From a98c743fdf721a2333220209ca15e147badb55d1 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Mon, 24 Feb 2020 13:19:13 +1030 Subject: [PATCH] Re: vms buffer overflows and large memory allocation The last patch wasn't quite correct. I'd missed the fact that sbm_off had been updated. * vms-lib.c (_bfd_vms_lib_archive_p): Correct overflow checks. --- bfd/ChangeLog | 4 ++++ bfd/vms-lib.c | 14 ++++++++------ 2 files changed, 12 insertions(+), 6 deletions(-) diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 58b560d1aa..eeb042c32f 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,7 @@ +2020-02-24 Alan Modra + + * vms-lib.c (_bfd_vms_lib_archive_p): Correct overflow checks. + 2020-02-24 Alan Modra * vms-lib.c (struct carsym_mem): Add limit. diff --git a/bfd/vms-lib.c b/bfd/vms-lib.c index 3b42857aa9..87f865864c 100644 --- a/bfd/vms-lib.c +++ b/bfd/vms-lib.c @@ -627,6 +627,8 @@ _bfd_vms_lib_archive_p (bfd *abfd, enum vms_lib_kind kind) sbm = (struct vms_dcxsbm *) (buf + sbm_off); sbm_sz = bfd_getl16 (sbm->size); sbm_off += sbm_sz; + if (sbm_off > reclen) + goto err; sbmdesc->min_char = sbm->min_char; BFD_ASSERT (sbmdesc->min_char == 0); @@ -639,21 +641,21 @@ _bfd_vms_lib_archive_p (bfd *abfd, enum vms_lib_kind kind) goto err; sbmdesc->flags = (unsigned char *)bfd_alloc (abfd, l); off = bfd_getl16 (sbm->flags); - if (off > reclen - sbm_off - || reclen - sbm_off - off < l) + if (off > sbm_sz + || sbm_sz - off < l) goto err; memcpy (sbmdesc->flags, (bfd_byte *) sbm + off, l); sbmdesc->nodes = (unsigned char *)bfd_alloc (abfd, 2 * sbm_len); off = bfd_getl16 (sbm->nodes); - if (off > reclen - sbm_off - || reclen - sbm_off - off < 2 * sbm_len) + if (off > sbm_sz + || sbm_sz - off < 2 * sbm_len) goto err; memcpy (sbmdesc->nodes, (bfd_byte *) sbm + off, 2 * sbm_len); off = bfd_getl16 (sbm->next); if (off != 0) { - if (off > reclen - sbm_off - || reclen - sbm_off - off < 2 * sbm_len) + if (off > sbm_sz + || sbm_sz - off < 2 * sbm_len) goto err; /* Read the 'next' array. */ sbmdesc->next = (unsigned short *) bfd_alloc (abfd, 2 * sbm_len); -- 2.34.1