34 lines
1019 B
Diff
34 lines
1019 B
Diff
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Bug 20019 - NULL pointer dereference in libc.so.6 IFUNC due to uninitialized GOT
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Prototype patch by H.J. Lu <hjl.tools@gmail.com> to error
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out when IFUNC being resolved is for another map that hasn't
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yet been relocated.
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--- a/sysdeps/x86_64/dl-machine.h
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+++ a/sysdeps/x86_64/dl-machine.h
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@@ -331,7 +331,23 @@ elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc,
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0)
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&& __builtin_expect (sym->st_shndx != SHN_UNDEF, 1)
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&& __builtin_expect (!skip_ifunc, 1))
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- value = ((ElfW(Addr) (*) (void)) value) ();
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+ {
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+# ifndef RTLD_BOOTSTRAP
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+ if (sym_map != map
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+ && sym_map->l_type != lt_executable
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+ && !sym_map->l_relocated)
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+ {
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+ const char *strtab
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+ = (const char *) D_PTR (map, l_info[DT_STRTAB]);
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+ _dl_fatal_printf ("\
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+%s: Relink `%s' with `%s' for IFUNC symbol `%s'\n",
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+ RTLD_PROGNAME, map->l_name,
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+ sym_map->l_name,
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+ strtab + refsym->st_name);
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+ }
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+#endif
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+ value = ((ElfW(Addr) (*) (void)) value) ();
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+ }
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switch (r_type)
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{
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