Bug 2320691 (CVE-2022-48985) - CVE-2022-48985 kernel: net: mana: Fix race on per-CQ variable napi work_done
Summary: CVE-2022-48985 kernel: net: mana: Fix race on per-CQ variable napi work_done
Keywords:
Status: NEW
Alias: CVE-2022-48985
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2024-10-21 21:03 UTC by OSIDB Bzimport
Modified: 2024-11-07 15:18 UTC (History)
4 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


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Description OSIDB Bzimport 2024-10-21 21:03:07 UTC
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.

Comment 1 Avinash Hanwate 2024-10-22 07:56:02 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024102147-CVE-2022-48985-40b5@gregkh/T


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