IT

Tracker / CVE-2021-47276

CVE-2021-47276

Medium 5.5

In the Linux kernel, the following vulnerability has been resolved: ftrace: Do not blindly read the ip address in ftrace_bug() It was reported that a bug on arm64 caused a bad ip address to be used for updating into a nop in ftrace_init(), but the error path (rightfully) returned -EINVAL and not -EFAULT, as the bug caused more than one error to occur. But because -EINVAL was returned, the ftrace_bug() tried to report what was at the location of the ip address, and read it directly. This caused the machine to panic, as the ip was not pointing to a valid memory address. Instead, read the ip address with copy_from_kernel_nofault() to safely access the memory, and if it faults, report that the address faulted, otherwise report what was in that location.

Affected products and versions

linux linux_kernel
linux linux_kernel · 2.6.28 → 4.4.273
linux linux_kernel · 4.10 → 4.14.237
linux linux_kernel · 4.15 → 4.19.195
linux linux_kernel · 4.20 → 5.4.126
linux linux_kernel · 4.5 → 4.9.273
linux linux_kernel · 5.11 → 5.12.11
linux linux_kernel · 5.5 → 5.10.44

Analysis

This page is not indexable yet.Until it carries original analysis — what it actually exposes, how to check in two minutes whether a system was touched, what to do if it was — the page stays noindex. The database decides that, not the template.

References