diff options
author | Ilya Leoshkevich <iii@linux.ibm.com> | 2021-10-12 04:25:21 +0200 |
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committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2021-10-26 11:29:55 -0300 |
commit | 3cde0135ca51de731314532a829b3e15fe3fd7e2 (patch) | |
tree | d395d6348c323ba5f14653a430db31e3635643a4 | |
parent | a9c99e98815f06bd034b2b32ce0a5114891f2370 (diff) | |
download | pahole-3cde0135ca51de731314532a829b3e15fe3fd7e2.tar.gz |
dwarf_loader: Fix heap overflow when accessing variable specification
Variables can be allocated with or without specification, however,
tag__recode_dwarf_type() always tries accessing it, leading to heap read
overflows and subsequent logic bugs.
Fix by introducing a bit that tracks whether or not specification is
present.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: bpf@vger.kernel.org
Cc: dwarves@vger.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-rw-r--r-- | dwarf_loader.c | 15 | ||||
-rw-r--r-- | dwarves.h | 1 |
2 files changed, 11 insertions, 5 deletions
diff --git a/dwarf_loader.c b/dwarf_loader.c index fc79770d..bed0019a 100644 --- a/dwarf_loader.c +++ b/dwarf_loader.c @@ -723,6 +723,7 @@ static struct variable *variable__new(Dwarf_Die *die, struct cu *cu, struct conf var->external = dwarf_hasattr(die, DW_AT_external); /* non-defining declaration of an object */ var->declaration = dwarf_hasattr(die, DW_AT_declaration); + var->has_specification = has_specification; var->scope = VSCOPE_UNKNOWN; INIT_LIST_HEAD(&var->annots); var->ip.addr = 0; @@ -2291,12 +2292,16 @@ static int tag__recode_dwarf_type(struct tag *tag, struct cu *cu) goto find_type; case DW_TAG_variable: { struct variable *var = tag__variable(tag); - dwarf_off_ref specification = dwarf_tag__spec(dtag); - if (specification.off) { - dtype = dwarf_cu__find_tag_by_ref(cu->priv, &specification); - if (dtype) - var->spec = tag__variable(dtype->tag); + if (var->has_specification) { + dwarf_off_ref specification = dwarf_tag__spec(dtag); + + if (specification.off) { + dtype = dwarf_cu__find_tag_by_ref(cu->priv, + &specification); + if (dtype) + var->spec = tag__variable(dtype->tag); + } } } @@ -693,6 +693,7 @@ struct variable { const char *name; uint8_t external:1; uint8_t declaration:1; + uint8_t has_specification:1; enum vscope scope; struct location location; struct hlist_node tool_hnode; |