Date: Fri, 23 Oct 2009 15:14:54 +0000 (UTC) From: John Baldwin <jhb@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r198411 - in head/sys: kern sys Message-ID: <200910231514.n9NFEsfW064873@svn.freebsd.org>
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Author: jhb Date: Fri Oct 23 15:14:54 2009 New Revision: 198411 URL: http://svn.freebsd.org/changeset/base/198411 Log: - Fix several off-by-one errors when using MAXCOMLEN. The p_comm[] and td_name[] arrays are actually MAXCOMLEN + 1 in size and a few places that created shadow copies of these arrays were just using MAXCOMLEN. - Prefer using sizeof() of an array type to explicit constants for the array length in a few places. - Ensure that all of p_comm[] and td_name[] is always zero'd during execve() to guard against any possible information leaks. Previously trailing garbage in p_comm[] could be leaked to userland in ktrace record headers via td_name[]. Reviewed by: bde Modified: head/sys/kern/kern_exec.c head/sys/kern/kern_ktrace.c head/sys/kern/subr_bus.c head/sys/kern/subr_taskqueue.c head/sys/sys/interrupt.h Modified: head/sys/kern/kern_exec.c ============================================================================== --- head/sys/kern/kern_exec.c Fri Oct 23 15:12:05 2009 (r198410) +++ head/sys/kern/kern_exec.c Fri Oct 23 15:14:54 2009 (r198411) @@ -326,7 +326,7 @@ do_execve(td, args, mac_p) struct ucred *newcred = NULL, *oldcred; struct uidinfo *euip; register_t *stack_base; - int error, len = 0, i; + int error, i; struct image_params image_params, *imgp; struct vattr attr; int (*img_first)(struct image_params *); @@ -602,18 +602,12 @@ interpret: execsigs(p); /* name this process - nameiexec(p, ndp) */ - if (args->fname) { - len = min(nd.ni_cnd.cn_namelen,MAXCOMLEN); - bcopy(nd.ni_cnd.cn_nameptr, p->p_comm, len); - } else { - if (vn_commname(binvp, p->p_comm, MAXCOMLEN + 1) == 0) - len = MAXCOMLEN; - else { - len = sizeof(fexecv_proc_title); - bcopy(fexecv_proc_title, p->p_comm, len); - } - } - p->p_comm[len] = 0; + bzero(p->p_comm, sizeof(p->p_comm)); + if (args->fname) + bcopy(nd.ni_cnd.cn_nameptr, p->p_comm, + min(nd.ni_cnd.cn_namelen, MAXCOMLEN)); + else if (vn_commname(binvp, p->p_comm, sizeof(p->p_comm)) != 0) + bcopy(fexecv_proc_title, p->p_comm, sizeof(fexecv_proc_title)); bcopy(p->p_comm, td->td_name, sizeof(td->td_name)); /* Modified: head/sys/kern/kern_ktrace.c ============================================================================== --- head/sys/kern/kern_ktrace.c Fri Oct 23 15:12:05 2009 (r198410) +++ head/sys/kern/kern_ktrace.c Fri Oct 23 15:14:54 2009 (r198411) @@ -256,6 +256,10 @@ ktrace_resize_pool(u_int newsize) return (ktr_requestpool); } +/* ktr_getrequest() assumes that ktr_comm[] is the same size as td_name[]. */ +CTASSERT(sizeof(((struct ktr_header *)NULL)->ktr_comm) == + (sizeof((struct thread *)NULL)->td_name)); + static struct ktr_request * ktr_getrequest(int type) { @@ -283,7 +287,8 @@ ktr_getrequest(int type) microtime(&req->ktr_header.ktr_time); req->ktr_header.ktr_pid = p->p_pid; req->ktr_header.ktr_tid = td->td_tid; - bcopy(td->td_name, req->ktr_header.ktr_comm, MAXCOMLEN + 1); + bcopy(td->td_name, req->ktr_header.ktr_comm, + sizeof(req->ktr_header.ktr_comm)); req->ktr_buffer = NULL; req->ktr_header.ktr_len = 0; } else { Modified: head/sys/kern/subr_bus.c ============================================================================== --- head/sys/kern/subr_bus.c Fri Oct 23 15:12:05 2009 (r198410) +++ head/sys/kern/subr_bus.c Fri Oct 23 15:14:54 2009 (r198411) @@ -3861,8 +3861,8 @@ int bus_describe_intr(device_t dev, struct resource *irq, void *cookie, const char *fmt, ...) { - char descr[MAXCOMLEN]; va_list ap; + char descr[MAXCOMLEN + 1]; if (dev->parent == NULL) return (EINVAL); Modified: head/sys/kern/subr_taskqueue.c ============================================================================== --- head/sys/kern/subr_taskqueue.c Fri Oct 23 15:12:05 2009 (r198410) +++ head/sys/kern/subr_taskqueue.c Fri Oct 23 15:14:54 2009 (r198411) @@ -301,7 +301,7 @@ taskqueue_start_threads(struct taskqueue struct thread *td; struct taskqueue *tq; int i, error; - char ktname[MAXCOMLEN]; + char ktname[MAXCOMLEN + 1]; if (count <= 0) return (EINVAL); @@ -309,7 +309,7 @@ taskqueue_start_threads(struct taskqueue tq = *tqp; va_start(ap, name); - vsnprintf(ktname, MAXCOMLEN, name, ap); + vsnprintf(ktname, sizeof(ktname), name, ap); va_end(ap); tq->tq_threads = malloc(sizeof(struct thread *) * count, M_TASKQUEUE, Modified: head/sys/sys/interrupt.h ============================================================================== --- head/sys/sys/interrupt.h Fri Oct 23 15:12:05 2009 (r198410) +++ head/sys/sys/interrupt.h Fri Oct 23 15:14:54 2009 (r198411) @@ -47,7 +47,7 @@ struct intr_handler { driver_intr_t *ih_handler; /* Threaded handler function. */ void *ih_argument; /* Argument to pass to handlers. */ int ih_flags; - char ih_name[MAXCOMLEN]; /* Name of handler. */ + char ih_name[MAXCOMLEN + 1]; /* Name of handler. */ struct intr_event *ih_event; /* Event we are connected to. */ int ih_need; /* Needs service. */ TAILQ_ENTRY(intr_handler) ih_next; /* Next handler for this event. */ @@ -104,8 +104,8 @@ struct intr_handler { struct intr_event { TAILQ_ENTRY(intr_event) ie_list; TAILQ_HEAD(, intr_handler) ie_handlers; /* Interrupt handlers. */ - char ie_name[MAXCOMLEN]; /* Individual event name. */ - char ie_fullname[MAXCOMLEN]; + char ie_name[MAXCOMLEN + 1]; /* Individual event name. */ + char ie_fullname[MAXCOMLEN + 1]; struct mtx ie_lock; void *ie_source; /* Cookie used by MD code. */ struct intr_thread *ie_thread; /* Thread we are connected to. */
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