From: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
To: Marc Zyngier <maz@kernel.org>,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Cc: Lee Jones <lee.jones@linaro.org>, Suman Anna <s-anna@ti.com>,
kernel-team@android.com, Arnd Bergmann <arnd@arndb.de>
Subject: Re: [PATCH] mfd: syscon: Don't free allocated name for regmap_config
Date: Tue, 16 Feb 2021 08:34:50 +0200 [thread overview]
Message-ID: <d35d3960-c2a6-491d-fd1a-cf3aa95ce109@ideasonboard.com> (raw)
In-Reply-To: <20200903160237.932818-1-maz@kernel.org>
Hi Marc,
On 03/09/2020 19:02, Marc Zyngier wrote:
> 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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next prev parent reply other threads:[~2021-02-16 6:36 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-03 16:02 [PATCH] mfd: syscon: Don't free allocated name for regmap_config Marc Zyngier
2020-09-08 8:22 ` Lee Jones
2020-09-24 12:39 ` Lee Jones
2020-09-26 0:28 ` Suman Anna
2020-09-28 9:19 ` Lee Jones
2021-02-16 6:34 ` Tomi Valkeinen [this message]
2021-02-16 8:42 ` Marc Zyngier
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