From: Jean Delvare jdelvare@suse.de
[ Upstream commit 81dde26de9c08bb04c4962a15608778aaffb3cf9 ]
Before reading the Extended Size field, we should ensure it fits in the DMI record. There is already a record length check but it does not cover that field.
It would take a seriously corrupted DMI table to hit that bug, so no need to worry, but we should still fix it.
Signed-off-by: Jean Delvare jdelvare@suse.de Fixes: 6deae96b42eb ("firmware, DMI: Add function to look up a handle and return DIMM size") Cc: Tony Luck tony.luck@intel.com Cc: Borislav Petkov bp@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/firmware/dmi_scan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c index f2483548cde9..0dc0c78f1fdb 100644 --- a/drivers/firmware/dmi_scan.c +++ b/drivers/firmware/dmi_scan.c @@ -407,7 +407,7 @@ static void __init save_mem_devices(const struct dmi_header *dm, void *v) bytes = ~0ull; else if (size & 0x8000) bytes = (u64)(size & 0x7fff) << 10; - else if (size != 0x7fff) + else if (size != 0x7fff || dm->length < 0x20) bytes = (u64)size << 20; else bytes = (u64)get_unaligned((u32 *)&d[0x1C]) << 20;