Linux Kernel up to 5.18.7 ar9331_switch null pointer dereference

Summaryinfo

A vulnerability has been found in Linux Kernel up to 5.18.7 and classified as critical. The affected element is the function ar9331_switch. Performing a manipulation results in null pointer dereference. This vulnerability is reported as CVE-2022-49692. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 5.18.7. This affects the function ar9331_switch. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: net: phy: at803x: fix NULL pointer dereference on AR9331 PHY Latest kernel will explode on the PHY interrupt config, since it depends now on allocated priv. So, run probe to allocate priv to fix it. ar9331_switch ethernet.1:10 lan0 (uninitialized): PHY [!ahb!ethernet@1a000000!mdio!switch@10:00] driver [Qualcomm Atheros AR9331 built-in PHY] (irq=13) CPU 0 Unable to handle kernel paging request at virtual address 0000000a, epc == 8050e8a8, ra == 80504b34 ... Call Trace: [] at803x_config_intr+0x5c/0xd0 [] phy_request_interrupt+0xa8/0xd0 [] phylink_bringup_phy+0x2d8/0x3ac [] phylink_fwnode_phy_connect+0x118/0x130 [] dsa_slave_create+0x270/0x420 [] dsa_port_setup+0x12c/0x148 [] dsa_register_switch+0xaf0/0xcc0 [] ar9331_sw_probe+0x370/0x388 [] mdio_probe+0x44/0x70 [] really_probe+0x200/0x424 [] __driver_probe_device+0x290/0x298 [] driver_probe_device+0x54/0xe4 [] __device_attach_driver+0xe4/0x130 [] bus_for_each_drv+0xb4/0xd8 [] __device_attach+0x104/0x1a4 [] bus_probe_device+0x48/0xc4 [] deferred_probe_work_func+0xf0/0x10c [] process_one_work+0x314/0x4d4 [] worker_thread+0x2a4/0x354 [] kthread+0x134/0x13c [] ret_from_kernel_thread+0x14/0x1c Same Issue would affect some other PHYs (QCA8081, QCA9561), so fix it too.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2022-49692 since 02/26/2025. The exploitability is told to be difficult. Technical details are known, but no exploit is available.

Upgrading to version 5.18.8 eliminates this vulnerability. Applying the patch 66fa352215e8455ba2e5f33793535795bd3e36ca/9926de7315be3d606cc011a305ad9adb9e8e14c9 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.18.0
• 5.18.1
• 5.18.2
• 5.18.3
• 5.18.4
• 5.18.5
• 5.18.6
• 5.18.7

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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