If phnum is zero make sure e_phoff is also zero and not some random value.
That would cause trouble in update_file. This could happen when ELF_F_LAYOUT
is set and the user copied over a ehdr from a bogus ELF file where the phdrs
are unreadable. In that case trying to write out the new ELF image would
crash trying to follow the bogus e_phdr value.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
+2015-05-13 Mark Wielaard <mjw@redhat.com>
+
+ * elf32_updatenull.c (default_ehdr): If e_phnum is zero then set
+ e_phoff also to zero.
+
2015-05-12 Mark Wielaard <mjw@redhat.com>
* elf32_updatenull.c (updatenull_wrlock): Check that sh_addralign
elf->state.ELFW(elf,LIBELFBITS).ehdr_flags |= ELF_F_DIRTY;
}
+ /* If phnum is zero make sure e_phoff is also zero and not some random
+ value. That would cause trouble in update_file. */
+ if (ehdr->e_phnum == 0 && ehdr->e_phoff != 0)
+ {
+ ehdr->e_phoff = 0;
+ elf->state.ELFW(elf,LIBELFBITS).ehdr_flags |= ELF_F_DIRTY;
+ }
+
return 0;
}