net: mctp: copy skb ext data when fragmenting

[ Upstream commit 1394c1dec1c619a46867ed32791a29695372bff8 ]

If we're fragmenting on local output, the original packet may contain
ext data for the MCT

net: mctp: copy skb ext data when fragmenting

[ Upstream commit 1394c1dec1c619a46867ed32791a29695372bff8 ]

If we're fragmenting on local output, the original packet may contain
ext data for the MCTP flows. We'll want this in the resulting fragment
skbs too.

So, do a skb_ext_copy() in the fragmentation path, and implement the
MCTP-specific parts of an ext copy operation.

Fixes: 67737c457281 ("mctp: Pass flow data & flow release events to drivers")
Reported-by: Jian Zhang <zhangjian.3032@bytedance.com>
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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net: mctp: take ownership of skb in mctp_local_output

[ Upstream commit 3773d65ae5154ed7df404b050fd7387a36ab5ef3 ]

Currently, mctp_local_output only takes ownership of skb on success, and
we may le

net: mctp: take ownership of skb in mctp_local_output

[ Upstream commit 3773d65ae5154ed7df404b050fd7387a36ab5ef3 ]

Currently, mctp_local_output only takes ownership of skb on success, and
we may leak an skb if mctp_local_output fails in specific states; the
skb ownership isn't transferred until the actual output routing occurs.

Instead, make mctp_local_output free the skb on all error paths up to
the route action, so it always consumes the passed skb.

Fixes: 833ef3b91de6 ("mctp: Populate socket implementation")
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240220081053.1439104-1-jk@codeconstruct.com.au
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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net: mctp: put sock on tag allocation failure

[ Upstream commit 9990889be14288d4f1743e4768222d5032a79c27 ]

We may hold an extra reference on a socket if a tag allocation fails: we
optimistically al

net: mctp: put sock on tag allocation failure

[ Upstream commit 9990889be14288d4f1743e4768222d5032a79c27 ]

We may hold an extra reference on a socket if a tag allocation fails: we
optimistically allocate the sk_key, and take a ref there, but do not
drop if we end up not using the allocated key.

Ensure we're dropping the sock on this failure by doing a proper unref
rather than directly kfree()ing.

Fixes: de8a6b15d965 ("net: mctp: add an explicit reference from a mctp_sk_key to sock")
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/ce9b61e44d1cdae7797be0c5e3141baf582d23a0.1707983487.git.jk@codeconstruct.com.au
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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mctp: perform route lookups under a RCU read-side lock

Our current route lookups (mctp_route_lookup and mctp_route_lookup_null)
traverse the net's route list without the RCU read lock held. This mea

mctp: perform route lookups under a RCU read-side lock

Our current route lookups (mctp_route_lookup and mctp_route_lookup_null)
traverse the net's route list without the RCU read lock held. This means
the route lookup is subject to preemption, resulting in an potential
grace period expiry, and so an eventual kfree() while we still have the
route pointer.

Add the proper read-side critical section locks around the route
lookups, preventing premption and a possible parallel kfree.

The remaining net->mctp.routes accesses are already under a
rcu_read_lock, or protected by the RTNL for updates.

Based on an analysis from Sili Luo <rootlab@huawei.com>, where
introducing a delay in the route lookup could cause a UAF on
simultaneous sendmsg() and route deletion.

Reported-by: Sili Luo <rootlab@huawei.com>
Fixes: 889b7da23abf ("mctp: Add initial routing framework")
Cc: stable@vger.kernel.org
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/29c4b0e67dc1bf3571df3982de87df90cae9b631.1696837310.git.jk@codeconstruct.com.au
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: mctp: remove redundant RTN_UNICAST check

Current mctp_newroute() contains two exactly same check against
rtm->rtm_type

static int mctp_newroute(...)
{
...
if (rtm->rtm_type != RTN_UNICAST)

net: mctp: remove redundant RTN_UNICAST check

Current mctp_newroute() contains two exactly same check against
rtm->rtm_type

static int mctp_newroute(...)
{
...
if (rtm->rtm_type != RTN_UNICAST) { // (1)
NL_SET_ERR_MSG(extack, "rtm_type must be RTN_UNICAST");
return -EINVAL;
}
...
if (rtm->rtm_type != RTN_UNICAST) // (2)
return -EINVAL;
...
}

This commits removes the (2) check as it is redundant.

Signed-off-by: Lin Ma <linma@zju.edu.cn>
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Acked-by: Jeremy Kerr <jk@codeconstruct.com.au>
Link: https://lore.kernel.org/r/20230615152240.1749428-1-linma@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: mctp: mark socks as dead on unhash, prevent re-add

Once a socket has been unhashed, we want to prevent it from being
re-used in a sk_key entry as part of a routing operation.

This change marks

net: mctp: mark socks as dead on unhash, prevent re-add

Once a socket has been unhashed, we want to prevent it from being
re-used in a sk_key entry as part of a routing operation.

This change marks the sk as SOCK_DEAD on unhash, which prevents addition
into the net's key list.

We need to do this during the key add path, rather than key lookup, as
we release the net keys_lock between those operations.

Fixes: 4a992bbd3650 ("mctp: Implement message fragmentation & reassembly")
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: mctp: hold key reference when looking up a general key

Currently, we have a race where we look up a sock through a "general"
(ie, not directly associated with the (src,dest,tag) tuple) key, the

net: mctp: hold key reference when looking up a general key

Currently, we have a race where we look up a sock through a "general"
(ie, not directly associated with the (src,dest,tag) tuple) key, then
drop the key reference while still holding the key's sock.

This change expands the key reference until we've finished using the
sock, and hence the sock reference too.

Commit message changes from Jeremy Kerr <jk@codeconstruct.com.au>.

Reported-by: Noam Rathaus <noamr@ssd-disclosure.com>
Fixes: 73c618456dc5 ("mctp: locking, lifetime and validity changes for sk_keys")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: mctp: add an explicit reference from a mctp_sk_key to sock

Currently, we correlate the mctp_sk_key lifetime to the sock lifetime
through the sock hash/unhash operations, but this is pretty tenu

net: mctp: add an explicit reference from a mctp_sk_key to sock

Currently, we correlate the mctp_sk_key lifetime to the sock lifetime
through the sock hash/unhash operations, but this is pretty tenuous, and
there are cases where we may have a temporary reference to an unhashed
sk.

This change makes the reference more explicit, by adding a hold on the
sock when it's associated with a mctp_sk_key, released on final key
unref.

Fixes: 73c618456dc5 ("mctp: locking, lifetime and validity changes for sk_keys")
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

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mctp: Fix an error handling path in mctp_init()

If mctp_neigh_init() return error, the routes resources should
be released in the error handling path. Otherwise some resources
leak.

Fixes: 4d8b9319

mctp: Fix an error handling path in mctp_init()

If mctp_neigh_init() return error, the routes resources should
be released in the error handling path. Otherwise some resources
leak.

Fixes: 4d8b9319282a ("mctp: Add neighbour implementation")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Matt Johnston <matt@codeconstruct.com.au>
Link: https://lore.kernel.org/r/20221108095517.620115-1-weiyongjun@huaweicloud.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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mctp: prevent double key removal and unref

Currently, we have a bug where a simultaneous DROPTAG ioctl and socket
close may race, as we attempt to remove a key from lists twice, and
perform an unref

mctp: prevent double key removal and unref

Currently, we have a bug where a simultaneous DROPTAG ioctl and socket
close may race, as we attempt to remove a key from lists twice, and
perform an unref for each removal operation. This may result in a uaf
when we attempt the second unref.

This change fixes the race by making __mctp_key_remove tolerant to being
called on a key that has already been removed from the socket/net lists,
and only performs the unref when we do the actual remove. We also need
to hold the list lock on the ioctl cleanup path.

This fix is based on a bug report and comprehensive analysis from
butt3rflyh4ck <butterflyhuangxx@gmail.com>, found via syzkaller.

Cc: stable@vger.kernel.org
Fixes: 63ed1aab3d40 ("mctp: Add SIOCMCTP{ALLOC,DROP}TAG ioctls for tag control")
Reported-by: butt3rflyh4ck <butterflyhuangxx@gmail.com>
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

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mctp: Use output netdev to allocate skb headroom

Previously the skb was allocated with headroom MCTP_HEADER_MAXLEN,
but that isn't sufficient if we are using devs that are not MCTP
specific.

This a

mctp: Use output netdev to allocate skb headroom

Previously the skb was allocated with headroom MCTP_HEADER_MAXLEN,
but that isn't sufficient if we are using devs that are not MCTP
specific.

This also adds a check that the smctp_halen provided to sendmsg for
extended addressing is the correct size for the netdev.

Fixes: 833ef3b91de6 ("mctp: Populate socket implementation")
Reported-by: Matthew Rinaldi <mjrinal@g.clemson.edu>
Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

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mctp: Fix check for dev_hard_header() result

dev_hard_header() returns the length of the header, so
we need to test for negative errors rather than non-zero.

Fixes: 889b7da23abf ("mctp: Add initial

mctp: Fix check for dev_hard_header() result

dev_hard_header() returns the length of the header, so
we need to test for negative errors rather than non-zero.

Fixes: 889b7da23abf ("mctp: Add initial routing framework")
Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

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mctp: Fix warnings reported by clang-analyzer

net/mctp/device.c:140:11: warning: Assigned value is garbage or undefined
[clang-analyzer-core.uninitialized.Assign]
mcb->idx = idx;

- Not a re

mctp: Fix warnings reported by clang-analyzer

net/mctp/device.c:140:11: warning: Assigned value is garbage or undefined
[clang-analyzer-core.uninitialized.Assign]
mcb->idx = idx;

- Not a real problem due to how the callback runs, fix the warning.

net/mctp/route.c:458:4: warning: Value stored to 'msk' is never read
[clang-analyzer-deadcode.DeadStores]
msk = container_of(key->sk, struct mctp_sock, sk);

- 'msk' dead assignment can be removed here.

Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

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mctp: Fix incorrect netdev unref for extended addr

In the extended addressing local route output codepath
dev_get_by_index_rcu() doesn't take a dev_hold() so we shouldn't
dev_put().

Signed-off-by:

mctp: Fix incorrect netdev unref for extended addr

In the extended addressing local route output codepath
dev_get_by_index_rcu() doesn't take a dev_hold() so we shouldn't
dev_put().

Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

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mctp: make __mctp_dev_get() take a refcount hold

Previously there was a race that could allow the mctp_dev refcount
to hit zero:

rcu_read_lock();
mdev = __mctp_dev_get(dev);
// mctp_unregister() ha

mctp: make __mctp_dev_get() take a refcount hold

Previously there was a race that could allow the mctp_dev refcount
to hit zero:

rcu_read_lock();
mdev = __mctp_dev_get(dev);
// mctp_unregister() happens here, mdev->refs hits zero
mctp_dev_hold(dev);
rcu_read_unlock();

Now we make __mctp_dev_get() take the hold itself. It is safe to test
against the zero refcount because __mctp_dev_get() is called holding
rcu_read_lock and mctp_dev uses kfree_rcu().

Reported-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

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mctp: add address validity checking for packet receive

This change adds some basic sanity checks for the source and dest
headers of packets on initial receive.

Signed-off-by: Jeremy Kerr <jk@codeco

mctp: add address validity checking for packet receive

This change adds some basic sanity checks for the source and dest
headers of packets on initial receive.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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mctp: replace mctp_address_ok with more fine-grained helpers

Currently, we have mctp_address_ok(), which checks if an EID is in the
"valid" range of 8-254 inclusive. However, 0 and 255 may also be v

mctp: replace mctp_address_ok with more fine-grained helpers

Currently, we have mctp_address_ok(), which checks if an EID is in the
"valid" range of 8-254 inclusive. However, 0 and 255 may also be valid
addresses, depending on context. 0 is the NULL EID, which may be set
when physical addressing is used. 255 is valid as a destination address
for broadcasts.

This change renames mctp_address_ok to mctp_address_unicast, and adds
similar helpers for broadcast and null EIDs, which will be used in an
upcoming commit.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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mctp: fix use after free

Clang static analysis reports this problem
route.c:425:4: warning: Use of memory after it is freed
trace_mctp_key_acquire(key);
^~~~~~~~~~~~~~~~~~~~~~~~~~~
When mctp_key

mctp: fix use after free

Clang static analysis reports this problem
route.c:425:4: warning: Use of memory after it is freed
trace_mctp_key_acquire(key);
^~~~~~~~~~~~~~~~~~~~~~~~~~~
When mctp_key_add() fails, key is freed but then is later
used in trace_mctp_key_acquire(). Add an else statement
to use the key only when mctp_key_add() is successful.

Fixes: 4f9e1ba6de45 ("mctp: Add tracepoints for tag/key handling")
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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mctp: Add SIOCMCTP{ALLOC,DROP}TAG ioctls for tag control

This change adds a couple of new ioctls for mctp sockets:
SIOCMCTPALLOCTAG and SIOCMCTPDROPTAG. These ioctls provide facilities
for explicit

mctp: Add SIOCMCTP{ALLOC,DROP}TAG ioctls for tag control

This change adds a couple of new ioctls for mctp sockets:
SIOCMCTPALLOCTAG and SIOCMCTPDROPTAG. These ioctls provide facilities
for explicit allocation / release of tags, overriding the automatic
allocate-on-send/release-on-reply and timeout behaviours. This allows
userspace more control over messages that may not fit a simple
request/response model.

In order to indicate a pre-allocated tag to the sendmsg() syscall, we
introduce a new flag to the struct sockaddr_mctp.smctp_tag value:
MCTP_TAG_PREALLOC.

Additional changes from Jeremy Kerr <jk@codeconstruct.com.au>.

Contains a fix that was:
Reported-by: kernel test robot <lkp@intel.com>

Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

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mctp: Allow keys matching any local address

Currently, we require an exact match on an incoming packet's dest
address, and the key's local_addr field.

In a future change, we may want to set up a ke

mctp: Allow keys matching any local address

Currently, we require an exact match on an incoming packet's dest
address, and the key's local_addr field.

In a future change, we may want to set up a key before packets are
routed, meaning we have no local address to match on.

This change allows key lookups to match on local_addr = MCTP_ADDR_ANY.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

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mctp: Add helper for address match checking

Currently, we have a couple of paths that check that an EID matches, or
the match value is MCTP_ADDR_ANY.

Rather than open coding this, add a little help

mctp: Add helper for address match checking

Currently, we have a couple of paths that check that an EID matches, or
the match value is MCTP_ADDR_ANY.

Rather than open coding this, add a little helper.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

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mctp: Remove redundant if statements

The 'if (dev)' statement already move into dev_{put , hold}, so remove
redundant if statements.

Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Signed-off-by: David

mctp: Remove redundant if statements

The 'if (dev)' statement already move into dev_{put , hold}, so remove
redundant if statements.

Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

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mctp: Don't let RTM_DELROUTE delete local routes

We need to test against the existing route type, not
the rtm_type in the netlink request.

Fixes: 83f0a0b7285b ("mctp: Specify route types, require r

mctp: Don't let RTM_DELROUTE delete local routes

We need to test against the existing route type, not
the rtm_type in the netlink request.

Fixes: 83f0a0b7285b ("mctp: Specify route types, require rtm_type in RTM_*ROUTE messages")
Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

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mctp: remove unnecessary check before calling kfree_skb()

The skb will be checked inside kfree_skb(), so remove the
outside check.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: htt

mctp: remove unnecessary check before calling kfree_skb()

The skb will be checked inside kfree_skb(), so remove the
outside check.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20211130031243.768823-1-yangyingliang@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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mctp: Pass flow data & flow release events to drivers

Now that we have an extension for MCTP data in skbs, populate the flow
when a key has been created for the packet, and add a device driver
opera

mctp: Pass flow data & flow release events to drivers

Now that we have an extension for MCTP data in skbs, populate the flow
when a key has been created for the packet, and add a device driver
operation to inform of flow destruction.

Includes a fix for a warning with test builds:
Reported-by: kernel test robot <lkp@intel.com>

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

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