| e4d8a517 | 07-May-2025 |
Andrew Jeffery <andrew@codeconstruct.com.au> |
net: mctp: Ensure keys maintain only one ref to corresponding dev
[ Upstream commit e4f349bd6e58051df698b82f94721f18a02a293d ]
mctp_flow_prepare_output() is called in mctp_route_output(), which
pla
net: mctp: Ensure keys maintain only one ref to corresponding dev
[ Upstream commit e4f349bd6e58051df698b82f94721f18a02a293d ]
mctp_flow_prepare_output() is called in mctp_route_output(), which
places outbound packets onto a given interface. The packet may represent
a message fragment, in which case we provoke an unbalanced reference
count to the underlying device. This causes trouble if we ever attempt
to remove the interface:
[ 48.702195] usb 1-1: USB disconnect, device number 2
[ 58.883056] unregister_netdevice: waiting for mctpusb0 to become free. Usage count = 2
[ 69.022548] unregister_netdevice: waiting for mctpusb0 to become free. Usage count = 2
[ 79.172568] unregister_netdevice: waiting for mctpusb0 to become free. Usage count = 2
...
Predicate the invocation of mctp_dev_set_key() in
mctp_flow_prepare_output() on not already having associated the device
with the key. It's not yet realistic to uphold the property that the key
maintains only one device reference earlier in the transmission sequence
as the route (and therefore the device) may not be known at the time the
key is associated with the socket.
Fixes: 67737c457281 ("mctp: Pass flow data & flow release events to drivers")
Acked-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
Link: https://patch.msgid.link/20250508-mctp-dev-refcount-v1-1-d4f965c67bb5@codeconstruct.com.au
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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| acab78ae | 08-May-2025 |
Matt Johnston <matt@codeconstruct.com.au> |
net: mctp: Don't access ifa_index when missing
[ Upstream commit f11cf946c0a92c560a890d68e4775723353599e1 ]
In mctp_dump_addrinfo, ifa_index can be used to filter interfaces, but
only when the stru
net: mctp: Don't access ifa_index when missing
[ Upstream commit f11cf946c0a92c560a890d68e4775723353599e1 ]
In mctp_dump_addrinfo, ifa_index can be used to filter interfaces, but
only when the struct ifaddrmsg is provided. Otherwise it will be
comparing to uninitialised memory - reproducible in the syzkaller case from
dhcpd, or busybox "ip addr show".
The kernel MCTP implementation has always filtered by ifa_index, so
existing userspace programs expecting to dump MCTP addresses must
already be passing a valid ifa_index value (either 0 or a real index).
BUG: KMSAN: uninit-value in mctp_dump_addrinfo+0x208/0xac0 net/mctp/device.c:128
mctp_dump_addrinfo+0x208/0xac0 net/mctp/device.c:128
rtnl_dump_all+0x3ec/0x5b0 net/core/rtnetlink.c:4380
rtnl_dumpit+0xd5/0x2f0 net/core/rtnetlink.c:6824
netlink_dump+0x97b/0x1690 net/netlink/af_netlink.c:2309
Fixes: 583be982d934 ("mctp: Add device handling and netlink interface")
Reported-by: syzbot+e76d52dadc089b9d197f@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/68135815.050a0220.3a872c.000e.GAE@google.com/
Reported-by: syzbot+1065a199625a388fce60@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/681357d6.050a0220.14dd7d.000d.GAE@google.com/
Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Link: https://patch.msgid.link/20250508-mctp-addr-dump-v2-1-c8a53fd2dd66@codeconstruct.com.au
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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| d05a73b0 | 05-Mar-2025 |
Matt Johnston <matt@codeconstruct.com.au> |
net: mctp: unshare packets when reassembling
Ensure that the frag_list used for reassembly isn't shared with other
packets. This avoids incorrect reassembly when packets are cloned, and
prevents a m
net: mctp: unshare packets when reassembling
Ensure that the frag_list used for reassembly isn't shared with other
packets. This avoids incorrect reassembly when packets are cloned, and
prevents a memory leak due to circular references between fragments and
their skb_shared_info.
The upcoming MCTP-over-USB driver uses skb_clone which can trigger the
problem - other MCTP drivers don't share SKBs.
A kunit test is added to reproduce the issue.
Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Fixes: 4a992bbd3650 ("mctp: Implement message fragmentation & reassembly")
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250306-matt-mctp-usb-v1-1-085502b3dd28@codeconstruct.com.au
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
(cherry picked from commit f5d83cf0eeb90fade4d5c4d17d24b8bee9ceeecc)
[aj: Dropped the kunit test due to conflicts]
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
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| b98e1a04 | 23-Jan-2023 |
Jeremy Kerr <jk@codeconstruct.com.au> |
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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| 6e54ea37 | 23-Jan-2023 |
Paolo Abeni <pabeni@redhat.com> |
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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| 5f41ae6f | 23-Jan-2023 |
Jeremy Kerr <jk@codeconstruct.com.au> |
net: mctp: move expiry timer delete to unhash
Currently, we delete the key expiry timer (in sk->close) before
unhashing the sk. This means that another thread may find the sk through
its presence on
net: mctp: move expiry timer delete to unhash
Currently, we delete the key expiry timer (in sk->close) before
unhashing the sk. This means that another thread may find the sk through
its presence on the key list, and re-queue the timer.
This change moves the timer deletion to the unhash, after we have made
the key no longer observable, so the timer cannot be re-queued.
Fixes: 7b14e15ae6f4 ("mctp: Implement a timeout for tags")
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
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