diff options
authorPhilipp Rudo <prudo@linux.vnet.ibm.com>2018-04-13 15:36:13 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-04-13 17:10:28 -0700
commitd2b8178ca7324a21495cb71049b4e4a041ab5942 (patch)
parentee6ebeda8ddc350700168f2c8052a97bd9c11e5b (diff)
kernel/kexec_file.c: remove checks in kexec_purgatory_load
Before the purgatory is loaded several checks are done whether the ELF file in kexec_purgatory is valid or not. These checks are incomplete. For example they don't check for the total size of the sections defined in the section header table or if the entry point actually points into the purgatory. On the other hand the purgatory, although an ELF file on its own, is part of the kernel. Thus not trusting the purgatory means not trusting the kernel build itself. So remove all validity checks on the purgatory and just trust the kernel build. Link: http://lkml.kernel.org/r/20180321112751.22196-3-prudo@linux.vnet.ibm.com Signed-off-by: Philipp Rudo <prudo@linux.vnet.ibm.com> Acked-by: Dave Young <dyoung@redhat.com> Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 files changed, 0 insertions, 14 deletions
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index b06b1fac5252..81ba4f782486 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -941,22 +941,8 @@ int kexec_load_purgatory(struct kimage *image, unsigned long min,
if (kexec_purgatory_size <= 0)
return -EINVAL;
- if (kexec_purgatory_size < sizeof(Elf_Ehdr))
- return -ENOEXEC;
pi->ehdr = (Elf_Ehdr *)kexec_purgatory;
- if (memcmp(pi->ehdr->e_ident, ELFMAG, SELFMAG) != 0
- || pi->ehdr->e_type != ET_REL
- || !elf_check_arch(pi->ehdr)
- || pi->ehdr->e_shentsize != sizeof(Elf_Shdr))
- return -ENOEXEC;
- if (pi->ehdr->e_shoff >= kexec_purgatory_size
- || (pi->ehdr->e_shnum * sizeof(Elf_Shdr) >
- kexec_purgatory_size - pi->ehdr->e_shoff))
- return -ENOEXEC;
ret = __kexec_load_purgatory(image, min, max, top_down);
if (ret)
return ret;

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