The patch titled
Subject: build-id: require program headers to be right after ELF header
has been added to the -mm mm-nonmm-unstable branch. Its filename is
build-id-require-program-headers-to-be-right-after-elf-header.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/build-id-require-program-headers-to-be-right-after-elf-header.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Subject: build-id: require program headers to be right after ELF header
Date: Fri, 21 Jun 2024 21:39:33 +0300
Neither ELF spec not ELF loader require program header to be placed right
after ELF header, but build-id code very much assumes such placement:
See
find_get_page(vma->vm_file->f_mapping, 0);
line and checks against PAGE_SIZE.
Returns errors for now until someone rewrites build-id parser
to be more inline with load_elf_binary().
Link: https://lkml.kernel.org/r/d58bc281-6ca7-467a-9a64-40fa214bd63e@p183
Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/buildid.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
--- a/lib/buildid.c~build-id-require-program-headers-to-be-right-after-elf-header
+++ a/lib/buildid.c
@@ -73,6 +73,13 @@ static int get_build_id_32(const void *p
Elf32_Phdr *phdr;
int i;
+ /*
+ * FIXME
+ * Neither ELF spec nor ELF loader require that program headers
+ * start immediately after ELF header.
+ */
+ if (ehdr->e_phoff != sizeof(Elf32_Ehdr))
+ return -EINVAL;
/* only supports phdr that fits in one page */
if (ehdr->e_phnum >
(PAGE_SIZE - sizeof(Elf32_Ehdr)) / sizeof(Elf32_Phdr))
@@ -98,6 +105,13 @@ static int get_build_id_64(const void *p
Elf64_Phdr *phdr;
int i;
+ /*
+ * FIXME
+ * Neither ELF spec nor ELF loader require that program headers
+ * start immediately after ELF header.
+ */
+ if (ehdr->e_phoff != sizeof(Elf64_Ehdr))
+ return -EINVAL;
/* only supports phdr that fits in one page */
if (ehdr->e_phnum >
(PAGE_SIZE - sizeof(Elf64_Ehdr)) / sizeof(Elf64_Phdr))
_
Patches currently in -mm which might be from adobriyan@xxxxxxxxx are
proc-test-kthread-field.patch
build-id-require-program-headers-to-be-right-after-elf-header.patch
