6.1-stable review patch. If anyone has any objections, please let me know.
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From: Alexey Dobriyan adobriyan@gmail.com
[ Upstream commit 961a2851324561caed579764ffbee3db82b32829 ]
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@gmail.com Reviewed-by: Jiri Olsa jolsa@kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Stable-dep-of: 905415ff3ffb ("lib/buildid: harden build ID parsing logic") Signed-off-by: Sasha Levin sashal@kernel.org --- lib/buildid.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/lib/buildid.c b/lib/buildid.c index dfc62625cae4e..493537344fc81 100644 --- a/lib/buildid.c +++ b/lib/buildid.c @@ -73,6 +73,13 @@ static int get_build_id_32(const void *page_addr, unsigned char *build_id, 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 *page_addr, unsigned char *build_id, 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))