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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-02-20 20:32:40 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-02-20 20:32:40 +0300 |
commit | 0389075ecfb6231818de9b0225d3a5a21a661171 (patch) | |
tree | 991154188efee4117974d9aa5bcd7497257c7656 /drivers | |
parent | 06b74c658c595e4ef9fd5746f927a1cb6c3a59d5 (diff) | |
parent | f4eafd8bcd5229e998aa252627703b8462c3b90f (diff) | |
download | linux-0389075ecfb6231818de9b0225d3a5a21a661171.tar.xz |
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"This is unusually large, partly due to the EFI fixes that prevent
accidental deletion of EFI variables through efivarfs that may brick
machines. These fixes are somewhat involved to maintain compatibility
with existing install methods and other usage modes, while trying to
turn off the 'rm -rf' bricking vector.
Other fixes are for large page ioremap()s and for non-temporal
user-memcpy()s"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Fix vmalloc_fault() to handle large pages properly
hpet: Drop stale URLs
x86/uaccess/64: Handle the caching of 4-byte nocache copies properly in __copy_user_nocache()
x86/uaccess/64: Make the __copy_user_nocache() assembly code more readable
lib/ucs2_string: Correct ucs2 -> utf8 conversion
efi: Add pstore variables to the deletion whitelist
efi: Make efivarfs entries immutable by default
efi: Make our variable validation list include the guid
efi: Do variable name validation tests in utf8
efi: Use ucs2_as_utf8 in efivarfs instead of open coding a bad version
lib/ucs2_string: Add ucs2 -> utf8 helper functions
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/char/hpet.c | 2 | ||||
-rw-r--r-- | drivers/firmware/efi/efivars.c | 35 | ||||
-rw-r--r-- | drivers/firmware/efi/vars.c | 144 |
3 files changed, 120 insertions, 61 deletions
diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c index 240b6cf1d97c..be54e5331a45 100644 --- a/drivers/char/hpet.c +++ b/drivers/char/hpet.c @@ -42,7 +42,7 @@ /* * The High Precision Event Timer driver. * This driver is closely modelled after the rtc.c driver. - * http://www.intel.com/hardwaredesign/hpetspec_1.pdf + * See HPET spec revision 1. */ #define HPET_USER_FREQ (64) #define HPET_DRIFT (500) diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c index 756eca8c4cf8..10e6774ab2a2 100644 --- a/drivers/firmware/efi/efivars.c +++ b/drivers/firmware/efi/efivars.c @@ -221,7 +221,7 @@ sanity_check(struct efi_variable *var, efi_char16_t *name, efi_guid_t vendor, } if ((attributes & ~EFI_VARIABLE_MASK) != 0 || - efivar_validate(name, data, size) == false) { + efivar_validate(vendor, name, data, size) == false) { printk(KERN_ERR "efivars: Malformed variable content\n"); return -EINVAL; } @@ -447,7 +447,8 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj, } if ((attributes & ~EFI_VARIABLE_MASK) != 0 || - efivar_validate(name, data, size) == false) { + efivar_validate(new_var->VendorGuid, name, data, + size) == false) { printk(KERN_ERR "efivars: Malformed variable content\n"); return -EINVAL; } @@ -540,38 +541,30 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj, static int efivar_create_sysfs_entry(struct efivar_entry *new_var) { - int i, short_name_size; + int short_name_size; char *short_name; - unsigned long variable_name_size; - efi_char16_t *variable_name; + unsigned long utf8_name_size; + efi_char16_t *variable_name = new_var->var.VariableName; int ret; - variable_name = new_var->var.VariableName; - variable_name_size = ucs2_strlen(variable_name) * sizeof(efi_char16_t); - /* - * Length of the variable bytes in ASCII, plus the '-' separator, + * Length of the variable bytes in UTF8, plus the '-' separator, * plus the GUID, plus trailing NUL */ - short_name_size = variable_name_size / sizeof(efi_char16_t) - + 1 + EFI_VARIABLE_GUID_LEN + 1; - - short_name = kzalloc(short_name_size, GFP_KERNEL); + utf8_name_size = ucs2_utf8size(variable_name); + short_name_size = utf8_name_size + 1 + EFI_VARIABLE_GUID_LEN + 1; + short_name = kmalloc(short_name_size, GFP_KERNEL); if (!short_name) return -ENOMEM; - /* Convert Unicode to normal chars (assume top bits are 0), - ala UTF-8 */ - for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) { - short_name[i] = variable_name[i] & 0xFF; - } + ucs2_as_utf8(short_name, variable_name, short_name_size); + /* This is ugly, but necessary to separate one vendor's private variables from another's. */ - - *(short_name + strlen(short_name)) = '-'; + short_name[utf8_name_size] = '-'; efi_guid_to_str(&new_var->var.VendorGuid, - short_name + strlen(short_name)); + short_name + utf8_name_size + 1); new_var->kobj.kset = efivars_kset; diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c index 70a0fb10517f..7f2ea21c730d 100644 --- a/drivers/firmware/efi/vars.c +++ b/drivers/firmware/efi/vars.c @@ -165,67 +165,133 @@ validate_ascii_string(efi_char16_t *var_name, int match, u8 *buffer, } struct variable_validate { + efi_guid_t vendor; char *name; bool (*validate)(efi_char16_t *var_name, int match, u8 *data, unsigned long len); }; +/* + * This is the list of variables we need to validate, as well as the + * whitelist for what we think is safe not to default to immutable. + * + * If it has a validate() method that's not NULL, it'll go into the + * validation routine. If not, it is assumed valid, but still used for + * whitelisting. + * + * Note that it's sorted by {vendor,name}, but globbed names must come after + * any other name with the same prefix. + */ static const struct variable_validate variable_validate[] = { - { "BootNext", validate_uint16 }, - { "BootOrder", validate_boot_order }, - { "DriverOrder", validate_boot_order }, - { "Boot*", validate_load_option }, - { "Driver*", validate_load_option }, - { "ConIn", validate_device_path }, - { "ConInDev", validate_device_path }, - { "ConOut", validate_device_path }, - { "ConOutDev", validate_device_path }, - { "ErrOut", validate_device_path }, - { "ErrOutDev", validate_device_path }, - { "Timeout", validate_uint16 }, - { "Lang", validate_ascii_string }, - { "PlatformLang", validate_ascii_string }, - { "", NULL }, + { EFI_GLOBAL_VARIABLE_GUID, "BootNext", validate_uint16 }, + { EFI_GLOBAL_VARIABLE_GUID, "BootOrder", validate_boot_order }, + { EFI_GLOBAL_VARIABLE_GUID, "Boot*", validate_load_option }, + { EFI_GLOBAL_VARIABLE_GUID, "DriverOrder", validate_boot_order }, + { EFI_GLOBAL_VARIABLE_GUID, "Driver*", validate_load_option }, + { EFI_GLOBAL_VARIABLE_GUID, "ConIn", validate_device_path }, + { EFI_GLOBAL_VARIABLE_GUID, "ConInDev", validate_device_path }, + { EFI_GLOBAL_VARIABLE_GUID, "ConOut", validate_device_path }, + { EFI_GLOBAL_VARIABLE_GUID, "ConOutDev", validate_device_path }, + { EFI_GLOBAL_VARIABLE_GUID, "ErrOut", validate_device_path }, + { EFI_GLOBAL_VARIABLE_GUID, "ErrOutDev", validate_device_path }, + { EFI_GLOBAL_VARIABLE_GUID, "Lang", validate_ascii_string }, + { EFI_GLOBAL_VARIABLE_GUID, "OsIndications", NULL }, + { EFI_GLOBAL_VARIABLE_GUID, "PlatformLang", validate_ascii_string }, + { EFI_GLOBAL_VARIABLE_GUID, "Timeout", validate_uint16 }, + { LINUX_EFI_CRASH_GUID, "*", NULL }, + { NULL_GUID, "", NULL }, }; +static bool +variable_matches(const char *var_name, size_t len, const char *match_name, + int *match) +{ + for (*match = 0; ; (*match)++) { + char c = match_name[*match]; + char u = var_name[*match]; + + /* Wildcard in the matching name means we've matched */ + if (c == '*') + return true; + + /* Case sensitive match */ + if (!c && *match == len) + return true; + + if (c != u) + return false; + + if (!c) + return true; + } + return true; +} + bool -efivar_validate(efi_char16_t *var_name, u8 *data, unsigned long len) +efivar_validate(efi_guid_t vendor, efi_char16_t *var_name, u8 *data, + unsigned long data_size) { int i; - u16 *unicode_name = var_name; + unsigned long utf8_size; + u8 *utf8_name; - for (i = 0; variable_validate[i].validate != NULL; i++) { - const char *name = variable_validate[i].name; - int match; + utf8_size = ucs2_utf8size(var_name); + utf8_name = kmalloc(utf8_size + 1, GFP_KERNEL); + if (!utf8_name) + return false; - for (match = 0; ; match++) { - char c = name[match]; - u16 u = unicode_name[match]; + ucs2_as_utf8(utf8_name, var_name, utf8_size); + utf8_name[utf8_size] = '\0'; - /* All special variables are plain ascii */ - if (u > 127) - return true; + for (i = 0; variable_validate[i].name[0] != '\0'; i++) { + const char *name = variable_validate[i].name; + int match = 0; - /* Wildcard in the matching name means we've matched */ - if (c == '*') - return variable_validate[i].validate(var_name, - match, data, len); + if (efi_guidcmp(vendor, variable_validate[i].vendor)) + continue; - /* Case sensitive match */ - if (c != u) + if (variable_matches(utf8_name, utf8_size+1, name, &match)) { + if (variable_validate[i].validate == NULL) break; - - /* Reached the end of the string while matching */ - if (!c) - return variable_validate[i].validate(var_name, - match, data, len); + kfree(utf8_name); + return variable_validate[i].validate(var_name, match, + data, data_size); } } - + kfree(utf8_name); return true; } EXPORT_SYMBOL_GPL(efivar_validate); +bool +efivar_variable_is_removable(efi_guid_t vendor, const char *var_name, + size_t len) +{ + int i; + bool found = false; + int match = 0; + + /* + * Check if our variable is in the validated variables list + */ + for (i = 0; variable_validate[i].name[0] != '\0'; i++) { + if (efi_guidcmp(variable_validate[i].vendor, vendor)) + continue; + + if (variable_matches(var_name, len, + variable_validate[i].name, &match)) { + found = true; + break; + } + } + + /* + * If it's in our list, it is removable. + */ + return found; +} +EXPORT_SYMBOL_GPL(efivar_variable_is_removable); + static efi_status_t check_var_size(u32 attributes, unsigned long size) { @@ -852,7 +918,7 @@ int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes, *set = false; - if (efivar_validate(name, data, *size) == false) + if (efivar_validate(*vendor, name, data, *size) == false) return -EINVAL; /* |