Bug 2536454 (CVE-2026-93074) - CVE-2026-93074 kernel: dax/fsdev: use __va(phys) for kaddr in direct_access
Summary: CVE-2026-93074 kernel: dax/fsdev: use __va(phys) for kaddr in direct_access
Keywords:
Status: NEW
Alias: CVE-2026-93074
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-17 17:59 UTC by OSIDB Bzimport
Modified: 2026-10-20 11:32 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
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Description OSIDB Bzimport 2026-09-17 17:59:54 UTC
In the Linux kernel, the following vulnerability has been resolved:

dax/fsdev: use __va(phys) for kaddr in direct_access

Use __va(phys) instead of virt_addr + linear_offset for the kaddr
return in __fsdev_dax_direct_access(). The previous code added a
device-linear byte offset to virt_addr (which is __va of ranges[0]),
but for multi-range devices with physical gaps between ranges, this
linear arithmetic crosses the gap and produces a wrong kernel virtual
address. Using __va(phys) where phys comes from dax_pgoff_to_phys()
is correct for any range layout because the direct map translates
each physical address independently.

This leaves dev_dax->virt_addr write-only, so remove the field
(suggested by Dave Jiang).


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