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authorJustin Stitt <justinstitt@google.com>2023-09-11 21:59:31 +0300
committerJuergen Gross <jgross@suse.com>2023-09-19 08:04:49 +0300
commit0fc6ff5a0f0488e09b496773c440ed5bb36d1f0d (patch)
tree4df01caf05793e0190afae897eb2beebd301eb8c /arch/x86
parent49147beb0ccbf4c5bb81a44be93ec3bc5e4a79f1 (diff)
downloadlinux-0fc6ff5a0f0488e09b496773c440ed5bb36d1f0d.tar.xz
xen/efi: refactor deprecated strncpy
`strncpy` is deprecated for use on NUL-terminated destination strings [1]. `efi_loader_signature` has space for 4 bytes. We are copying "Xen" (3 bytes) plus a NUL-byte which makes 4 total bytes. With that being said, there is currently not a bug with the current `strncpy()` implementation in terms of buffer overreads but we should favor a more robust string interface either way. A suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on the destination buffer while being functionally the same in this case. Link: www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings[1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Justin Stitt <justinstitt@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20230911-strncpy-arch-x86-xen-efi-c-v1-1-96ab2bba2feb@google.com Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/xen/efi.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/xen/efi.c b/arch/x86/xen/efi.c
index 863d0d6b3edc..7250d0e0e1a9 100644
--- a/arch/x86/xen/efi.c
+++ b/arch/x86/xen/efi.c
@@ -138,7 +138,7 @@ void __init xen_efi_init(struct boot_params *boot_params)
if (efi_systab_xen == NULL)
return;
- strncpy((char *)&boot_params->efi_info.efi_loader_signature, "Xen",
+ strscpy((char *)&boot_params->efi_info.efi_loader_signature, "Xen",
sizeof(boot_params->efi_info.efi_loader_signature));
boot_params->efi_info.efi_systab = (__u32)__pa(efi_systab_xen);
boot_params->efi_info.efi_systab_hi = (__u32)(__pa(efi_systab_xen) >> 32);