Description
In the Linux kernel, the following vulnerability has been resolved: parisc: Revise gateway LWS calls to probe user read access We use load and stbys,e instructions to trigger memory reference interruptions without writing to memory. Because of the way read access support is implemented, read access interruptions are only triggered at privilege levels 2 and 3. The kernel and gateway page execute at privilege level 0, so this code never triggers a read access interruption. Thus, it is currently possible for user code to execute a LWS compare and swap operation at an address that is read protected at privilege level 3 (PRIV_USER). Fix this by probing read access rights at privilege level 3 and branching to lws_fault if access isn't allowed.
Affected products
linux: linux kernel; debian: debian linux
References7
- git.kernel.org/stable/c/8bccf47adbf658293528e86960e6d6f736b1c9f7 Patch
- git.kernel.org/stable/c/9b6af875baba9c4679b55f4561e201485451305f Patch
- git.kernel.org/stable/c/bc0a24c24ceebabb5ba65900e332233d79e625e6 Patch
- git.kernel.org/stable/c/e8b496c52aa0c6572d88db7cab85aeea6f9c194d Patch
- git.kernel.org/stable/c/f6334f4ae9a4e962ba74b026e1d965dfdf8cbef8 Patch
- lists.debian.org/debian-lts-announce/2025/10/msg00008.html Third Party Advisory
- cert-portal.siemens.com/productcert/html/ssa-032379.html
Metrics
- CVSS 3.1
-
5.5
MEDIUM
Score source: NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 0% percentile: 5 · as of 8 November 2026
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