From b0ee912984fe1cebdb765a9626bcb49659cd44c9 Mon Sep 17 00:00:00 2001 From: Mark Johnston Date: Tue, 10 Mar 2015 21:08:58 +0000 Subject: CTF containers use the ctf_dtoldid field as a threshold type index which indicates the range of type indices which have been committed to the container by ctf_update(). However, the top bit of the dtd_type field is not part of the type index; rather, it is a flag used to indicate that the corresponding CTF container is a parent. This is why the maximum CTF type index is 2^15 - 1 rather than 2^16 - 1. Therefore, this flag must be masked off (using the CTF_TYPE_TO_INDEX macro) when comparing a type index with the ctf_dtoldid field of a container. This bug was causing libctf to erroneously free committed type definitions in ctf_discard(). libdtrace holds some references to such types, resulting in a use-after-free. MFC after: 2 weeks Sponsored by: EMC / Isilon Storage Division --- cddl/contrib/opensolaris/common/ctf/ctf_create.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/cddl/contrib/opensolaris/common/ctf/ctf_create.c b/cddl/contrib/opensolaris/common/ctf/ctf_create.c index 41e81e50fd08..679ed18798a7 100644 --- a/cddl/contrib/opensolaris/common/ctf/ctf_create.c +++ b/cddl/contrib/opensolaris/common/ctf/ctf_create.c @@ -584,7 +584,7 @@ ctf_discard(ctf_file_t *fp) for (dtd = ctf_list_prev(&fp->ctf_dtdefs); dtd != NULL; dtd = ntd) { ntd = ctf_list_prev(dtd); - if (dtd->dtd_type <= fp->ctf_dtoldid) + if (CTF_TYPE_TO_INDEX(dtd->dtd_type) <= fp->ctf_dtoldid) continue; /* skip types that have been committed */ ctf_dtd_delete(fp, dtd); @@ -1328,7 +1328,7 @@ ctf_add_type(ctf_file_t *dst_fp, ctf_file_t *src_fp, ctf_id_t src_type) */ if (dst_type == CTF_ERR && name[0] != '\0') { for (dtd = ctf_list_prev(&dst_fp->ctf_dtdefs); dtd != NULL && - dtd->dtd_type > dst_fp->ctf_dtoldid; + CTF_TYPE_TO_INDEX(dtd->dtd_type) > dst_fp->ctf_dtoldid; dtd = ctf_list_prev(dtd)) { if (CTF_INFO_KIND(dtd->dtd_data.ctt_info) == kind && dtd->dtd_name != NULL && -- cgit v1.2.3