Commit f91b1fea authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Catalin Marinas
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arm64/efi: map the entire UEFI vendor string before reading it

At boot, the UTF-16 UEFI vendor string is copied from the system
table into a char array with a size of 100 bytes. However, this
size of 100 bytes is also used for memremapping() the source,
which may not be sufficient if the vendor string exceeds 50
UTF-16 characters, and the placement of the vendor string inside
a 4 KB page happens to leave the end unmapped.

So use the correct '100 * sizeof(efi_char16_t)' for the size of
the mapping.

Signed-off-by: default avatarArd Biesheuvel <>
Fixes: f84d0275

 ("arm64: add EFI runtime services")
Cc: <> # 3.16+
Signed-off-by: Catalin Marinas's avatarCatalin Marinas <>
parent cbfe8fa6
......@@ -122,12 +122,12 @@ static int __init uefi_init(void)
/* Show what we know for posterity */
c16 = early_memremap(efi_to_phys(efi.systab->fw_vendor),
sizeof(vendor) * sizeof(efi_char16_t));
if (c16) {
for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
vendor[i] = c16[i];
vendor[i] = '\0';
early_memunmap(c16, sizeof(vendor));
early_memunmap(c16, sizeof(vendor) * sizeof(efi_char16_t));
pr_info("EFI v%u.%.02u by %s\n",
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