From: Ard Biesheuvel <ardb@xxxxxxxxxx>
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@xxxxxxxxxxxxxxx> # v6.0
Fixes: bbc6d2c6ef22 ("efi: vars: Switch to new wrapper layer")
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Tested-by: Aditya Garg <gargaditya08@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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;
}
--
2.38.1
