clk: zynq: handle kasprintf() failure in periph_clk registration

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>
Reviewed-by: Michal Simek <michal.simek@amd.com>
Signed-off-by: Brian Masney <bmasney@redhat.com>
This commit is contained in:
William Theesfeld 2026-06-01 16:35:00 -04:00 • committed by Brian Masney
commit d4d0d335e8