[PATCH] libfdt: Handle failed get_name() on BEGIN_NODE

[PATCH] libfdt: Handle failed get_name() on BEGIN_NODE

[Pierre-Clément Tosi]

Validate the return value of fdt_get_name() as an ill-formed DT, causing
it to fail, could result in fdt_check_full() dereferencing NULL.

fixes: a2def5479950 ("libfdt: Check that the root-node name is empty")
Signed-off-by: Pierre-Clément Tosi <ptosi-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
---
 libfdt/fdt_check.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libfdt/fdt_check.c b/libfdt/fdt_check.c
index fa410a8..71390ee 100644
--- a/libfdt/fdt_check.c
+++ b/libfdt/fdt_check.c
@@ -66,7 +66,7 @@ int fdt_check_full(const void *fdt, size_t bufsize)
 				int len;
 
 				name = fdt_get_name(fdt, offset, &len);
-				if (*name || len)
+				if (!name || *name || len)
 					return -FDT_ERR_BADSTRUCTURE;
 			}
 			break;
-- 
2.37.0.170.g444d1eabd0-goog

Re: [PATCH] libfdt: Handle failed get_name() on BEGIN_NODE

[David Gibson]

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On Thu, Jul 14, 2022 at 09:38:48AM +0100, Pierre-Clément Tosi wrote:
> Validate the return value of fdt_get_name() as an ill-formed DT, causing
> it to fail, could result in fdt_check_full() dereferencing NULL.
> 
> fixes: a2def5479950 ("libfdt: Check that the root-node name is empty")
> Signed-off-by: Pierre-Clément Tosi <ptosi-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>

Applied, thanks.  Sorry it took me so long to look at this.

> ---
>  libfdt/fdt_check.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/libfdt/fdt_check.c b/libfdt/fdt_check.c
> index fa410a8..71390ee 100644
> --- a/libfdt/fdt_check.c
> +++ b/libfdt/fdt_check.c
> @@ -66,7 +66,7 @@ int fdt_check_full(const void *fdt, size_t bufsize)
>  				int len;
>  
>  				name = fdt_get_name(fdt, offset, &len);
> -				if (*name || len)
> +				if (!name || *name || len)
>  					return -FDT_ERR_BADSTRUCTURE;
>  			}
>  			break;

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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