net: mctp: unshare packets when reassembling

Browse source

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: 4a992bbd36 ("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>

...

This commit is contained in:

Matt Johnston 2025-03-06 10:32:45 +08:00 • committed by Paolo Abeni

parent 62531a1eff

commit f5d83cf0ee

2 changed files with 117 additions and 2 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

10

net/mctp/route.c

View file

109

net/mctp/test/route-test.c

View file