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| author | Alan Modra <amodra@gmail.com> | 2019-11-19 11:38:36 +1030 |
|---|---|---|
| committer | Alan Modra <amodra@gmail.com> | 2019-11-19 12:31:22 +1030 |
| commit | f14080d440fab16dcb498c1a46864a5a1be37aaa (patch) | |
| tree | b5013d182ac1d7722342c1ce5fa4d93c6ce3fa02 | |
| parent | df56ecde8aeed75693f49c9e290427ee5030b05c (diff) | |
| download | gdb-f14080d440fab16dcb498c1a46864a5a1be37aaa.zip gdb-f14080d440fab16dcb498c1a46864a5a1be37aaa.tar.gz gdb-f14080d440fab16dcb498c1a46864a5a1be37aaa.tar.bz2 | |
PR25197, assertion fail coffgen.c
The testcase in this PR triggered "BFD_ASSERT (p2->is_sym)" by
sneakily generating a C_FILE sym whose value pointed into auxents.
The fix then is in the last changed line of this patch, to check
p->is_sym as well as p->u.syment.n_sclass. The other changes fix
various overflow checks that weren't as solid as they could be.
PR 25197
* coffgen.c (coff_find_nearest_line_with_names): Check that C_FILE
u.syment.n_value does point at another C_FILE sym and not into
some auxent that happens to look like a C_FILE. Properly check
for integer overflow and avoid possible pointer wrap-around.
Simplify pr17512 checks.
| -rw-r--r-- | bfd/ChangeLog | 9 | ||||
| -rw-r--r-- | bfd/coffgen.c | 25 |
2 files changed, 19 insertions, 15 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog index d13d969..ffe527c 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,5 +1,14 @@ 2019-11-19 Alan Modra <amodra@gmail.com> + PR 25197 + * coffgen.c (coff_find_nearest_line_with_names): Check that C_FILE + u.syment.n_value does point at another C_FILE sym and not into + some auxent that happens to look like a C_FILE. Properly check + for integer overflow and avoid possible pointer wrap-around. + Simplify pr17512 checks. + +2019-11-19 Alan Modra <amodra@gmail.com> + PR 25200 * reloc.c (bfd_default_reloc_type_lookup): Don't BFD_FAIL. * elf.c (_bfd_elf_validate_reloc): Don't segfault on NULL howto. diff --git a/bfd/coffgen.c b/bfd/coffgen.c index ba7bb5e..7f26e18 100644 --- a/bfd/coffgen.c +++ b/bfd/coffgen.c @@ -1814,10 +1814,11 @@ coff_get_normalized_symtab (bfd *abfd) if (! _bfd_coff_get_external_symbols (abfd)) return NULL; - size = obj_raw_syment_count (abfd) * sizeof (combined_entry_type); + size = obj_raw_syment_count (abfd); /* Check for integer overflow. */ - if (size < obj_raw_syment_count (abfd)) + if (size > (bfd_size_type) -1 / sizeof (combined_entry_type)) return NULL; + size *= sizeof (combined_entry_type); internal = (combined_entry_type *) bfd_zalloc (abfd, size); if (internal == NULL && size != 0) return NULL; @@ -1844,29 +1845,20 @@ coff_get_normalized_symtab (bfd *abfd) symbol_ptr = internal_ptr; internal_ptr->is_sym = TRUE; - /* PR 17512: file: 1353-1166-0.004. */ - if (symbol_ptr->u.syment.n_sclass == C_FILE - && symbol_ptr->u.syment.n_numaux > 0 - && raw_src + symesz + symbol_ptr->u.syment.n_numaux - * symesz > raw_end) - { - bfd_release (abfd, internal); - return NULL; - } - for (i = 0; i < symbol_ptr->u.syment.n_numaux; i++) { internal_ptr++; + raw_src += symesz; + /* PR 17512: Prevent buffer overrun. */ - if (internal_ptr >= internal_end) + if (raw_src >= raw_end || internal_ptr >= internal_end) { bfd_release (abfd, internal); return NULL; } - raw_src += symesz; bfd_coff_swap_aux_in (abfd, (void *) raw_src, symbol_ptr->u.syment.n_type, symbol_ptr->u.syment.n_sclass, @@ -2408,13 +2400,16 @@ coff_find_nearest_line_with_names (bfd *abfd, maxdiff = offset + sec_vma - p2->u.syment.n_value; } + if (p->u.syment.n_value >= cof->raw_syment_count) + break; + /* Avoid endless loops on erroneous files by ensuring that we always move forward in the file. */ if (p >= cof->raw_syments + p->u.syment.n_value) break; p = cof->raw_syments + p->u.syment.n_value; - if (p > pend || p->u.syment.n_sclass != C_FILE) + if (!p->is_sym || p->u.syment.n_sclass != C_FILE) break; } } |