dpll: fix xa_alloc_cyclic() error handling

[ Upstream commit 3614bf90130d60f191a5fe218d04f6251c678e13 ]

In case of returning 1 from xa_alloc_cyclic() (wrapping) ERR_PTR(1) will
be returned, which will cause IS_ERR() to be false. Which can lead to
dereference not allocated pointer (pin).

Fix it by checking if err is lower than zero.

This wasn't found in real usecase, only noticed. Credit to Pierre.

Fixes: 97f265ef7f5b ("dpll: allocate pin ids in cycle")
Signed-off-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Reviewed-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/dpll/dpll_core.c b/drivers/dpll/dpll_core.c
index 32019dc33cca7e286550e7314edb119c389bb8d6..1877201d1aa9fef1ec45c524297b70b7ad55563e 100644 (file)
--- a/drivers/dpll/dpll_core.c
+++ b/drivers/dpll/dpll_core.c
@@ -505,7 +505,7 @@ dpll_pin_alloc(u64 clock_id, u32 pin_idx, struct module *module,
        xa_init_flags(&pin->parent_refs, XA_FLAGS_ALLOC);
        ret = xa_alloc_cyclic(&dpll_pin_xa, &pin->id, pin, xa_limit_32b,
                              &dpll_pin_xa_id, GFP_KERNEL);
-       if (ret)
+       if (ret < 0)
                goto err_xa_alloc;
        return pin;
 err_xa_alloc: