[PATCH] efi_loader: efi_allocate_pages: check parameter pages

[Heinrich Schuchardt]

On 2/16/23 11:53, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan at nxp.com>
>
> On i.MX8MM-EVK, when doing UEFI Capsule On Disk, we met such issue,
> It will create Boot option for capsule on disk:
> Boot0000: VenHw(E61D73B9-A384-4ACC-AEAB-82E828F3628B)/eMMC(0x2)/eMMC(0x1)/HD(1,GPT,F5CC8412-CD9F-4C9E-A782-0E945461E89E,0x800,0x32000)
> But when capsule update finished, the updated image booting will trigger:
> Loading Boot0000 'UEFI Capsule On Disk' failed
> EFI boot manager: Cannot load any image
> Found EFI removable media binary efi/boot/bootaa64.efi
> "Synchronous Abort" handler, esr 0x96000004
> elr: 000000004029f40c lr : 00000000402802f0 (reloc)
> elr: 00000000bcd8b40c lr : 00000000bcd6c2f0
> x0 : 02029ee86154940e x1 : 00000000bcd95458
> x2 : 0000000000000010 x3 : 00000000bad31ad0
> x4 : 0000000000000000 x5 : 02029ee86154940e
> x6 : 0000000007f00000 x7 : 0000000000000007
> x8 : 0000000000000009 x9 : 0000000000000008
> x10: 0000000000000035 x11: 0000000000000010
> x12: 0000000000000022 x13: 0000000000000001
> x14: 00000000bacdedf0 x15: 0000000000000021
> x16: 00000000bcd304d0 x17: 00000000000041a0
> x18: 00000000bacebdb0 x19: 00000000b9c9f040
> x20: 00000000bccecb28 x21: 00000000bcd95458
> x22: 0000000000000001 x23: 00000000bad1f010
> x24: 00000000bcdced70 x25: 0000000000001000
> x26: 00000000b9c9e000 x27: 0000000040000000
> x28: 0000000000000001 x29: 00000000bacdd030
>
> If is the pages is 0, the efi_find_free_memory will return the next used
> memory, check the parameter pages, and return EFI_INVALID_PARAMETER if it
> is 0.
>
> Reviewed-by: Ye Li <ye.li at nxp.com>
> Reported-by: Vincent Stehlé <vincent.stehle at arm.com>
> Signed-off-by: Peng Fan <peng.fan at nxp.com>
> ---
>   lib/efi_loader/efi_memory.c | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
> index b7bee98f79c..acca542033d 100644
> --- a/lib/efi_loader/efi_memory.c
> +++ b/lib/efi_loader/efi_memory.c
> @@ -495,6 +495,9 @@ efi_status_t efi_allocate_pages(enum efi_allocate_type type,
>   	if (!memory)
>   		return EFI_INVALID_PARAMETER;
>
> +	if (!pages)
> +		return EFI_INVALID_PARAMETER;
> +

Looking at the UEFI specification this looks wrong. The EFI
specification does not forbid calling AllocatePages() with pages == 0.
So we should return EFI_SUCCESS.

EDK II returns EFI_NOT_FOUND for pages == 0. But this has no basis in
the specification.

Which function is the caller invoking AllocatePages() with pages = 0.
Where is the patch to fix it?

Best regards

Heinrich

>   	switch (type) {
>   	case EFI_ALLOCATE_ANY_PAGES:
>   		/* Any page */