[src/netbsd-1-5]: src/sys/kern Pullup 1.59 and 1.60 [christos]:

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

details:   https://anonhg.NetBSD.org/src/rev/c4ea376cf320
branches:  netbsd-1-5
changeset: 489891:c4ea376cf320
user:      tv <tv%NetBSD.org@localhost>
date:      Wed Oct 18 03:41:36 2000 +0000

description:
Pullup 1.59 and 1.60 [christos]:
Don't set P_SUGID if the calls to set{e,}{u,g}id(), setreuid(),
setgroups() did not result in actual changes. This has the nice
side effect that we don't needlesly allocate new credential and
resource limit data structures.

[releng: this is needed for proper operation of issetugid()]

diffstat:

 sys/kern/kern_prot.c |  73 +++++++++++++++++++++++++++++++++++++++++----------
 1 files changed, 58 insertions(+), 15 deletions(-)

diffs (190 lines):

diff -r 913c1c9f13f4 -r c4ea376cf320 sys/kern/kern_prot.c
--- a/sys/kern/kern_prot.c      Wed Oct 18 03:39:11 2000 +0000
+++ b/sys/kern/kern_prot.c      Wed Oct 18 03:41:36 2000 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_prot.c,v 1.58 2000/05/27 00:40:46 sommerfeld Exp $        */
+/*     $NetBSD: kern_prot.c,v 1.58.4.1 2000/10/18 03:41:36 tv Exp $    */
 
 /*
  * Copyright (c) 1982, 1986, 1989, 1990, 1991, 1993
@@ -124,7 +124,7 @@
                return (ESRCH);
 found:
        *retval = p->p_session->s_sid;
-       return 0;
+       return (0);
 }
 
 int
@@ -143,7 +143,7 @@
                return (ESRCH);
 found:
        *retval = p->p_pgid;
-       return 0;
+       return (0);
 }
 
 /* ARGSUSED */
@@ -326,6 +326,12 @@
            (error = suser(pc->pc_ucred, &p->p_acflag)))
                return (error);
        /*
+        * Check if we are all set, and this is a no-op.
+        */
+       if (pc->p_ruid == uid && pc->p_svuid == uid &&
+           pc->pc_ucred->cr_uid == uid)
+               return (0);
+       /*
         * Everything's okay, do it.
         * Transfer proc count to new user.
         * Copy credentials so other references do not see our changes.
@@ -359,6 +365,12 @@
            (error = suser(pc->pc_ucred, &p->p_acflag)))
                return (error);
        /*
+        * Check if we are all set, and this is a no-op.
+        */
+       if (pc->pc_ucred->cr_uid == euid)
+               return (0);
+
+       /*
         * Everything's okay, do it.  Copy credentials so other references do
         * not see our changes.
         */
@@ -380,7 +392,7 @@
        } */ *uap = v;
        struct pcred *pc = p->p_cred;
        uid_t ruid, euid;
-       int error;
+       int error, changed = 0;
 
        ruid = SCARG(uap, ruid);
        euid = SCARG(uap, euid);
@@ -396,19 +408,22 @@
            (error = suser(pc->pc_ucred, &p->p_acflag)))
                return (error);
 
-       if (euid != (uid_t)-1) {
+       if (euid != (uid_t)-1 && euid != pc->pc_ucred->cr_uid) {
                pc->pc_ucred = crcopy(pc->pc_ucred);
                pc->pc_ucred->cr_uid = euid;
+               changed++;
        }
 
-       if (ruid != (uid_t)-1) {
+       if (ruid != (uid_t)-1 &&
+           (pc->p_ruid != ruid || pc->p_svuid != pc->pc_ucred->cr_uid)) {
                (void)chgproccnt(pc->p_ruid, -1);
                (void)chgproccnt(ruid, 1);
                pc->p_ruid = ruid;
                pc->p_svuid = pc->pc_ucred->cr_uid;
+               changed++;
        }
 
-       if (euid != (uid_t)-1 && ruid != (uid_t)-1)
+       if (changed)
                p_sugid(p);
        return (0);
 }
@@ -431,6 +446,13 @@
        if (gid != pc->p_rgid &&
            (error = suser(pc->pc_ucred, &p->p_acflag)))
                return (error);
+       /*
+        * Check if we are all set, and this is a no-op.
+        */
+       if (pc->pc_ucred->cr_gid == gid && pc->p_rgid == gid &&
+           pc->p_svgid == gid)
+               return (0);
+
        pc->pc_ucred = crcopy(pc->pc_ucred);
        pc->pc_ucred->cr_gid = gid;
        pc->p_rgid = gid;
@@ -457,6 +479,12 @@
        if (egid != pc->p_rgid && egid != pc->p_svgid &&
            (error = suser(pc->pc_ucred, &p->p_acflag)))
                return (error);
+       /*
+        * Check if we are all set, and this is a no-op.
+        */
+       if (pc->pc_ucred->cr_gid == egid)
+               return (0);
+
        pc->pc_ucred = crcopy(pc->pc_ucred);
        pc->pc_ucred->cr_gid = egid;
        p_sugid(p);
@@ -475,7 +503,7 @@
        } */ *uap = v;
        struct pcred *pc = p->p_cred;
        gid_t rgid, egid;
-       int error;
+       int error, changed = 0;
 
        rgid = SCARG(uap, rgid);
        egid = SCARG(uap, egid);
@@ -491,17 +519,20 @@
            (error = suser(pc->pc_ucred, &p->p_acflag)))
                return (error);
 
-       if (egid != (gid_t)-1) {
+       if (egid != (gid_t)-1 && pc->pc_ucred->cr_gid != egid) {
                pc->pc_ucred = crcopy(pc->pc_ucred);
                pc->pc_ucred->cr_gid = egid;
+               changed++;
        }
 
-       if (rgid != (gid_t)-1) {
+       if (rgid != (gid_t)-1 &&
+           (pc->p_rgid != rgid || pc->p_svgid != pc->pc_ucred->cr_gid)) {
                pc->p_rgid = rgid;
                pc->p_svgid = pc->pc_ucred->cr_gid;
+               changed++;
        }
 
-       if (egid != (gid_t)-1 && rgid != (gid_t)-1)
+       if (changed)
                p_sugid(p);
        return (0);
 }
@@ -521,7 +552,7 @@
         * that libc *might* have put in their data segment.
         */
        *retval = (p->p_flag & P_SUGID) != 0;
-       return 0;
+       return (0);
 }
 
 /* ARGSUSED */
@@ -538,17 +569,29 @@
        struct pcred *pc = p->p_cred;
        int ngrp;
        int error;
+       gid_t grp[NGROUPS];
+       size_t grsize;
 
        if ((error = suser(pc->pc_ucred, &p->p_acflag)) != 0)
                return (error);
+
        ngrp = SCARG(uap, gidsetsize);
        if ((u_int)ngrp > NGROUPS)
                return (EINVAL);
-       pc->pc_ucred = crcopy(pc->pc_ucred);
-       error = copyin(SCARG(uap, gidset), pc->pc_ucred->cr_groups,
-           ngrp * sizeof(gid_t));
+
+       grsize = ngrp * sizeof(gid_t);
+       error = copyin(SCARG(uap, gidset), grp, grsize);
        if (error)
                return (error);
+       /*
+        * Check if this is a no-op.
+        */
+       if (pc->pc_ucred->cr_ngroups == ngrp &&
+           memcmp(grp, pc->pc_ucred->cr_groups, grsize) == 0)
+               return (0);
+
+       pc->pc_ucred = crcopy(pc->pc_ucred);
+       (void)memcpy(pc->pc_ucred->cr_groups, grp, grsize);
        pc->pc_ucred->cr_ngroups = ngrp;
        p_sugid(p);
        return (0);