Merge tag 'pstore-v4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull pstore fix from Kees Cook:
 "Marta noticed another misbehavior in EFI pstore, which this fixes.

  Hopefully this is the last of the v4.12 fixes for pstore!"

* tag 'pstore-v4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  efi-pstore: Fix write/erase id tracking

1 files changed, 11 insertions, 6 deletions

diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
index ab3a951a17e6..ef1fafdad400 100644
--- a/drivers/firmware/efi/efi-pstore.c
+++ b/drivers/firmware/efi/efi-pstore.c
@@ -53,6 +53,7 @@ static int efi_pstore_read_func(struct efivar_entry *entry,
         if (sscanf(name, "dump-type%u-%u-%d-%lu-%c",
                    &record->type, &part, &cnt, &time, &data_type) == 5) {
                 record->id = generic_id(time, part, cnt);
+                record->part = part;
                 record->count = cnt;
                 record->time.tv_sec = time;
                 record->time.tv_nsec = 0;
@@ -64,6 +65,7 @@ static int efi_pstore_read_func(struct efivar_entry *entry,
         } else if (sscanf(name, "dump-type%u-%u-%d-%lu",
                    &record->type, &part, &cnt, &time) == 4) {
                 record->id = generic_id(time, part, cnt);
+                record->part = part;
                 record->count = cnt;
                 record->time.tv_sec = time;
                 record->time.tv_nsec = 0;
@@ -77,6 +79,7 @@ static int efi_pstore_read_func(struct efivar_entry *entry,
                  * multiple logs, remains.
                  */
                 record->id = generic_id(time, part, 0);
+                record->part = part;
                 record->count = 0;
                 record->time.tv_sec = time;
                 record->time.tv_nsec = 0;
@@ -241,9 +244,15 @@ static int efi_pstore_write(struct pstore_record *record)
         efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
         int i, ret = 0;
 
+        record->time.tv_sec = get_seconds();
+        record->time.tv_nsec = 0;
+
+        record->id = generic_id(record->time.tv_sec, record->part,
+                                record->count);
+
         snprintf(name, sizeof(name), "dump-type%u-%u-%d-%lu-%c",
                  record->type, record->part, record->count,
-                 get_seconds(), record->compressed ? 'C' : 'D');
+                 record->time.tv_sec, record->compressed ? 'C' : 'D');
 
         for (i = 0; i < DUMP_NAME_LEN; i++)
                 efi_name[i] = name[i];
@@ -255,7 +264,6 @@ static int efi_pstore_write(struct pstore_record *record)
         if (record->reason == KMSG_DUMP_OOPS)
                 efivar_run_worker();
 
-        record->id = record->part;
         return ret;
 };
 
@@ -287,7 +295,7 @@ static int efi_pstore_erase_func(struct efivar_entry *entry, void *data)
                  * holding multiple logs, remains.
                  */
                 snprintf(name_old, sizeof(name_old), "dump-type%u-%u-%lu",
-                        ed->record->type, (unsigned int)ed->record->id,
+                        ed->record->type, ed->record->part,
                         ed->record->time.tv_sec);
 
                 for (i = 0; i < DUMP_NAME_LEN; i++)
@@ -320,10 +328,7 @@ static int efi_pstore_erase(struct pstore_record *record)
         char name[DUMP_NAME_LEN];
         efi_char16_t efi_name[DUMP_NAME_LEN];
         int found, i;
-        unsigned int part;
 
-        do_div(record->id, 1000);
-        part = do_div(record->id, 100);
         snprintf(name, sizeof(name), "dump-type%u-%u-%d-%lu",
                  record->type, record->part, record->count,
                  record->time.tv_sec);