CVE-2025-39715
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.
Does this matter?
Lower severity and a low EPSS score (0.14%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 5.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.14% probability · 4th percentile
- CISA KEV
- Not listed
- Affected
- linux/linux kernel · debian/debian linux
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/8bccf47adbf658293528e86960e6d6f736b1c9f7Patch
- https://git.kernel.org/stable/c/9b6af875baba9c4679b55f4561e201485451305fPatch
- https://git.kernel.org/stable/c/bc0a24c24ceebabb5ba65900e332233d79e625e6Patch
- https://git.kernel.org/stable/c/e8b496c52aa0c6572d88db7cab85aeea6f9c194dPatch
- https://git.kernel.org/stable/c/f6334f4ae9a4e962ba74b026e1d965dfdf8cbef8Patch
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.htmlThird Party Advisory
- https://cert-portal.siemens.com/productcert/html/ssa-032379.html
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.