Re: [PATCH] mfd: syscon: Don't free allocated name for regmap_config
From: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Date: 2021-02-16 06:35:53
Also in:
lkml
Hi Marc, On 03/09/2020 19:02, Marc Zyngier wrote:
quoted hunk ↗ jump to hunk
The name allocated for the regmap_config structure is freed pretty early, right after the registration of the MMIO region. Unfortunately, that doesn't follow the life cycle that debugfs expects, as it can access the name field long after the free has occured. Move the free on the error path, and keep it forever otherwise. Fixes: e15d7f2b81d2 ("mfd: syscon: Use a unique name with regmap_config") Signed-off-by: Marc Zyngier <maz@kernel.org> --- drivers/mfd/syscon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c index 75859e492984..7a660411c562 100644 --- a/drivers/mfd/syscon.c +++ b/drivers/mfd/syscon.c@@ -108,7 +108,6 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk) syscon_config.max_register = resource_size(&res) - reg_io_width; regmap = regmap_init_mmio(NULL, base, &syscon_config); - kfree(syscon_config.name); if (IS_ERR(regmap)) { pr_err("regmap init failed\n"); ret = PTR_ERR(regmap);@@ -145,6 +144,7 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk) regmap_exit(regmap); err_regmap: iounmap(base); + kfree(syscon_config.name); err_map: kfree(syscon); return ERR_PTR(ret);
This patch causes lots of kmemleak reports, for example:
unreferenced object 0xc8e6f000 (size 64):
comm "kworker/1:1", pid 22, jiffies 4294938454 (age 95.540s)
hex dump (first 32 bytes):
64 73 70 5f 73 79 73 74 65 6d 40 34 30 64 30 30 dsp_system@40d00
30 30 30 00 e0 09 4d c1 ac 1b 4d c1 64 74 4c c1 000...M...M.dtL.
backtrace:
[<(ptrval)>] __kmalloc_track_caller+0x2bc/0x418
[<(ptrval)>] kvasprintf+0x9c/0x124
[<(ptrval)>] kasprintf+0x70/0xac
[<(ptrval)>] of_syscon_register+0x1f0/0x4f0
[<(ptrval)>] device_node_get_regmap+0x12c/0x158
[<(ptrval)>] syscon_regmap_lookup_by_phandle+0x5c/0x6c
[<(ptrval)>] omap_iommu_probe+0x6ac/0xc28
[<(ptrval)>] platform_probe+0x120/0x1e0
[<(ptrval)>] really_probe+0x2b4/0x121c
[<(ptrval)>] driver_probe_device+0x10c/0x4c0
[<(ptrval)>] __device_attach_driver+0x1d8/0x26c
[<(ptrval)>] bus_for_each_drv+0x174/0x200
[<(ptrval)>] __device_attach+0x2f0/0x45c
[<(ptrval)>] device_initial_probe+0x1c/0x20
[<(ptrval)>] bus_probe_device+0x224/0x2b8
[<(ptrval)>] device_add+0xad0/0x1e18
Tomi
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