Differential D2379 Diff 5705 files/fix-sprintf-formatting.patch

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files/fix-sprintf-formatting.patch

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				From cd8f7d79f84155d1dfbff3bb169558a8b06fb719 Mon Sep 17 00:00:00 2001
				From: Peter Jones <pjones@redhat.com>
				Date: Fri, 19 May 2017 16:39:56 -0400
				Subject: [PATCH] Fix sprintf formatting for Boot####.
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				If you give it enough compiler flags, gcc believes the following:
				-----------------------
				libfwup.c: In function ‘set_up_boot_next’:
				libfwup.c:1049:27: error: ‘__builtin___sprintf_chk’ may write a terminating nul past the end of the destination [-Werror=format-overflow=]
				sprintf(boot_next_name, "Boot%04X", boot_next);
				^~~~~~~~~~
				In file included from /usr/include/stdio.h:939:0,
				from libfwup.c:17:
				/usr/include/bits/stdio2.h:33:10: note: ‘__builtin___sprintf_chk’ output between 9 and 10 bytes into a destination of size 9
				return __builtin___sprintf_chk (__s, __USE_FORTIFY_LEVEL - 1,
				^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
				__bos (__s), __fmt, __va_arg_pack ());
				~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
				cc1: all warnings being treated as errors
				make[1]: *** [Makefile:70: libfwup.o] Error 1
				make[1]: Leaving directory '/home/pjones/devel/rhel/fwupdate/fwupdate-9/linux'
				make: *** [Makefile:10: all] Error 2
				-----------------------

				The code in question is:
				-----------------------
				if (boot_next >= 0x10000) {
				efi_error("no free boot variables!");
				goto out;
				}

				sprintf(boot_next_name, "Boot%04X", boot_next);
				-----------------------

				It really should know it can't be a higher value than 0xffff. Even
				so, while it's not true that this can happen, since we never get to that
				code if boot_next is > 0xffff, the compiler can't figure that out, so
				it's complaining about an int being crammed into 4 bytes of hex.

				So this patch just tells it the maximum value is 0xffff.

				Signed-off-by: Peter Jones <pjones@redhat.com>
				---
				linux/libfwup.c \| 2 +-
				1 file changed, 1 insertion(+), 1 deletion(-)

				diff --git a/linux/libfwup.c b/linux/libfwup.c
				index 929c106..1b9b72a 100644
				--- a/linux/libfwup.c
				+++ b/linux/libfwup.c
				@@ -1046,7 +1046,7 @@ set_up_boot_next(void)
				goto out;
				}

				- sprintf(boot_next_name, "Boot%04X", boot_next);
				+ sprintf(boot_next_name, "Boot%04hX", boot_next & 0xffff);
				rc = efi_set_variable(efi_guid_global, boot_next_name, opt,
				opt_size,
				EFI_VARIABLE_NON_VOLATILE \|