| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.1 221/267] firmware: dmi_scan: Only honor end-of-table for 64-bit tables | Date | Fri, 31 Jul 2015 12:41:12 -0700 |
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4.1-stable review patch. If anyone has any objections, please let me know.
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From: Jean Delvare <jdelvare@suse.de>
commit 17cd5bd5391e6e7b363d66335e1bc6760ae969b9 upstream.
A 32-bit entry point to a DMI table says how many structures the table contains. The SMBIOS specification explicitly says that end-of-table markers should be ignored if they are not actually at the end of the DMI table. So only honor the end-of-table marker for tables accessed through 64-bit entry points, as they do not specify a structure count.
Fixes: fc43026278 ("dmi: add support for SMBIOS 3.0 64-bit entry point") Signed-off-by: Jean Delvare <jdelvare@suse.de> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/firmware/dmi_scan.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
--- a/drivers/firmware/dmi_scan.c +++ b/drivers/firmware/dmi_scan.c @@ -89,9 +89,9 @@ static void dmi_table(u8 *buf, /* * Stop when we have seen all the items the table claimed to have - * (SMBIOS < 3.0 only) OR we reach an end-of-table marker OR we run - * off the end of the table (should never happen but sometimes does - * on bogus implementations.) + * (SMBIOS < 3.0 only) OR we reach an end-of-table marker (SMBIOS + * >= 3.0 only) OR we run off the end of the table (should never + * happen but sometimes does on bogus implementations.) */ while ((!dmi_num || i < dmi_num) && (data - buf + sizeof(struct dmi_header)) <= dmi_len) { @@ -110,8 +110,13 @@ static void dmi_table(u8 *buf, /* * 7.45 End-of-Table (Type 127) [SMBIOS reference spec v3.0.0] + * For tables behind a 64-bit entry point, we have no item + * count and no exact table length, so stop on end-of-table + * marker. For tables behind a 32-bit entry point, we have + * seen OEM structures behind the end-of-table marker on + * some systems, so don't trust it. */ - if (dm->type == DMI_ENTRY_END_OF_TABLE) + if (!dmi_num && dm->type == DMI_ENTRY_END_OF_TABLE) break; data += 2;
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