[GIT PULL] EFI fixes
From: Ingo Molnar
Date: Mon Mar 02 2020 - 02:10:38 EST
Linus,
Please pull the latest efi-urgent-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git efi-urgent-for-linus
# HEAD: be36f9e7517e17810ec369626a128d7948942259 efi: READ_ONCE rng seed size before munmap
Three fixes to EFI mixed boot mode, mostly related to x86-64 vmap stacks
activated years ago, bug-fixed recently for EFI, which had knock-on
effects of various 1:1 mapping assumptions in mixed mode.
There's also a READ_ONCE() fix for reading an mmap-ed EFI firmware data
field only once, out of caution.
Thanks,
Ingo
------------------>
Ard Biesheuvel (3):
efi/x86: Align GUIDs to their size in the mixed mode runtime wrapper
efi/x86: Remove support for EFI time and counter services in mixed mode
efi/x86: Handle by-ref arguments covering multiple pages in mixed mode
Jason A. Donenfeld (1):
efi: READ_ONCE rng seed size before munmap
arch/x86/platform/efi/efi_64.c | 151 ++++++++++++++---------------------------
drivers/firmware/efi/efi.c | 4 +-
2 files changed, 54 insertions(+), 101 deletions(-)
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index fa8506e76bbe..d19a2edd63cb 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -180,7 +180,7 @@ void efi_sync_low_kernel_mappings(void)
static inline phys_addr_t
virt_to_phys_or_null_size(void *va, unsigned long size)
{
- bool bad_size;
+ phys_addr_t pa;
if (!va)
return 0;
@@ -188,16 +188,13 @@ virt_to_phys_or_null_size(void *va, unsigned long size)
if (virt_addr_valid(va))
return virt_to_phys(va);
- /*
- * A fully aligned variable on the stack is guaranteed not to
- * cross a page bounary. Try to catch strings on the stack by
- * checking that 'size' is a power of two.
- */
- bad_size = size > PAGE_SIZE || !is_power_of_2(size);
+ pa = slow_virt_to_phys(va);
- WARN_ON(!IS_ALIGNED((unsigned long)va, size) || bad_size);
+ /* check if the object crosses a page boundary */
+ if (WARN_ON((pa ^ (pa + size - 1)) & PAGE_MASK))
+ return 0;
- return slow_virt_to_phys(va);
+ return pa;
}
#define virt_to_phys_or_null(addr) \
@@ -568,85 +565,25 @@ efi_thunk_set_virtual_address_map(unsigned long memory_map_size,
static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
{
- efi_status_t status;
- u32 phys_tm, phys_tc;
- unsigned long flags;
-
- spin_lock(&rtc_lock);
- spin_lock_irqsave(&efi_runtime_lock, flags);
-
- phys_tm = virt_to_phys_or_null(tm);
- phys_tc = virt_to_phys_or_null(tc);
-
- status = efi_thunk(get_time, phys_tm, phys_tc);
-
- spin_unlock_irqrestore(&efi_runtime_lock, flags);
- spin_unlock(&rtc_lock);
-
- return status;
+ return EFI_UNSUPPORTED;
}
static efi_status_t efi_thunk_set_time(efi_time_t *tm)
{
- efi_status_t status;
- u32 phys_tm;
- unsigned long flags;
-
- spin_lock(&rtc_lock);
- spin_lock_irqsave(&efi_runtime_lock, flags);
-
- phys_tm = virt_to_phys_or_null(tm);
-
- status = efi_thunk(set_time, phys_tm);
-
- spin_unlock_irqrestore(&efi_runtime_lock, flags);
- spin_unlock(&rtc_lock);
-
- return status;
+ return EFI_UNSUPPORTED;
}
static efi_status_t
efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
efi_time_t *tm)
{
- efi_status_t status;
- u32 phys_enabled, phys_pending, phys_tm;
- unsigned long flags;
-
- spin_lock(&rtc_lock);
- spin_lock_irqsave(&efi_runtime_lock, flags);
-
- phys_enabled = virt_to_phys_or_null(enabled);
- phys_pending = virt_to_phys_or_null(pending);
- phys_tm = virt_to_phys_or_null(tm);
-
- status = efi_thunk(get_wakeup_time, phys_enabled,
- phys_pending, phys_tm);
-
- spin_unlock_irqrestore(&efi_runtime_lock, flags);
- spin_unlock(&rtc_lock);
-
- return status;
+ return EFI_UNSUPPORTED;
}
static efi_status_t
efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
{
- efi_status_t status;
- u32 phys_tm;
- unsigned long flags;
-
- spin_lock(&rtc_lock);
- spin_lock_irqsave(&efi_runtime_lock, flags);
-
- phys_tm = virt_to_phys_or_null(tm);
-
- status = efi_thunk(set_wakeup_time, enabled, phys_tm);
-
- spin_unlock_irqrestore(&efi_runtime_lock, flags);
- spin_unlock(&rtc_lock);
-
- return status;
+ return EFI_UNSUPPORTED;
}
static unsigned long efi_name_size(efi_char16_t *name)
@@ -658,6 +595,8 @@ static efi_status_t
efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
u32 *attr, unsigned long *data_size, void *data)
{
+ u8 buf[24] __aligned(8);
+ efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
efi_status_t status;
u32 phys_name, phys_vendor, phys_attr;
u32 phys_data_size, phys_data;
@@ -665,14 +604,19 @@ efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
spin_lock_irqsave(&efi_runtime_lock, flags);
+ *vnd = *vendor;
+
phys_data_size = virt_to_phys_or_null(data_size);
- phys_vendor = virt_to_phys_or_null(vendor);
+ phys_vendor = virt_to_phys_or_null(vnd);
phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
phys_attr = virt_to_phys_or_null(attr);
phys_data = virt_to_phys_or_null_size(data, *data_size);
- status = efi_thunk(get_variable, phys_name, phys_vendor,
- phys_attr, phys_data_size, phys_data);
+ if (!phys_name || (data && !phys_data))
+ status = EFI_INVALID_PARAMETER;
+ else
+ status = efi_thunk(get_variable, phys_name, phys_vendor,
+ phys_attr, phys_data_size, phys_data);
spin_unlock_irqrestore(&efi_runtime_lock, flags);
@@ -683,19 +627,25 @@ static efi_status_t
efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
u32 attr, unsigned long data_size, void *data)
{
+ u8 buf[24] __aligned(8);
+ efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
u32 phys_name, phys_vendor, phys_data;
efi_status_t status;
unsigned long flags;
spin_lock_irqsave(&efi_runtime_lock, flags);
+ *vnd = *vendor;
+
phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
- phys_vendor = virt_to_phys_or_null(vendor);
+ phys_vendor = virt_to_phys_or_null(vnd);
phys_data = virt_to_phys_or_null_size(data, data_size);
- /* If data_size is > sizeof(u32) we've got problems */
- status = efi_thunk(set_variable, phys_name, phys_vendor,
- attr, data_size, phys_data);
+ if (!phys_name || !phys_data)
+ status = EFI_INVALID_PARAMETER;
+ else
+ status = efi_thunk(set_variable, phys_name, phys_vendor,
+ attr, data_size, phys_data);
spin_unlock_irqrestore(&efi_runtime_lock, flags);
@@ -707,6 +657,8 @@ efi_thunk_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor,
u32 attr, unsigned long data_size,
void *data)
{
+ u8 buf[24] __aligned(8);
+ efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
u32 phys_name, phys_vendor, phys_data;
efi_status_t status;
unsigned long flags;
@@ -714,13 +666,17 @@ efi_thunk_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor,
if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
return EFI_NOT_READY;
+ *vnd = *vendor;
+
phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
- phys_vendor = virt_to_phys_or_null(vendor);
+ phys_vendor = virt_to_phys_or_null(vnd);
phys_data = virt_to_phys_or_null_size(data, data_size);
- /* If data_size is > sizeof(u32) we've got problems */
- status = efi_thunk(set_variable, phys_name, phys_vendor,
- attr, data_size, phys_data);
+ if (!phys_name || !phys_data)
+ status = EFI_INVALID_PARAMETER;
+ else
+ status = efi_thunk(set_variable, phys_name, phys_vendor,
+ attr, data_size, phys_data);
spin_unlock_irqrestore(&efi_runtime_lock, flags);
@@ -732,39 +688,36 @@ efi_thunk_get_next_variable(unsigned long *name_size,
efi_char16_t *name,
efi_guid_t *vendor)
{
+ u8 buf[24] __aligned(8);
+ efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
efi_status_t status;
u32 phys_name_size, phys_name, phys_vendor;
unsigned long flags;
spin_lock_irqsave(&efi_runtime_lock, flags);
+ *vnd = *vendor;
+
phys_name_size = virt_to_phys_or_null(name_size);
- phys_vendor = virt_to_phys_or_null(vendor);
+ phys_vendor = virt_to_phys_or_null(vnd);
phys_name = virt_to_phys_or_null_size(name, *name_size);
- status = efi_thunk(get_next_variable, phys_name_size,
- phys_name, phys_vendor);
+ if (!phys_name)
+ status = EFI_INVALID_PARAMETER;
+ else
+ status = efi_thunk(get_next_variable, phys_name_size,
+ phys_name, phys_vendor);
spin_unlock_irqrestore(&efi_runtime_lock, flags);
+ *vendor = *vnd;
return status;
}
static efi_status_t
efi_thunk_get_next_high_mono_count(u32 *count)
{
- efi_status_t status;
- u32 phys_count;
- unsigned long flags;
-
- spin_lock_irqsave(&efi_runtime_lock, flags);
-
- phys_count = virt_to_phys_or_null(count);
- status = efi_thunk(get_next_high_mono_count, phys_count);
-
- spin_unlock_irqrestore(&efi_runtime_lock, flags);
-
- return status;
+ return EFI_UNSUPPORTED;
}
static void
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 621220ab3d0e..21ea99f65113 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -552,7 +552,7 @@ int __init efi_config_parse_tables(void *config_tables, int count, int sz,
seed = early_memremap(efi.rng_seed, sizeof(*seed));
if (seed != NULL) {
- size = seed->size;
+ size = READ_ONCE(seed->size);
early_memunmap(seed, sizeof(*seed));
} else {
pr_err("Could not map UEFI random seed!\n");
@@ -562,7 +562,7 @@ int __init efi_config_parse_tables(void *config_tables, int count, int sz,
sizeof(*seed) + size);
if (seed != NULL) {
pr_notice("seeding entropy pool\n");
- add_bootloader_randomness(seed->bits, seed->size);
+ add_bootloader_randomness(seed->bits, size);
early_memunmap(seed, sizeof(*seed) + size);
} else {
pr_err("Could not map UEFI random seed!\n");