CVE-2024-36962

Summary

In the Linux kernel, the following vulnerability has been resolved:

net: ks8851: Queue RX packets in IRQ handler instead of disabling BHs

Currently the driver uses local_bh_disable()/local_bh_enable() in its IRQ handler to avoid triggering net_rx_action() softirq on exit from netif_rx(). The net_rx_action() could trigger this driver .start_xmit callback, which is protected by the same lock as the IRQ handler, so calling the .start_xmit from netif_rx() from the IRQ handler critical section protected by the lock could lead to an attempt to claim the already claimed lock, and a hang.

The local_bh_disable()/local_bh_enable() approach works only in case the IRQ handler is protected by a spinlock, but does not work if the IRQ handler is protected by mutex, i.e. this works for KS8851 with Parallel bus interface, but not for KS8851 with SPI bus interface.

Remove the BH manipulation and instead of calling netif_rx() inside the IRQ handler code protected by the lock, queue all the received SKBs in the IRQ handler into a queue first, and once the IRQ handler exits the critical section protected by the lock, dequeue all the queued SKBs and push them all into netif_rx(). At this point, it is safe to trigger the net_rx_action() softirq, since the netif_rx() call is outside of the lock that protects the IRQ handler.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux492337a4fbd1421b42df684ee9b34be2a2722540 < 8a3ff43dcbab7c96f9e8cf2bd1049ab8d6e59545affected
LinuxLinuxcba376eb036c2c20077b41d47b317d8218fe754f < ae87f661f3c1a3134a7ed86ab69bf9f12af88993affected
LinuxLinux49d5d70538b6b8f2a3f8f1ac30c1f921d4a0929b < 7e2901a2a9195da76111f351584bf77552a038f0affected
LinuxLinuxbe0384bf599cf1eb8d337517feeb732d71f75a6f < e0863634bf9f7cf36291ebb5bfa2d16632f79c49affected
LinuxLinux6.1.87 < 6.1.91affected
LinuxLinux6.6.28 < 6.6.31affected
LinuxLinux6.8.7 < 6.8.10affected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

CVE Program Container

Additional References

References