CVS commit: src/sys/kern

[Taylor R Campbell]

Module Name:    src
Committed By:   riastradh
Date:           Sat Sep 11 10:09:14 UTC 2021

Modified Files:
        src/sys/kern: sys_descrip.c vfs_vnops.c

Log Message:
sys/kern: Avoid fp->f_offset without the object (here, vnode) lock.


To generate a diff of this commit:
cvs rdiff -u -r1.37 -r1.38 src/sys/kern/sys_descrip.c
cvs rdiff -u -r1.222 -r1.223 src/sys/kern/vfs_vnops.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.


Modified files:

Index: src/sys/kern/sys_descrip.c
diff -u src/sys/kern/sys_descrip.c:1.37 src/sys/kern/sys_descrip.c:1.38
--- src/sys/kern/sys_descrip.c:1.37	Sun Feb 23 15:46:41 2020
+++ src/sys/kern/sys_descrip.c	Sat Sep 11 10:09:13 2021
@@ -1,4 +1,4 @@
-/*	$NetBSD: sys_descrip.c,v 1.37 2020/02/23 15:46:41 ad Exp $	*/
+/*	$NetBSD: sys_descrip.c,v 1.38 2021/09/11 10:09:13 riastradh Exp $	*/
 
 /*-
  * Copyright (c) 2008, 2020 The NetBSD Foundation, Inc.
@@ -67,7 +67,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sys_descrip.c,v 1.37 2020/02/23 15:46:41 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_descrip.c,v 1.38 2021/09/11 10:09:13 riastradh Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -243,8 +243,11 @@ do_fcntl_lock(int fd, int cmd, struct fl
 		return error;
 
 	vp = fp->f_vnode;
-	if (fl->l_whence == SEEK_CUR)
+	if (fl->l_whence == SEEK_CUR) {
+		vn_lock(vp, LK_SHARED | LK_RETRY);
 		fl->l_start += fp->f_offset;
+		VOP_UNLOCK(vp);
+	}
 
 	flg = F_POSIX;
 	p = curproc;

Index: src/sys/kern/vfs_vnops.c
diff -u src/sys/kern/vfs_vnops.c:1.222 src/sys/kern/vfs_vnops.c:1.223
--- src/sys/kern/vfs_vnops.c:1.222	Sat Sep 11 10:08:55 2021
+++ src/sys/kern/vfs_vnops.c	Sat Sep 11 10:09:13 2021
@@ -1,4 +1,4 @@
-/*	$NetBSD: vfs_vnops.c,v 1.222 2021/09/11 10:08:55 riastradh Exp $	*/
+/*	$NetBSD: vfs_vnops.c,v 1.223 2021/09/11 10:09:13 riastradh Exp $	*/
 
 /*-
  * Copyright (c) 2009 The NetBSD Foundation, Inc.
@@ -66,7 +66,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_vnops.c,v 1.222 2021/09/11 10:08:55 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_vnops.c,v 1.223 2021/09/11 10:09:13 riastradh Exp $");
 
 #include "veriexec.h"
 
@@ -817,10 +817,11 @@ vn_ioctl(file_t *fp, u_long com, void *d
 		if (com == FIONREAD) {
 			vn_lock(vp, LK_SHARED | LK_RETRY);
 			error = VOP_GETATTR(vp, &vattr, kauth_cred_get());
+			if (error == 0)
+				*(int *)data = vattr.va_size - fp->f_offset;
 			VOP_UNLOCK(vp);
 			if (error)
 				return (error);
-			*(int *)data = vattr.va_size - fp->f_offset;
 			return (0);
 		}
 		if ((com == FIONWRITE) || (com == FIONSPACE)) {