From c799eddb3512a4ce2b5c11bd91f888f30241faf6 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Tue, 13 Dec 2022 10:05:17 +1030 Subject: [PATCH] asan: mips_hi16_list segfault in bfd_get_section_limit_octets static variables like mips_hi16_list are nasty for applications using bfd. It is possible when opening and closing bfds with mis-matched hi/lo relocs to leave a stale section pointer on the list. That can cause a segfault if multiple bfds are being processed. Tidying the list when closing is sufficient to stop this happening (and fixes small memory leaks). This patch goes further and moves mips_hi16_list to where it belongs in the bfd tdata. * elf32-mips.c (bfd_elf32_close_and_cleanup(: Define. * elf64-mips.c (bfd_elf64_close_and_cleanup): Define. * elfn32-mips.c (bfd_elf32_close_and_cleanup(: Define. * elfxx-mips.c (struct mips_hi16): Move earlier. (mips_hi16_list): Move to.. (struct mips_elf_obj_tdata): ..here. (_bfd_mips_elf_close_and_cleanup): New function. (_bfd_mips_elf_hi16_reloc, _bfd_mips_elf_lo16_reloc), (_bfd_elf_mips_get_relocated_section_contents): Adjust uses of mips_hi16_list. * elfxx-mips.h (_bfd_mips_elf_close_and_cleanup): Declare. --- bfd/elf32-mips.c | 1 + bfd/elf64-mips.c | 1 + bfd/elfn32-mips.c | 1 + bfd/elfxx-mips.c | 69 ++++++++++++++++++++++++++++++----------------- bfd/elfxx-mips.h | 2 ++ 5 files changed, 50 insertions(+), 24 deletions(-) diff --git a/bfd/elf32-mips.c b/bfd/elf32-mips.c index be28d1a3b1c..0ffa9017d7b 100644 --- a/bfd/elf32-mips.c +++ b/bfd/elf32-mips.c @@ -2599,6 +2599,7 @@ static const struct ecoff_debug_swap mips_elf32_ecoff_debug_swap = { _bfd_mips_elf_print_private_bfd_data #define bfd_elf32_bfd_relax_section _bfd_mips_elf_relax_section #define bfd_elf32_mkobject _bfd_mips_elf_mkobject +#define bfd_elf32_close_and_cleanup _bfd_mips_elf_close_and_cleanup /* Support for SGI-ish mips targets. */ #define TARGET_LITTLE_SYM mips_elf32_le_vec diff --git a/bfd/elf64-mips.c b/bfd/elf64-mips.c index 419d9bc6dbd..9b0120b8167 100644 --- a/bfd/elf64-mips.c +++ b/bfd/elf64-mips.c @@ -4815,6 +4815,7 @@ const struct elf_size_info mips_elf64_size_info = #define bfd_elf64_get_dynamic_reloc_upper_bound mips_elf64_get_dynamic_reloc_upper_bound #define bfd_elf64_mkobject _bfd_mips_elf_mkobject +#define bfd_elf64_close_and_cleanup _bfd_mips_elf_close_and_cleanup /* The SGI style (n)64 NewABI. */ #define TARGET_LITTLE_SYM mips_elf64_le_vec diff --git a/bfd/elfn32-mips.c b/bfd/elfn32-mips.c index d222d1a5d15..452a2a7b74b 100644 --- a/bfd/elfn32-mips.c +++ b/bfd/elfn32-mips.c @@ -4197,6 +4197,7 @@ static const struct ecoff_debug_swap mips_elf32_ecoff_debug_swap = { #define bfd_elf32_bfd_print_private_bfd_data \ _bfd_mips_elf_print_private_bfd_data #define bfd_elf32_mkobject mips_elf_n32_mkobject +#define bfd_elf32_close_and_cleanup _bfd_mips_elf_close_and_cleanup /* Support for SGI-ish mips targets using n32 ABI. */ diff --git a/bfd/elfxx-mips.c b/bfd/elfxx-mips.c index 618fb43540c..f77ccde8409 100644 --- a/bfd/elfxx-mips.c +++ b/bfd/elfxx-mips.c @@ -549,6 +549,19 @@ struct mips_htab_traverse_info bool error; }; +/* Used to store a REL high-part relocation such as R_MIPS_HI16 or + R_MIPS_GOT16. REL is the relocation, INPUT_SECTION is the section + that contains the relocation field and DATA points to the start of + INPUT_SECTION. */ + +struct mips_hi16 +{ + struct mips_hi16 *next; + bfd_byte *data; + asection *input_section; + arelent rel; +}; + /* MIPS ELF private object data. */ struct mips_elf_obj_tdata @@ -584,6 +597,8 @@ struct mips_elf_obj_tdata asymbol *elf_text_symbol; asection *elf_data_section; asection *elf_text_section; + + struct mips_hi16 *mips_hi16_list; }; /* Get MIPS ELF private object data from BFD's tdata. */ @@ -1365,6 +1380,23 @@ _bfd_mips_elf_mkobject (bfd *abfd) MIPS_ELF_DATA); } +bool +_bfd_mips_elf_close_and_cleanup (bfd *abfd) +{ + struct mips_elf_obj_tdata *tdata = mips_elf_tdata (abfd); + if (tdata != NULL && bfd_get_format (abfd) == bfd_object) + { + BFD_ASSERT (tdata->root.object_id == MIPS_ELF_DATA); + while (tdata->mips_hi16_list != NULL) + { + struct mips_hi16 *hi = tdata->mips_hi16_list; + tdata->mips_hi16_list = hi->next; + free (hi); + } + } + return _bfd_elf_close_and_cleanup (abfd); +} + bool _bfd_mips_elf_new_section_hook (bfd *abfd, asection *sec) { @@ -2481,23 +2513,6 @@ _bfd_mips_elf_gprel16_with_gp (bfd *abfd, asymbol *symbol, return bfd_reloc_ok; } -/* Used to store a REL high-part relocation such as R_MIPS_HI16 or - R_MIPS_GOT16. REL is the relocation, INPUT_SECTION is the section - that contains the relocation field and DATA points to the start of - INPUT_SECTION. */ - -struct mips_hi16 -{ - struct mips_hi16 *next; - bfd_byte *data; - asection *input_section; - arelent rel; -}; - -/* FIXME: This should not be a static variable. */ - -static struct mips_hi16 *mips_hi16_list; - /* A howto special_function for REL *HI16 relocations. We can only calculate the correct value once we've seen the partnering *LO16 relocation, so just save the information for later. @@ -2508,12 +2523,13 @@ static struct mips_hi16 *mips_hi16_list; simplies the relocation handling in gcc. */ bfd_reloc_status_type -_bfd_mips_elf_hi16_reloc (bfd *abfd ATTRIBUTE_UNUSED, arelent *reloc_entry, +_bfd_mips_elf_hi16_reloc (bfd *abfd, arelent *reloc_entry, asymbol *symbol ATTRIBUTE_UNUSED, void *data, asection *input_section, bfd *output_bfd, char **error_message ATTRIBUTE_UNUSED) { struct mips_hi16 *n; + struct mips_elf_obj_tdata *tdata; if (reloc_entry->address > bfd_get_section_limit (abfd, input_section)) return bfd_reloc_outofrange; @@ -2522,11 +2538,12 @@ _bfd_mips_elf_hi16_reloc (bfd *abfd ATTRIBUTE_UNUSED, arelent *reloc_entry, if (n == NULL) return bfd_reloc_outofrange; - n->next = mips_hi16_list; + tdata = mips_elf_tdata (abfd); + n->next = tdata->mips_hi16_list; n->data = data; n->input_section = input_section; n->rel = *reloc_entry; - mips_hi16_list = n; + tdata->mips_hi16_list = n; if (output_bfd != NULL) reloc_entry->address += input_section->output_offset; @@ -2566,6 +2583,7 @@ _bfd_mips_elf_lo16_reloc (bfd *abfd, arelent *reloc_entry, asymbol *symbol, { bfd_vma vallo; bfd_byte *location = (bfd_byte *) data + reloc_entry->address; + struct mips_elf_obj_tdata *tdata; if (!bfd_reloc_offset_in_range (reloc_entry->howto, abfd, input_section, reloc_entry->address)) @@ -2577,12 +2595,13 @@ _bfd_mips_elf_lo16_reloc (bfd *abfd, arelent *reloc_entry, asymbol *symbol, _bfd_mips_elf_reloc_shuffle (abfd, reloc_entry->howto->type, false, location); - while (mips_hi16_list != NULL) + tdata = mips_elf_tdata (abfd); + while (tdata->mips_hi16_list != NULL) { bfd_reloc_status_type ret; struct mips_hi16 *hi; - hi = mips_hi16_list; + hi = tdata->mips_hi16_list; /* R_MIPS*_GOT16 relocations are something of a special case. We want to install the addend in the same way as for a R_MIPS*_HI16 @@ -2606,7 +2625,7 @@ _bfd_mips_elf_lo16_reloc (bfd *abfd, arelent *reloc_entry, asymbol *symbol, if (ret != bfd_reloc_ok) return ret; - mips_hi16_list = hi->next; + tdata->mips_hi16_list = hi->next; free (hi); } @@ -13294,12 +13313,14 @@ _bfd_elf_mips_get_relocated_section_contents reloc_vector = (arelent **) bfd_malloc (reloc_size); if (reloc_vector == NULL) { + struct mips_elf_obj_tdata *tdata; struct mips_hi16 **hip, *hi; error_return: /* If we are going to return an error, remove entries on mips_hi16_list that point into this section's data. Data will typically be freed on return from this function. */ - hip = &mips_hi16_list; + tdata = mips_elf_tdata (abfd); + hip = &tdata->mips_hi16_list; while ((hi = *hip) != NULL) { if (hi->input_section == input_section) diff --git a/bfd/elfxx-mips.h b/bfd/elfxx-mips.h index 6b22fdab3ae..7d40808496d 100644 --- a/bfd/elfxx-mips.h +++ b/bfd/elfxx-mips.h @@ -31,6 +31,8 @@ enum reloc_check extern bool _bfd_mips_elf_mkobject (bfd *); +extern bool _bfd_mips_elf_close_and_cleanup + (bfd *); extern bool _bfd_mips_elf_new_section_hook (bfd *, asection *); extern void _bfd_mips_elf_symbol_processing -- 2.30.2