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Commit 95a2c279 authored by Todd Poynor's avatar Todd Poynor Committed by Greg Kroah-Hartman
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staging: gasket: core: protect against races during unregister 



Keep mutex held across the unregistration operation, until the
driver_desc field of the global table is removed, to prevent a
concurrent accessor from looking up the driver_desc while
gasket_unregister_device() is in the processing of removing it.

Reported-by: default avatarGuenter Roeck <groeck@chromium.org>
Signed-off-by: default avatarTodd Poynor <toddpoynor@google.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 71934948

drivers/staging/gasket/gasket_core.c

+1 −2
Original line number Diff line number Diff line
@@ -1765,9 +1765,9 @@ void gasket_unregister_device(const struct gasket_driver_desc *driver_desc) 
			break;

		}

	}

	mutex_unlock(&g_mutex);



	if (!internal_desc) {

		mutex_unlock(&g_mutex);

		pr_err("request to unregister unknown desc: %s, %d:%d\n",

		       driver_desc->name, driver_desc->major,

		       driver_desc->minor);
@@ -1780,7 +1780,6 @@ void gasket_unregister_device(const struct gasket_driver_desc *driver_desc) 
	class_destroy(internal_desc->class);



	/* Finally, effectively "remove" the driver. */

	mutex_lock(&g_mutex);

	g_descs[desc_idx].driver_desc = NULL;

	mutex_unlock(&g_mutex);