Bug 1227093 (CVE-2024-39461)

Summary: VUL-0: CVE-2024-39461: kernel: clk: bcm: rpi: Assign ->num before accessing ->hws
Product: [Novell Products] SUSE Security Incidents Reporter: SMASH SMASH <smash_bz>
Component: IncidentsAssignee: Security Team bot <security-team>
Status: RESOLVED INVALID QA Contact: Security Team bot <security-team>
Severity: Normal    
Priority: P3 - Medium CC: carlos.lopez, ivan.ivanov
Version: unspecified   
Target Milestone: ---   
Hardware: Other   
OS: Other   
URL: https://smash.suse.de/issue/412095/
Whiteboard: CVSSv3.1:SUSE:CVE-2024-39461:5.5:(AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
Found By: Security Response Team Services Priority:
Business Priority: Blocker: ---
Marketing QA Status: --- IT Deployment: ---

Description SMASH SMASH 2024-06-26 14:24:25 UTC
In the Linux kernel, the following vulnerability has been resolved:

clk: bcm: rpi: Assign ->num before accessing ->hws

Commit f316cdff8d67 ("clk: Annotate struct clk_hw_onecell_data with
__counted_by") annotated the hws member of 'struct clk_hw_onecell_data'
with __counted_by, which informs the bounds sanitizer about the number
of elements in hws, so that it can warn when hws is accessed out of
bounds. As noted in that change, the __counted_by member must be
initialized with the number of elements before the first array access
happens, otherwise there will be a warning from each access prior to the
initialization because the number of elements is zero. This occurs in
raspberrypi_discover_clocks() due to ->num being assigned after ->hws
has been accessed:

  UBSAN: array-index-out-of-bounds in drivers/clk/bcm/clk-raspberrypi.c:374:4
  index 3 is out of range for type 'struct clk_hw *[] __counted_by(num)' (aka 'struct clk_hw *[]')

Move the ->num initialization to before the first access of ->hws, which
clears up the warning.

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-39461
https://www.cve.org/CVERecord?id=CVE-2024-39461
https://git.kernel.org/stable/c/6dc445c1905096b2ed4db1a84570375b4e00cc0f
https://git.kernel.org/stable/c/9562dbe5cdbb16ac887d27ef6f179980bb99193c
https://git.kernel.org/stable/c/cdf9c7871d58d3df59d2775982e3533adb8ec920
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2024/CVE-2024-39461.mbox
https://bugzilla.redhat.com/show_bug.cgi?id=2294293
Comment 2 Ivan Ivanov 2024-06-27 08:17:46 UTC
I think we can safely ignore this "CVE" report as invalid.
We don't use UBSAN and this just silence UBSAN warning no,
functional changes. Back to security team.
Comment 3 Carlos López 2024-06-27 08:19:52 UTC
Nothing to do, closing.