ACK/Cmnt: [SRU][J][PATCH 0/1] Cherry-pick a patch to reject connection when malformed L2CAP signal packet is received

[Tim Gardner]

On 1/8/24 8:07 PM, Hui Wang wrote:
> BugLink: https://bugs.launchpad.net/bugs/2047634
> 
> The patch is merged in mainline kernel v6.7-rc7, so Noble kernel
> already have this fix. And this patch is CCed to stable at vger.kernel.org,
> M and L kernel will have this fix with the SRU update sooner or later.
> For Jammy kernel, an OEM customer is waiting for this patch
> to be merged to Jammy kernel and OEM kernel, here I submit the
> review reqeust for Jammy only.
> 
> [Impact]
> An OEM customer want to do the bluetooth profile testing suite (PTS)
> test, and they found if sending 2 commands and one of them is "unknown
> comands", the bluetooth stack doesn't reply the ack as expected, this
> broke the customer's PTS test.
> 
> [Fix]
> Cherry-pick a mainline kernel patch, this could fix this issue.
> 
> [Test]
> After applying the patch, test it with PTS:
> 
> 1. Configure the PTS: set PSM to 0x1011, so that it initiates L2CAP connection
>     over PSM 0x1011, which is the default PSM for l2test, the testing tool for
>     L2CAP layer provided by bluez.
> 
> 2. Set device as connectable:
>   $ sudo btmgmt connectable on
> 
> 3. Run l2test on the device in preparation for testing:
>   $ sudo l2test -d
> 
> 4. Run the L2CAP/COS/CED/BI-02-C test on PTS. The test suite will initiate
>     L2CAP connection automatically.
> 
> 5. Verify that the test verdict on the PTS is PASS.
> 
> And I also tested the patched kernel with 2 bt headsets, 1 bt keyboard and
> my mobile phone, all worked as well as before.
> 
> [Where problems could occur]
> This makes L2CAP implementation more conforming to the specification.
> It has possibility to make some bt devices could not work with patched
> kernel, but this possibility is very low, I tested the patched kernel
> with 2 bt headsets, 1 bt keyboard and my Android mobile phone, all
> worked as well as before.
> 
> 
> Frédéric Danis (1):
>    Bluetooth: L2CAP: Send reject on command corrupted request
> 
>   net/bluetooth/l2cap_core.c | 21 +++++++++++++++------
>   1 file changed, 15 insertions(+), 6 deletions(-)
> 
Acked-by: Tim Gardner <tim.gardner at canonical.com>

We really should apply to Mantic and Lunar as well. Stable updates can 
be slow to arrive.
-- 
-----------
Tim Gardner
Canonical, Inc