2023-04-11 11:16:29

by Jiaxun Yang

Subject: [PATCH] MIPS: fw: Allow firmware to pass a empty env

fw_getenv will use env entry to determine style of env,
however it is legal for firmware to just pass a empty list.

Check if first entry exist before running strchr to avoid
null pointer dereference.

Cc: [email protected]
Link: https://github.com/clbr/n64bootloader/issues/5
Signed-off-by: Jiaxun Yang <[email protected]>
---
Note: Fixes tag is intentionally omitted for this patch, although
the booting issue only comes in 6.1, the logic issue is been since very start.
---
arch/mips/fw/lib/cmdline.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/fw/lib/cmdline.c b/arch/mips/fw/lib/cmdline.c
index f24cbb4a39b5..892765b742bb 100644
--- a/arch/mips/fw/lib/cmdline.c
+++ b/arch/mips/fw/lib/cmdline.c
@@ -53,7 +53,7 @@ char *fw_getenv(char *envname)
{
char *result = NULL;

- if (_fw_envp != NULL) {
+ if (_fw_envp != NULL && fw_envp(0) != NULL) {
/*
* Return a pointer to the given environment variable.
* YAMON uses "name", "value" pairs, while U-Boot uses
--
2.39.2 (Apple Git-143)

2023-04-12 13:40:25

by Thomas Bogendoerfer

Subject: Re: [PATCH] MIPS: fw: Allow firmware to pass a empty env

On Tue, Apr 11, 2023 at 12:14:26PM +0100, Jiaxun Yang wrote:
> fw_getenv will use env entry to determine style of env,
> however it is legal for firmware to just pass a empty list.
>
> Check if first entry exist before running strchr to avoid
> null pointer dereference.
>
> Cc: [email protected]
> Link: https://github.com/clbr/n64bootloader/issues/5
> Signed-off-by: Jiaxun Yang <[email protected]>
> ---
> Note: Fixes tag is intentionally omitted for this patch, although
> the booting issue only comes in 6.1, the logic issue is been since very start.
> ---
> arch/mips/fw/lib/cmdline.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/mips/fw/lib/cmdline.c b/arch/mips/fw/lib/cmdline.c
> index f24cbb4a39b5..892765b742bb 100644
> --- a/arch/mips/fw/lib/cmdline.c
> +++ b/arch/mips/fw/lib/cmdline.c
> @@ -53,7 +53,7 @@ char *fw_getenv(char *envname)
> {
> char *result = NULL;
>
> - if (_fw_envp != NULL) {
> + if (_fw_envp != NULL && fw_envp(0) != NULL) {
> /*
> * Return a pointer to the given environment variable.
> * YAMON uses "name", "value" pairs, while U-Boot uses
> --
> 2.39.2 (Apple Git-143)

applied to mips-next.

Thomas.

--
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea. [ RFC1925, 2.3 ]