6.14-stable review patch. If anyone has any objections, please let me know.
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From: Eder Zulian ezulian@redhat.com
[ Upstream commit ba09916efb29f80e438a54e634970209ce12750f ]
Add a consistency check to avoid assigning an invalid value to max_register due to a possible DT misconfiguration.
Suggested-by: Mark Langsdorf mlangsdo@redhat.com Signed-off-by: Eder Zulian ezulian@redhat.com Link: https://lore.kernel.org/r/20250212184524.585882-1-ezulian@redhat.com Signed-off-by: Lee Jones lee@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/mfd/syscon.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c index aa4a9940b569a..ae71a2710bed8 100644 --- a/drivers/mfd/syscon.c +++ b/drivers/mfd/syscon.c @@ -47,6 +47,7 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_res) struct regmap_config syscon_config = syscon_regmap_config; struct resource res; struct reset_control *reset; + resource_size_t res_size;
WARN_ON(!mutex_is_locked(&syscon_list_lock));
@@ -96,6 +97,12 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_res) } }
+ res_size = resource_size(&res); + if (res_size < reg_io_width) { + ret = -EFAULT; + goto err_regmap; + } + syscon_config.name = kasprintf(GFP_KERNEL, "%pOFn@%pa", np, &res.start); if (!syscon_config.name) { ret = -ENOMEM; @@ -103,7 +110,7 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_res) } syscon_config.reg_stride = reg_io_width; syscon_config.val_bits = reg_io_width * 8; - syscon_config.max_register = resource_size(&res) - reg_io_width; + syscon_config.max_register = res_size - reg_io_width; if (!syscon_config.max_register) syscon_config.max_register_is_0 = true;