2024-04-23 14:02:38

by Hagar Hemdan

Subject: [PATCH v2] efi: libstub: only free priv.runtime_map when allocated

priv.runtime_map is only allocated when efi_novamap is not set.
Otherwise, it is an uninitialized value.
In the error path, it is freed unconditionally.
Avoid passing an uninitialized value to free_pool.
Free priv.runtime_map only when it was allocated.

This bug was discovered and resolved using Coverity Static Analysis
Security Testing (SAST) by Synopsys, Inc.

Fixes: f80d26043af9 ("efi: libstub: avoid efi_get_memory_map() for allocating the virt map")
Cc: [email protected]
Signed-off-by: Hagar Hemdan <[email protected]>
---
v2: added Cc stable tag to the commit message as requested by kernel
test robot.
---
drivers/firmware/efi/libstub/fdt.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
index 70e9789ff9de..6a337f1f8787 100644
--- a/drivers/firmware/efi/libstub/fdt.c
+++ b/drivers/firmware/efi/libstub/fdt.c
@@ -335,8 +335,8 @@ efi_status_t allocate_new_fdt_and_exit_boot(void *handle,

fail:
efi_free(fdt_size, fdt_addr);
-
- efi_bs_call(free_pool, priv.runtime_map);
+ if (!efi_novamap)
+ efi_bs_call(free_pool, priv.runtime_map);

return EFI_LOAD_ERROR;
}
--
2.40.1

2024-04-29 15:48:28

by Ard Biesheuvel

Subject: Re: [PATCH v2] efi: libstub: only free priv.runtime_map when allocated

On Tue, 23 Apr 2024 at 16:00, Hagar Hemdan <[email protected]> wrote:
>
> priv.runtime_map is only allocated when efi_novamap is not set.
> Otherwise, it is an uninitialized value.
> In the error path, it is freed unconditionally.
> Avoid passing an uninitialized value to free_pool.
> Free priv.runtime_map only when it was allocated.
>
> This bug was discovered and resolved using Coverity Static Analysis
> Security Testing (SAST) by Synopsys, Inc.
>
> Fixes: f80d26043af9 ("efi: libstub: avoid efi_get_memory_map() for allocating the virt map")
> Cc: [email protected]
> Signed-off-by: Hagar Hemdan <[email protected]>
> ---
> v2: added Cc stable tag to the commit message as requested by kernel
> test robot.
> ---
> drivers/firmware/efi/libstub/fdt.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>

Queued up in efi/next, thanks.

> diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
> index 70e9789ff9de..6a337f1f8787 100644
> --- a/drivers/firmware/efi/libstub/fdt.c
> +++ b/drivers/firmware/efi/libstub/fdt.c
> @@ -335,8 +335,8 @@ efi_status_t allocate_new_fdt_and_exit_boot(void *handle,
>
> fail:
> efi_free(fdt_size, fdt_addr);
> -
> - efi_bs_call(free_pool, priv.runtime_map);
> + if (!efi_novamap)
> + efi_bs_call(free_pool, priv.runtime_map);
>
> return EFI_LOAD_ERROR;
> }
> --
> 2.40.1
>