Updated: 2026-02-27 03:49:12.095828
Description:
In the Linux kernel, the following vulnerability has been resolved: perf: Fix sample vs do_exit() Baisheng Gao reported an ARM64 crash, which Mark decoded as being a synchronous external abort -- most likely due to trying to access MMIO in bad ways. The crash further shows perf trying to do a user stack sample while in exit_mmap()'s tlb_finish_mmu() -- i.e. while tearing down the address space it is trying to access. It turns out that we stop perf after we tear down the userspace mm; a receipie for disaster, since perf likes to access userspace for various reasons. Flip this order by moving up where we stop perf in do_exit(). Additionally, harden PERF_SAMPLE_CALLCHAIN and PERF_SAMPLE_STACK_USER to abort when the current task does not have an mm (exit_mm() makes sure to set current->mm = NULL; before commencing with the actual teardown). Such that CPU wide events don't trip on this same problem.
| Links | NIST | CIRCL | RHEL | Ubuntu |
| Severity | Score | |
|---|---|---|
| CVSS Version 2.x | 0.0 | |
| CVSS Version 3.x | MEDIUM | 5.5 |
| OS name | Project name | Version | Score | Severity | Status | Errata | Last updated | Statement |
|---|---|---|---|---|---|---|---|---|
| Ubuntu 16.04 ELS | linux-hwe | 4.15.0 | 5.5 | MEDIUM | Ignored | 2026-01-17 01:18:48 | This flaw is a local-only availability issue in the kernel’s perf subsystem that can panic a host ... | |
| Ubuntu 16.04 ELS | linux | 4.4.0 | 5.5 | MEDIUM | Ignored | 2026-01-17 01:14:01 | This flaw is a local-only availability issue in the kernel’s perf subsystem that can panic a host ... | |
| Ubuntu 18.04 ELS | linux | 4.15.0 | 5.5 | MEDIUM | Ignored | 2026-01-17 01:14:02 | This flaw is a local-only availability issue in the kernel’s perf subsystem that can panic a host ... | |
| Ubuntu 20.04 ELS | linux | 5.4.0 | 5.5 | MEDIUM | Ignored | 2026-01-17 01:14:01 | This flaw is a local-only availability issue in the kernel’s perf subsystem that can panic a host ... |