CVE - CVE-2021-47436

CVE-ID
CVE-2021-47436	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
Description
In the Linux kernel, the following vulnerability has been resolved: usb: musb: dsps: Fix the probe error path Commit 7c75bde329d7 ("usb: musb: musb_dsps: request_irq() after initializing musb") has inverted the calls to dsps_setup_optional_vbus_irq() and dsps_create_musb_pdev() without updating correctly the error path. dsps_create_musb_pdev() allocates and registers a new platform device which must be unregistered and freed with platform_device_unregister(), and this is missing upon dsps_setup_optional_vbus_irq() error. While on the master branch it seems not to trigger any issue, I observed a kernel crash because of a NULL pointer dereference with a v5.10.70 stable kernel where the patch mentioned above was backported. With this kernel version, -EPROBE_DEFER is returned the first time dsps_setup_optional_vbus_irq() is called which triggers the probe to error out without unregistering the platform device. Unfortunately, on the Beagle Bone Black Wireless, the platform device still living in the system is being used by the USB Ethernet gadget driver, which during the boot phase triggers the crash. My limited knowledge of the musb world prevents me to revert this commit which was sent to silence a robot warning which, as far as I understand, does not make sense. The goal of this patch was to prevent an IRQ to fire before the platform device being registered. I think this cannot ever happen due to the fact that enabling the interrupts is done by the ->enable() callback of the platform musb device, and this platform device must be already registered in order for the core or any other user to use this callback. Hence, I decided to fix the error path, which might prevent future errors on mainline kernels while also fixing older ones.
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
MISC:https://git.kernel.org/stable/c/5ed60a430fb5f3d93e7fef66264daef466b4d10c URL:https://git.kernel.org/stable/c/5ed60a430fb5f3d93e7fef66264daef466b4d10c MISC:https://git.kernel.org/stable/c/9ab5d539bc975b8dcde86eca1b58d836b657732e URL:https://git.kernel.org/stable/c/9ab5d539bc975b8dcde86eca1b58d836b657732e MISC:https://git.kernel.org/stable/c/9d89e287116796bf987cc48f5c8632ef3048f8eb URL:https://git.kernel.org/stable/c/9d89e287116796bf987cc48f5c8632ef3048f8eb MISC:https://git.kernel.org/stable/c/c2115b2b16421d93d4993f3fe4c520e91d6fe801 URL:https://git.kernel.org/stable/c/c2115b2b16421d93d4993f3fe4c520e91d6fe801 MISC:https://git.kernel.org/stable/c/e923bce31ffefe4f60edfc6b84f62d4a858f3676 URL:https://git.kernel.org/stable/c/e923bce31ffefe4f60edfc6b84f62d4a858f3676 MISC:https://git.kernel.org/stable/c/ff9249aab39820be11b6975a10d94253b7d426fc URL:https://git.kernel.org/stable/c/ff9249aab39820be11b6975a10d94253b7d426fc
Assigning CNA
kernel.org
Date Record Created
20240521	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20240521)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
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