CVE-2024-39462clk: bcm: dvp: Assign ->num before accessing ->hws

Official description

In the Linux kernel, the following vulnerability has been resolved: clk: bcm: dvp: 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 clk_dvp_probe() due to ->num being assigned after ->hws has been accessed: UBSAN: array-index-out-of-bounds in drivers/clk/bcm/clk-bcm2711-dvp.c:59:2 index 0 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.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/0dc913217fb79096597005bba9ba738e2db5cd02
• https://git.kernel.org/stable/c/a1dd92fca0d6b58b55ed0484f75d4205dbb77010
• https://git.kernel.org/stable/c/9368cdf90f52a68120d039887ccff74ff33b4444