efi-pstore: Fix read iter after pstore API refactor

During the internal pstore API refactoring, the EFI vars read entry was
accidentally made to update a stack variable instead of the pstore
private data pointer. This corrects the problem (and removes the now
needless argument).

Fixes: 00e6cd2cd6ef ("pstore: Replace arguments for read() API")
Signed-off-by: Kees Cook <keescook@chromium.org>

diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
index 93d8cdbe7ef49361bd28a49083eb86478e0a0f4f..44148fd4c9f241df67571d1ae10a49a5053605c5 100644 (file)
--- a/drivers/firmware/efi/efi-pstore.c
+++ b/drivers/firmware/efi/efi-pstore.c
@@ -155,19 +155,14 @@ static int efi_pstore_scan_sysfs_exit(struct efivar_entry *pos,
  * efi_pstore_sysfs_entry_iter
  *
  * @record: pstore record to pass to callback
- * @pos: entry to begin iterating from
  *
  * You MUST call efivar_enter_iter_begin() before this function, and
  * efivar_entry_iter_end() afterwards.
  *
- * It is possible to begin iteration from an arbitrary entry within
- * the list by passing @pos. @pos is updated on return to point to
- * the next entry of the last one passed to efi_pstore_read_func().
- * To begin iterating from the beginning of the list @pos must be %NULL.
  */
-static int efi_pstore_sysfs_entry_iter(struct pstore_record *record,
-                                      struct efivar_entry **pos)
+static int efi_pstore_sysfs_entry_iter(struct pstore_record *record)
 {
+       struct efivar_entry **pos = (struct efivar_entry **)&record->psi->data;
        struct efivar_entry *entry, *n;
        struct list_head *head = &efivar_sysfs_list;
        int size = 0;
@@ -218,7 +213,6 @@ static int efi_pstore_sysfs_entry_iter(struct pstore_record *record,
  */
 static ssize_t efi_pstore_read(struct pstore_record *record)
 {
-       struct efivar_entry *entry = (struct efivar_entry *)record->psi->data;
        ssize_t size;
 
        record->buf = kzalloc(EFIVARS_DATA_SIZE_MAX, GFP_KERNEL);
@@ -229,7 +223,7 @@ static ssize_t efi_pstore_read(struct pstore_record *record)
                size = -EINTR;
                goto out;
        }
-       size = efi_pstore_sysfs_entry_iter(record, &entry);
+       size = efi_pstore_sysfs_entry_iter(record);
        efivar_entry_iter_end();
 
 out: