CVE-2022-48985

Summary

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

net: mana: Fix race on per-CQ variable napi work_done

After calling napi_complete_done(), the NAPIF_STATE_SCHED bit may be cleared, and another CPU can start napi thread and access per-CQ variable, cq->work_done. If the other thread (for example, from busy_poll) sets it to a value >= budget, this thread will continue to run when it should stop, and cause memory corruption and panic.

To fix this issue, save the per-CQ work_done variable in a local variable before napi_complete_done(), so it won't be corrupted by a possible concurrent thread after napi_complete_done().

Also, add a flag bit to advertise to the NIC firmware: the NAPI work_done variable race is fixed, so the driver is able to reliably support features like busy_poll.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxe1b5683ff62e7b328317aec08869495992053e9d < fe50a9bbeb1f042e756c5cfa7708112c944368deaffected
LinuxLinuxe1b5683ff62e7b328317aec08869495992053e9d < 6740d8572ccd1bca50d8a1ca2bedc333f50ed5f3affected
LinuxLinuxe1b5683ff62e7b328317aec08869495992053e9d < 18010ff776fa42340efc428b3ea6d19b3e7c7b21affected
LinuxLinux5.15affected
LinuxLinux0 < 5.15unaffected
LinuxLinux5.15.83 <= 5.15.*unaffected
LinuxLinux6.0.13 <= 6.0.*unaffected
LinuxLinux6.1 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

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

References