"value":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: core: Fix NULL module pointer assignment at card init\n\nThe commit 81033c6b584b (\"ALSA: core: Warn on empty module\")\nintroduced a WARN_ON() for a NULL module pointer passed at snd_card\nobject creation, and it also wraps the code around it with '#ifdef\nMODULE'. This works in most cases, but the devils are always in\ndetails. \"MODULE\" is defined when the target code (i.e. the sound\ncore) is built as a module; but this doesn't mean that the caller is\nalso built-in or not. Namely, when only the sound core is built-in\n(CONFIG_SND=y) while the driver is a module (CONFIG_SND_USB_AUDIO=m),\nthe passed module pointer is ignored even if it's non-NULL, and\ncard->module remains as NULL. This would result in the missing module\nreference up/down at the device open/close, leading to a race with the\ncode execution after the module removal.\n\nFor addressing the bug, move the assignment of card->module again out\nof ifdef. The WARN_ON() is still wrapped with ifdef because the\nmodule can be really NULL when all sound drivers are built-in.\n\nNote that we keep 'ifdef MODULE' for WARN_ON(), otherwise it would\nlead to a false-positive NULL module check. Admittedly it won't catch\nperfectly, i.e. no check is performed when CONFIG_SND=y. But, it's no\nreal problem as it's only for debugging, and the condition is pretty\nrare."
