Re: [PATCH] clk: zynq: handle kasprintf() failure in periph_clk registration

[Brian Masney <bmasney@redhat.com>]

On Mon, Jun 01, 2026 at 04:35:00PM -0400, William Theesfeld wrote:
> zynq_clk_register_periph_clk() ignores the return value of the two
> kasprintf() calls used to build the mux and divider clock names, and
> passes the resulting (possibly NULL) pointers straight into
> clk_register_mux(), clk_register_divider() and clk_register_gate() as
> the clock '"'name'"' argument.  On allocation failure that name later
> gets dereferenced by the clock framework (e.g. in debugfs name
> formatting), causing a NULL-pointer dereference.
> 
> Check both kasprintf() returns.  On failure unwind any allocated name
> buffer and the spinlock, then fall through to the existing err label
> which sets clks[] to ERR_PTR(-ENOMEM).  Freeing the spinlock on the
> error path is correct here because no clk_register_*() call has had
> a chance to take ownership of it; the success path intentionally
> hands it off to the registered clocks.
> 
> The neighbouring zynq_clk_register_fclk() in the same file already
> uses this per-allocation goto-label cleanup pattern; this change
> brings periph_clk into line with it.
> 
> Signed-off-by: William Theesfeld <william@theesfeld.net>

Reviewed-by: Brian Masney <bmasney@redhat.com>