linux/fs/nfs/nfs4idmap.c

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/*
* fs/nfs/idmap.c
*
* UID and GID to name mapping for clients.
*
* Copyright (c) 2002 The Regents of the University of Michigan.
* All rights reserved.
*
* Marius Aamodt Eriksen <marius@umich.edu>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <linux/types.h>
#include <linux/parser.h>
#include <linux/fs.h>
#include <net/net_namespace.h>
#include <linux/sunrpc/rpc_pipe_fs.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_fs_sb.h>
#include <linux/key.h>
#include <linux/keyctl.h>
#include <linux/key-type.h>
#include <keys/user-type.h>
#include <keys/request_key_auth-type.h>
#include <linux/module.h>
#include <linux/user_namespace.h>
#include "internal.h"
#include "netns.h"
#include "nfs4idmap.h"
#include "nfs4trace.h"
#define NFS_UINT_MAXLEN 11
static const struct cred *id_resolver_cache;
static struct key_type key_type_id_resolver_legacy;
struct idmap_legacy_upcalldata {
struct rpc_pipe_msg pipe_msg;
struct idmap_msg idmap_msg;
struct key *authkey;
struct idmap *idmap;
};
struct idmap {
struct rpc_pipe_dir_object idmap_pdo;
struct rpc_pipe *idmap_pipe;
struct idmap_legacy_upcalldata *idmap_upcall_data;
struct mutex idmap_mutex;
struct user_namespace *user_ns;
};
static struct user_namespace *idmap_userns(const struct idmap *idmap)
{
if (idmap && idmap->user_ns)
return idmap->user_ns;
return &init_user_ns;
}
/**
* nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
* @fattr: fully initialised struct nfs_fattr
* @owner_name: owner name string cache
* @group_name: group name string cache
*/
void nfs_fattr_init_names(struct nfs_fattr *fattr,
struct nfs4_string *owner_name,
struct nfs4_string *group_name)
{
fattr->owner_name = owner_name;
fattr->group_name = group_name;
}
static void nfs_fattr_free_owner_name(struct nfs_fattr *fattr)
{
fattr->valid &= ~NFS_ATTR_FATTR_OWNER_NAME;
kfree(fattr->owner_name->data);
}
static void nfs_fattr_free_group_name(struct nfs_fattr *fattr)
{
fattr->valid &= ~NFS_ATTR_FATTR_GROUP_NAME;
kfree(fattr->group_name->data);
}
static bool nfs_fattr_map_owner_name(struct nfs_server *server, struct nfs_fattr *fattr)
{
struct nfs4_string *owner = fattr->owner_name;
kuid_t uid;
if (!(fattr->valid & NFS_ATTR_FATTR_OWNER_NAME))
return false;
if (nfs_map_name_to_uid(server, owner->data, owner->len, &uid) == 0) {
fattr->uid = uid;
fattr->valid |= NFS_ATTR_FATTR_OWNER;
}
return true;
}
static bool nfs_fattr_map_group_name(struct nfs_server *server, struct nfs_fattr *fattr)
{
struct nfs4_string *group = fattr->group_name;
kgid_t gid;
if (!(fattr->valid & NFS_ATTR_FATTR_GROUP_NAME))
return false;
if (nfs_map_group_to_gid(server, group->data, group->len, &gid) == 0) {
fattr->gid = gid;
fattr->valid |= NFS_ATTR_FATTR_GROUP;
}
return true;
}
/**
* nfs_fattr_free_names - free up the NFSv4 owner and group strings
* @fattr: a fully initialised nfs_fattr structure
*/
void nfs_fattr_free_names(struct nfs_fattr *fattr)
{
if (fattr->valid & NFS_ATTR_FATTR_OWNER_NAME)
nfs_fattr_free_owner_name(fattr);
if (fattr->valid & NFS_ATTR_FATTR_GROUP_NAME)
nfs_fattr_free_group_name(fattr);
}
/**
* nfs_fattr_map_and_free_names - map owner/group strings into uid/gid and free
* @server: pointer to the filesystem nfs_server structure
* @fattr: a fully initialised nfs_fattr structure
*
* This helper maps the cached NFSv4 owner/group strings in fattr into
* their numeric uid/gid equivalents, and then frees the cached strings.
*/
void nfs_fattr_map_and_free_names(struct nfs_server *server, struct nfs_fattr *fattr)
{
if (nfs_fattr_map_owner_name(server, fattr))
nfs_fattr_free_owner_name(fattr);
if (nfs_fattr_map_group_name(server, fattr))
nfs_fattr_free_group_name(fattr);
}
int nfs_map_string_to_numeric(const char *name, size_t namelen, __u32 *res)
{
unsigned long val;
char buf[16];
if (memchr(name, '@', namelen) != NULL || namelen >= sizeof(buf))
return 0;
memcpy(buf, name, namelen);
buf[namelen] = '\0';
if (kstrtoul(buf, 0, &val) != 0)
return 0;
*res = val;
return 1;
}
EXPORT_SYMBOL_GPL(nfs_map_string_to_numeric);
static int nfs_map_numeric_to_string(__u32 id, char *buf, size_t buflen)
{
return snprintf(buf, buflen, "%u", id);
}
static struct key_type key_type_id_resolver = {
.name = "id_resolver",
.preparse = user_preparse,
.free_preparse = user_free_preparse,
.instantiate = generic_key_instantiate,
.revoke = user_revoke,
.destroy = user_destroy,
.describe = user_describe,
.read = user_read,
};
int nfs_idmap_init(void)
{
struct cred *cred;
struct key *keyring;
int ret = 0;
printk(KERN_NOTICE "NFS: Registering the %s key type\n",
key_type_id_resolver.name);
cred = prepare_kernel_cred(NULL);
if (!cred)
return -ENOMEM;
keyring = keyring_alloc(".id_resolver",
GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
(KEY_POS_ALL & ~KEY_POS_SETATTR) |
KEY_USR_VIEW | KEY_USR_READ,
KEYS: Add a facility to restrict new links into a keyring Add a facility whereby proposed new links to be added to a keyring can be vetted, permitting them to be rejected if necessary. This can be used to block public keys from which the signature cannot be verified or for which the signature verification fails. It could also be used to provide blacklisting. This affects operations like add_key(), KEYCTL_LINK and KEYCTL_INSTANTIATE. To this end: (1) A function pointer is added to the key struct that, if set, points to the vetting function. This is called as: int (*restrict_link)(struct key *keyring, const struct key_type *key_type, unsigned long key_flags, const union key_payload *key_payload), where 'keyring' will be the keyring being added to, key_type and key_payload will describe the key being added and key_flags[*] can be AND'ed with KEY_FLAG_TRUSTED. [*] This parameter will be removed in a later patch when KEY_FLAG_TRUSTED is removed. The function should return 0 to allow the link to take place or an error (typically -ENOKEY, -ENOPKG or -EKEYREJECTED) to reject the link. The pointer should not be set directly, but rather should be set through keyring_alloc(). Note that if called during add_key(), preparse is called before this method, but a key isn't actually allocated until after this function is called. (2) KEY_ALLOC_BYPASS_RESTRICTION is added. This can be passed to key_create_or_update() or key_instantiate_and_link() to bypass the restriction check. (3) KEY_FLAG_TRUSTED_ONLY is removed. The entire contents of a keyring with this restriction emplaced can be considered 'trustworthy' by virtue of being in the keyring when that keyring is consulted. (4) key_alloc() and keyring_alloc() take an extra argument that will be used to set restrict_link in the new key. This ensures that the pointer is set before the key is published, thus preventing a window of unrestrictedness. Normally this argument will be NULL. (5) As a temporary affair, keyring_restrict_trusted_only() is added. It should be passed to keyring_alloc() as the extra argument instead of setting KEY_FLAG_TRUSTED_ONLY on a keyring. This will be replaced in a later patch with functions that look in the appropriate places for authoritative keys. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-04-06 15:14:24 +00:00
KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto failed_put_cred;
}
ret = register_key_type(&key_type_id_resolver);
if (ret < 0)
goto failed_put_key;
NFS: Fix a number of bugs in the idmapper Fix a number of bugs in the NFS idmapper code: (1) Only registered key types can be passed to the core keys code, so register the legacy idmapper key type. This is a requirement because the unregister function cleans up keys belonging to that key type so that there aren't dangling pointers to the module left behind - including the key->type pointer. (2) Rename the legacy key type. You can't have two key types with the same name, and (1) would otherwise require that. (3) complete_request_key() must be called in the error path of nfs_idmap_legacy_upcall(). (4) There is one idmap struct for each nfs_client struct. This means that idmap->idmap_key_cons is shared without the use of a lock. This is a problem because key_instantiate_and_link() - as called indirectly by idmap_pipe_downcall() - releases anyone waiting for the key to be instantiated. What happens is that idmap_pipe_downcall() running in the rpc.idmapd thread, releases the NFS filesystem in whatever thread that is running in to continue. This may then make another idmapper call, overwriting idmap_key_cons before idmap_pipe_downcall() gets the chance to call complete_request_key(). I *think* that reading idmap_key_cons only once, before key_instantiate_and_link() is called, and then caching the result in a variable is sufficient. Bug (4) is the cause of: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [< (null)>] (null) PGD 0 Oops: 0010 [#1] SMP CPU 1 Modules linked in: ppdev parport_pc lp parport ip6table_filter ip6_tables ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack nfs fscache xt_CHECKSUM auth_rpcgss iptable_mangle nfs_acl bridge stp llc lockd be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb4i cxgb4 cxgb3i libcxgbi cxgb3 mdio ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi snd_hda_codec_realtek snd_usb_audio snd_hda_intel snd_hda_codec snd_seq snd_pcm snd_hwdep snd_usbmidi_lib snd_rawmidi snd_timer uvcvideo videobuf2_core videodev media videobuf2_vmalloc snd_seq_device videobuf2_memops e1000e vhost_net iTCO_wdt joydev coretemp snd soundcore macvtap macvlan i2c_i801 snd_page_alloc tun iTCO_vendor_support microcode kvm_intel kvm sunrpc hid_logitech_dj usb_storage i915 drm_kms_helper drm i2c_algo_bit i2c_core video [last unloaded: scsi_wait_scan] Pid: 1229, comm: rpc.idmapd Not tainted 3.4.2-1.fc16.x86_64 #1 Gateway DX4710-UB801A/G33M05G1 RIP: 0010:[<0000000000000000>] [< (null)>] (null) RSP: 0018:ffff8801a3645d40 EFLAGS: 00010246 RAX: ffff880077707e30 RBX: ffff880077707f50 RCX: ffff8801a18ccd80 RDX: 0000000000000006 RSI: ffff8801a3645e75 RDI: ffff880077707f50 RBP: ffff8801a3645d88 R08: ffff8801a430f9c0 R09: ffff8801a3645db0 R10: 000000000000000a R11: 0000000000000246 R12: ffff8801a18ccd80 R13: ffff8801a3645e75 R14: ffff8801a430f9c0 R15: 0000000000000006 FS: 00007fb6fb51a700(0000) GS:ffff8801afc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000001a49b0000 CR4: 00000000000027e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process rpc.idmapd (pid: 1229, threadinfo ffff8801a3644000, task ffff8801a3bf9710) Stack: ffffffff81260878 ffff8801a3645db0 ffff8801a3645db0 ffff880077707a90 ffff880077707f50 ffff8801a18ccd80 0000000000000006 ffff8801a3645e75 ffff8801a430f9c0 ffff8801a3645dd8 ffffffff81260983 ffff8801a3645de8 Call Trace: [<ffffffff81260878>] ? __key_instantiate_and_link+0x58/0x100 [<ffffffff81260983>] key_instantiate_and_link+0x63/0xa0 [<ffffffffa057062b>] idmap_pipe_downcall+0x1cb/0x1e0 [nfs] [<ffffffffa0107f57>] rpc_pipe_write+0x67/0x90 [sunrpc] [<ffffffff8117f833>] vfs_write+0xb3/0x180 [<ffffffff8117fb5a>] sys_write+0x4a/0x90 [<ffffffff81600329>] system_call_fastpath+0x16/0x1b Code: Bad RIP value. RIP [< (null)>] (null) RSP <ffff8801a3645d40> CR2: 0000000000000000 Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Steve Dickson <steved@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@vger.kernel.org [>= 3.4]
2012-07-25 15:53:36 +00:00
ret = register_key_type(&key_type_id_resolver_legacy);
if (ret < 0)
goto failed_reg_legacy;
set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
cred->thread_keyring = keyring;
cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
id_resolver_cache = cred;
return 0;
NFS: Fix a number of bugs in the idmapper Fix a number of bugs in the NFS idmapper code: (1) Only registered key types can be passed to the core keys code, so register the legacy idmapper key type. This is a requirement because the unregister function cleans up keys belonging to that key type so that there aren't dangling pointers to the module left behind - including the key->type pointer. (2) Rename the legacy key type. You can't have two key types with the same name, and (1) would otherwise require that. (3) complete_request_key() must be called in the error path of nfs_idmap_legacy_upcall(). (4) There is one idmap struct for each nfs_client struct. This means that idmap->idmap_key_cons is shared without the use of a lock. This is a problem because key_instantiate_and_link() - as called indirectly by idmap_pipe_downcall() - releases anyone waiting for the key to be instantiated. What happens is that idmap_pipe_downcall() running in the rpc.idmapd thread, releases the NFS filesystem in whatever thread that is running in to continue. This may then make another idmapper call, overwriting idmap_key_cons before idmap_pipe_downcall() gets the chance to call complete_request_key(). I *think* that reading idmap_key_cons only once, before key_instantiate_and_link() is called, and then caching the result in a variable is sufficient. Bug (4) is the cause of: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [< (null)>] (null) PGD 0 Oops: 0010 [#1] SMP CPU 1 Modules linked in: ppdev parport_pc lp parport ip6table_filter ip6_tables ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack nfs fscache xt_CHECKSUM auth_rpcgss iptable_mangle nfs_acl bridge stp llc lockd be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb4i cxgb4 cxgb3i libcxgbi cxgb3 mdio ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi snd_hda_codec_realtek snd_usb_audio snd_hda_intel snd_hda_codec snd_seq snd_pcm snd_hwdep snd_usbmidi_lib snd_rawmidi snd_timer uvcvideo videobuf2_core videodev media videobuf2_vmalloc snd_seq_device videobuf2_memops e1000e vhost_net iTCO_wdt joydev coretemp snd soundcore macvtap macvlan i2c_i801 snd_page_alloc tun iTCO_vendor_support microcode kvm_intel kvm sunrpc hid_logitech_dj usb_storage i915 drm_kms_helper drm i2c_algo_bit i2c_core video [last unloaded: scsi_wait_scan] Pid: 1229, comm: rpc.idmapd Not tainted 3.4.2-1.fc16.x86_64 #1 Gateway DX4710-UB801A/G33M05G1 RIP: 0010:[<0000000000000000>] [< (null)>] (null) RSP: 0018:ffff8801a3645d40 EFLAGS: 00010246 RAX: ffff880077707e30 RBX: ffff880077707f50 RCX: ffff8801a18ccd80 RDX: 0000000000000006 RSI: ffff8801a3645e75 RDI: ffff880077707f50 RBP: ffff8801a3645d88 R08: ffff8801a430f9c0 R09: ffff8801a3645db0 R10: 000000000000000a R11: 0000000000000246 R12: ffff8801a18ccd80 R13: ffff8801a3645e75 R14: ffff8801a430f9c0 R15: 0000000000000006 FS: 00007fb6fb51a700(0000) GS:ffff8801afc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000001a49b0000 CR4: 00000000000027e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process rpc.idmapd (pid: 1229, threadinfo ffff8801a3644000, task ffff8801a3bf9710) Stack: ffffffff81260878 ffff8801a3645db0 ffff8801a3645db0 ffff880077707a90 ffff880077707f50 ffff8801a18ccd80 0000000000000006 ffff8801a3645e75 ffff8801a430f9c0 ffff8801a3645dd8 ffffffff81260983 ffff8801a3645de8 Call Trace: [<ffffffff81260878>] ? __key_instantiate_and_link+0x58/0x100 [<ffffffff81260983>] key_instantiate_and_link+0x63/0xa0 [<ffffffffa057062b>] idmap_pipe_downcall+0x1cb/0x1e0 [nfs] [<ffffffffa0107f57>] rpc_pipe_write+0x67/0x90 [sunrpc] [<ffffffff8117f833>] vfs_write+0xb3/0x180 [<ffffffff8117fb5a>] sys_write+0x4a/0x90 [<ffffffff81600329>] system_call_fastpath+0x16/0x1b Code: Bad RIP value. RIP [< (null)>] (null) RSP <ffff8801a3645d40> CR2: 0000000000000000 Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Steve Dickson <steved@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@vger.kernel.org [>= 3.4]
2012-07-25 15:53:36 +00:00
failed_reg_legacy:
unregister_key_type(&key_type_id_resolver);
failed_put_key:
key_put(keyring);
failed_put_cred:
put_cred(cred);
return ret;
}
void nfs_idmap_quit(void)
{
key_revoke(id_resolver_cache->thread_keyring);
unregister_key_type(&key_type_id_resolver);
NFS: Fix a number of bugs in the idmapper Fix a number of bugs in the NFS idmapper code: (1) Only registered key types can be passed to the core keys code, so register the legacy idmapper key type. This is a requirement because the unregister function cleans up keys belonging to that key type so that there aren't dangling pointers to the module left behind - including the key->type pointer. (2) Rename the legacy key type. You can't have two key types with the same name, and (1) would otherwise require that. (3) complete_request_key() must be called in the error path of nfs_idmap_legacy_upcall(). (4) There is one idmap struct for each nfs_client struct. This means that idmap->idmap_key_cons is shared without the use of a lock. This is a problem because key_instantiate_and_link() - as called indirectly by idmap_pipe_downcall() - releases anyone waiting for the key to be instantiated. What happens is that idmap_pipe_downcall() running in the rpc.idmapd thread, releases the NFS filesystem in whatever thread that is running in to continue. This may then make another idmapper call, overwriting idmap_key_cons before idmap_pipe_downcall() gets the chance to call complete_request_key(). I *think* that reading idmap_key_cons only once, before key_instantiate_and_link() is called, and then caching the result in a variable is sufficient. Bug (4) is the cause of: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [< (null)>] (null) PGD 0 Oops: 0010 [#1] SMP CPU 1 Modules linked in: ppdev parport_pc lp parport ip6table_filter ip6_tables ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack nfs fscache xt_CHECKSUM auth_rpcgss iptable_mangle nfs_acl bridge stp llc lockd be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb4i cxgb4 cxgb3i libcxgbi cxgb3 mdio ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi snd_hda_codec_realtek snd_usb_audio snd_hda_intel snd_hda_codec snd_seq snd_pcm snd_hwdep snd_usbmidi_lib snd_rawmidi snd_timer uvcvideo videobuf2_core videodev media videobuf2_vmalloc snd_seq_device videobuf2_memops e1000e vhost_net iTCO_wdt joydev coretemp snd soundcore macvtap macvlan i2c_i801 snd_page_alloc tun iTCO_vendor_support microcode kvm_intel kvm sunrpc hid_logitech_dj usb_storage i915 drm_kms_helper drm i2c_algo_bit i2c_core video [last unloaded: scsi_wait_scan] Pid: 1229, comm: rpc.idmapd Not tainted 3.4.2-1.fc16.x86_64 #1 Gateway DX4710-UB801A/G33M05G1 RIP: 0010:[<0000000000000000>] [< (null)>] (null) RSP: 0018:ffff8801a3645d40 EFLAGS: 00010246 RAX: ffff880077707e30 RBX: ffff880077707f50 RCX: ffff8801a18ccd80 RDX: 0000000000000006 RSI: ffff8801a3645e75 RDI: ffff880077707f50 RBP: ffff8801a3645d88 R08: ffff8801a430f9c0 R09: ffff8801a3645db0 R10: 000000000000000a R11: 0000000000000246 R12: ffff8801a18ccd80 R13: ffff8801a3645e75 R14: ffff8801a430f9c0 R15: 0000000000000006 FS: 00007fb6fb51a700(0000) GS:ffff8801afc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000001a49b0000 CR4: 00000000000027e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process rpc.idmapd (pid: 1229, threadinfo ffff8801a3644000, task ffff8801a3bf9710) Stack: ffffffff81260878 ffff8801a3645db0 ffff8801a3645db0 ffff880077707a90 ffff880077707f50 ffff8801a18ccd80 0000000000000006 ffff8801a3645e75 ffff8801a430f9c0 ffff8801a3645dd8 ffffffff81260983 ffff8801a3645de8 Call Trace: [<ffffffff81260878>] ? __key_instantiate_and_link+0x58/0x100 [<ffffffff81260983>] key_instantiate_and_link+0x63/0xa0 [<ffffffffa057062b>] idmap_pipe_downcall+0x1cb/0x1e0 [nfs] [<ffffffffa0107f57>] rpc_pipe_write+0x67/0x90 [sunrpc] [<ffffffff8117f833>] vfs_write+0xb3/0x180 [<ffffffff8117fb5a>] sys_write+0x4a/0x90 [<ffffffff81600329>] system_call_fastpath+0x16/0x1b Code: Bad RIP value. RIP [< (null)>] (null) RSP <ffff8801a3645d40> CR2: 0000000000000000 Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Steve Dickson <steved@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@vger.kernel.org [>= 3.4]
2012-07-25 15:53:36 +00:00
unregister_key_type(&key_type_id_resolver_legacy);
put_cred(id_resolver_cache);
}
/*
* Assemble the description to pass to request_key()
* This function will allocate a new string and update dest to point
* at it. The caller is responsible for freeing dest.
*
* On error 0 is returned. Otherwise, the length of dest is returned.
*/
static ssize_t nfs_idmap_get_desc(const char *name, size_t namelen,
const char *type, size_t typelen, char **desc)
{
char *cp;
size_t desclen = typelen + namelen + 2;
*desc = kmalloc(desclen, GFP_KERNEL);
if (!*desc)
return -ENOMEM;
cp = *desc;
memcpy(cp, type, typelen);
cp += typelen;
*cp++ = ':';
memcpy(cp, name, namelen);
cp += namelen;
*cp = '\0';
return desclen;
}
static struct key *nfs_idmap_request_key(const char *name, size_t namelen,
const char *type, struct idmap *idmap)
{
char *desc;
struct key *rkey = ERR_PTR(-EAGAIN);
ssize_t ret;
ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc);
if (ret < 0)
return ERR_PTR(ret);
if (!idmap->user_ns || idmap->user_ns == &init_user_ns)
rkey = request_key(&key_type_id_resolver, desc, "");
if (IS_ERR(rkey)) {
mutex_lock(&idmap->idmap_mutex);
rkey = request_key_with_auxdata(&key_type_id_resolver_legacy,
desc, NULL, "", 0, idmap);
mutex_unlock(&idmap->idmap_mutex);
}
if (!IS_ERR(rkey))
set_bit(KEY_FLAG_ROOT_CAN_INVAL, &rkey->flags);
kfree(desc);
return rkey;
}
static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
const char *type, void *data,
size_t data_size, struct idmap *idmap)
{
const struct cred *saved_cred;
struct key *rkey;
const struct user_key_payload *payload;
ssize_t ret;
saved_cred = override_creds(id_resolver_cache);
rkey = nfs_idmap_request_key(name, namelen, type, idmap);
revert_creds(saved_cred);
if (IS_ERR(rkey)) {
ret = PTR_ERR(rkey);
goto out;
}
rcu_read_lock();
rkey->perm |= KEY_USR_VIEW;
ret = key_validate(rkey);
if (ret < 0)
goto out_up;
KEYS: Differentiate uses of rcu_dereference_key() and user_key_payload() rcu_dereference_key() and user_key_payload() are currently being used in two different, incompatible ways: (1) As a wrapper to rcu_dereference() - when only the RCU read lock used to protect the key. (2) As a wrapper to rcu_dereference_protected() - when the key semaphor is used to protect the key and the may be being modified. Fix this by splitting both of the key wrappers to produce: (1) RCU accessors for keys when caller has the key semaphore locked: dereference_key_locked() user_key_payload_locked() (2) RCU accessors for keys when caller holds the RCU read lock: dereference_key_rcu() user_key_payload_rcu() This should fix following warning in the NFS idmapper =============================== [ INFO: suspicious RCU usage. ] 4.10.0 #1 Tainted: G W ------------------------------- ./include/keys/user-type.h:53 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 0 1 lock held by mount.nfs/5987: #0: (rcu_read_lock){......}, at: [<d000000002527abc>] nfs_idmap_get_key+0x15c/0x420 [nfsv4] stack backtrace: CPU: 1 PID: 5987 Comm: mount.nfs Tainted: G W 4.10.0 #1 Call Trace: dump_stack+0xe8/0x154 (unreliable) lockdep_rcu_suspicious+0x140/0x190 nfs_idmap_get_key+0x380/0x420 [nfsv4] nfs_map_name_to_uid+0x2a0/0x3b0 [nfsv4] decode_getfattr_attrs+0xfac/0x16b0 [nfsv4] decode_getfattr_generic.constprop.106+0xbc/0x150 [nfsv4] nfs4_xdr_dec_lookup_root+0xac/0xb0 [nfsv4] rpcauth_unwrap_resp+0xe8/0x140 [sunrpc] call_decode+0x29c/0x910 [sunrpc] __rpc_execute+0x140/0x8f0 [sunrpc] rpc_run_task+0x170/0x200 [sunrpc] nfs4_call_sync_sequence+0x68/0xa0 [nfsv4] _nfs4_lookup_root.isra.44+0xd0/0xf0 [nfsv4] nfs4_lookup_root+0xe0/0x350 [nfsv4] nfs4_lookup_root_sec+0x70/0xa0 [nfsv4] nfs4_find_root_sec+0xc4/0x100 [nfsv4] nfs4_proc_get_rootfh+0x5c/0xf0 [nfsv4] nfs4_get_rootfh+0x6c/0x190 [nfsv4] nfs4_server_common_setup+0xc4/0x260 [nfsv4] nfs4_create_server+0x278/0x3c0 [nfsv4] nfs4_remote_mount+0x50/0xb0 [nfsv4] mount_fs+0x74/0x210 vfs_kern_mount+0x78/0x220 nfs_do_root_mount+0xb0/0x140 [nfsv4] nfs4_try_mount+0x60/0x100 [nfsv4] nfs_fs_mount+0x5ec/0xda0 [nfs] mount_fs+0x74/0x210 vfs_kern_mount+0x78/0x220 do_mount+0x254/0xf70 SyS_mount+0x94/0x100 system_call+0x38/0xe0 Reported-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-03-01 15:11:23 +00:00
payload = user_key_payload_rcu(rkey);
if (IS_ERR_OR_NULL(payload)) {
ret = PTR_ERR(payload);
goto out_up;
}
ret = payload->datalen;
if (ret > 0 && ret <= data_size)
memcpy(data, payload->data, ret);
else
ret = -EINVAL;
out_up:
rcu_read_unlock();
key_put(rkey);
out:
return ret;
}
/* ID -> Name */
static ssize_t nfs_idmap_lookup_name(__u32 id, const char *type, char *buf,
size_t buflen, struct idmap *idmap)
{
char id_str[NFS_UINT_MAXLEN];
int id_len;
ssize_t ret;
NFSv4: Fix possible 1-byte stack overflow in nfs_idmap_read_and_verify_message In nfs_idmap_read_and_verify_message there is an incorrect sprintf '%d' that converts the __u32 'im_id' from struct idmap_msg to 'id_str', which is a stack char array variable of length NFS_UINT_MAXLEN == 11. If a uid or gid value is > 2147483647 = 0x7fffffff, the conversion overflows into a negative value, for example: crash> p (unsigned) (0x80000000) $1 = 2147483648 crash> p (signed) (0x80000000) $2 = -2147483648 The '-' sign is written to the buffer and this causes a 1 byte overflow when the NULL byte is written, which corrupts kernel stack memory. If CONFIG_CC_STACKPROTECTOR_STRONG is set we see a stack-protector panic: [11558053.616565] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffffa05b8a8c [11558053.639063] CPU: 6 PID: 9423 Comm: rpc.idmapd Tainted: G W ------------ T 3.10.0-514.el7.x86_64 #1 [11558053.641990] Hardware name: Red Hat OpenStack Compute, BIOS 1.10.2-3.el7_4.1 04/01/2014 [11558053.644462] ffffffff818c7bc0 00000000b1f3aec1 ffff880de0f9bd48 ffffffff81685eac [11558053.646430] ffff880de0f9bdc8 ffffffff8167f2b3 ffffffff00000010 ffff880de0f9bdd8 [11558053.648313] ffff880de0f9bd78 00000000b1f3aec1 ffffffff811dcb03 ffffffffa05b8a8c [11558053.650107] Call Trace: [11558053.651347] [<ffffffff81685eac>] dump_stack+0x19/0x1b [11558053.653013] [<ffffffff8167f2b3>] panic+0xe3/0x1f2 [11558053.666240] [<ffffffff811dcb03>] ? kfree+0x103/0x140 [11558053.682589] [<ffffffffa05b8a8c>] ? idmap_pipe_downcall+0x1cc/0x1e0 [nfsv4] [11558053.689710] [<ffffffff810855db>] __stack_chk_fail+0x1b/0x30 [11558053.691619] [<ffffffffa05b8a8c>] idmap_pipe_downcall+0x1cc/0x1e0 [nfsv4] [11558053.693867] [<ffffffffa00209d6>] rpc_pipe_write+0x56/0x70 [sunrpc] [11558053.695763] [<ffffffff811fe12d>] vfs_write+0xbd/0x1e0 [11558053.702236] [<ffffffff810acccc>] ? task_work_run+0xac/0xe0 [11558053.704215] [<ffffffff811fec4f>] SyS_write+0x7f/0xe0 [11558053.709674] [<ffffffff816964c9>] system_call_fastpath+0x16/0x1b Fix this by calling the internally defined nfs_map_numeric_to_string() function which properly uses '%u' to convert this __u32. For consistency, also replace the one other place where snprintf is called. Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Reported-by: Stephen Johnston <sjohnsto@redhat.com> Fixes: cf4ab538f1516 ("NFSv4: Fix the string length returned by the idmapper") Cc: stable@vger.kernel.org # v3.4+ Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-05-29 21:47:30 +00:00
id_len = nfs_map_numeric_to_string(id, id_str, sizeof(id_str));
ret = nfs_idmap_get_key(id_str, id_len, type, buf, buflen, idmap);
if (ret < 0)
return -EINVAL;
return ret;
}
/* Name -> ID */
static int nfs_idmap_lookup_id(const char *name, size_t namelen, const char *type,
__u32 *id, struct idmap *idmap)
{
char id_str[NFS_UINT_MAXLEN];
long id_long;
ssize_t data_size;
int ret = 0;
data_size = nfs_idmap_get_key(name, namelen, type, id_str, NFS_UINT_MAXLEN, idmap);
if (data_size <= 0) {
ret = -EINVAL;
} else {
ret = kstrtol(id_str, 10, &id_long);
if (!ret)
*id = (__u32)id_long;
}
return ret;
}
/* idmap classic begins here */
enum {
Opt_find_uid, Opt_find_gid, Opt_find_user, Opt_find_group, Opt_find_err
};
static const match_table_t nfs_idmap_tokens = {
{ Opt_find_uid, "uid:%s" },
{ Opt_find_gid, "gid:%s" },
{ Opt_find_user, "user:%s" },
{ Opt_find_group, "group:%s" },
{ Opt_find_err, NULL }
};
static int nfs_idmap_legacy_upcall(struct key *, void *);
static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
size_t);
static void idmap_release_pipe(struct inode *);
static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
static const struct rpc_pipe_ops idmap_upcall_ops = {
.upcall = rpc_pipe_generic_upcall,
.downcall = idmap_pipe_downcall,
.release_pipe = idmap_release_pipe,
.destroy_msg = idmap_pipe_destroy_msg,
};
static struct key_type key_type_id_resolver_legacy = {
NFS: Fix a number of bugs in the idmapper Fix a number of bugs in the NFS idmapper code: (1) Only registered key types can be passed to the core keys code, so register the legacy idmapper key type. This is a requirement because the unregister function cleans up keys belonging to that key type so that there aren't dangling pointers to the module left behind - including the key->type pointer. (2) Rename the legacy key type. You can't have two key types with the same name, and (1) would otherwise require that. (3) complete_request_key() must be called in the error path of nfs_idmap_legacy_upcall(). (4) There is one idmap struct for each nfs_client struct. This means that idmap->idmap_key_cons is shared without the use of a lock. This is a problem because key_instantiate_and_link() - as called indirectly by idmap_pipe_downcall() - releases anyone waiting for the key to be instantiated. What happens is that idmap_pipe_downcall() running in the rpc.idmapd thread, releases the NFS filesystem in whatever thread that is running in to continue. This may then make another idmapper call, overwriting idmap_key_cons before idmap_pipe_downcall() gets the chance to call complete_request_key(). I *think* that reading idmap_key_cons only once, before key_instantiate_and_link() is called, and then caching the result in a variable is sufficient. Bug (4) is the cause of: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [< (null)>] (null) PGD 0 Oops: 0010 [#1] SMP CPU 1 Modules linked in: ppdev parport_pc lp parport ip6table_filter ip6_tables ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack nfs fscache xt_CHECKSUM auth_rpcgss iptable_mangle nfs_acl bridge stp llc lockd be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb4i cxgb4 cxgb3i libcxgbi cxgb3 mdio ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi snd_hda_codec_realtek snd_usb_audio snd_hda_intel snd_hda_codec snd_seq snd_pcm snd_hwdep snd_usbmidi_lib snd_rawmidi snd_timer uvcvideo videobuf2_core videodev media videobuf2_vmalloc snd_seq_device videobuf2_memops e1000e vhost_net iTCO_wdt joydev coretemp snd soundcore macvtap macvlan i2c_i801 snd_page_alloc tun iTCO_vendor_support microcode kvm_intel kvm sunrpc hid_logitech_dj usb_storage i915 drm_kms_helper drm i2c_algo_bit i2c_core video [last unloaded: scsi_wait_scan] Pid: 1229, comm: rpc.idmapd Not tainted 3.4.2-1.fc16.x86_64 #1 Gateway DX4710-UB801A/G33M05G1 RIP: 0010:[<0000000000000000>] [< (null)>] (null) RSP: 0018:ffff8801a3645d40 EFLAGS: 00010246 RAX: ffff880077707e30 RBX: ffff880077707f50 RCX: ffff8801a18ccd80 RDX: 0000000000000006 RSI: ffff8801a3645e75 RDI: ffff880077707f50 RBP: ffff8801a3645d88 R08: ffff8801a430f9c0 R09: ffff8801a3645db0 R10: 000000000000000a R11: 0000000000000246 R12: ffff8801a18ccd80 R13: ffff8801a3645e75 R14: ffff8801a430f9c0 R15: 0000000000000006 FS: 00007fb6fb51a700(0000) GS:ffff8801afc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000001a49b0000 CR4: 00000000000027e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process rpc.idmapd (pid: 1229, threadinfo ffff8801a3644000, task ffff8801a3bf9710) Stack: ffffffff81260878 ffff8801a3645db0 ffff8801a3645db0 ffff880077707a90 ffff880077707f50 ffff8801a18ccd80 0000000000000006 ffff8801a3645e75 ffff8801a430f9c0 ffff8801a3645dd8 ffffffff81260983 ffff8801a3645de8 Call Trace: [<ffffffff81260878>] ? __key_instantiate_and_link+0x58/0x100 [<ffffffff81260983>] key_instantiate_and_link+0x63/0xa0 [<ffffffffa057062b>] idmap_pipe_downcall+0x1cb/0x1e0 [nfs] [<ffffffffa0107f57>] rpc_pipe_write+0x67/0x90 [sunrpc] [<ffffffff8117f833>] vfs_write+0xb3/0x180 [<ffffffff8117fb5a>] sys_write+0x4a/0x90 [<ffffffff81600329>] system_call_fastpath+0x16/0x1b Code: Bad RIP value. RIP [< (null)>] (null) RSP <ffff8801a3645d40> CR2: 0000000000000000 Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Steve Dickson <steved@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@vger.kernel.org [>= 3.4]
2012-07-25 15:53:36 +00:00
.name = "id_legacy",
.preparse = user_preparse,
.free_preparse = user_free_preparse,
.instantiate = generic_key_instantiate,
.revoke = user_revoke,
.destroy = user_destroy,
.describe = user_describe,
.read = user_read,
.request_key = nfs_idmap_legacy_upcall,
};
static void nfs_idmap_pipe_destroy(struct dentry *dir,
struct rpc_pipe_dir_object *pdo)
{
struct idmap *idmap = pdo->pdo_data;
struct rpc_pipe *pipe = idmap->idmap_pipe;
if (pipe->dentry) {
rpc_unlink(pipe->dentry);
pipe->dentry = NULL;
}
}
static int nfs_idmap_pipe_create(struct dentry *dir,
struct rpc_pipe_dir_object *pdo)
{
struct idmap *idmap = pdo->pdo_data;
struct rpc_pipe *pipe = idmap->idmap_pipe;
struct dentry *dentry;
dentry = rpc_mkpipe_dentry(dir, "idmap", idmap, pipe);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
pipe->dentry = dentry;
return 0;
}
static const struct rpc_pipe_dir_object_ops nfs_idmap_pipe_dir_object_ops = {
.create = nfs_idmap_pipe_create,
.destroy = nfs_idmap_pipe_destroy,
};
int
nfs_idmap_new(struct nfs_client *clp)
{
struct idmap *idmap;
struct rpc_pipe *pipe;
int error;
idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
if (idmap == NULL)
return -ENOMEM;
mutex_init(&idmap->idmap_mutex);
idmap->user_ns = get_user_ns(clp->cl_rpcclient->cl_cred->user_ns);
rpc_init_pipe_dir_object(&idmap->idmap_pdo,
&nfs_idmap_pipe_dir_object_ops,
idmap);
pipe = rpc_mkpipe_data(&idmap_upcall_ops, 0);
if (IS_ERR(pipe)) {
error = PTR_ERR(pipe);
goto err;
}
idmap->idmap_pipe = pipe;
error = rpc_add_pipe_dir_object(clp->cl_net,
&clp->cl_rpcclient->cl_pipedir_objects,
&idmap->idmap_pdo);
if (error)
goto err_destroy_pipe;
clp->cl_idmap = idmap;
return 0;
err_destroy_pipe:
rpc_destroy_pipe_data(idmap->idmap_pipe);
err:
get_user_ns(idmap->user_ns);
kfree(idmap);
return error;
}
void
nfs_idmap_delete(struct nfs_client *clp)
{
struct idmap *idmap = clp->cl_idmap;
if (!idmap)
return;
clp->cl_idmap = NULL;
rpc_remove_pipe_dir_object(clp->cl_net,
&clp->cl_rpcclient->cl_pipedir_objects,
&idmap->idmap_pdo);
rpc_destroy_pipe_data(idmap->idmap_pipe);
put_user_ns(idmap->user_ns);
kfree(idmap);
}
static int nfs_idmap_prepare_message(char *desc, struct idmap *idmap,
struct idmap_msg *im,
struct rpc_pipe_msg *msg)
{
substring_t substr;
int token, ret;
im->im_type = IDMAP_TYPE_GROUP;
token = match_token(desc, nfs_idmap_tokens, &substr);
switch (token) {
case Opt_find_uid:
im->im_type = IDMAP_TYPE_USER;
fallthrough;
case Opt_find_gid:
im->im_conv = IDMAP_CONV_NAMETOID;
ret = match_strlcpy(im->im_name, &substr, IDMAP_NAMESZ);
break;
case Opt_find_user:
im->im_type = IDMAP_TYPE_USER;
fallthrough;
case Opt_find_group:
im->im_conv = IDMAP_CONV_IDTONAME;
ret = match_int(&substr, &im->im_id);
if (ret)
goto out;
break;
default:
ret = -EINVAL;
goto out;
}
msg->data = im;
msg->len = sizeof(struct idmap_msg);
out:
return ret;
}
static bool
nfs_idmap_prepare_pipe_upcall(struct idmap *idmap,
struct idmap_legacy_upcalldata *data)
{
if (idmap->idmap_upcall_data != NULL) {
WARN_ON_ONCE(1);
return false;
}
idmap->idmap_upcall_data = data;
return true;
}
static void
nfs_idmap_complete_pipe_upcall_locked(struct idmap *idmap, int ret)
{
struct key *authkey = idmap->idmap_upcall_data->authkey;
kfree(idmap->idmap_upcall_data);
idmap->idmap_upcall_data = NULL;
complete_request_key(authkey, ret);
key_put(authkey);
}
static void
nfs_idmap_abort_pipe_upcall(struct idmap *idmap, int ret)
{
if (idmap->idmap_upcall_data != NULL)
nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
}
static int nfs_idmap_legacy_upcall(struct key *authkey, void *aux)
{
struct idmap_legacy_upcalldata *data;
struct request_key_auth *rka = get_request_key_auth(authkey);
struct rpc_pipe_msg *msg;
struct idmap_msg *im;
struct idmap *idmap = (struct idmap *)aux;
struct key *key = rka->target_key;
int ret = -ENOKEY;
if (!aux)
goto out1;
/* msg and im are freed in idmap_pipe_destroy_msg */
ret = -ENOMEM;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
goto out1;
msg = &data->pipe_msg;
im = &data->idmap_msg;
data->idmap = idmap;
data->authkey = key_get(authkey);
ret = nfs_idmap_prepare_message(key->description, idmap, im, msg);
if (ret < 0)
goto out2;
ret = -EAGAIN;
if (!nfs_idmap_prepare_pipe_upcall(idmap, data))
goto out2;
ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
if (ret < 0)
nfs_idmap_abort_pipe_upcall(idmap, ret);
return ret;
out2:
kfree(data);
out1:
complete_request_key(authkey, ret);
return ret;
}
static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *data, size_t datalen)
{
return key_instantiate_and_link(key, data, datalen,
id_resolver_cache->thread_keyring,
authkey);
}
static int nfs_idmap_read_and_verify_message(struct idmap_msg *im,
struct idmap_msg *upcall,
struct key *key, struct key *authkey)
{
char id_str[NFS_UINT_MAXLEN];
size_t len;
int ret = -ENOKEY;
/* ret = -ENOKEY */
if (upcall->im_type != im->im_type || upcall->im_conv != im->im_conv)
goto out;
switch (im->im_conv) {
case IDMAP_CONV_NAMETOID:
if (strcmp(upcall->im_name, im->im_name) != 0)
break;
/* Note: here we store the NUL terminator too */
NFSv4: Fix possible 1-byte stack overflow in nfs_idmap_read_and_verify_message In nfs_idmap_read_and_verify_message there is an incorrect sprintf '%d' that converts the __u32 'im_id' from struct idmap_msg to 'id_str', which is a stack char array variable of length NFS_UINT_MAXLEN == 11. If a uid or gid value is > 2147483647 = 0x7fffffff, the conversion overflows into a negative value, for example: crash> p (unsigned) (0x80000000) $1 = 2147483648 crash> p (signed) (0x80000000) $2 = -2147483648 The '-' sign is written to the buffer and this causes a 1 byte overflow when the NULL byte is written, which corrupts kernel stack memory. If CONFIG_CC_STACKPROTECTOR_STRONG is set we see a stack-protector panic: [11558053.616565] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffffa05b8a8c [11558053.639063] CPU: 6 PID: 9423 Comm: rpc.idmapd Tainted: G W ------------ T 3.10.0-514.el7.x86_64 #1 [11558053.641990] Hardware name: Red Hat OpenStack Compute, BIOS 1.10.2-3.el7_4.1 04/01/2014 [11558053.644462] ffffffff818c7bc0 00000000b1f3aec1 ffff880de0f9bd48 ffffffff81685eac [11558053.646430] ffff880de0f9bdc8 ffffffff8167f2b3 ffffffff00000010 ffff880de0f9bdd8 [11558053.648313] ffff880de0f9bd78 00000000b1f3aec1 ffffffff811dcb03 ffffffffa05b8a8c [11558053.650107] Call Trace: [11558053.651347] [<ffffffff81685eac>] dump_stack+0x19/0x1b [11558053.653013] [<ffffffff8167f2b3>] panic+0xe3/0x1f2 [11558053.666240] [<ffffffff811dcb03>] ? kfree+0x103/0x140 [11558053.682589] [<ffffffffa05b8a8c>] ? idmap_pipe_downcall+0x1cc/0x1e0 [nfsv4] [11558053.689710] [<ffffffff810855db>] __stack_chk_fail+0x1b/0x30 [11558053.691619] [<ffffffffa05b8a8c>] idmap_pipe_downcall+0x1cc/0x1e0 [nfsv4] [11558053.693867] [<ffffffffa00209d6>] rpc_pipe_write+0x56/0x70 [sunrpc] [11558053.695763] [<ffffffff811fe12d>] vfs_write+0xbd/0x1e0 [11558053.702236] [<ffffffff810acccc>] ? task_work_run+0xac/0xe0 [11558053.704215] [<ffffffff811fec4f>] SyS_write+0x7f/0xe0 [11558053.709674] [<ffffffff816964c9>] system_call_fastpath+0x16/0x1b Fix this by calling the internally defined nfs_map_numeric_to_string() function which properly uses '%u' to convert this __u32. For consistency, also replace the one other place where snprintf is called. Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Reported-by: Stephen Johnston <sjohnsto@redhat.com> Fixes: cf4ab538f1516 ("NFSv4: Fix the string length returned by the idmapper") Cc: stable@vger.kernel.org # v3.4+ Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-05-29 21:47:30 +00:00
len = 1 + nfs_map_numeric_to_string(im->im_id, id_str,
sizeof(id_str));
ret = nfs_idmap_instantiate(key, authkey, id_str, len);
break;
case IDMAP_CONV_IDTONAME:
if (upcall->im_id != im->im_id)
break;
len = strlen(im->im_name);
ret = nfs_idmap_instantiate(key, authkey, im->im_name, len);
break;
default:
ret = -EINVAL;
}
out:
return ret;
}
static ssize_t
idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
{
struct request_key_auth *rka;
struct rpc_inode *rpci = RPC_I(file_inode(filp));
struct idmap *idmap = (struct idmap *)rpci->private;
struct key *authkey;
struct idmap_msg im;
size_t namelen_in;
int ret = -ENOKEY;
NFS: Fix a number of bugs in the idmapper Fix a number of bugs in the NFS idmapper code: (1) Only registered key types can be passed to the core keys code, so register the legacy idmapper key type. This is a requirement because the unregister function cleans up keys belonging to that key type so that there aren't dangling pointers to the module left behind - including the key->type pointer. (2) Rename the legacy key type. You can't have two key types with the same name, and (1) would otherwise require that. (3) complete_request_key() must be called in the error path of nfs_idmap_legacy_upcall(). (4) There is one idmap struct for each nfs_client struct. This means that idmap->idmap_key_cons is shared without the use of a lock. This is a problem because key_instantiate_and_link() - as called indirectly by idmap_pipe_downcall() - releases anyone waiting for the key to be instantiated. What happens is that idmap_pipe_downcall() running in the rpc.idmapd thread, releases the NFS filesystem in whatever thread that is running in to continue. This may then make another idmapper call, overwriting idmap_key_cons before idmap_pipe_downcall() gets the chance to call complete_request_key(). I *think* that reading idmap_key_cons only once, before key_instantiate_and_link() is called, and then caching the result in a variable is sufficient. Bug (4) is the cause of: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [< (null)>] (null) PGD 0 Oops: 0010 [#1] SMP CPU 1 Modules linked in: ppdev parport_pc lp parport ip6table_filter ip6_tables ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack nfs fscache xt_CHECKSUM auth_rpcgss iptable_mangle nfs_acl bridge stp llc lockd be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb4i cxgb4 cxgb3i libcxgbi cxgb3 mdio ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi snd_hda_codec_realtek snd_usb_audio snd_hda_intel snd_hda_codec snd_seq snd_pcm snd_hwdep snd_usbmidi_lib snd_rawmidi snd_timer uvcvideo videobuf2_core videodev media videobuf2_vmalloc snd_seq_device videobuf2_memops e1000e vhost_net iTCO_wdt joydev coretemp snd soundcore macvtap macvlan i2c_i801 snd_page_alloc tun iTCO_vendor_support microcode kvm_intel kvm sunrpc hid_logitech_dj usb_storage i915 drm_kms_helper drm i2c_algo_bit i2c_core video [last unloaded: scsi_wait_scan] Pid: 1229, comm: rpc.idmapd Not tainted 3.4.2-1.fc16.x86_64 #1 Gateway DX4710-UB801A/G33M05G1 RIP: 0010:[<0000000000000000>] [< (null)>] (null) RSP: 0018:ffff8801a3645d40 EFLAGS: 00010246 RAX: ffff880077707e30 RBX: ffff880077707f50 RCX: ffff8801a18ccd80 RDX: 0000000000000006 RSI: ffff8801a3645e75 RDI: ffff880077707f50 RBP: ffff8801a3645d88 R08: ffff8801a430f9c0 R09: ffff8801a3645db0 R10: 000000000000000a R11: 0000000000000246 R12: ffff8801a18ccd80 R13: ffff8801a3645e75 R14: ffff8801a430f9c0 R15: 0000000000000006 FS: 00007fb6fb51a700(0000) GS:ffff8801afc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000001a49b0000 CR4: 00000000000027e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process rpc.idmapd (pid: 1229, threadinfo ffff8801a3644000, task ffff8801a3bf9710) Stack: ffffffff81260878 ffff8801a3645db0 ffff8801a3645db0 ffff880077707a90 ffff880077707f50 ffff8801a18ccd80 0000000000000006 ffff8801a3645e75 ffff8801a430f9c0 ffff8801a3645dd8 ffffffff81260983 ffff8801a3645de8 Call Trace: [<ffffffff81260878>] ? __key_instantiate_and_link+0x58/0x100 [<ffffffff81260983>] key_instantiate_and_link+0x63/0xa0 [<ffffffffa057062b>] idmap_pipe_downcall+0x1cb/0x1e0 [nfs] [<ffffffffa0107f57>] rpc_pipe_write+0x67/0x90 [sunrpc] [<ffffffff8117f833>] vfs_write+0xb3/0x180 [<ffffffff8117fb5a>] sys_write+0x4a/0x90 [<ffffffff81600329>] system_call_fastpath+0x16/0x1b Code: Bad RIP value. RIP [< (null)>] (null) RSP <ffff8801a3645d40> CR2: 0000000000000000 Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Steve Dickson <steved@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@vger.kernel.org [>= 3.4]
2012-07-25 15:53:36 +00:00
/* If instantiation is successful, anyone waiting for key construction
* will have been woken up and someone else may now have used
* idmap_key_cons - so after this point we may no longer touch it.
*/
if (idmap->idmap_upcall_data == NULL)
goto out_noupcall;
NFS: Fix a number of bugs in the idmapper Fix a number of bugs in the NFS idmapper code: (1) Only registered key types can be passed to the core keys code, so register the legacy idmapper key type. This is a requirement because the unregister function cleans up keys belonging to that key type so that there aren't dangling pointers to the module left behind - including the key->type pointer. (2) Rename the legacy key type. You can't have two key types with the same name, and (1) would otherwise require that. (3) complete_request_key() must be called in the error path of nfs_idmap_legacy_upcall(). (4) There is one idmap struct for each nfs_client struct. This means that idmap->idmap_key_cons is shared without the use of a lock. This is a problem because key_instantiate_and_link() - as called indirectly by idmap_pipe_downcall() - releases anyone waiting for the key to be instantiated. What happens is that idmap_pipe_downcall() running in the rpc.idmapd thread, releases the NFS filesystem in whatever thread that is running in to continue. This may then make another idmapper call, overwriting idmap_key_cons before idmap_pipe_downcall() gets the chance to call complete_request_key(). I *think* that reading idmap_key_cons only once, before key_instantiate_and_link() is called, and then caching the result in a variable is sufficient. Bug (4) is the cause of: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [< (null)>] (null) PGD 0 Oops: 0010 [#1] SMP CPU 1 Modules linked in: ppdev parport_pc lp parport ip6table_filter ip6_tables ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack nfs fscache xt_CHECKSUM auth_rpcgss iptable_mangle nfs_acl bridge stp llc lockd be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb4i cxgb4 cxgb3i libcxgbi cxgb3 mdio ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi snd_hda_codec_realtek snd_usb_audio snd_hda_intel snd_hda_codec snd_seq snd_pcm snd_hwdep snd_usbmidi_lib snd_rawmidi snd_timer uvcvideo videobuf2_core videodev media videobuf2_vmalloc snd_seq_device videobuf2_memops e1000e vhost_net iTCO_wdt joydev coretemp snd soundcore macvtap macvlan i2c_i801 snd_page_alloc tun iTCO_vendor_support microcode kvm_intel kvm sunrpc hid_logitech_dj usb_storage i915 drm_kms_helper drm i2c_algo_bit i2c_core video [last unloaded: scsi_wait_scan] Pid: 1229, comm: rpc.idmapd Not tainted 3.4.2-1.fc16.x86_64 #1 Gateway DX4710-UB801A/G33M05G1 RIP: 0010:[<0000000000000000>] [< (null)>] (null) RSP: 0018:ffff8801a3645d40 EFLAGS: 00010246 RAX: ffff880077707e30 RBX: ffff880077707f50 RCX: ffff8801a18ccd80 RDX: 0000000000000006 RSI: ffff8801a3645e75 RDI: ffff880077707f50 RBP: ffff8801a3645d88 R08: ffff8801a430f9c0 R09: ffff8801a3645db0 R10: 000000000000000a R11: 0000000000000246 R12: ffff8801a18ccd80 R13: ffff8801a3645e75 R14: ffff8801a430f9c0 R15: 0000000000000006 FS: 00007fb6fb51a700(0000) GS:ffff8801afc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000001a49b0000 CR4: 00000000000027e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process rpc.idmapd (pid: 1229, threadinfo ffff8801a3644000, task ffff8801a3bf9710) Stack: ffffffff81260878 ffff8801a3645db0 ffff8801a3645db0 ffff880077707a90 ffff880077707f50 ffff8801a18ccd80 0000000000000006 ffff8801a3645e75 ffff8801a430f9c0 ffff8801a3645dd8 ffffffff81260983 ffff8801a3645de8 Call Trace: [<ffffffff81260878>] ? __key_instantiate_and_link+0x58/0x100 [<ffffffff81260983>] key_instantiate_and_link+0x63/0xa0 [<ffffffffa057062b>] idmap_pipe_downcall+0x1cb/0x1e0 [nfs] [<ffffffffa0107f57>] rpc_pipe_write+0x67/0x90 [sunrpc] [<ffffffff8117f833>] vfs_write+0xb3/0x180 [<ffffffff8117fb5a>] sys_write+0x4a/0x90 [<ffffffff81600329>] system_call_fastpath+0x16/0x1b Code: Bad RIP value. RIP [< (null)>] (null) RSP <ffff8801a3645d40> CR2: 0000000000000000 Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Steve Dickson <steved@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@vger.kernel.org [>= 3.4]
2012-07-25 15:53:36 +00:00
authkey = idmap->idmap_upcall_data->authkey;
rka = get_request_key_auth(authkey);
NFS: Fix a number of bugs in the idmapper Fix a number of bugs in the NFS idmapper code: (1) Only registered key types can be passed to the core keys code, so register the legacy idmapper key type. This is a requirement because the unregister function cleans up keys belonging to that key type so that there aren't dangling pointers to the module left behind - including the key->type pointer. (2) Rename the legacy key type. You can't have two key types with the same name, and (1) would otherwise require that. (3) complete_request_key() must be called in the error path of nfs_idmap_legacy_upcall(). (4) There is one idmap struct for each nfs_client struct. This means that idmap->idmap_key_cons is shared without the use of a lock. This is a problem because key_instantiate_and_link() - as called indirectly by idmap_pipe_downcall() - releases anyone waiting for the key to be instantiated. What happens is that idmap_pipe_downcall() running in the rpc.idmapd thread, releases the NFS filesystem in whatever thread that is running in to continue. This may then make another idmapper call, overwriting idmap_key_cons before idmap_pipe_downcall() gets the chance to call complete_request_key(). I *think* that reading idmap_key_cons only once, before key_instantiate_and_link() is called, and then caching the result in a variable is sufficient. Bug (4) is the cause of: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [< (null)>] (null) PGD 0 Oops: 0010 [#1] SMP CPU 1 Modules linked in: ppdev parport_pc lp parport ip6table_filter ip6_tables ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack nfs fscache xt_CHECKSUM auth_rpcgss iptable_mangle nfs_acl bridge stp llc lockd be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb4i cxgb4 cxgb3i libcxgbi cxgb3 mdio ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi snd_hda_codec_realtek snd_usb_audio snd_hda_intel snd_hda_codec snd_seq snd_pcm snd_hwdep snd_usbmidi_lib snd_rawmidi snd_timer uvcvideo videobuf2_core videodev media videobuf2_vmalloc snd_seq_device videobuf2_memops e1000e vhost_net iTCO_wdt joydev coretemp snd soundcore macvtap macvlan i2c_i801 snd_page_alloc tun iTCO_vendor_support microcode kvm_intel kvm sunrpc hid_logitech_dj usb_storage i915 drm_kms_helper drm i2c_algo_bit i2c_core video [last unloaded: scsi_wait_scan] Pid: 1229, comm: rpc.idmapd Not tainted 3.4.2-1.fc16.x86_64 #1 Gateway DX4710-UB801A/G33M05G1 RIP: 0010:[<0000000000000000>] [< (null)>] (null) RSP: 0018:ffff8801a3645d40 EFLAGS: 00010246 RAX: ffff880077707e30 RBX: ffff880077707f50 RCX: ffff8801a18ccd80 RDX: 0000000000000006 RSI: ffff8801a3645e75 RDI: ffff880077707f50 RBP: ffff8801a3645d88 R08: ffff8801a430f9c0 R09: ffff8801a3645db0 R10: 000000000000000a R11: 0000000000000246 R12: ffff8801a18ccd80 R13: ffff8801a3645e75 R14: ffff8801a430f9c0 R15: 0000000000000006 FS: 00007fb6fb51a700(0000) GS:ffff8801afc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000001a49b0000 CR4: 00000000000027e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process rpc.idmapd (pid: 1229, threadinfo ffff8801a3644000, task ffff8801a3bf9710) Stack: ffffffff81260878 ffff8801a3645db0 ffff8801a3645db0 ffff880077707a90 ffff880077707f50 ffff8801a18ccd80 0000000000000006 ffff8801a3645e75 ffff8801a430f9c0 ffff8801a3645dd8 ffffffff81260983 ffff8801a3645de8 Call Trace: [<ffffffff81260878>] ? __key_instantiate_and_link+0x58/0x100 [<ffffffff81260983>] key_instantiate_and_link+0x63/0xa0 [<ffffffffa057062b>] idmap_pipe_downcall+0x1cb/0x1e0 [nfs] [<ffffffffa0107f57>] rpc_pipe_write+0x67/0x90 [sunrpc] [<ffffffff8117f833>] vfs_write+0xb3/0x180 [<ffffffff8117fb5a>] sys_write+0x4a/0x90 [<ffffffff81600329>] system_call_fastpath+0x16/0x1b Code: Bad RIP value. RIP [< (null)>] (null) RSP <ffff8801a3645d40> CR2: 0000000000000000 Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Steve Dickson <steved@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@vger.kernel.org [>= 3.4]
2012-07-25 15:53:36 +00:00
if (mlen != sizeof(im)) {
ret = -ENOSPC;
goto out;
}
if (copy_from_user(&im, src, mlen) != 0) {
ret = -EFAULT;
goto out;
}
if (!(im.im_status & IDMAP_STATUS_SUCCESS)) {
ret = -ENOKEY;
goto out;
}
namelen_in = strnlen(im.im_name, IDMAP_NAMESZ);
if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
ret = -EINVAL;
goto out;
}
ret = nfs_idmap_read_and_verify_message(&im,
&idmap->idmap_upcall_data->idmap_msg,
rka->target_key, authkey);
if (ret >= 0) {
key_set_timeout(rka->target_key, nfs_idmap_cache_timeout);
ret = mlen;
}
out:
nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
out_noupcall:
return ret;
}
static void
idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
{
struct idmap_legacy_upcalldata *data = container_of(msg,
struct idmap_legacy_upcalldata,
pipe_msg);
struct idmap *idmap = data->idmap;
if (msg->errno)
nfs_idmap_abort_pipe_upcall(idmap, msg->errno);
}
static void
idmap_release_pipe(struct inode *inode)
{
struct rpc_inode *rpci = RPC_I(inode);
struct idmap *idmap = (struct idmap *)rpci->private;
nfs_idmap_abort_pipe_upcall(idmap, -EPIPE);
}
int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, kuid_t *uid)
{
struct idmap *idmap = server->nfs_client->cl_idmap;
__u32 id = -1;
int ret = 0;
if (!nfs_map_string_to_numeric(name, namelen, &id))
ret = nfs_idmap_lookup_id(name, namelen, "uid", &id, idmap);
if (ret == 0) {
*uid = make_kuid(idmap_userns(idmap), id);
if (!uid_valid(*uid))
ret = -ERANGE;
}
trace_nfs4_map_name_to_uid(name, namelen, id, ret);
return ret;
}
int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, kgid_t *gid)
{
struct idmap *idmap = server->nfs_client->cl_idmap;
__u32 id = -1;
int ret = 0;
if (!nfs_map_string_to_numeric(name, namelen, &id))
ret = nfs_idmap_lookup_id(name, namelen, "gid", &id, idmap);
if (ret == 0) {
*gid = make_kgid(idmap_userns(idmap), id);
if (!gid_valid(*gid))
ret = -ERANGE;
}
trace_nfs4_map_group_to_gid(name, namelen, id, ret);
return ret;
}
int nfs_map_uid_to_name(const struct nfs_server *server, kuid_t uid, char *buf, size_t buflen)
{
struct idmap *idmap = server->nfs_client->cl_idmap;
int ret = -EINVAL;
__u32 id;
id = from_kuid_munged(idmap_userns(idmap), uid);
if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
ret = nfs_idmap_lookup_name(id, "user", buf, buflen, idmap);
if (ret < 0)
ret = nfs_map_numeric_to_string(id, buf, buflen);
trace_nfs4_map_uid_to_name(buf, ret, id, ret);
return ret;
}
int nfs_map_gid_to_group(const struct nfs_server *server, kgid_t gid, char *buf, size_t buflen)
{
struct idmap *idmap = server->nfs_client->cl_idmap;
int ret = -EINVAL;
__u32 id;
id = from_kgid_munged(idmap_userns(idmap), gid);
if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
ret = nfs_idmap_lookup_name(id, "group", buf, buflen, idmap);
if (ret < 0)
ret = nfs_map_numeric_to_string(id, buf, buflen);
trace_nfs4_map_gid_to_group(buf, ret, id, ret);
return ret;
}