[src/trunk]: src/sys/miscfs/genfs Fix EPERM vs EACCES return.

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a34c6c78e3ed
branches:  trunk
changeset: 933023:a34c6c78e3ed
user:      christos <christos%NetBSD.org@localhost>
date:      Mon May 18 19:42:16 2020 +0000

description:
Fix EPERM vs EACCES return.

diffstat:

 sys/miscfs/genfs/genfs_vnops.c |  38 ++++++++++++++++++++++++++++++--------
 1 files changed, 30 insertions(+), 8 deletions(-)

diffs (87 lines):

diff -r 68be0e55fe5e -r a34c6c78e3ed sys/miscfs/genfs/genfs_vnops.c
--- a/sys/miscfs/genfs/genfs_vnops.c    Mon May 18 16:42:05 2020 +0000
+++ b/sys/miscfs/genfs/genfs_vnops.c    Mon May 18 19:42:16 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: genfs_vnops.c,v 1.204 2020/05/16 18:31:51 christos Exp $       */
+/*     $NetBSD: genfs_vnops.c,v 1.205 2020/05/18 19:42:16 christos Exp $       */
 
 /*-
  * Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -57,7 +57,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: genfs_vnops.c,v 1.204 2020/05/16 18:31:51 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: genfs_vnops.c,v 1.205 2020/05/18 19:42:16 christos Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -695,7 +695,13 @@
 
        KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0);
        KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE));
-
+#ifdef ACL_DEBUG
+       char buf[128];
+       snprintb(buf, sizeof(buf), __VNODE_PERM_BITS, accmode);
+       printf("%s: %s cred_uid=%d cred_gid=%d file_uid=%d file_gid=%d\n",
+           __func__, buf, kauth_cred_geteuid(cred), kauth_cred_getegid(cred),
+           file_uid, file_gid);
+#endif
        /*
         * Look for a normal, non-privileged way to access the file/directory
         * as requested.  If it exists, go with that.
@@ -713,7 +719,11 @@
                if (file_mode & S_IWUSR)
                        dac_granted |= (VWRITE | VAPPEND);
 
-               return (accmode & dac_granted) == accmode ? 0 : EPERM;
+#ifdef ACL_DEBUG
+               printf("%s: owner %o %o\n", __func__,
+                   accmode & dac_granted, accmode);
+#endif
+               goto privchk;
        }
 
        /* Otherwise, check the groups (first match) */
@@ -729,7 +739,11 @@
                if (file_mode & S_IWGRP)
                        dac_granted |= (VWRITE | VAPPEND);
 
-               return (accmode & dac_granted) == accmode ? 0 : EACCES;
+#ifdef ACL_DEBUG
+               printf("%s: group %o %o\n", __func__,
+                   accmode & dac_granted, accmode);
+#endif
+               goto privchk;
        }
 
        /* Otherwise, check everyone else. */
@@ -739,8 +753,16 @@
                dac_granted |= VREAD;
        if (file_mode & S_IWOTH)
                dac_granted |= (VWRITE | VAPPEND);
-       return (accmode & dac_granted) == accmode ? 0 : EACCES;
-               return (0);
+
+#ifdef ACL_DEBUG
+       printf("%s: others %o %o\n", __func__,
+           accmode & dac_granted, accmode);
+#endif
+privchk:
+       if ((accmode & dac_granted) == accmode)
+               return 0;
+
+       return (accmode & VADMIN) ? EPERM : EACCES;
 }
 
 /*
@@ -1108,7 +1130,7 @@
 #ifdef ACL_DEBUG
        char buf[128];
        snprintb(buf, sizeof(buf), __VNODE_PERM_BITS, accmode);
-       printf("%s: %s uid=%d gid=%d\n", __func__, buf, file_uid, file_gid);
+       printf("%s: %s file_uid=%d file_gid=%d\n", __func__, buf, file_uid, file_gid);
 #endif
 
        if (accmode & VADMIN)