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authorUlrich Drepper <drepper@redhat.com>2010-03-18 13:15:27 -0700
committerUlrich Drepper <drepper@redhat.com>2010-03-18 13:15:27 -0700
commit04f2902d9fadb2b8221162247412fb2c4667d95e (patch)
treeaf23898e6bc77fb23b49bafb54a2f251da96f372
parentb170ff0f8fb25d43dc6d6e9484fc33234110fd8d (diff)
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Future safety in checking ELF header.
If we should use further fields in the e_ident array in the ELF header of files we want zero to mean the default. Enforce zero for now so that non-optional features indicated by nonzero values are not go unnoticed when using an old dynamic linker.
-rw-r--r--ChangeLog6
-rw-r--r--elf/dl-load.c10
2 files changed, 14 insertions, 2 deletions
diff --git a/ChangeLog b/ChangeLog
index 92b6a91..9ff497d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2010-03-18 Ulrich Drepper <drepper@redhat.com>
+
+ * elf/dl-load.c (open_verify): Extend expected to the full size of the
+ e_ident array. When loading, check that the fields in e_ident we don't
+ know are zero to allow future extensions.
+
2010-03-18 H.J. Lu <hongjiu.lu@intel.com>
* sysdeps/i386/i686/multiarch/memcmp-ssse3.S: Update %xmm3
diff --git a/elf/dl-load.c b/elf/dl-load.c
index 756816f..d8f9131 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -1573,7 +1573,7 @@ open_verify (const char *name, struct filebuf *fbp, struct link_map *loader,
#elif defined MORE_ELF_HEADER_DATA
MORE_ELF_HEADER_DATA;
#endif
- static const unsigned char expected[EI_PAD] =
+ static const unsigned char expected[EI_NIDENT] =
{
[EI_MAG0] = ELFMAG0,
[EI_MAG1] = ELFMAG1,
@@ -1657,7 +1657,10 @@ open_verify (const char *name, struct filebuf *fbp, struct link_map *loader,
if (__builtin_expect (! VALID_ELF_HEADER (ehdr->e_ident, expected,
EI_ABIVERSION)
|| !VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
- ehdr->e_ident[EI_ABIVERSION]),
+ ehdr->e_ident[EI_ABIVERSION])
+ || memcmp (&ehdr->e_ident[EI_PAD],
+ &expected[EI_PAD],
+ EI_NIDENT - EI_PAD) != 0,
0))
{
/* Something is wrong. */
@@ -1701,6 +1704,9 @@ open_verify (const char *name, struct filebuf *fbp, struct link_map *loader,
else if (!VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
ehdr->e_ident[EI_ABIVERSION]))
errstring = N_("ELF file ABI version invalid");
+ else if (memcmp (&ehdr->e_ident[EI_PAD], &expected[EI_PAD],
+ EI_NIDENT - EI_PAD) != 0)
+ errstring = N_("nonzero padding in e_ident");
else
/* Otherwise we don't know what went wrong. */
errstring = N_("internal error");