CVE-2022-49501
HighIn the Linux kernel, the following vulnerability has been resolved: usbnet: Run unregister_netdev() before unbind() again Commit 2c9d6c2b871d ("usbnet: run unbind() before unregister_netdev()") sought to fix a use-after-free on disconnect of USB Ethernet adapters. It turns out that a different fix is necessary to address the issue: https://lore.kernel.org/netdev/18b3541e5372bc9b9fc733d422f4e698c089077c.1650177997.git.lukas@wunner.de/ So the commit was not necessary. The commit made binding and unbinding of USB Ethernet asymmetrical: Before, usbnet_probe() first invoked the ->bind() callback and then register_netdev(). usbnet_disconnect() mirrored that by first invoking unregister_netdev() and then ->unbind(). Since the commit, the order in usbnet_disconnect() is reversed and no longer mirrors usbnet_probe(). One consequence is that a PHY disconnected (and stopped) in ->unbind() is afterwards stopped once more by unregister_netdev() as it closes the netdev before unregistering. That necessitates a contortion in ->stop() because the PHY may only be stopped if it hasn't already been disconnected. Reverting the commit allows making the call to phy_stop() unconditional in ->stop().
CVSS 3.1 score
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness type
CWE-416CVE-2022-49501 is a Use After Free vulnerability
What is Use After Free?
The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE
Affected versions
Linux kernel versions
5.14
and later are affected. Fixed in
5.15.46,
5.17.14,
5.18.3,
5.19
and their respective stable series.
References
The following references provide additional information about CVE-2022-49501 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/6d5deb242874d924beccf7eb3cef04c1c3b0da79
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PatchKernel patch commithttps://git.kernel.org/stable/c/969a1b3ea3cb7d58a16fe12fd1b04bfc0ea40509
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PatchKernel patch commithttps://git.kernel.org/stable/c/d1408f6b4dd78fb1b9e26bcf64477984e5f85409
Frequently asked questions
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What is CVE-2022-49501?
CVE-2022-49501 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Use After Free flaw (CWE-416) . It affects Linux kernel versions from 5.14 onward and has been patched in 5.15.46, 5.17.14, 5.18.3 and others. CVE-2022-49501 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2022-49501?
CVE-2022-49501 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. -
Is there a patch available for CVE-2022-49501?
Yes — CVE-2022-49501 has been patched. Fixed versions include 5.15.46, 5.17.14, 5.18.3 and others. If you are running Linux kernel 5.14 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2022-49501 actively exploited?
No — CVE-2022-49501 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is Use After Free (CWE-416)?
The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. View CWE-416 on MITRE CWE →