> On 8 Sep 2025, at 11:40 PM, Srish Srinivasan <[email protected]> wrote:
>
> Many modules call grub_unregister_{command(), extcmd()} from
> GRUB_MOD_FINI() without checking for a failure in registration.
> This could lead to a NULL pointer dereference in unregistration.
>
> Perform explicit NULL check in both the unregister helpers.
>
> Signed-off-by: Srish Srinivasan <[email protected]>
> ---
> grub-core/commands/extcmd.c | 2 ++
> grub-core/kern/command.c | 2 ++
> 2 files changed, 4 insertions(+)
>
> diff --git a/grub-core/commands/extcmd.c b/grub-core/commands/extcmd.c
> index c236be13a..f142305ed 100644
> --- a/grub-core/commands/extcmd.c
> +++ b/grub-core/commands/extcmd.c
> @@ -139,6 +139,8 @@ grub_register_extcmd_lockdown (const char *name,
> grub_extcmd_func_t func,
> void
> grub_unregister_extcmd (grub_extcmd_t ext)
> {
> + if (!ext)
For pointer, use ext == NULL
> + return;
It would be nice if add empty line here
> grub_unregister_command (ext->cmd);
> grub_free (ext);
> }
> diff --git a/grub-core/kern/command.c b/grub-core/kern/command.c
> index 5812e131c..3ab93ce20 100644
> --- a/grub-core/kern/command.c
> +++ b/grub-core/kern/command.c
> @@ -104,6 +104,8 @@ grub_register_command_lockdown (const char *name,
> void
> grub_unregister_command (grub_command_t cmd)
> {
> + if (!cmd)
For pointer, use cmd == NULL
> + return;
It would be nice if add empty line here
Thanks,
Sudhakar
> if ((cmd->prio & GRUB_COMMAND_FLAG_ACTIVE) && (cmd->next))
> cmd->next->prio |= GRUB_COMMAND_FLAG_ACTIVE;
> grub_list_remove (GRUB_AS_LIST (cmd));
> --
> 2.48.1
>
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