From 0e6d3adc60d8073397af6a320e594d98d7fbedde Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Fri, 28 Oct 2016 09:11:55 -0700 Subject: [PATCH] Check IFUNC definition in unrelocated shared library [BZ #20019] Calling an IFUNC function defined in unrelocated shared library may lead to segfault. This patch issues an error message to request relinking the shared library if it references IFUNC function defined in the unrelocated shared library. [BZ #20019] * sysdeps/i386/dl-machine.h (elf_machine_rel): Check IFUNC definition in unrelocated shared library. * sysdeps/x86_64/dl-machine.h (elf_machine_rela): Likewise. --- ChangeLog | 7 +++++++ sysdeps/i386/dl-machine.h | 18 +++++++++++++++++- sysdeps/x86_64/dl-machine.h | 18 +++++++++++++++++- 3 files changed, 41 insertions(+), 2 deletions(-) diff --git a/ChangeLog b/ChangeLog index b5626ed5cad..995720ec690 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,10 @@ +2016-10-28 H.J. Lu + + [BZ #20019] + * sysdeps/i386/dl-machine.h (elf_machine_rel): Check IFUNC + definition in unrelocated shared library. + * sysdeps/x86_64/dl-machine.h (elf_machine_rela): Likewise. + 2016-10-28 Florian Weimer [BZ #20729] diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h index 4e3968a8aaa..e5ad0c513d2 100644 --- a/sysdeps/i386/dl-machine.h +++ b/sysdeps/i386/dl-machine.h @@ -321,7 +321,23 @@ elf_machine_rel (struct link_map *map, const Elf32_Rel *reloc, 0) && __builtin_expect (sym->st_shndx != SHN_UNDEF, 1) && __builtin_expect (!skip_ifunc, 1)) - value = ((Elf32_Addr (*) (void)) value) (); + { +# ifndef RTLD_BOOTSTRAP + if (sym_map != map + && sym_map->l_type != lt_executable + && !sym_map->l_relocated) + { + const char *strtab + = (const char *) D_PTR (map, l_info[DT_STRTAB]); + _dl_fatal_printf ("\ +%s: Relink `%s' with `%s' for IFUNC symbol `%s'\n", + RTLD_PROGNAME, map->l_name, + sym_map->l_name, + strtab + refsym->st_name); + } +# endif + value = ((Elf32_Addr (*) (void)) value) (); + } switch (r_type) { diff --git a/sysdeps/x86_64/dl-machine.h b/sysdeps/x86_64/dl-machine.h index c0f0fa16a23..5c021dcf992 100644 --- a/sysdeps/x86_64/dl-machine.h +++ b/sysdeps/x86_64/dl-machine.h @@ -331,7 +331,23 @@ elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc, 0) && __builtin_expect (sym->st_shndx != SHN_UNDEF, 1) && __builtin_expect (!skip_ifunc, 1)) - value = ((ElfW(Addr) (*) (void)) value) (); + { +# ifndef RTLD_BOOTSTRAP + if (sym_map != map + && sym_map->l_type != lt_executable + && !sym_map->l_relocated) + { + const char *strtab + = (const char *) D_PTR (map, l_info[DT_STRTAB]); + _dl_fatal_printf ("\ +%s: Relink `%s' with `%s' for IFUNC symbol `%s'\n", + RTLD_PROGNAME, map->l_name, + sym_map->l_name, + strtab + refsym->st_name); + } +# endif + value = ((ElfW(Addr) (*) (void)) value) (); + } switch (r_type) { -- 2.47.2