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 | 3 +++ grub-core/kern/command.c | 3 +++ 2 files changed, 6 insertions(+) diff --git a/grub-core/commands/extcmd.c b/grub-core/commands/extcmd.c index c236be13a..7f8cb3f67 100644 --- a/grub-core/commands/extcmd.c +++ b/grub-core/commands/extcmd.c @@ -139,6 +139,9 @@ grub_register_extcmd_lockdown (const char *name, grub_extcmd_func_t func, void grub_unregister_extcmd (grub_extcmd_t ext) { + if (ext == NULL) + return; + grub_unregister_command (ext->cmd); grub_free (ext); } diff --git a/grub-core/kern/command.c b/grub-core/kern/command.c index 5812e131c..a1b4c81a9 100644 --- a/grub-core/kern/command.c +++ b/grub-core/kern/command.c @@ -104,6 +104,9 @@ grub_register_command_lockdown (const char *name, void grub_unregister_command (grub_command_t cmd) { + if (cmd == NULL) + return; + if ((cmd->prio & GRUB_COMMAND_FLAG_ACTIVE) && (cmd->next)) cmd->next->prio |= GRUB_COMMAND_FLAG_ACTIVE; grub_list_remove (GRUB_AS_LIST (cmd)); -- 2.51.0 _______________________________________________ Grub-devel mailing list [email protected] https://lists.gnu.org/mailman/listinfo/grub-devel
