git: b56b601c5ba6 - main - dtrace: Improve DOF string table validation

The branch main has been updated by markj:

URL: https://cgit.FreeBSD.org/src/commit/?id=b56b601c5ba603031312b9bc7ae895ecb0dcdaec

commit b56b601c5ba603031312b9bc7ae895ecb0dcdaec
Author:     Mark Johnston <markj@FreeBSD.org>
AuthorDate: 2026-07-06 13:21:24 +0000
Commit:     Mark Johnston <markj@FreeBSD.org>
CommitDate: 2026-07-06 13:21:24 +0000

    dtrace: Improve DOF string table validation
    
    The check for a nul terminator implicitly assumes that the section size
    is positive.  Make the assumption explicit.
    
    Reviewed by:    christos
    MFC after:      2 weeks
    Sponsored by:   CHERI Research Centre
    Differential Revision:  https://reviews.freebsd.org/D57977
---
 sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c b/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c
index aa8716908cb1..ff31d806664b 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c
@@ -14288,8 +14288,9 @@ dtrace_dof_slurp(dof_hdr_t *dof, dtrace_vstate_t *vstate, cred_t *cr,
 			return (-1);
 		}
 
-		if (sec->dofs_type == DOF_SECT_STRTAB && *((char *)daddr +
-		    sec->dofs_offset + sec->dofs_size - 1) != '\0') {
+		if (sec->dofs_type == DOF_SECT_STRTAB && (sec->dofs_size == 0 ||
+		    *((char *)daddr + sec->dofs_offset + sec->dofs_size - 1) !=
+		    '\0')) {
 			dtrace_dof_error(dof, "non-terminating string table");
 			return (-1);
 		}