CVE-2024-56617 Affecting kernel-zfcpdump-modules package, versions *


Severity

Recommended
low

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.05% (18th percentile)

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  • Snyk IDSNYK-RHEL8-KERNELZFCPDUMPMODULES-8585106
  • published31 Dec 2024
  • disclosed27 Dec 2024

Introduced: 27 Dec 2024

NewCVE-2024-56617  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:8 kernel-zfcpdump-modules.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-zfcpdump-modules package and not the kernel-zfcpdump-modules package as distributed by RHEL. See How to fix? for RHEL:8 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

cacheinfo: Allocate memory during CPU hotplug if not done from the primary CPU

Commit

5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU")

adds functionality that architectures can use to optionally allocate and build cacheinfo early during boot. Commit

6539cffa9495 ("cacheinfo: Add arch specific early level initializer")

lets secondary CPUs correct (and reallocate memory) cacheinfo data if needed.

If the early build functionality is not used and cacheinfo does not need correction, memory for cacheinfo is never allocated. x86 does not use the early build functionality. Consequently, during the cacheinfo CPU hotplug callback, last_level_cache_is_valid() attempts to dereference a NULL pointer:

BUG: kernel NULL pointer dereference, address: 0000000000000100 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not present page PGD 0 P4D 0 Oops: 0000 [#1] PREEPMT SMP NOPTI CPU: 0 PID 19 Comm: cpuhp/0 Not tainted 6.4.0-rc2 #1 RIP: 0010: last_level_cache_is_valid+0x95/0xe0a

Allocate memory for cacheinfo during the cacheinfo CPU hotplug callback if not done earlier.

Moreover, before determining the validity of the last-level cache info, ensure that it has been allocated. Simply checking for non-zero cache_leaves() is not sufficient, as some architectures (e.g., Intel processors) have non-zero cache_leaves() before allocation.

Dereferencing NULL cacheinfo can occur in update_per_cpu_data_slice_size(). This function iterates over all online CPUs. However, a CPU may have come online recently, but its cacheinfo may not have been allocated yet.

While here, remove an unnecessary indentation in allocate_cache_info().

[ bp: Massage. ]

CVSS Scores

version 3.1