Re: [PATCH v4] mtd: rawnand: meson: initialize struct with zeroes

From: Miquel Raynal
Date: Tue Mar 07 2023 - 14:35:05 EST


On Mon, 2023-02-27 at 10:24:25 UTC, Arseniy Krasnov wrote:
> This structure must be zeroed, because it's field 'hw->core' is used as
> 'parent' in 'clk_core_fill_parent_index()', but it will be uninitialized.
> This happens, because when this struct is not zeroed, pointer 'hw' is
> "initialized" by garbage, which is valid pointer, but points to some
> garbage. So 'hw' will be dereferenced, but 'core' contains some random
> data which will be interpreted as a pointer. The following backtrace is
> result of dereference of such pointer:
>
> [ 1.081319] __clk_register+0x414/0x820
> [ 1.085113] devm_clk_register+0x64/0xd0
> [ 1.088995] meson_nfc_probe+0x258/0x6ec
> [ 1.092875] platform_probe+0x70/0xf0
> [ 1.096498] really_probe+0xc8/0x3e0
> [ 1.100034] __driver_probe_device+0x84/0x190
> [ 1.104346] driver_probe_device+0x44/0x120
> [ 1.108487] __driver_attach+0xb4/0x220
> [ 1.112282] bus_for_each_dev+0x78/0xd0
> [ 1.116077] driver_attach+0x2c/0x40
> [ 1.119613] bus_add_driver+0x184/0x240
> [ 1.123408] driver_register+0x80/0x140
> [ 1.127203] __platform_driver_register+0x30/0x40
> [ 1.131860] meson_nfc_driver_init+0x24/0x30
>
> Changelog:
> v1 -> v2:
> * More details in the commit message.
> v2 -> v3:
> * Add 'a' article to "interpreted as a pointer".
> v3 -> v4:
> * Add changelog.
>
> Fixes: 1e4d3ba66888 ("mtd: rawnand: meson: fix the clock")
> Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
> Acked-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
> Reviewed-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>

Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git mtd/fixes, thanks.

Miquel