CVE-2022-49692: net: phy: at803x: fix NULL pointer dereference on AR9331 PHY

Severity: medium (CVSS 5.5 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: 2025-02-26 · updated 2026-06-17
Weakness: CWE-476

Description

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: [<8050e8a8>] at803x_config_intr+0x5c/0xd0 [<80504b34>] phy_request_interrupt+0xa8/0xd0 [<8050289c>] phylink_bringup_phy+0x2d8/0x3ac [<80502b68>] phylink_fwnode_phy_connect+0x118/0x130 [<8074d8ec>] dsa_slave_create+0x270/0x420 [<80743b04>] dsa_port_setup+0x12c/0x148 [<8074580c>] dsa_register_switch+0xaf0/0xcc0 [<80511344>] ar9331_sw_probe+0x370/0x388 [<8050cb78>] mdio_probe+0x44/0x70 [<804df300>] really_probe+0x200/0x424 [<804df7b4>] __driver_probe_device+0x290/0x298 [<804df810>] driver_probe_device+0x54/0xe4 [<804dfd50>] __device_attach_driver+0xe4/0x130 [<804dcb00>] bus_for_each_drv+0xb4/0xd8 [<804dfac4>] __device_attach+0x104/0x1a4 [<804ddd24>] bus_probe_device+0x48/0xc4 [<804deb44>] deferred_probe_work_func+0xf0/0x10c [<800a0ffc>] process_one_work+0x314/0x4d4 [<800a17fc>] worker_thread+0x2a4/0x354 [<800a9a54>] kthread+0x134/0x13c [<8006306c>] ret_from_kernel_thread+0x14/0x1c Same Issue would affect some other PHYs (QCA8081, QCA9561), so fix it too.

Affected products

Linux kernel: from 5.18 before 5.18.8; 5.19-rc1, 5.19-rc2, 5.19-rc3 — fixed in 5.18.8

How to fix

Upgrade to a fixed version: Linux kernel 5.18.8. Check the vendor advisory for mitigations.

References

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