From 5a805384b831e5946cc8dae13a75617cb4b9c080 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Fri, 25 Sep 2020 10:05:57 +0930 Subject: [PATCH] asan: readelf buffer overflow and abort * elfcomm.c (byte_put_little_endian, byte_put_big_endian): Support more field sizes. * readelf.c (target_specific_reloc_handling ): Limit allowed reloc_size. Don't read_leb128 outside of section. --- binutils/ChangeLog | 7 ++++++ binutils/elfcomm.c | 59 ++++++++++------------------------------------ binutils/readelf.c | 9 +++---- 3 files changed, 24 insertions(+), 51 deletions(-) diff --git a/binutils/ChangeLog b/binutils/ChangeLog index c1e78305edc..59750dd1a26 100644 --- a/binutils/ChangeLog +++ b/binutils/ChangeLog @@ -1,3 +1,10 @@ +2020-09-25 Alan Modra + + * elfcomm.c (byte_put_little_endian, byte_put_big_endian): Support + more field sizes. + * readelf.c (target_specific_reloc_handling ): Limit + allowed reloc_size. Don't read_leb128 outside of section. + 2020-09-23 Mark Wielaard * dwarf.c (process_debug_info): Print Unit Type for DWARF5. diff --git a/binutils/elfcomm.c b/binutils/elfcomm.c index 37f9dbe7eef..81742bf75b1 100644 --- a/binutils/elfcomm.c +++ b/binutils/elfcomm.c @@ -67,66 +67,31 @@ void (*byte_put) (unsigned char *, elf_vma, int); void byte_put_little_endian (unsigned char * field, elf_vma value, int size) { - switch (size) + if (size <= 0 || size > 8) { - case 8: - field[7] = (((value >> 24) >> 24) >> 8) & 0xff; - field[6] = ((value >> 24) >> 24) & 0xff; - field[5] = ((value >> 24) >> 16) & 0xff; - field[4] = ((value >> 24) >> 8) & 0xff; - /* Fall through. */ - case 4: - field[3] = (value >> 24) & 0xff; - /* Fall through. */ - case 3: - field[2] = (value >> 16) & 0xff; - /* Fall through. */ - case 2: - field[1] = (value >> 8) & 0xff; - /* Fall through. */ - case 1: - field[0] = value & 0xff; - break; - - default: error (_("Unhandled data length: %d\n"), size); abort (); } + while (size--) + { + *field++ = value & 0xff; + value >>= 8; + } } void byte_put_big_endian (unsigned char * field, elf_vma value, int size) { - switch (size) + if (size <= 0 || size > 8) { - case 8: - field[7] = value & 0xff; - field[6] = (value >> 8) & 0xff; - field[5] = (value >> 16) & 0xff; - field[4] = (value >> 24) & 0xff; - value >>= 16; - value >>= 16; - /* Fall through. */ - case 4: - field[3] = value & 0xff; - value >>= 8; - /* Fall through. */ - case 3: - field[2] = value & 0xff; - value >>= 8; - /* Fall through. */ - case 2: - field[1] = value & 0xff; - value >>= 8; - /* Fall through. */ - case 1: - field[0] = value & 0xff; - break; - - default: error (_("Unhandled data length: %d\n"), size); abort (); } + while (size--) + { + field[size] = value & 0xff; + value >>= 8; + } } elf_vma (*byte_get) (const unsigned char *, int); diff --git a/binutils/readelf.c b/binutils/readelf.c index 95720ea0552..9ba4e29a659 100644 --- a/binutils/readelf.c +++ b/binutils/readelf.c @@ -12622,7 +12622,7 @@ target_specific_reloc_handling (Filedata * filedata, if (saved_sym != NULL) { bfd_vma value; - unsigned int reloc_size; + unsigned int reloc_size = 0; int leb_ret = 0; switch (reloc_type) { @@ -12631,15 +12631,16 @@ target_specific_reloc_handling (Filedata * filedata, break; case 11: /* R_MSP430_GNU_SET_ULEB128 */ case 22: /* R_MSP430X_GNU_SET_ULEB128 */ - read_leb128 (start + reloc->r_offset, end, FALSE, - &reloc_size, &leb_ret); + if (reloc->r_offset < (size_t) (end - start)) + read_leb128 (start + reloc->r_offset, end, FALSE, + &reloc_size, &leb_ret); break; default: reloc_size = 2; break; } - if (leb_ret != 0) + if (leb_ret != 0 || reloc_size == 0 || reloc_size > 8) error (_("MSP430 ULEB128 field at 0x%lx contains invalid " "ULEB128 value\n"), (long) reloc->r_offset); -- 2.30.2