dmi: prevent linked list corruption
Adding the same item to a given linked list more than once is guaranteed
to break and corrupt the list. This is however what we do in dmi_scan
since commit 79da4721117fcf188b4b007b775738a530f574da ("x86: fix DMI out
of memory problems").
Given that there is absolutely no interest in saving empty OEM strings
anyway, I propose the simple and efficient fix below: we discard the empty
OEM strings altogether.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Parag Warudkar <parag.warudkar@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index de30275..4072449 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -217,10 +217,6 @@
}
}
-static struct dmi_device empty_oem_string_dev = {
- .name = dmi_empty_string,
-};
-
static void __init dmi_save_oem_strings_devices(const struct dmi_header *dm)
{
int i, count = *(u8 *)(dm + 1);
@@ -229,10 +225,8 @@
for (i = 1; i <= count; i++) {
char *devname = dmi_string(dm, i);
- if (!strcmp(devname, dmi_empty_string)) {
- list_add(&empty_oem_string_dev.list, &dmi_devices);
+ if (devname == dmi_empty_string)
continue;
- }
dev = dmi_alloc(sizeof(*dev));
if (!dev) {