| Message ID | 1437915540-7553-1-git-send-email-ard.biesheuvel@linaro.org |
|---|---|
| State | Accepted |
| Commit | f91b1feada0b6f0a4d33648155b3ded2c4e0707e |
| Headers | show |
On 27 July 2015 at 14:14, Catalin Marinas <catalin.marinas@arm.com> wrote: > On Sun, Jul 26, 2015 at 02:59:00PM +0200, Ard Biesheuvel wrote: >> 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 <ard.biesheuvel@linaro.org> >> --- >> Hello Catalin, >> >> I think this should go into v4.2 with a cc: stable. > > If it's cc stable, do you have a Fixes: tag? (it saves me some > searching). > Ah sure, I forgot. Fixes: f84d02755f5a ("arm64: add EFI runtime services")
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",
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 <ard.biesheuvel@linaro.org> --- Hello Catalin, I think this should go into v4.2 with a cc: stable. Thanks, Ard. arch/arm64/kernel/efi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)