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CVE-2026-89489

openrisc: fix arbitrary kernel memory access via or1k_atomic syscall

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109, and 2 more
None on Exploit-DB, Metasploit or GitHub

Summary

In the Linux kernel, the following vulnerability has been resolved: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [shorne@gmail.com: fix comment style]

Timeline

  1. CVE published
  2. Record last updated

Affected versions

  • Linux Linux

    From 9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a · fixed in bf310718c6fa6adeee06d207a55489546d860e2c; From 9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a · fixed in 497cba0b02e5555d99fe9ee1dc478af743ab7f7a; From 9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a · fixed in 1f2e92e499d863f81df1732af59b4a3559969193; From 9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a · fixed in 574ae2ac2b314aa33498cd2c28add106cbe644f2; From 9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a · fixed in a520e8cac54fb403f3800125b606f55fcad42cb9; From 9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a · fixed in d64a75369cd0f2ee79afcc9d9ca34a3890989379; From 9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a · fixed in b53435c079c78f89f70a62dd5a322cca4e292b34; From 9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a · fixed in 78004e9a87f240df03e2f73120d291763c32e0a7

  • Linux Linux

    3.1

  • KernelLinux

    From 3.1.0 · fixed in 5.10.270; From 5.11.0 · fixed in 5.15.221; From 5.16.0 · fixed in 6.1.188; From 6.2.0 · fixed in 6.6.157; From 6.7.0 · fixed in 6.12.109; From 6.13.0 · fixed in 6.18.50; From 6.19.0 · fixed in 7.2.4

References 8

git.kernel.org