From c9aba14362a6eec583819ec8f4b872c1816f5cbe Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Thu, 15 Jun 2017 13:46:00 +0200 Subject: [PATCH 1/4] firmware: dmi_scan: Look for SMBIOS 3 entry point first Since version 3.0.0 of the SMBIOS specification, there can be multiple entry points in memory, pointing to one or two DMI tables. If both a 32-bit ("_SM_") entry point and a 64-bit ("_SM3_") entry point are present, the specification requires that the latter points to a table which is a super-set of the table pointed to by the former. Therefore we should give preference to the 64-bit ("_SM3_") entry point. However, currently the code is picking the first valid entry point it finds. Per specification, we should look for a 64-bit ("_SM3_") entry point first, and if we can't find any, look for a 32-bit ("_SM_" or "_DMI_") entry point. Modify the code to do that. Signed-off-by: Jean Delvare --- drivers/firmware/dmi_scan.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c index 93f7acdaac7a..82ee042f075c 100644 --- a/drivers/firmware/dmi_scan.c +++ b/drivers/firmware/dmi_scan.c @@ -649,6 +649,21 @@ void __init dmi_scan_machine(void) if (p == NULL) goto error; + /* + * Same logic as above, look for a 64-bit entry point + * first, and if not found, fall back to 32-bit entry point. + */ + memcpy_fromio(buf, p, 16); + for (q = p + 16; q < p + 0x10000; q += 16) { + memcpy_fromio(buf + 16, q, 16); + if (!dmi_smbios3_present(buf)) { + dmi_available = 1; + dmi_early_unmap(p, 0x10000); + goto out; + } + memcpy(buf, buf + 16, 16); + } + /* * Iterate over all possible DMI header addresses q. * Maintain the 32 bytes around q in buf. On the @@ -659,7 +674,7 @@ void __init dmi_scan_machine(void) memset(buf, 0, 16); for (q = p; q < p + 0x10000; q += 16) { memcpy_fromio(buf + 16, q, 16); - if (!dmi_smbios3_present(buf) || !dmi_present(buf)) { + if (!dmi_present(buf)) { dmi_available = 1; dmi_early_unmap(p, 0x10000); goto out; From c926820085437a27b27e78996b2c7a5ad94e8055 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Thu, 15 Jun 2017 13:46:00 +0200 Subject: [PATCH 2/4] firmware: dmi_scan: Make dmi_walk and dmi_walk_early return real error codes Currently they return -1 on error, which will confuse callers if they try to interpret it as a normal negative error code. Signed-off-by: Andy Lutomirski Signed-off-by: Darren Hart (VMware) Signed-off-by: Jean Delvare --- drivers/firmware/dmi_scan.c | 9 +++++---- include/linux/dmi.h | 2 +- 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c index 82ee042f075c..fc30249132f5 100644 --- a/drivers/firmware/dmi_scan.c +++ b/drivers/firmware/dmi_scan.c @@ -144,7 +144,7 @@ static int __init dmi_walk_early(void (*decode)(const struct dmi_header *, buf = dmi_early_remap(dmi_base, orig_dmi_len); if (buf == NULL) - return -1; + return -ENOMEM; dmi_decode_table(buf, decode, NULL); @@ -1008,7 +1008,8 @@ EXPORT_SYMBOL(dmi_get_date); * @decode: Callback function * @private_data: Private data to be passed to the callback function * - * Returns -1 when the DMI table can't be reached, 0 on success. + * Returns 0 on success, -ENXIO if DMI is not selected or not present, + * or a different negative error code if DMI walking fails. */ int dmi_walk(void (*decode)(const struct dmi_header *, void *), void *private_data) @@ -1016,11 +1017,11 @@ int dmi_walk(void (*decode)(const struct dmi_header *, void *), u8 *buf; if (!dmi_available) - return -1; + return -ENXIO; buf = dmi_remap(dmi_base, dmi_len); if (buf == NULL) - return -1; + return -ENOMEM; dmi_decode_table(buf, decode, private_data); diff --git a/include/linux/dmi.h b/include/linux/dmi.h index 5e9c74cf8894..9bbf21a516e4 100644 --- a/include/linux/dmi.h +++ b/include/linux/dmi.h @@ -136,7 +136,7 @@ static inline int dmi_name_in_vendors(const char *s) { return 0; } static inline int dmi_name_in_serial(const char *s) { return 0; } #define dmi_available 0 static inline int dmi_walk(void (*decode)(const struct dmi_header *, void *), - void *private_data) { return -1; } + void *private_data) { return -ENXIO; } static inline bool dmi_match(enum dmi_field f, const char *str) { return false; } static inline void dmi_memdev_name(u16 handle, const char **bank, From e0733e975385d25d88c1384dafb8ea4dcf7513c0 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Thu, 15 Jun 2017 13:46:01 +0200 Subject: [PATCH 3/4] firmware: dmi: Fix permissions of product_family This is not sensitive information like serial numbers, we can allow all users to read it. Fix odd alignment while we're here. Signed-off-by: Jean Delvare Fixes: c61872c9833d ("firmware: dmi: Add DMI_PRODUCT_FAMILY identification string") Reviewed-by: Andy Shevchenko Reviewed-by: Mika Westerberg Cc: Dmitry Torokhov Cc: Linus Walleij --- drivers/firmware/dmi-id.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/firmware/dmi-id.c b/drivers/firmware/dmi-id.c index dc269cb288c2..951b6c79f166 100644 --- a/drivers/firmware/dmi-id.c +++ b/drivers/firmware/dmi-id.c @@ -47,7 +47,7 @@ DEFINE_DMI_ATTR_WITH_SHOW(product_name, 0444, DMI_PRODUCT_NAME); DEFINE_DMI_ATTR_WITH_SHOW(product_version, 0444, DMI_PRODUCT_VERSION); DEFINE_DMI_ATTR_WITH_SHOW(product_serial, 0400, DMI_PRODUCT_SERIAL); DEFINE_DMI_ATTR_WITH_SHOW(product_uuid, 0400, DMI_PRODUCT_UUID); -DEFINE_DMI_ATTR_WITH_SHOW(product_family, 0400, DMI_PRODUCT_FAMILY); +DEFINE_DMI_ATTR_WITH_SHOW(product_family, 0444, DMI_PRODUCT_FAMILY); DEFINE_DMI_ATTR_WITH_SHOW(board_vendor, 0444, DMI_BOARD_VENDOR); DEFINE_DMI_ATTR_WITH_SHOW(board_name, 0444, DMI_BOARD_NAME); DEFINE_DMI_ATTR_WITH_SHOW(board_version, 0444, DMI_BOARD_VERSION); @@ -192,7 +192,7 @@ static void __init dmi_id_init_attr_table(void) ADD_DMI_ATTR(product_version, DMI_PRODUCT_VERSION); ADD_DMI_ATTR(product_serial, DMI_PRODUCT_SERIAL); ADD_DMI_ATTR(product_uuid, DMI_PRODUCT_UUID); - ADD_DMI_ATTR(product_family, DMI_PRODUCT_FAMILY); + ADD_DMI_ATTR(product_family, DMI_PRODUCT_FAMILY); ADD_DMI_ATTR(board_vendor, DMI_BOARD_VENDOR); ADD_DMI_ATTR(board_name, DMI_BOARD_NAME); ADD_DMI_ATTR(board_version, DMI_BOARD_VERSION); From a814c3597a6b6040e2ef9459748081a6d5b7312d Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Thu, 15 Jun 2017 13:46:01 +0200 Subject: [PATCH 4/4] firmware: dmi_scan: Check DMI structure length Before accessing DMI data to record it for later, we should ensure that the DMI structures are large enough to contain the data in question. Signed-off-by: Jean Delvare Reviewed-by: Mika Westerberg Cc: Dmitry Torokhov Cc: Andy Shevchenko Cc: Linus Walleij --- drivers/firmware/dmi_scan.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c index fc30249132f5..783041964439 100644 --- a/drivers/firmware/dmi_scan.c +++ b/drivers/firmware/dmi_scan.c @@ -178,7 +178,7 @@ static void __init dmi_save_ident(const struct dmi_header *dm, int slot, const char *d = (const char *) dm; const char *p; - if (dmi_ident[slot]) + if (dmi_ident[slot] || dm->length <= string) return; p = dmi_string(dm, d[string]); @@ -191,13 +191,14 @@ static void __init dmi_save_ident(const struct dmi_header *dm, int slot, static void __init dmi_save_uuid(const struct dmi_header *dm, int slot, int index) { - const u8 *d = (u8 *) dm + index; + const u8 *d; char *s; int is_ff = 1, is_00 = 1, i; - if (dmi_ident[slot]) + if (dmi_ident[slot] || dm->length <= index + 16) return; + d = (u8 *) dm + index; for (i = 0; i < 16 && (is_ff || is_00); i++) { if (d[i] != 0x00) is_00 = 0; @@ -228,16 +229,17 @@ static void __init dmi_save_uuid(const struct dmi_header *dm, int slot, static void __init dmi_save_type(const struct dmi_header *dm, int slot, int index) { - const u8 *d = (u8 *) dm + index; + const u8 *d; char *s; - if (dmi_ident[slot]) + if (dmi_ident[slot] || dm->length <= index) return; s = dmi_alloc(4); if (!s) return; + d = (u8 *) dm + index; sprintf(s, "%u", *d & 0x7F); dmi_ident[slot] = s; } @@ -278,9 +280,13 @@ static void __init dmi_save_devices(const struct dmi_header *dm) static void __init dmi_save_oem_strings_devices(const struct dmi_header *dm) { - int i, count = *(u8 *)(dm + 1); + int i, count; struct dmi_device *dev; + if (dm->length < 0x05) + return; + + count = *(u8 *)(dm + 1); for (i = 1; i <= count; i++) { const char *devname = dmi_string(dm, i); @@ -353,6 +359,9 @@ static void __init dmi_save_extended_devices(const struct dmi_header *dm) const char *name; const u8 *d = (u8 *)dm; + if (dm->length < 0x0B) + return; + /* Skip disabled device */ if ((d[0x5] & 0x80) == 0) return; @@ -387,7 +396,7 @@ static void __init save_mem_devices(const struct dmi_header *dm, void *v) const char *d = (const char *)dm; static int nr; - if (dm->type != DMI_ENTRY_MEM_DEVICE) + if (dm->type != DMI_ENTRY_MEM_DEVICE || dm->length < 0x12) return; if (nr >= dmi_memdev_nr) { pr_warn(FW_BUG "Too many DIMM entries in SMBIOS table\n");