Module Name: src
Committed By: christos
Date: Fri Sep 23 00:03:29 UTC 2011
Modified Files:
src/sys/kern: kern_core.c
Log Message:
PR/45393: Greg A. Woods: The mount point validation code (that looks for
nocoredump filesystems to avoid dumping on them) only worked for core
filenames that dump in the current working directory. Update the code to
validate the mount point of the parent directory of the core file if needed.
To generate a diff of this commit:
cvs rdiff -u -r1.18 -r1.19 src/sys/kern/kern_core.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/kern_core.c
diff -u src/sys/kern/kern_core.c:1.18 src/sys/kern/kern_core.c:1.19
--- src/sys/kern/kern_core.c:1.18 Fri Apr 29 18:57:54 2011
+++ src/sys/kern/kern_core.c Thu Sep 22 20:03:29 2011
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_core.c,v 1.18 2011/04/29 22:57:54 rmind Exp $ */
+/* $NetBSD: kern_core.c,v 1.19 2011/09/23 00:03:29 christos Exp $ */
/*
* Copyright (c) 1982, 1986, 1989, 1991, 1993
@@ -37,7 +37,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_core.c,v 1.18 2011/04/29 22:57:54 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_core.c,v 1.19 2011/09/23 00:03:29 christos Exp $");
#include <sys/param.h>
#include <sys/vnode.h>
@@ -102,7 +102,7 @@
struct coredump_iostate io;
struct plimit *lim;
int error, error1;
- char *name;
+ char *name, *lastslash;
name = PNBUF_GET();
@@ -133,24 +133,6 @@
cred = p->p_cred;
/*
- * The core dump will go in the current working directory. Make
- * sure that the directory is still there and that the mount flags
- * allow us to write core dumps there.
- *
- * XXX: this is partially bogus, it should be checking the directory
- * into which the file is actually written - which probably needs
- * a flag on namei()
- */
- vp = p->p_cwdi->cwdi_cdir;
- if (vp->v_mount == NULL ||
- (vp->v_mount->mnt_flag & MNT_NOCOREDUMP) != 0) {
- error = EPERM;
- mutex_exit(p->p_lock);
- mutex_exit(proc_lock);
- goto done;
- }
-
- /*
* Make sure the process has not set-id, to prevent data leaks,
* unless it was specifically requested to allow set-id coredumps.
*/
@@ -173,10 +155,52 @@
error = coredump_buildname(p, name, pattern, MAXPATHLEN);
mutex_exit(&lim->pl_lock);
+ /*
+ * On a simple filename, see if the filesystem allow us to write
+ * core dumps there.
+ */
+ lastslash = strrchr(name, '/');
+ if (!lastslash) {
+ vp = p->p_cwdi->cwdi_cdir;
+ if (vp->v_mount == NULL ||
+ (vp->v_mount->mnt_flag & MNT_NOCOREDUMP) != 0)
+ error = EPERM;
+ }
+
mutex_exit(p->p_lock);
mutex_exit(proc_lock);
- if (error) {
+ if (error)
goto done;
+
+ /*
+ * On a complex filename, see if the filesystem allow us to write
+ * core dumps there.
+ *
+ * XXX: We should have an API that avoids double lookups
+ */
+ if (lastslash) {
+ char c[2];
+
+ if (lastslash - name >= MAXPATHLEN - 2) {
+ error = EPERM;
+ goto done;
+ }
+
+ c[0] = lastslash[1];
+ c[1] = lastslash[2];
+ lastslash[1] = '.';
+ lastslash[2] = '\0';
+ error = namei_simple_kernel(name, NSM_FOLLOW_NOEMULROOT, &vp);
+ if (error)
+ goto done;
+ if (vp->v_mount == NULL ||
+ (vp->v_mount->mnt_flag & MNT_NOCOREDUMP) != 0)
+ error = EPERM;
+ vrele(vp);
+ if (error)
+ goto done;
+ lastslash[1] = c[0];
+ lastslash[2] = c[1];
}
pb = pathbuf_create(name);
