pstore: fix potential logic issue in pstore read interface
1) in the calling of erst_read, the parameter of buffer size
maybe overflows and cause crash
2) the return value of erst_read should be checked more strictly
Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index ddb68c4..e6cef8e 100644
--- a/drivers/acpi/apei/erst.c
+++ b/drivers/acpi/apei/erst.c
@@ -1006,7 +1006,14 @@
}
len = erst_read(record_id, &rcd->hdr, sizeof(*rcd) +
- erst_erange.size);
+ erst_info.bufsize);
+ /* The record may be cleared by others, try read next record */
+ if (len == -ENOENT)
+ goto skip;
+ else if (len < 0) {
+ rc = -1;
+ goto out;
+ }
if (uuid_le_cmp(rcd->hdr.creator_id, CPER_CREATOR_PSTORE) != 0)
goto skip;