spi: mpc52xx: Add cancel_work_sync before module remove

BugLink: https://bugs.launchpad.net/bugs/2095283

[ Upstream commit 9848366 ]

If we remove the module which will call mpc52xx_spi_remove
it will free 'ms' through spi_unregister_controller.
while the work ms->work will be used. The sequence of operations
that may lead to a UAF bug.

Fix it by ensuring that the work is canceled before proceeding with
the cleanup in mpc52xx_spi_remove.

Fixes: ca632f5 ("spi: reorganize drivers")
Signed-off-by: Pei Xiao <[email protected]>
Link: https://patch.msgid.link/1f16f8ae0e50ca9adb1dc849bf2ac65a40c9ceb9.1732783000.git.xiaopei01@kylinos.cn
Signed-off-by: Mark Brown <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
CVE-2024-50051
Signed-off-by: Koichiro Den <[email protected]>

Author: Pei Xiao

drivers/spi/spi-mpc52xx.c

@@ -521,6 +521,7 @@ static int mpc52xx_spi_remove(struct platform_device *op)
 	struct mpc52xx_spi *ms = spi_master_get_devdata(master);
 	int i;
 
+	cancel_work_sync(&ms->work);
 	free_irq(ms->irq0, ms);
 	free_irq(ms->irq1, ms);