From: Todd Poynor Date: Sun, 5 Aug 2018 20:07:47 +0000 (-0700) Subject: staging: gasket: core: protect against races during unregister X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=95a2c279b2c7c2e59977d5b0773a15ba26b7ce4b;p=linux.git 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: Guenter Roeck Signed-off-by: Todd Poynor Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/gasket/gasket_core.c b/drivers/staging/gasket/gasket_core.c index ace92f107ed58..a6462b6d702f1 100644 --- a/drivers/staging/gasket/gasket_core.c +++ b/drivers/staging/gasket/gasket_core.c @@ -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);