From 0f2c8af3ba82ac54acc63ab7cb068578a6c0d96e Mon Sep 17 00:00:00 2001 From: Mark Wielaard Date: Sun, 8 May 2022 11:00:42 +0200 Subject: strip: Add more NULL check When gelf_getshdr, gelf_getrela, gelf_getrel or gelf_getsymshndx return NULL it is an internal error which we want to report instead of crashing. Signed-off-by: Mark Wielaard --- src/ChangeLog | 5 +++++ src/strip.c | 12 ++++++++++-- 2 files changed, 15 insertions(+), 2 deletions(-) (limited to 'src') diff --git a/src/ChangeLog b/src/ChangeLog index ae09eb1f..8c9f5ddd 100644 --- a/src/ChangeLog +++ b/src/ChangeLog @@ -1,3 +1,8 @@ +2022-05-09 Mark Wielaard + + * strip.c (remove_debug_relocations): Check gelf_getshdr, gelf_getrela, + gelf_getrel and gelf_getsymshndx don't return NULL. + 2022-05-10 Mark Wielaard * elfcompress.c (process_file): Sanity check shstrtab_name, diff --git a/src/strip.c b/src/strip.c index 30a1f9da..452b1279 100644 --- a/src/strip.c +++ b/src/strip.c @@ -576,7 +576,8 @@ remove_debug_relocations (Ebl *ebl, Elf *elf, GElf_Ehdr *ehdr, might want to change the size. */ GElf_Shdr shdr_mem; GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); - if (shdr->sh_type == SHT_REL || shdr->sh_type == SHT_RELA) + if (shdr != NULL + && (shdr->sh_type == SHT_REL || shdr->sh_type == SHT_RELA)) { /* Make sure that this relocation section points to a section to relocate with contents, that isn't @@ -584,7 +585,8 @@ remove_debug_relocations (Ebl *ebl, Elf *elf, GElf_Ehdr *ehdr, Elf_Scn *tscn = elf_getscn (elf, shdr->sh_info); GElf_Shdr tshdr_mem; GElf_Shdr *tshdr = gelf_getshdr (tscn, &tshdr_mem); - if (tshdr->sh_type == SHT_NOBITS + if (tshdr == NULL + || tshdr->sh_type == SHT_NOBITS || tshdr->sh_size == 0 || (tshdr->sh_flags & SHF_ALLOC) != 0) continue; @@ -653,6 +655,8 @@ remove_debug_relocations (Ebl *ebl, Elf *elf, GElf_Ehdr *ehdr, if (is_rela) { GElf_Rela *r = gelf_getrela (reldata, relidx, &mem.rela); + if (r == NULL) + INTERNAL_ERROR (fname); offset = r->r_offset; addend = r->r_addend; rtype = GELF_R_TYPE (r->r_info); @@ -662,6 +666,8 @@ remove_debug_relocations (Ebl *ebl, Elf *elf, GElf_Ehdr *ehdr, else { GElf_Rel *r = gelf_getrel (reldata, relidx, &mem.rel); + if (r == NULL) + INTERNAL_ERROR (fname); offset = r->r_offset; addend = 0; rtype = GELF_R_TYPE (r->r_info); @@ -685,6 +691,8 @@ remove_debug_relocations (Ebl *ebl, Elf *elf, GElf_Ehdr *ehdr, GElf_Sym *sym = gelf_getsymshndx (symdata, xndxdata, symndx, &sym_mem, &xndx); + if (sym == NULL) + INTERNAL_ERROR (fname); Elf32_Word sec = (sym->st_shndx == SHN_XINDEX ? xndx : sym->st_shndx); -- cgit v1.2.1