CVE-2024-58084

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

firmware: qcom: scm: Fix missing read barrier in qcom_scm_get_tzmem_pool()

Commit 2e4955167ec5 ("firmware: qcom: scm: Fix __scm and waitq completion variable initialization") introduced a write barrier in probe function to store global '__scm' variable. We all known barriers are paired (see memory-barriers.txt: "Note that write barriers should normally be paired with read or address-dependency barriers"), therefore accessing it from concurrent contexts requires read barrier. Previous commit added such barrier in qcom_scm_is_available(), so let's use that directly.

Lack of this read barrier can result in fetching stale '__scm' variable value, NULL, and dereferencing it.

Note that barrier in qcom_scm_is_available() satisfies here the control dependency.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.