CVE-2021-47101: asix: fix uninit-value in asix_mdio_read()

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-03-04 · updated 2026-06-17
Weakness: CWE-908

Description

In the Linux kernel, the following vulnerability has been resolved: asix: fix uninit-value in asix_mdio_read() asix_read_cmd() may read less than sizeof(smsr) bytes and in this case smsr will be uninitialized. Fail log: BUG: KMSAN: uninit-value in asix_check_host_enable drivers/net/usb/asix_common.c:82 [inline] BUG: KMSAN: uninit-value in asix_check_host_enable drivers/net/usb/asix_common.c:82 [inline] drivers/net/usb/asix_common.c:497 BUG: KMSAN: uninit-value in asix_mdio_read+0x3c1/0xb00 drivers/net/usb/asix_common.c:497 drivers/net/usb/asix_common.c:497 asix_check_host_enable drivers/net/usb/asix_common.c:82 [inline] asix_check_host_enable drivers/net/usb/asix_common.c:82 [inline] drivers/net/usb/asix_common.c:497 asix_mdio_read+0x3c1/0xb00 drivers/net/usb/asix_common.c:497 drivers/net/usb/asix_common.c:497

Affected products

Linux kernel: from 4.9 before 5.15.12; 5.16-rc1, 5.16-rc2, 5.16-rc3, 5.16-rc4, 5.16-rc5, 5.16-rc6 — fixed in 5.15.12

How to fix

Upgrade to a fixed version: Linux kernel 5.15.12. Check the vendor advisory for mitigations.

References

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