read_lock() has been called.
There is no point stacking more rcu_read_lock()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 7e4196935069 ("fou: Fix null-ptr-deref in GRO.")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit fc1ca3348a74a1afaa7ffebc2b2f2cc149e11278 ]
All gro_receive() handlers are called from dev_gro_receive()
while rcu_read_lock() has been called.
There is no point stacking more rcu_read_lock()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 7e4196935069 ("fou: Fix null-ptr-deref in GRO.")
Signed-off-by: Sasha Levin <sashal@kernel.org>
