From: Ard Biesheuvel ardb@kernel.org
commit f11a74b45d330ad1ab986852b099747161052526 upstream.
Commit 8a254d90a775 ("efi: efivars: Fix variable writes without query_variable_store()") addressed an issue that was introduced during the EFI variable store refactor, where alternative implementations of the efivars layer that lacked query_variable_store() would no longer work.
Unfortunately, there is another case to consider here, which was missed: if the efivars layer is backed by the EFI runtime services as usual, but the EFI implementation predates the introduction of QueryVariableInfo(), we will return EFI_UNSUPPORTED, and this is no longer being dealt with correctly.
So let's fix this, and while at it, clean up the code a bit, by merging the check_var_size() routines as well as their callers.
Cc: stable@vger.kernel.org # v6.0 Fixes: bbc6d2c6ef22 ("efi: vars: Switch to new wrapper layer") Signed-off-by: Ard Biesheuvel ardb@kernel.org Tested-by: Aditya Garg gargaditya08@live.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/firmware/efi/vars.c | 68 +++++++++++-------------------------- 1 file changed, 20 insertions(+), 48 deletions(-)
diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c index 433b61587139..0ba9f18312f5 100644 --- a/drivers/firmware/efi/vars.c +++ b/drivers/firmware/efi/vars.c @@ -21,29 +21,22 @@ static struct efivars *__efivars;
static DEFINE_SEMAPHORE(efivars_lock);
-static efi_status_t check_var_size(u32 attributes, unsigned long size) -{ - const struct efivar_operations *fops; - - fops = __efivars->ops; - - if (!fops->query_variable_store) - return (size <= SZ_64K) ? EFI_SUCCESS : EFI_OUT_OF_RESOURCES; - - return fops->query_variable_store(attributes, size, false); -} - -static -efi_status_t check_var_size_nonblocking(u32 attributes, unsigned long size) +static efi_status_t check_var_size(bool nonblocking, u32 attributes, + unsigned long size) { const struct efivar_operations *fops; + efi_status_t status;
fops = __efivars->ops;
if (!fops->query_variable_store) + status = EFI_UNSUPPORTED; + else + status = fops->query_variable_store(attributes, size, + nonblocking); + if (status == EFI_UNSUPPORTED) return (size <= SZ_64K) ? EFI_SUCCESS : EFI_OUT_OF_RESOURCES; - - return fops->query_variable_store(attributes, size, true); + return status; }
/** @@ -195,26 +188,6 @@ efi_status_t efivar_get_next_variable(unsigned long *name_size, } EXPORT_SYMBOL_NS_GPL(efivar_get_next_variable, EFIVAR);
-/* - * efivar_set_variable_blocking() - local helper function for set_variable - * - * Must be called with efivars_lock held. - */ -static efi_status_t -efivar_set_variable_blocking(efi_char16_t *name, efi_guid_t *vendor, - u32 attr, unsigned long data_size, void *data) -{ - efi_status_t status; - - if (data_size > 0) { - status = check_var_size(attr, data_size + - ucs2_strsize(name, 1024)); - if (status != EFI_SUCCESS) - return status; - } - return __efivars->ops->set_variable(name, vendor, attr, data_size, data); -} - /* * efivar_set_variable_locked() - set a variable identified by name/vendor * @@ -228,23 +201,21 @@ efi_status_t efivar_set_variable_locked(efi_char16_t *name, efi_guid_t *vendor, efi_set_variable_t *setvar; efi_status_t status;
- if (!nonblocking) - return efivar_set_variable_blocking(name, vendor, attr, - data_size, data); + if (data_size > 0) { + status = check_var_size(nonblocking, attr, + data_size + ucs2_strsize(name, 1024)); + if (status != EFI_SUCCESS) + return status; + }
/* * If no _nonblocking variant exists, the ordinary one * is assumed to be non-blocking. */ - setvar = __efivars->ops->set_variable_nonblocking ?: - __efivars->ops->set_variable; + setvar = __efivars->ops->set_variable_nonblocking; + if (!setvar || !nonblocking) + setvar = __efivars->ops->set_variable;
- if (data_size > 0) { - status = check_var_size_nonblocking(attr, data_size + - ucs2_strsize(name, 1024)); - if (status != EFI_SUCCESS) - return status; - } return setvar(name, vendor, attr, data_size, data); } EXPORT_SYMBOL_NS_GPL(efivar_set_variable_locked, EFIVAR); @@ -264,7 +235,8 @@ efi_status_t efivar_set_variable(efi_char16_t *name, efi_guid_t *vendor, if (efivar_lock()) return EFI_ABORTED;
- status = efivar_set_variable_blocking(name, vendor, attr, data_size, data); + status = efivar_set_variable_locked(name, vendor, attr, data_size, + data, false); efivar_unlock(); return status; }