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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-03-15 12:42:03 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-03-15 12:42:03 -0700 |
| commit | b67775e124572a7028e930c306ed68cc2f90b29b (patch) | |
| tree | f7031471854dd2bf99d707735ba72e0fddf3defa | |
| parent | de28a65cd0e39d031dfcdc61fbe06268cb4a5f94 (diff) | |
| parent | d6c066fda90d578aacdf19771a027ed484a79825 (diff) | |
| download | lwn-b67775e124572a7028e930c306ed68cc2f90b29b.tar.gz lwn-b67775e124572a7028e930c306ed68cc2f90b29b.zip | |
Merge tag 'efi-urgent-2020-03-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI fixes from Thomas Gleixner:
"Two EFI fixes:
- Prevent a race and buffer overflow in the sysfs efivars interface
which causes kernel memory corruption.
- Add the missing NULL pointer checks in efivar_store_raw()"
* tag 'efi-urgent-2020-03-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi: Add a sanity check to efivar_store_raw()
efi: Fix a race and a buffer overflow while reading efivars via sysfs
| -rw-r--r-- | drivers/firmware/efi/efivars.c | 32 |
1 files changed, 23 insertions, 9 deletions
diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c index 7576450c8254..aff3dfb4d7ba 100644 --- a/drivers/firmware/efi/efivars.c +++ b/drivers/firmware/efi/efivars.c @@ -83,13 +83,16 @@ static ssize_t efivar_attr_read(struct efivar_entry *entry, char *buf) { struct efi_variable *var = &entry->var; + unsigned long size = sizeof(var->Data); char *str = buf; + int ret; if (!entry || !buf) return -EINVAL; - var->DataSize = 1024; - if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data)) + ret = efivar_entry_get(entry, &var->Attributes, &size, var->Data); + var->DataSize = size; + if (ret) return -EIO; if (var->Attributes & EFI_VARIABLE_NON_VOLATILE) @@ -116,13 +119,16 @@ static ssize_t efivar_size_read(struct efivar_entry *entry, char *buf) { struct efi_variable *var = &entry->var; + unsigned long size = sizeof(var->Data); char *str = buf; + int ret; if (!entry || !buf) return -EINVAL; - var->DataSize = 1024; - if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data)) + ret = efivar_entry_get(entry, &var->Attributes, &size, var->Data); + var->DataSize = size; + if (ret) return -EIO; str += sprintf(str, "0x%lx\n", var->DataSize); @@ -133,12 +139,15 @@ static ssize_t efivar_data_read(struct efivar_entry *entry, char *buf) { struct efi_variable *var = &entry->var; + unsigned long size = sizeof(var->Data); + int ret; if (!entry || !buf) return -EINVAL; - var->DataSize = 1024; - if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data)) + ret = efivar_entry_get(entry, &var->Attributes, &size, var->Data); + var->DataSize = size; + if (ret) return -EIO; memcpy(buf, var->Data, var->DataSize); @@ -199,6 +208,9 @@ efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count) u8 *data; int err; + if (!entry || !buf) + return -EINVAL; + if (in_compat_syscall()) { struct compat_efi_variable *compat; @@ -250,14 +262,16 @@ efivar_show_raw(struct efivar_entry *entry, char *buf) { struct efi_variable *var = &entry->var; struct compat_efi_variable *compat; + unsigned long datasize = sizeof(var->Data); size_t size; + int ret; if (!entry || !buf) return 0; - var->DataSize = 1024; - if (efivar_entry_get(entry, &entry->var.Attributes, - &entry->var.DataSize, entry->var.Data)) + ret = efivar_entry_get(entry, &var->Attributes, &datasize, var->Data); + var->DataSize = datasize; + if (ret) return -EIO; if (in_compat_syscall()) { |