From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Ard Biesheuvel , Catalin Marinas , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 096/130] arm64/efi: map the entire UEFI vendor string before reading it Date: Thu, 27 Aug 2015 15:11:27 -0700 Message-Id: <1440713521-5906-97-git-send-email-kamal@canonical.com> In-Reply-To: <1440713521-5906-1-git-send-email-kamal@canonical.com> References: <1440713521-5906-1-git-send-email-kamal@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.19.8-ckt6 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Ard Biesheuvel commit f91b1feada0b6f0a4d33648155b3ded2c4e0707e upstream. 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") Signed-off-by: Catalin Marinas Signed-off-by: Kamal Mostafa --- arch/arm64/kernel/efi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c index 2bb4347..dabc3f1 100644 --- a/arch/arm64/kernel/efi.c +++ b/arch/arm64/kernel/efi.c @@ -100,12 +100,12 @@ static int __init uefi_init(void) /* Show what we know for posterity */ c16 = early_memremap(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", -- 1.9.1