[PATCH] sysctl-controlled number of groups.

From: Rusty Russell
Date: Wed Sep 24 2003 - 23:01:19 EST

We have a client (using SAMBA) who has people in 190 groups. Since NT
has hierarchical groups, this is not all that rare.

What do people think of this patch?

Name: Dynamic Allocation of Groups Array When Required: With Refcounting
Author: Rusty Russell
Status: Tested on 2.6.0-test5-bk5
Depends: Misc/qemu-page-offset.patch.gz

D: This patch allows the maximum number of groups can be varied using
D: sysctl. To do this, we use a separate group allocation if >
D: NGROUPS_INTERNAL, which we reference count (sharing being
D: v. v. common).
D:
D: Changes:
D: 1) Remove the NGROUPS define from archs.
D: 2) Fixup the few places which declare [NGROUPS] arrays on the stack.
D: 3) The ia64, s390 and sparc64 ports have their own setgroups/getgroups
D: implementations: unify them on the ia64 one, which calls the core
D: functions.
D: 4) Change the task_struct to have an [NGROUPS_INTERNAL] array and
D: a pointer (not convinced this is worth it at all, might skip it
D: and always use external).
D: 5) Use a reference counted external array, fix up fork() to deal.
D: 6) Introduce max_groups and use it instead of NGROUPS.
D: 7) Add a sysctl to vary max_groups.
D:
D: This patch scars nfs: artificially restrict the groups there to
D: SVC_CRED_NGROUPS (32), which is probably wrong, but won't break if
D: they don't change the default.
D:
D: This patch breaks intermezzo: I'm not sure how they want to deal
D: with it.

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/arch/ia64/ia32/sys_ia32.c .13015-linux-2.6.0-test5-bk11.updated/arch/ia64/ia32/sys_ia32.c
--- .13015-linux-2.6.0-test5-bk11/arch/ia64/ia32/sys_ia32.c 2003-09-25 09:56:18.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/arch/ia64/ia32/sys_ia32.c 2003-09-25 13:08:28.000000000 +1000
@@ -2432,17 +2432,24 @@ asmlinkage long
sys32_getgroups16 (int gidsetsize, short *grouplist)
{
mm_segment_t old_fs = get_fs();
- gid_t gl[NGROUPS];
+ gid_t *gl;
int ret, i;

+ gl = kmalloc(sizeof(gl[0]) * current->ngroups, GFP_KERNEL);
+ if (!gl)
+ return -ENOMEM;
+
set_fs(KERNEL_DS);
ret = sys_getgroups(gidsetsize, gl);
set_fs(old_fs);

- if (gidsetsize && ret > 0 && ret <= NGROUPS)
+ if (gidsetsize && ret > 0)
for (i = 0; i < ret; i++, grouplist++)
- if (put_user(gl[i], grouplist))
- return -EFAULT;
+ if (put_user(gl[i], grouplist)) {
+ ret = -EFAULT;
+ break;
+ }
+ kfree(gl);
return ret;
}

@@ -2452,17 +2459,23 @@ asmlinkage long
sys32_setgroups16 (int gidsetsize, short *grouplist)
{
mm_segment_t old_fs = get_fs();
- gid_t gl[NGROUPS];
+ gid_t *gl;
int ret, i;

- if ((unsigned) gidsetsize > NGROUPS)
+ if ((unsigned) gidsetsize > max_groups)
return -EINVAL;
+ gl = kmalloc(sizeof(gl[0]) * gidsetsize, GFP_KERNEL);
+ if (!gl)
+ return -ENOMEM;
for (i = 0; i < gidsetsize; i++, grouplist++)
- if (get_user(gl[i], grouplist))
+ if (get_user(gl[i], grouplist)) {
+ kfree(gl);
return -EFAULT;
+ }
set_fs(KERNEL_DS);
ret = sys_setgroups(gidsetsize, gl);
set_fs(old_fs);
+ kfree(gl);
return ret;
}

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/arch/mips/kernel/sysirix.c .13015-linux-2.6.0-test5-bk11.updated/arch/mips/kernel/sysirix.c
--- .13015-linux-2.6.0-test5-bk11/arch/mips/kernel/sysirix.c 2003-09-25 09:56:19.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/arch/mips/kernel/sysirix.c 2003-09-25 12:58:43.000000000 +1000
@@ -368,7 +368,7 @@ asmlinkage int irix_syssgi(struct pt_reg
retval = HZ;
goto out;
case 4:
- retval = NGROUPS;
+ retval = max_groups;
goto out;
case 5:
retval = NR_OPEN;
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/arch/s390/kernel/compat_linux.c .13015-linux-2.6.0-test5-bk11.updated/arch/s390/kernel/compat_linux.c
--- .13015-linux-2.6.0-test5-bk11/arch/s390/kernel/compat_linux.c 2003-09-25 09:56:22.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/arch/s390/kernel/compat_linux.c 2003-09-25 13:08:21.000000000 +1000
@@ -189,40 +189,57 @@ asmlinkage long sys32_setfsgid16(u16 gid
return sys_setfsgid((gid_t)gid);
}

-asmlinkage long sys32_getgroups16(int gidsetsize, u16 *grouplist)
+extern asmlinkage long sys_getgroups (int gidsetsize, gid_t *grouplist);
+
+asmlinkage long
+sys32_getgroups16 (int gidsetsize, short *grouplist)
{
- u16 groups[NGROUPS];
- int i,j;
+ mm_segment_t old_fs = get_fs();
+ gid_t *gl;
+ int ret, i;

- if (gidsetsize < 0)
- return -EINVAL;
- i = current->ngroups;
- if (gidsetsize) {
- if (i > gidsetsize)
- return -EINVAL;
- for(j=0;j<i;j++)
- groups[j] = current->groups[j];
- if (copy_to_user(grouplist, groups, sizeof(u16)*i))
- return -EFAULT;
- }
- return i;
+ gl = kmalloc(sizeof(gl[0]) * current->ngroups, GFP_KERNEL);
+ if (!gl)
+ return -ENOMEM;
+
+ set_fs(KERNEL_DS);
+ ret = sys_getgroups(gidsetsize, gl);
+ set_fs(old_fs);
+
+ if (gidsetsize && ret > 0)
+ for (i = 0; i < ret; i++, grouplist++)
+ if (put_user(gl[i], grouplist)) {
+ ret = -EFAULT;
+ break;
+ }
+ kfree(gl);
+ return ret;
}

-asmlinkage long sys32_setgroups16(int gidsetsize, u16 *grouplist)
+extern asmlinkage long sys_setgroups (int gidsetsize, gid_t *grouplist);
+
+asmlinkage long
+sys32_setgroups16 (int gidsetsize, short *grouplist)
{
- u16 groups[NGROUPS];
- int i;
+ mm_segment_t old_fs = get_fs();
+ gid_t *gl;
+ int ret, i;

- if (!capable(CAP_SETGID))
- return -EPERM;
- if ((unsigned) gidsetsize > NGROUPS)
+ if ((unsigned) gidsetsize > max_groups)
return -EINVAL;
- if (copy_from_user(groups, grouplist, gidsetsize * sizeof(u16)))
- return -EFAULT;
- for (i = 0 ; i < gidsetsize ; i++)
- current->groups[i] = (gid_t)groups[i];
- current->ngroups = gidsetsize;
- return 0;
+ gl = kmalloc(sizeof(gl[0]) * gidsetsize, GFP_KERNEL);
+ if (!gl)
+ return -ENOMEM;
+ for (i = 0; i < gidsetsize; i++, grouplist++)
+ if (get_user(gl[i], grouplist)) {
+ kfree(gl);
+ return -EFAULT;
+ }
+ set_fs(KERNEL_DS);
+ ret = sys_setgroups(gidsetsize, gl);
+ set_fs(old_fs);
+ kfree(gl);
+ return ret;
}

asmlinkage long sys32_getuid16(void)
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/arch/sparc/kernel/sys_sunos.c .13015-linux-2.6.0-test5-bk11.updated/arch/sparc/kernel/sys_sunos.c
--- .13015-linux-2.6.0-test5-bk11/arch/sparc/kernel/sys_sunos.c 2003-09-22 10:27:56.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/arch/sparc/kernel/sys_sunos.c 2003-09-25 12:58:43.000000000 +1000
@@ -896,7 +896,7 @@ extern asmlinkage long sunos_sysconf (in
ret = HZ;
break;
case _SC_NGROUPS_MAX:
- ret = NGROUPS_MAX;
+ ret = max_groups;
break;
case _SC_OPEN_MAX:
ret = OPEN_MAX;
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/arch/sparc64/kernel/sys_sparc32.c .13015-linux-2.6.0-test5-bk11.updated/arch/sparc64/kernel/sys_sparc32.c
--- .13015-linux-2.6.0-test5-bk11/arch/sparc64/kernel/sys_sparc32.c 2003-09-25 09:56:22.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/arch/sparc64/kernel/sys_sparc32.c 2003-09-25 13:08:15.000000000 +1000
@@ -206,40 +206,57 @@ asmlinkage long sys32_setfsgid16(u16 gid
return sys_setfsgid((gid_t)gid);
}

-asmlinkage long sys32_getgroups16(int gidsetsize, u16 *grouplist)
+extern asmlinkage long sys_getgroups (int gidsetsize, gid_t *grouplist);
+
+asmlinkage long
+sys32_getgroups16 (int gidsetsize, short *grouplist)
{
- u16 groups[NGROUPS];
- int i,j;
+ mm_segment_t old_fs = get_fs();
+ gid_t *gl;
+ int ret, i;

- if (gidsetsize < 0)
- return -EINVAL;
- i = current->ngroups;
- if (gidsetsize) {
- if (i > gidsetsize)
- return -EINVAL;
- for(j=0;j<i;j++)
- groups[j] = current->groups[j];
- if (copy_to_user(grouplist, groups, sizeof(u16)*i))
- return -EFAULT;
- }
- return i;
+ gl = kmalloc(sizeof(gl[0]) * current->ngroups, GFP_KERNEL);
+ if (!gl)
+ return -ENOMEM;
+
+ set_fs(KERNEL_DS);
+ ret = sys_getgroups(gidsetsize, gl);
+ set_fs(old_fs);
+
+ if (gidsetsize && ret > 0)
+ for (i = 0; i < ret; i++, grouplist++)
+ if (put_user(gl[i], grouplist)) {
+ ret = -EFAULT;
+ break;
+ }
+ kfree(gl);
+ return ret;
}

-asmlinkage long sys32_setgroups16(int gidsetsize, u16 *grouplist)
+extern asmlinkage long sys_setgroups (int gidsetsize, gid_t *grouplist);
+
+asmlinkage long
+sys32_setgroups16 (int gidsetsize, short *grouplist)
{
- u16 groups[NGROUPS];
- int i;
+ mm_segment_t old_fs = get_fs();
+ gid_t *gl;
+ int ret, i;

- if (!capable(CAP_SETGID))
- return -EPERM;
- if ((unsigned) gidsetsize > NGROUPS)
+ if ((unsigned) gidsetsize > max_groups)
return -EINVAL;
- if (copy_from_user(groups, grouplist, gidsetsize * sizeof(u16)))
- return -EFAULT;
- for (i = 0 ; i < gidsetsize ; i++)
- current->groups[i] = (gid_t)groups[i];
- current->ngroups = gidsetsize;
- return 0;
+ gl = kmalloc(sizeof(gl[0]) * gidsetsize, GFP_KERNEL);
+ if (!gl)
+ return -ENOMEM;
+ for (i = 0; i < gidsetsize; i++, grouplist++)
+ if (get_user(gl[i], grouplist)) {
+ kfree(gl);
+ return -EFAULT;
+ }
+ set_fs(KERNEL_DS);
+ ret = sys_setgroups(gidsetsize, gl);
+ set_fs(old_fs);
+ kfree(gl);
+ return ret;
}

asmlinkage long sys32_getuid16(void)
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/arch/sparc64/kernel/sys_sunos32.c .13015-linux-2.6.0-test5-bk11.updated/arch/sparc64/kernel/sys_sunos32.c
--- .13015-linux-2.6.0-test5-bk11/arch/sparc64/kernel/sys_sunos32.c 2003-09-22 10:27:56.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/arch/sparc64/kernel/sys_sunos32.c 2003-09-25 12:58:43.000000000 +1000
@@ -859,7 +859,7 @@ extern asmlinkage s32 sunos_sysconf (int
ret = HZ;
break;
case _SC_NGROUPS_MAX:
- ret = NGROUPS_MAX;
+ ret = max_groups;
break;
case _SC_OPEN_MAX:
ret = OPEN_MAX;
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/fs/nfsd/auth.c .13015-linux-2.6.0-test5-bk11.updated/fs/nfsd/auth.c
--- .13015-linux-2.6.0-test5-bk11/fs/nfsd/auth.c 2003-09-22 10:21:34.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/fs/nfsd/auth.c 2003-09-25 12:58:43.000000000 +1000
@@ -26,7 +26,7 @@ nfsd_setuser(struct svc_rqst *rqstp, str
cred->cr_uid = exp->ex_anon_uid;
if (!cred->cr_gid)
cred->cr_gid = exp->ex_anon_gid;
- for (i = 0; i < NGROUPS; i++)
+ for (i = 0; i < SVC_CRED_NGROUPS; i++)
if (!cred->cr_groups[i])
cred->cr_groups[i] = exp->ex_anon_gid;
}
@@ -39,7 +39,9 @@ nfsd_setuser(struct svc_rqst *rqstp, str
current->fsgid = cred->cr_gid;
else
current->fsgid = exp->ex_anon_gid;
- for (i = 0; i < NGROUPS; i++) {
+
+ /* We can do this because cow_current_groups() was done at birth. */
+ for (i = 0; i < SVC_CRED_NGROUPS; i++) {
gid_t group = cred->cr_groups[i];
if (group == (gid_t) NOGROUP)
break;
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/fs/nfsd/nfs4state.c .13015-linux-2.6.0-test5-bk11.updated/fs/nfsd/nfs4state.c
--- .13015-linux-2.6.0-test5-bk11/fs/nfsd/nfs4state.c 2003-09-25 09:56:32.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/fs/nfsd/nfs4state.c 2003-09-25 12:58:43.000000000 +1000
@@ -244,7 +244,7 @@ copy_cred(struct svc_cred *target, struc

target->cr_uid = source->cr_uid;
target->cr_gid = source->cr_gid;
- for(i = 0; i < NGROUPS; i++)
+ for(i = 0; i < SVC_CREDS_NGROUPS; i++)
target->cr_groups[i] = source->cr_groups[i];
}

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/fs/nfsd/nfssvc.c .13015-linux-2.6.0-test5-bk11.updated/fs/nfsd/nfssvc.c
--- .13015-linux-2.6.0-test5-bk11/fs/nfsd/nfssvc.c 2003-09-22 10:26:12.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/fs/nfsd/nfssvc.c 2003-09-25 12:58:43.000000000 +1000
@@ -182,6 +182,11 @@ nfsd(struct svc_rqst *rqstp)
daemonize("nfsd");
current->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;

+ if (cow_current_groups(SVC_CRED_NGROUPS) < 0) {
+ printk("Unable to start nfsd thread: can't set groups\n");
+ goto out;
+ }
+
/* After daemonize() this kernel thread shares current->fs
* with the init process. We need to create files with a
* umask of 0 instead of init's umask. */
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/asm-alpha/param.h .13015-linux-2.6.0-test5-bk11.updated/include/asm-alpha/param.h
--- .13015-linux-2.6.0-test5-bk11/include/asm-alpha/param.h 2003-09-21 17:27:17.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/asm-alpha/param.h 2003-09-25 12:58:43.000000000 +1000
@@ -19,10 +19,6 @@

#define EXEC_PAGESIZE 8192

-#ifndef NGROUPS
-#define NGROUPS 32
-#endif
-
#ifndef NOGROUP
#define NOGROUP (-1)
#endif
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/asm-arm/param.h .13015-linux-2.6.0-test5-bk11.updated/include/asm-arm/param.h
--- .13015-linux-2.6.0-test5-bk11/include/asm-arm/param.h 2003-09-22 10:28:10.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/asm-arm/param.h 2003-09-25 12:58:43.000000000 +1000
@@ -26,10 +26,6 @@

#define EXEC_PAGESIZE 4096

-#ifndef NGROUPS
-#define NGROUPS 32
-#endif
-
#ifndef NOGROUP
#define NOGROUP (-1)
#endif
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/asm-arm26/param.h .13015-linux-2.6.0-test5-bk11.updated/include/asm-arm26/param.h
--- .13015-linux-2.6.0-test5-bk11/include/asm-arm26/param.h 2003-09-22 10:09:07.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/asm-arm26/param.h 2003-09-25 12:58:43.000000000 +1000
@@ -22,10 +22,6 @@
# define HZ 100
#endif

-#ifndef NGROUPS
-#define NGROUPS 32
-#endif
-
#ifndef NOGROUP
#define NOGROUP (-1)
#endif
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/asm-cris/param.h .13015-linux-2.6.0-test5-bk11.updated/include/asm-cris/param.h
--- .13015-linux-2.6.0-test5-bk11/include/asm-cris/param.h 2003-09-22 10:23:13.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/asm-cris/param.h 2003-09-25 12:58:43.000000000 +1000
@@ -14,10 +14,6 @@

#define EXEC_PAGESIZE 8192

-#ifndef NGROUPS
-#define NGROUPS 32
-#endif
-
#ifndef NOGROUP
#define NOGROUP (-1)
#endif
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/asm-h8300/param.h .13015-linux-2.6.0-test5-bk11.updated/include/asm-h8300/param.h
--- .13015-linux-2.6.0-test5-bk11/include/asm-h8300/param.h 2003-09-22 10:07:04.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/asm-h8300/param.h 2003-09-25 12:58:43.000000000 +1000
@@ -14,10 +14,6 @@

#define EXEC_PAGESIZE 4096

-#ifndef NGROUPS
-#define NGROUPS 32
-#endif
-
#ifndef NOGROUP
#define NOGROUP (-1)
#endif
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/asm-i386/param.h .13015-linux-2.6.0-test5-bk11.updated/include/asm-i386/param.h
--- .13015-linux-2.6.0-test5-bk11/include/asm-i386/param.h 2003-09-25 12:58:41.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/asm-i386/param.h 2003-09-25 12:58:43.000000000 +1000
@@ -18,10 +18,6 @@

#define EXEC_PAGESIZE 4096

-#ifndef NGROUPS
-#define NGROUPS 32
-#endif
-
#ifndef NOGROUP
#define NOGROUP (-1)
#endif
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/asm-ia64/param.h .13015-linux-2.6.0-test5-bk11.updated/include/asm-ia64/param.h
--- .13015-linux-2.6.0-test5-bk11/include/asm-ia64/param.h 2003-09-25 09:56:35.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/asm-ia64/param.h 2003-09-25 12:58:43.000000000 +1000
@@ -10,10 +10,6 @@

#define EXEC_PAGESIZE 65536

-#ifndef NGROUPS
-# define NGROUPS 32
-#endif
-
#ifndef NOGROUP
# define NOGROUP (-1)
#endif
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/asm-m68k/param.h .13015-linux-2.6.0-test5-bk11.updated/include/asm-m68k/param.h
--- .13015-linux-2.6.0-test5-bk11/include/asm-m68k/param.h 2003-09-21 17:26:43.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/asm-m68k/param.h 2003-09-25 12:58:43.000000000 +1000
@@ -13,10 +13,6 @@

#define EXEC_PAGESIZE 8192

-#ifndef NGROUPS
-#define NGROUPS 32
-#endif
-
#ifndef NOGROUP
#define NOGROUP (-1)
#endif
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/asm-m68knommu/param.h .13015-linux-2.6.0-test5-bk11.updated/include/asm-m68knommu/param.h
--- .13015-linux-2.6.0-test5-bk11/include/asm-m68knommu/param.h 2003-09-21 17:31:31.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/asm-m68knommu/param.h 2003-09-25 12:58:43.000000000 +1000
@@ -44,10 +44,6 @@

#define EXEC_PAGESIZE 4096

-#ifndef NGROUPS
-#define NGROUPS 32
-#endif
-
#ifndef NOGROUP
#define NOGROUP (-1)
#endif
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/asm-mips/param.h .13015-linux-2.6.0-test5-bk11.updated/include/asm-mips/param.h
--- .13015-linux-2.6.0-test5-bk11/include/asm-mips/param.h 2003-09-22 10:22:44.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/asm-mips/param.h 2003-09-25 12:58:43.000000000 +1000
@@ -33,10 +33,6 @@

#define EXEC_PAGESIZE 4096

-#ifndef NGROUPS
-#define NGROUPS 32
-#endif
-
#ifndef NOGROUP
#define NOGROUP (-1)
#endif
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/asm-parisc/param.h .13015-linux-2.6.0-test5-bk11.updated/include/asm-parisc/param.h
--- .13015-linux-2.6.0-test5-bk11/include/asm-parisc/param.h 2003-09-21 17:31:10.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/asm-parisc/param.h 2003-09-25 12:58:43.000000000 +1000
@@ -17,10 +17,6 @@

#define EXEC_PAGESIZE 4096

-#ifndef NGROUPS
-#define NGROUPS 32
-#endif
-
#ifndef NOGROUP
#define NOGROUP (-1)
#endif
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/asm-ppc/param.h .13015-linux-2.6.0-test5-bk11.updated/include/asm-ppc/param.h
--- .13015-linux-2.6.0-test5-bk11/include/asm-ppc/param.h 2003-09-22 09:47:27.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/asm-ppc/param.h 2003-09-25 12:58:43.000000000 +1000
@@ -13,10 +13,6 @@

#define EXEC_PAGESIZE 4096

-#ifndef NGROUPS
-#define NGROUPS 32
-#endif
-
#ifndef NOGROUP
#define NOGROUP (-1)
#endif
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/asm-ppc64/param.h .13015-linux-2.6.0-test5-bk11.updated/include/asm-ppc64/param.h
--- .13015-linux-2.6.0-test5-bk11/include/asm-ppc64/param.h 2003-09-21 17:26:44.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/asm-ppc64/param.h 2003-09-25 12:58:43.000000000 +1000
@@ -20,10 +20,6 @@

#define EXEC_PAGESIZE 4096

-#ifndef NGROUPS
-#define NGROUPS 32
-#endif
-
#ifndef NOGROUP
#define NOGROUP (-1)
#endif
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/asm-s390/param.h .13015-linux-2.6.0-test5-bk11.updated/include/asm-s390/param.h
--- .13015-linux-2.6.0-test5-bk11/include/asm-s390/param.h 2003-09-21 17:29:29.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/asm-s390/param.h 2003-09-25 12:58:43.000000000 +1000
@@ -21,10 +21,6 @@

#define EXEC_PAGESIZE 4096

-#ifndef NGROUPS
-#define NGROUPS 32
-#endif
-
#ifndef NOGROUP
#define NOGROUP (-1)
#endif
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/asm-sh/param.h .13015-linux-2.6.0-test5-bk11.updated/include/asm-sh/param.h
--- .13015-linux-2.6.0-test5-bk11/include/asm-sh/param.h 2003-09-22 10:23:00.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/asm-sh/param.h 2003-09-25 12:58:43.000000000 +1000
@@ -17,10 +17,6 @@

#define EXEC_PAGESIZE 4096

-#ifndef NGROUPS
-#define NGROUPS 32
-#endif
-
#ifndef NOGROUP
#define NOGROUP (-1)
#endif
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/asm-sparc/param.h .13015-linux-2.6.0-test5-bk11.updated/include/asm-sparc/param.h
--- .13015-linux-2.6.0-test5-bk11/include/asm-sparc/param.h 2003-09-21 17:26:18.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/asm-sparc/param.h 2003-09-25 12:58:43.000000000 +1000
@@ -14,10 +14,6 @@

#define EXEC_PAGESIZE 8192 /* Thanks for sun4's we carry baggage... */

-#ifndef NGROUPS
-#define NGROUPS 32
-#endif
-
#ifndef NOGROUP
#define NOGROUP (-1)
#endif
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/asm-sparc64/param.h .13015-linux-2.6.0-test5-bk11.updated/include/asm-sparc64/param.h
--- .13015-linux-2.6.0-test5-bk11/include/asm-sparc64/param.h 2003-09-21 17:26:18.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/asm-sparc64/param.h 2003-09-25 12:58:43.000000000 +1000
@@ -14,10 +14,6 @@

#define EXEC_PAGESIZE 8192 /* Thanks for sun4's we carry baggage... */

-#ifndef NGROUPS
-#define NGROUPS 32
-#endif
-
#ifndef NOGROUP
#define NOGROUP (-1)
#endif
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/asm-um/param.h .13015-linux-2.6.0-test5-bk11.updated/include/asm-um/param.h
--- .13015-linux-2.6.0-test5-bk11/include/asm-um/param.h 2003-09-21 17:28:16.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/asm-um/param.h 2003-09-25 12:58:43.000000000 +1000
@@ -3,10 +3,6 @@

#define EXEC_PAGESIZE 4096

-#ifndef NGROUPS
-#define NGROUPS 32
-#endif
-
#ifndef NOGROUP
#define NOGROUP (-1)
#endif
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/asm-v850/param.h .13015-linux-2.6.0-test5-bk11.updated/include/asm-v850/param.h
--- .13015-linux-2.6.0-test5-bk11/include/asm-v850/param.h 2003-09-21 17:31:32.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/asm-v850/param.h 2003-09-25 12:58:43.000000000 +1000
@@ -18,10 +18,6 @@

#define EXEC_PAGESIZE 4096

-#ifndef NGROUPS
-#define NGROUPS 32
-#endif
-
#ifndef NOGROUP
#define NOGROUP (-1)
#endif
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/asm-x86_64/param.h .13015-linux-2.6.0-test5-bk11.updated/include/asm-x86_64/param.h
--- .13015-linux-2.6.0-test5-bk11/include/asm-x86_64/param.h 2003-09-21 17:30:30.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/asm-x86_64/param.h 2003-09-25 12:58:43.000000000 +1000
@@ -13,10 +13,6 @@

#define EXEC_PAGESIZE 4096

-#ifndef NGROUPS
-#define NGROUPS 32
-#endif
-
#ifndef NOGROUP
#define NOGROUP (-1)
#endif
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/linux/init_task.h .13015-linux-2.6.0-test5-bk11.updated/include/linux/init_task.h
--- .13015-linux-2.6.0-test5-bk11/include/linux/init_task.h 2003-09-22 10:27:37.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/linux/init_task.h 2003-09-25 12:58:43.000000000 +1000
@@ -108,6 +108,7 @@
.proc_lock = SPIN_LOCK_UNLOCKED, \
.switch_lock = SPIN_LOCK_UNLOCKED, \
.journal_info = NULL, \
+ .groups = &(tsk).internal_groups, \
}


diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/linux/sched.h .13015-linux-2.6.0-test5-bk11.updated/include/linux/sched.h
--- .13015-linux-2.6.0-test5-bk11/include/linux/sched.h 2003-09-25 09:56:38.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/linux/sched.h 2003-09-25 12:58:43.000000000 +1000
@@ -328,6 +328,17 @@ struct k_itimer {
struct io_context; /* See blkdev.h */
void exit_io_context(void);

+/* Size is determined by task_struct's ngroups. */
+struct task_groups
+{
+ atomic_t usage;
+ gid_t groups[0];
+};
+
+extern int max_groups;
+
+#define NGROUPS_INTERNAL 1 /* For testing. */
+
struct task_struct {
volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */
struct thread_info *thread_info;
@@ -403,7 +414,8 @@ struct task_struct {
uid_t uid,euid,suid,fsuid;
gid_t gid,egid,sgid,fsgid;
int ngroups;
- gid_t groups[NGROUPS];
+ gid_t *groups; /* == internal_groups, or task_groups->groups */
+ gid_t internal_groups[NGROUPS_INTERNAL];
kernel_cap_t cap_effective, cap_inheritable, cap_permitted;
int keep_capabilities:1;
struct user_struct *user;
@@ -602,6 +614,12 @@ extern int send_group_sigqueue(int, stru
extern int do_sigaction(int, const struct k_sigaction *, struct k_sigaction *);
extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);

+/* container_of doesn't like arrays. */
+static inline struct task_groups *task_groups(gid_t *groups)
+{
+ return (void *)groups - offsetof(struct task_groups, groups);
+}
+
/* These can be the second arg to send_sig_info/send_group_sig_info. */
#define SEND_SIG_NOINFO ((struct siginfo *) 0)
#define SEND_SIG_PRIV ((struct siginfo *) 1)
@@ -678,6 +696,10 @@ extern int do_execve(char *, char __user
extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
extern struct task_struct * copy_process(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);

+/* Copy-on-write current groups to this size, if possible. 0 or -err. */
+extern int cow_current_groups(unsigned int ngroups);
+extern void release_groups(gid_t *groups);
+
#ifdef CONFIG_SMP
extern void wait_task_inactive(task_t * p);
#else
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/linux/sunrpc/svcauth.h .13015-linux-2.6.0-test5-bk11.updated/include/linux/sunrpc/svcauth.h
--- .13015-linux-2.6.0-test5-bk11/include/linux/sunrpc/svcauth.h 2003-09-22 09:47:41.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/linux/sunrpc/svcauth.h 2003-09-25 12:58:43.000000000 +1000
@@ -16,10 +16,12 @@
#include <linux/sunrpc/cache.h>
#include <linux/hash.h>

+#define SVC_CRED_NGROUPS 32
+
struct svc_cred {
uid_t cr_uid;
gid_t cr_gid;
- gid_t cr_groups[NGROUPS];
+ gid_t cr_groups[SVC_CRED_NGROUPS];
};

struct svc_rqst; /* forward decl */
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/include/linux/sysctl.h .13015-linux-2.6.0-test5-bk11.updated/include/linux/sysctl.h
--- .13015-linux-2.6.0-test5-bk11/include/linux/sysctl.h 2003-09-22 10:28:13.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/include/linux/sysctl.h 2003-09-25 12:58:43.000000000 +1000
@@ -127,6 +127,7 @@ enum
KERN_PANIC_ON_OOPS=57, /* int: whether we will panic on an oops */
KERN_HPPA_PWRSW=58, /* int: hppa soft-power enable */
KERN_HPPA_UNALIGNED=59, /* int: hppa unaligned-trap enable */
+ KERN_MAX_GROUPS=60, /* int: setgroups limit */
};


diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/kernel/fork.c .13015-linux-2.6.0-test5-bk11.updated/kernel/fork.c
--- .13015-linux-2.6.0-test5-bk11/kernel/fork.c 2003-09-25 09:56:39.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/kernel/fork.c 2003-09-25 12:58:43.000000000 +1000
@@ -73,6 +73,8 @@ static kmem_cache_t *task_struct_cachep;

static void free_task(struct task_struct *tsk)
{
+ if (unlikely(tsk->groups != tsk->internal_groups))
+ release_groups(tsk->groups);
free_thread_info(tsk->thread_info);
free_task_struct(tsk);
}
@@ -213,6 +215,11 @@ static struct task_struct *dup_task_stru
tsk->thread_info = ti;
ti->task = tsk;

+ if (unlikely(orig->groups != orig->internal_groups))
+ atomic_inc(&task_groups(orig->groups)->usage);
+ else
+ tsk->groups = tsk->internal_groups;
+
/* One for us, one for whoever does the "release_task()" (usually parent) */
atomic_set(&tsk->usage,2);
return tsk;
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/kernel/sys.c .13015-linux-2.6.0-test5-bk11.updated/kernel/sys.c
--- .13015-linux-2.6.0-test5-bk11/kernel/sys.c 2003-09-25 09:56:39.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/kernel/sys.c 2003-09-25 12:58:43.000000000 +1000
@@ -1066,6 +1066,67 @@ out:
return err;
}

+int max_groups = 32;
+
+/* Caller checks that groups != current->internal_groups */
+void release_groups(gid_t *groups)
+{
+ struct task_groups *tgrp = task_groups(groups);
+
+ if (atomic_dec_and_test(&tgrp->usage))
+ kfree(tgrp);
+}
+
+/* This does the actual copy and changeover. Caller sets
+ * current->ngroups, once copy is successful. */
+static int alloc_new_groups(unsigned int ngroups)
+{
+ struct task_groups *tgrp;
+
+ if (ngroups < current->ngroups)
+ ngroups = current->ngroups;
+
+ tgrp = kmalloc(sizeof(*tgrp) + sizeof(tgrp->groups[0])*ngroups,
+ GFP_KERNEL);
+ if (!tgrp)
+ return -ENOMEM;
+ atomic_set(&tgrp->usage, 1);
+
+ memcpy(tgrp->groups, current->groups,
+ sizeof(tgrp->groups[0]) * current->ngroups);
+
+ if (current->groups != current->internal_groups)
+ release_groups(current->groups);
+
+ current->groups = tgrp->groups;
+ return 0;
+}
+
+/* Unshare and maybe enlarge current groups to this size, if possible.
+ * 0 or -err. */
+int cow_current_groups(unsigned int ngroups)
+{
+ if (ngroups > max_groups)
+ return -EINVAL;
+
+ /* Currently external? */
+ if (unlikely(current->ngroups > NGROUPS_INTERNAL)) {
+ /* Shared? */
+ if (atomic_read(&task_groups(current->groups)->usage) > 1)
+ return alloc_new_groups(ngroups);
+ /* Want more? */
+ if (ngroups > current->ngroups)
+ return alloc_new_groups(ngroups);
+ return 0;
+ }
+
+ /* Internal. Maybe new one will be too big? */
+ if (ngroups > NGROUPS_INTERNAL)
+ return alloc_new_groups(ngroups);
+
+ return 0;
+}
+
/*
* Supplementary group IDs
*/
@@ -1097,21 +1158,29 @@ asmlinkage long sys_getgroups(int gidset

asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist)
{
- gid_t groups[NGROUPS];
+ gid_t *groups;
int retval;

if (!capable(CAP_SETGID))
return -EPERM;
- if ((unsigned) gidsetsize > NGROUPS)
- return -EINVAL;
- if (copy_from_user(groups, grouplist, gidsetsize * sizeof(gid_t)))
- return -EFAULT;
+ retval = cow_current_groups(gidsetsize);
+ if (retval < 0)
+ return retval;
+ groups = kmalloc(sizeof(groups[0]) * gidsetsize, GFP_KERNEL);
+ if (!groups)
+ return -ENOMEM;
+ if (copy_from_user(groups, grouplist, gidsetsize * sizeof(gid_t))) {
+ retval = -EFAULT;
+ goto out;
+ }
retval = security_task_setgroups(gidsetsize, groups);
if (retval)
- return retval;
+ goto out;
memcpy(current->groups, groups, gidsetsize * sizeof(gid_t));
current->ngroups = gidsetsize;
- return 0;
+out:
+ kfree(groups);
+ return retval;
}

static int supplemental_group_member(gid_t grp)
@@ -1431,6 +1500,7 @@ asmlinkage long sys_prctl(int option, un
return error;
}

+EXPORT_SYMBOL(cow_current_groups);
EXPORT_SYMBOL(notifier_chain_register);
EXPORT_SYMBOL(notifier_chain_unregister);
EXPORT_SYMBOL(notifier_call_chain);
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/kernel/sysctl.c .13015-linux-2.6.0-test5-bk11.updated/kernel/sysctl.c
--- .13015-linux-2.6.0-test5-bk11/kernel/sysctl.c 2003-09-25 09:56:39.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/kernel/sysctl.c 2003-09-25 12:58:43.000000000 +1000
@@ -581,6 +581,14 @@ static ctl_table kern_table[] = {
.mode = 0644,
.proc_handler = &proc_dointvec,
},
+ {
+ .ctl_name = KERN_MAX_GROUPS,
+ .procname = "max_groups",
+ .data = &max_groups,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
{ .ctl_name = 0 }
};

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/kernel/uid16.c .13015-linux-2.6.0-test5-bk11.updated/kernel/uid16.c
--- .13015-linux-2.6.0-test5-bk11/kernel/uid16.c 2003-09-22 10:07:19.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/kernel/uid16.c 2003-09-25 12:58:43.000000000 +1000
@@ -109,7 +109,6 @@ asmlinkage long sys_setfsgid16(old_gid_t

asmlinkage long sys_getgroups16(int gidsetsize, old_gid_t __user *grouplist)
{
- old_gid_t groups[NGROUPS];
int i,j;

if (gidsetsize < 0)
@@ -118,34 +117,48 @@ asmlinkage long sys_getgroups16(int gids
if (gidsetsize) {
if (i > gidsetsize)
return -EINVAL;
- for(j=0;j<i;j++)
- groups[j] = current->groups[j];
- if (copy_to_user(grouplist, groups, sizeof(old_gid_t)*i))
+ if (!access_ok(VERIFY_WRITE, grouplist, sizeof(old_gid_t)*i))
return -EFAULT;
+ for(j=0;j<i;j++) {
+ old_gid_t group;
+ group = current->groups[j];
+ if (copy_to_user(grouplist+j, &group, sizeof(group)))
+ return -EFAULT;
+ }
}
return i;
}

asmlinkage long sys_setgroups16(int gidsetsize, old_gid_t __user *grouplist)
{
- old_gid_t groups[NGROUPS];
- gid_t new_groups[NGROUPS];
- int i;
+ old_gid_t *groups;
+ gid_t *new_groups;
+ int i, ret;

if (!capable(CAP_SETGID))
return -EPERM;
- if ((unsigned) gidsetsize > NGROUPS)
- return -EINVAL;
+
+ if ((ret = cow_current_groups(gidsetsize)) < 0)
+ return ret;
+ ret = -ENOMEM;
+ groups = kmalloc(sizeof(groups[0]) * gidsetsize, GFP_KERNEL);
+ new_groups = kmalloc(sizeof(new_groups[0]) * gidsetsize, GFP_KERNEL);
+ if (!groups || !new_groups)
+ goto out;
+ ret = -EFAULT;
if (copy_from_user(groups, grouplist, gidsetsize * sizeof(old_gid_t)))
- return -EFAULT;
+ goto out;
for (i = 0 ; i < gidsetsize ; i++)
new_groups[i] = (gid_t)groups[i];
- i = security_task_setgroups(gidsetsize, new_groups);
- if (i)
- return i;
+ ret = security_task_setgroups(gidsetsize, new_groups);
+ if (ret)
+ goto out;
memcpy(current->groups, new_groups, gidsetsize * sizeof(gid_t));
current->ngroups = gidsetsize;
- return 0;
+out:
+ kfree(groups);
+ kfree(groups);
+ return ret;
}

asmlinkage long sys_getuid16(void)
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .13015-linux-2.6.0-test5-bk11/net/sunrpc/svcauth_unix.c .13015-linux-2.6.0-test5-bk11.updated/net/sunrpc/svcauth_unix.c
--- .13015-linux-2.6.0-test5-bk11/net/sunrpc/svcauth_unix.c 2003-09-22 10:23:05.000000000 +1000
+++ .13015-linux-2.6.0-test5-bk11.updated/net/sunrpc/svcauth_unix.c 2003-09-25 12:58:43.000000000 +1000
@@ -434,11 +434,11 @@ svcauth_unix_accept(struct svc_rqst *rqs
if (slen > 16 || (len -= (slen + 2)*4) < 0)
goto badcred;
for (i = 0; i < slen; i++)
- if (i < NGROUPS)
+ if (i < SVC_CRED_NGROUPS)
cred->cr_groups[i] = ntohl(svc_getu32(argv));
else
svc_getu32(argv);
- if (i < NGROUPS)
+ if (i < SVC_CRED_NGROUPS)
cred->cr_groups[i] = NOGROUP;

if (svc_getu32(argv) != RPC_AUTH_NULL || svc_getu32(argv) != 0) {
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.
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