From: Ard Biesheuvel Date: Sun, 26 Jul 2015 12:59:00 +0000 (+0200) Subject: arm64/efi: map the entire UEFI vendor string before reading it X-Git-Tag: firefly_0821_release~176^2~1351^2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=f91b1feada0b6f0a4d33648155b3ded2c4e0707e;p=firefly-linux-kernel-4.4.55.git 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: Ard Biesheuvel Fixes: f84d02755f5a ("arm64: add EFI runtime services") Cc: # 3.16+ Signed-off-by: Catalin Marinas --- diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c index 9d4aa18f2a82..e8ca6eaedd02 100644 --- a/arch/arm64/kernel/efi.c +++ b/arch/arm64/kernel/efi.c @@ -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(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",