From 5c1ac56b51b9d222ab202dec1ac2f4215346129d Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Thu, 14 May 2015 14:40:50 +0200 Subject: [PATCH] firmware: dmi_scan: Fix ordering of product_uuid In function dmi_present(), dmi_walk_early() calls dmi_table(), which calls dmi_decode(), which ultimately calls dmi_save_uuid(). This last function makes a decision based on the value of global variable dmi_ver. The problem is that this variable is set right _after_ dmi_walk_early() returns. So dmi_save_uuid() always sees dmi_ver == 0 regardless of the actual version implemented. This causes /sys/class/dmi/id/product_uuid to always use the old ordering even on systems implementing DMI/SMBIOS 2.6 or later, which should use the new ordering. This is broken since kernel v3.8 for legacy DMI implementations and since kernel v3.10 for SMBIOS 2 implementations. SMBIOS 3 implementations with the 64-bit entry point are not affected. The first breakage does not matter much as in practice legacy DMI implementations are always for versions older than 2.6, which is when the UUID ordering changed. The second breakage is more problematic as it affects the vast majority of x86 systems manufactured since 2009. Signed-off-by: Jean Delvare Fixes: 9f9c9cbb6057 ("drivers/firmware/dmi_scan.c: fetch dmi version from SMBIOS if it exists") Fixes: 79bae42d51a5 ("dmi_scan: refactor dmi_scan_machine(), {smbios,dmi}_present()") Acked-by: Zhenzhong Duan Cc: Ben Hutchings Cc: Artem Savkov Cc: Ivan Khoronzhuk Cc: Matt Fleming Cc: stable@vger.kernel.org [v3.10+] --- drivers/firmware/dmi_scan.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c index 5ebb6ceeabfc..97b1616aa391 100644 --- a/drivers/firmware/dmi_scan.c +++ b/drivers/firmware/dmi_scan.c @@ -499,18 +499,19 @@ static int __init dmi_present(const u8 *buf) buf += 16; if (memcmp(buf, "_DMI_", 5) == 0 && dmi_checksum(buf, 15)) { + if (smbios_ver) + dmi_ver = smbios_ver; + else + dmi_ver = (buf[14] & 0xF0) << 4 | (buf[14] & 0x0F); dmi_num = get_unaligned_le16(buf + 12); dmi_len = get_unaligned_le16(buf + 6); dmi_base = get_unaligned_le32(buf + 8); if (dmi_walk_early(dmi_decode) == 0) { if (smbios_ver) { - dmi_ver = smbios_ver; pr_info("SMBIOS %d.%d present.\n", dmi_ver >> 8, dmi_ver & 0xFF); } else { - dmi_ver = (buf[14] & 0xF0) << 4 | - (buf[14] & 0x0F); pr_info("Legacy DMI %d.%d present.\n", dmi_ver >> 8, dmi_ver & 0xFF); } -- 2.30.2