mirror of
https://github.com/torvalds/linux
synced 2024-11-05 18:23:50 +00:00
1995266727
Commitbdcf0a423e("kernel: make groups_sort calling a responsibility group_info allocators") appears to break nfsd rootsquash in a pretty major way. It adds a call to groups_sort() inside the loop that copies/squashes gids, which means the valid gids are sorted along with the following garbage. The net result is that the highest numbered valid gids are replaced with any lower-valued garbage gids, possibly including 0. We should sort only once, after filling in all the gids. Fixes:bdcf0a423e("kernel: make groups_sort calling a responsibility ...") Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Acked-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
94 lines
2.1 KiB
C
94 lines
2.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> */
|
|
|
|
#include <linux/sched.h>
|
|
#include "nfsd.h"
|
|
#include "auth.h"
|
|
|
|
int nfsexp_flags(struct svc_rqst *rqstp, struct svc_export *exp)
|
|
{
|
|
struct exp_flavor_info *f;
|
|
struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
|
|
|
|
for (f = exp->ex_flavors; f < end; f++) {
|
|
if (f->pseudoflavor == rqstp->rq_cred.cr_flavor)
|
|
return f->flags;
|
|
}
|
|
return exp->ex_flags;
|
|
|
|
}
|
|
|
|
int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp)
|
|
{
|
|
struct group_info *rqgi;
|
|
struct group_info *gi;
|
|
struct cred *new;
|
|
int i;
|
|
int flags = nfsexp_flags(rqstp, exp);
|
|
|
|
validate_process_creds();
|
|
|
|
/* discard any old override before preparing the new set */
|
|
revert_creds(get_cred(current_real_cred()));
|
|
new = prepare_creds();
|
|
if (!new)
|
|
return -ENOMEM;
|
|
|
|
new->fsuid = rqstp->rq_cred.cr_uid;
|
|
new->fsgid = rqstp->rq_cred.cr_gid;
|
|
|
|
rqgi = rqstp->rq_cred.cr_group_info;
|
|
|
|
if (flags & NFSEXP_ALLSQUASH) {
|
|
new->fsuid = exp->ex_anon_uid;
|
|
new->fsgid = exp->ex_anon_gid;
|
|
gi = groups_alloc(0);
|
|
if (!gi)
|
|
goto oom;
|
|
} else if (flags & NFSEXP_ROOTSQUASH) {
|
|
if (uid_eq(new->fsuid, GLOBAL_ROOT_UID))
|
|
new->fsuid = exp->ex_anon_uid;
|
|
if (gid_eq(new->fsgid, GLOBAL_ROOT_GID))
|
|
new->fsgid = exp->ex_anon_gid;
|
|
|
|
gi = groups_alloc(rqgi->ngroups);
|
|
if (!gi)
|
|
goto oom;
|
|
|
|
for (i = 0; i < rqgi->ngroups; i++) {
|
|
if (gid_eq(GLOBAL_ROOT_GID, rqgi->gid[i]))
|
|
gi->gid[i] = exp->ex_anon_gid;
|
|
else
|
|
gi->gid[i] = rqgi->gid[i];
|
|
}
|
|
|
|
/* Each thread allocates its own gi, no race */
|
|
groups_sort(gi);
|
|
} else {
|
|
gi = get_group_info(rqgi);
|
|
}
|
|
|
|
if (uid_eq(new->fsuid, INVALID_UID))
|
|
new->fsuid = exp->ex_anon_uid;
|
|
if (gid_eq(new->fsgid, INVALID_GID))
|
|
new->fsgid = exp->ex_anon_gid;
|
|
|
|
set_groups(new, gi);
|
|
put_group_info(gi);
|
|
|
|
if (!uid_eq(new->fsuid, GLOBAL_ROOT_UID))
|
|
new->cap_effective = cap_drop_nfsd_set(new->cap_effective);
|
|
else
|
|
new->cap_effective = cap_raise_nfsd_set(new->cap_effective,
|
|
new->cap_permitted);
|
|
validate_process_creds();
|
|
put_cred(override_creds(new));
|
|
put_cred(new);
|
|
validate_process_creds();
|
|
return 0;
|
|
|
|
oom:
|
|
abort_creds(new);
|
|
return -ENOMEM;
|
|
}
|
|
|