On 4/12/22 2:01 PM, Niels Dossche wrote:
On 4/12/22 21:45, Shuah Khan wrote:
On 4/12/22 10:50 AM, Niels Dossche wrote:
The function documentation of usb_set_configuration says that its
callers should hold the device lock. This lock is held for all
callsites except tweak_set_configuration_cmd. The code path can be
executed for example when attaching a remote USB device.
The solution is to surround the call by the device lock.
This bug was found using my experimental own-developed static analysis
tool, which reported the missing lock on v5.17.2. I manually verified
this bug report by doing code review as well. I runtime checked that
the required lock is not held. I compiled and runtime tested this on
x86_64 with a USB mouse. After applying this patch, my analyser no
longer reports this potential bug.
How did you run-time check that the lock isn't held? Also x86_64 with a
USB mouse - did you test it over loopback?
I checked the lock isn't held with lockdep_assert_not_held and also by
checking the return value of usb_trylock_device to be equal to 1 in my testing.
I checked my USB mouse over loopback yes, binding the mouse for remote use and
attaching on loopback.
Great. Thank you for a detailed answer.
Fixes: 2c8c98158946 ("staging: usbip: let client choose device configuration")
Signed-off-by: Niels Dossche <dossche.niels@xxxxxxxxx>
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Looks good to me with the above questions answered.
Reviewed-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
Greg, please pick this patch up.
thanks,
-- Shuah
