[LU-7947] Suspicious dereference of pointer before NULL check in llog_cancel_rec()

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.11.0
• Affects Version/s: Lustre 2.9.0
• Labels: kw
• Severity: 3
• Assignee: WC Triage
• Reporter: Dmitry Eremin (Inactive)

Description

Suspicious dereference of pointer 'loghandle' before NULL check at line 218

• An event which alters the program's state, leading to the defect
  llog.c:202: 'loghandle' is dereferenced.
• An event which alters the program's state, leading to the defect
  llog.c:218: 'loghandle' is checked for NULL.

197		int llog_cancel_rec(const struct lu_env *env, struct llog_handle *loghandle,
198				    int index)
199		{
200			struct llog_thread_info *lgi = llog_info(env);
201			struct dt_device	*dt;
202			struct llog_log_hdr	*llh = loghandle->lgh_hdr;
203			struct thandle		*th;
204			int			 rc;
205			int rc1;
206			bool subtract_count = false;
207		 
208			ENTRY;
209		 
210			CDEBUG(D_RPCTRACE, "Canceling %d in log "DOSTID"\n", index,
211			       POSTID(&loghandle->lgh_id.lgl_oi));
212		 
213			if (index == 0) {...}
217		 
218			LASSERT(loghandle != NULL);