Commit 4af9ed57 authored Aug 30, 2016 by Andrzej Hajda Committed by Matt Fleming Sep 05, 2016

efi: Fix handling error value in fdt_find_uefi_params



of_get_flat_dt_subnode_by_name can return negative value in case of error.
Assigning the result to unsigned variable and checking if the variable
is lesser than zero is incorrect and always false.
The patch fixes it by using signed variable to check the result.

The problem has been detected using semantic patch
scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Shawn Lin <shawn.lin@rock-chips.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>

parent d4c4fed0

drivers/firmware/efi/efi.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -657,9 +657,12 @@ static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
		}

		if (subnode) {
		node = of_get_flat_dt_subnode_by_name(node, subnode);
		if (node < 0)
		int err = of_get_flat_dt_subnode_by_name(node, subnode);

		if (err < 0)
		return 0;

		node = err;
		}

		return __find_uefi_params(node, info, dt_params[i].params);