[tip: x86/boot] x86/boot: Ignore relocations in .notes sections in walk_relocs() too

[tip-bot2 for Guixiong Wei]

The following commit has been merged into the x86/boot branch of tip:

Commit-ID:     76e9762d66373354b45c33b60e9a53ef2a3c5ff2
Gitweb:        https://git.kernel.org/tip/76e9762d66373354b45c33b60e9a53ef2a3c5ff2
Author:        Guixiong Wei <weiguixiong@xxxxxxxxxxxxx>
AuthorDate:    Sun, 17 Mar 2024 23:05:47 +08:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Fri, 22 Mar 2024 09:48:59 +01:00

x86/boot: Ignore relocations in .notes sections in walk_relocs() too

Commit:

  aaa8736370db ("x86, relocs: Ignore relocations in .notes section")

.. only started ignoring the .notes sections in print_absolute_relocs(),
but the same logic should also by applied in walk_relocs() to avoid
such relocations.

[ mingo: Fixed various typos in the changelog, removed extra curly braces from the code. ]

Fixes: aaa8736370db ("x86, relocs: Ignore relocations in .notes section")
Fixes: 5ead97c84fa7 ("xen: Core Xen implementation")
Fixes: da1a679cde9b ("Add /sys/kernel/notes")
Signed-off-by: Guixiong Wei <weiguixiong@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240317150547.24910-1-weiguixiong@xxxxxxxxxxxxx
---
 arch/x86/tools/relocs.c |  9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
index b029fb8..e7a44a7 100644
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -746,6 +746,15 @@ static void walk_relocs(int (*process)(struct section *sec, Elf_Rel *rel,
 		if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) {
 			continue;
 		}
+
+		/*
+		 * Do not perform relocations in .notes sections; any
+		 * values there are meant for pre-boot consumption (e.g.
+		 * startup_xen).
+		 */
+		if (sec_applies->shdr.sh_type == SHT_NOTE)
+			continue;
+
 		sh_symtab = sec_symtab->symtab;
 		sym_strtab = sec_symtab->link->strtab;
 		for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) {