RE: [PATCH] aout: incorrct use of strncpy fixed.

[David Laight]

From: Derek Robson
> Sent: 02 February 2019 00:55
> 
> Found a bug with the source / dest length
> updated to have size limit as the size of dest not size or source.
> 
> Signed-off-by: Derek Robson <robsonde@xxxxxxxxx>
> ---
>  arch/x86/ia32/ia32_aout.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/ia32/ia32_aout.c b/arch/x86/ia32/ia32_aout.c
> index f65b78d32f5e..1e7f71723ee0 100644
> --- a/arch/x86/ia32/ia32_aout.c
> +++ b/arch/x86/ia32/ia32_aout.c
> @@ -157,7 +157,7 @@ static int aout_core_dump(struct coredump_params *cprm)
>  	fs = get_fs();
>  	set_fs(KERNEL_DS);
>  	has_dumped = 1;
> -	strncpy(dump.u_comm, current->comm, sizeof(current->comm));
> +	strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));

That can be right if the destination is guaranteed to be longer than
the source and the source might not be '\0' terminated
(and the target has been zeroed).

	David

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