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Commit 65f8a203 authored by Jann Horn's avatar Jann Horn Committed by Greg Kroah-Hartman
Browse files

efivars: Respect "block" flag in efivar_entry_set_safe() 



commit 258dd902022cb10c83671176688074879517fd21 upstream.

When the "block" flag is false, the old code would sometimes still call
check_var_size(), which wrongly tells ->query_variable_store() that it can
block.

As far as I can tell, this can't really materialize as a bug at the moment,
because ->query_variable_store only does something on X86 with generic EFI,
and in that configuration we always take the efivar_entry_set_nonblocking()
path.

Fixes: ca0e30dc ("efi: Add nonblocking option to efi_query_variable_store()")
Signed-off-by: default avatarJann Horn <jannh@google.com>
Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220218180559.1432559-1-jannh@google.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent b838add9

drivers/firmware/efi/vars.c

+4 −1
Original line number Diff line number Diff line
@@ -763,6 +763,7 @@ int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes, 
{

	const struct efivar_operations *ops;

	efi_status_t status;

	unsigned long varsize;



	if (!__efivars)

		return -EINVAL;
@@ -785,15 +786,17 @@ int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes, 
		return efivar_entry_set_nonblocking(name, vendor, attributes,

						    size, data);



	varsize = size + ucs2_strsize(name, 1024);

	if (!block) {

		if (down_trylock(&efivars_lock))

			return -EBUSY;

		status = check_var_size_nonblocking(attributes, varsize);

	} else {

		if (down_interruptible(&efivars_lock))

			return -EINTR;

		status = check_var_size(attributes, varsize);

	}



	status = check_var_size(attributes, size + ucs2_strsize(name, 1024));

	if (status != EFI_SUCCESS) {

		up(&efivars_lock);

		return -ENOSPC;