Switch build-deps from gcc-10 to gcc-12. Closes: #1022184

Also needs backports from upstream commits to fix warnings/errors
from using gcc 12:

be8eb0eed util/mkimage: Fix dangling pointer may be used error
acffb8148 build: Fix -Werror=array-bounds array subscript 0 is outside array bounds
3ce13d974 lib/reed_solomon: Fix array subscript 0 is outside array bounds

debian/changelog

@@ -5,6 +5,7 @@ grub2 (2.06-8) UNRELEASED; urgency=medium
   * Fix an issue in an f2fs security fix which caused mount
     failures. Closes: #1021846. Thanks to программист некто for helping
     to debug the problem!
+  * Switch build-deps from gcc-10 to gcc-12. Closes: #1022184
 
  -- Steve McIntyre <93sam@debian.org>  Sun, 11 Dec 2022 12:08:44 +0000
 

debian/control

@@ -11,8 +11,8 @@ Build-Depends: debhelper-compat (= 13),
  po-debconf,
  help2man,
  texinfo,
- gcc-10,
- gcc-10-multilib [i386 kopensolaris-i386 any-amd64 any-ppc64 any-sparc],
+ gcc-12,
+ gcc-12-multilib [i386 kopensolaris-i386 any-amd64 any-ppc64 any-sparc],
  xfonts-unifont,
  libfreetype6-dev,
  gettext,

debian/patches/gcc12_build_array_bounds2.patch

+commit 3ce13d974b887338ae972c79b41ff6fc0eee6388
+Author: Michael Chang <mchang@suse.com>
+Date:   Mon Mar 28 15:00:54 2022 +0800
+
+    lib/reed_solomon: Fix array subscript 0 is outside array bounds
+    
+    The grub_absolute_pointer() is a compound expression that can only work
+    within a function. We are out of luck here when the pointer variables
+    require global definition due to ATTRIBUTE_TEXT that have to use fully
+    initialized global definition because of the way linkers work.
+    
+      static gf_single_t * const gf_powx ATTRIBUTE_TEXT = (void *) 0x100000;
+    
+    For the reason given above, use GCC diagnostic pragmas to suppress the
+    array-bounds warning.
+    
+    Signed-off-by: Michael Chang <mchang@suse.com>
+    Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+
+diff --git a/grub-core/lib/reed_solomon.c b/grub-core/lib/reed_solomon.c
+index 82779a296..562bd2e3e 100644
+--- a/grub-core/lib/reed_solomon.c
++++ b/grub-core/lib/reed_solomon.c
+@@ -102,6 +102,11 @@ static gf_single_t errvals[256];
+ static gf_single_t eqstat[65536 + 256];
+ #endif
+ 
++#if __GNUC__ == 12
++#pragma GCC diagnostic push
++#pragma GCC diagnostic ignored "-Warray-bounds"
++#endif
++
+ static gf_single_t
+ gf_mul (gf_single_t a, gf_single_t b)
+ {
+@@ -319,6 +324,10 @@ decode_block (gf_single_t *ptr, grub_size_t s,
+     }
+ }
+ 
++#if __GNUC__ == 12
++#pragma GCC diagnostic pop
++#endif
++
+ #if !defined (STANDALONE)
+ static void
+ encode_block (gf_single_t *ptr, grub_size_t s,

debian/patches/gcc12_build_dangling_pointer.patch

+Borrowed and tweaked fix from:
+
+commit be8eb0eed69f8bc9ac20837eae58e55218011880
+Author: Michael Chang <mchang@suse.com>
+Date:   Mon Mar 28 15:00:52 2022 +0800
+
+    util/mkimage: Fix dangling pointer may be used error
+
+diff --git a/util/mkimage.c b/util/mkimage.c
+index a26cf76f7..58c199f7c 100644
+--- a/util/mkimage	2022-12-11 15:41:56.717934782 +0000
++++ b/util/mkimage.c	2022-12-11 15:43:05.318432532 +0000
+@@ -1383,6 +1383,10 @@
+ 	    section = (struct grub_pe32_section_table *)(o64 + 1);
+ 	  }
+ 
++#if __GNUC__ >= 12
++#pragma GCC diagnostic push
++#pragma GCC diagnostic ignored "-Wdangling-pointer"
++#endif
+ 	PE_OHDR (o32, o64, header_size) = grub_host_to_target32 (header_size);
+ 	PE_OHDR (o32, o64, entry_addr) = grub_host_to_target32 (layout.start_address);
+ 	PE_OHDR (o32, o64, image_base) = 0;
+@@ -1402,6 +1406,9 @@
+ 	/* The sections.  */
+ 	PE_OHDR (o32, o64, code_base) = grub_host_to_target32 (vma);
+ 	PE_OHDR (o32, o64, code_size) = grub_host_to_target32 (layout.exec_size);
++#if __GNUC__ >= 12
++#pragma GCC diagnostic pop
++#endif
+ 	section = init_pe_section (image_target, section, ".text",
+ 				   &vma, layout.exec_size,
+ 				   image_target->section_align,
+@@ -1413,10 +1420,17 @@
+ 	raw_size = layout.kernel_size - layout.exec_size;
+ 	scn_size = ALIGN_UP (raw_size, GRUB_PE32_FILE_ALIGNMENT);
+ 	/* ALIGN_UP (sbat_size, GRUB_PE32_FILE_ALIGNMENT) is done earlier. */
++#if __GNUC__ >= 12
++#pragma GCC diagnostic push
++#pragma GCC diagnostic ignored "-Wdangling-pointer"
++#endif
+ 	PE_OHDR (o32, o64, data_size) = grub_host_to_target32 (scn_size + sbat_size +
+ 							       ALIGN_UP (total_module_size,
+ 									 GRUB_PE32_FILE_ALIGNMENT));
+ 
++#if __GNUC__ >= 12
++#pragma GCC diagnostic pop
++#endif
+ 	section = init_pe_section (image_target, section, ".data",
+ 				   &vma, scn_size, image_target->section_align,
+ 				   &raw_data, raw_size,
+@@ -1448,8 +1462,15 @@
+ 	  }
+ 
+ 	scn_size = ALIGN_UP (layout.reloc_size, GRUB_PE32_FILE_ALIGNMENT);
++#if __GNUC__ >= 12
++#pragma GCC diagnostic push
++#pragma GCC diagnostic ignored "-Wdangling-pointer"
++#endif
+ 	PE_OHDR (o32, o64, base_relocation_table.rva) = grub_host_to_target32 (vma);
+ 	PE_OHDR (o32, o64, base_relocation_table.size) = grub_host_to_target32 (scn_size);
++#if __GNUC__ >= 12
++#pragma GCC diagnostic pop
++#endif
+ 	memcpy (pe_img + raw_data, layout.reloc_section, scn_size);
+ 	init_pe_section (image_target, section, ".reloc",
+ 			 &vma, scn_size, image_target->section_align,

debian/patches/series

@@ -107,3 +107,6 @@ cve_2022_2601/0013-font-Assign-null_font-to-glyphs-in-ascii_font_glyph.patch
 cve_2022_2601/0014-normal-charset-Fix-an-integer-overflow-in-grub_unico.patch
 font-Try-opening-fonts-from-the-bundled-memdisk.patch
 kern-file-Fix-error-handling-in-grub_file_open.patch
+gcc12_build_dangling_pointer.patch
+gcc12_build_array_bounds.patch
+gcc12_build_array_bounds2.patch

debian/rules

@@ -37,7 +37,7 @@ else
 with_check := yes
 endif
 
-CC := gcc-10
+CC := gcc-12
 
 confflags = \
 	PACKAGE_VERSION="$(deb_version)" PACKAGE_STRING="GRUB $(deb_version)" \