misc: fastrpc: Fix double free of 'buf' in error path

commit e8c276d4dc upstream.

smatch warning:
drivers/misc/fastrpc.c:1926 fastrpc_req_mmap() error: double free of 'buf'

In fastrpc_req_mmap() error path, the fastrpc buffer is freed in
fastrpc_req_munmap_impl() if unmap is successful.

But in the end, there is an unconditional call to fastrpc_buf_free().
So the above case triggers the double free of fastrpc buf.

Fixes: 72fa6f7820 ("misc: fastrpc: Rework fastrpc_req_munmap")
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Sukrut Bellary <sukrut.bellary@linux.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20240902141409.70371-2-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Sukrut Bellary 2024-09-02 15:14:09 +01:00 committed by Greg Kroah-Hartman
parent 7d301dd272
commit f77dc8a758

View file

@ -1912,7 +1912,8 @@ static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
&args[0]);
if (err) {
dev_err(dev, "mmap error (len 0x%08llx)\n", buf->size);
goto err_invoke;
fastrpc_buf_free(buf);
return err;
}
/* update the buffer to be able to deallocate the memory on the DSP */
@ -1950,8 +1951,6 @@ static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
err_assign:
fastrpc_req_munmap_impl(fl, buf);
err_invoke:
fastrpc_buf_free(buf);
return err;
}