misc: fastrpc: reject new invocations during device removal
commit 46248400 upstream. The channel's rpmsg object allows new invocations to be made. After old invocations are already interrupted, the driver shouldn't try to invoke anymore. Invalidating the rpmsg at the end of the driver removal function makes it easy to cause a race condition in userspace. Even closing a file descriptor before the driver finishes its cleanup can cause an invocation via fastrpc_release_current_dsp_process() and subsequent timeout. Invalidate the channel before the invocations are interrupted to make sure that no invocations can be created to hang after the device closes. Fixes: c68cfb71 ("misc: fastrpc: Add support for context Invoke method") Cc: stable <stable@kernel.org> Signed-off-by:Richard Acayan <mailingradian@gmail.com> Signed-off-by:
Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20230523152550.438363-5-srinivas.kandagatla@linaro.org Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
parent
cebe84b9
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