CVE - CVE-2021-47229

CVE-ID
CVE-2021-47229	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: PCI: aardvark: Fix kernel panic during PIO transfer Trying to start a new PIO transfer by writing value 0 in PIO_START register when previous transfer has not yet completed (which is indicated by value 1 in PIO_START) causes an External Abort on CPU, which results in kernel panic: SError Interrupt on CPU0, code 0xbf000002 -- SError Kernel panic - not syncing: Asynchronous SError Interrupt To prevent kernel panic, it is required to reject a new PIO transfer when previous one has not finished yet. If previous PIO transfer is not finished yet, the kernel may issue a new PIO request only if the previous PIO transfer timed out. In the past the root cause of this issue was incorrectly identified (as it often happens during link retraining or after link down event) and special hack was implemented in Trusted Firmware to catch all SError events in EL3, to ignore errors with code 0xbf000002 and not forwarding any other errors to kernel and instead throw panic from EL3 Trusted Firmware handler. Links to discussion and patches about this issue: https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/commit/?id=3c7dcdac5c50 https://lore.kernel.org/linux-pci/20190316161243.29517-1-repk@triplefau.lt/ https://lore.kernel.org/linux-pci/971be151d24312cc533989a64bd454b4@www.loen.fr/ https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/1541 But the real cause was the fact that during link retraining or after link down event the PIO transfer may take longer time, up to the 1.44s until it times out. This increased probability that a new PIO transfer would be issued by kernel while previous one has not finished yet. After applying this change into the kernel, it is possible to revert the mentioned TF-A hack and SError events do not have to be caught in TF-A EL3.
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/1a1dbc4473974867fe8c5f195c17b341c8e82867 URL:https://git.kernel.org/stable/c/1a1dbc4473974867fe8c5f195c17b341c8e82867 MISC:https://git.kernel.org/stable/c/3d213a4ddf49a860be6e795482c17f87e0c82b2a URL:https://git.kernel.org/stable/c/3d213a4ddf49a860be6e795482c17f87e0c82b2a MISC:https://git.kernel.org/stable/c/400e6b1860c8be61388d0b77814c53260f96e17a URL:https://git.kernel.org/stable/c/400e6b1860c8be61388d0b77814c53260f96e17a MISC:https://git.kernel.org/stable/c/4c90f90a91d75c3c73dd633827c90e8746d9f54d URL:https://git.kernel.org/stable/c/4c90f90a91d75c3c73dd633827c90e8746d9f54d MISC:https://git.kernel.org/stable/c/b00a9aaa4be20ad6e3311fb78a485eae0899e89a URL:https://git.kernel.org/stable/c/b00a9aaa4be20ad6e3311fb78a485eae0899e89a MISC:https://git.kernel.org/stable/c/f18139966d072dab8e4398c95ce955a9742e04f7 URL:https://git.kernel.org/stable/c/f18139966d072dab8e4398c95ce955a9742e04f7
Assigning CNA
kernel.org
Date Record Created
20240410	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 (20240410)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
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