linux-stable/fs/smb/server/smbacl.h
Namjae Jeon 864fb5d371 ksmbd: fix possible deadlock in smb2_open
[ 8743.393379] ======================================================
[ 8743.393385] WARNING: possible circular locking dependency detected
[ 8743.393391] 6.4.0-rc1+ #11 Tainted: G           OE
[ 8743.393397] ------------------------------------------------------
[ 8743.393402] kworker/0:2/12921 is trying to acquire lock:
[ 8743.393408] ffff888127a14460 (sb_writers#8){.+.+}-{0:0}, at: ksmbd_vfs_setxattr+0x3d/0xd0 [ksmbd]
[ 8743.393510]
               but task is already holding lock:
[ 8743.393515] ffff8880360d97f0 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: ksmbd_vfs_kern_path_locked+0x181/0x670 [ksmbd]
[ 8743.393618]
               which lock already depends on the new lock.

[ 8743.393623]
               the existing dependency chain (in reverse order) is:
[ 8743.393628]
               -> #1 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}:
[ 8743.393648]        down_write_nested+0x9a/0x1b0
[ 8743.393660]        filename_create+0x128/0x270
[ 8743.393670]        do_mkdirat+0xab/0x1f0
[ 8743.393680]        __x64_sys_mkdir+0x47/0x60
[ 8743.393690]        do_syscall_64+0x5d/0x90
[ 8743.393701]        entry_SYSCALL_64_after_hwframe+0x72/0xdc
[ 8743.393711]
               -> #0 (sb_writers#8){.+.+}-{0:0}:
[ 8743.393728]        __lock_acquire+0x2201/0x3b80
[ 8743.393737]        lock_acquire+0x18f/0x440
[ 8743.393746]        mnt_want_write+0x5f/0x240
[ 8743.393755]        ksmbd_vfs_setxattr+0x3d/0xd0 [ksmbd]
[ 8743.393839]        ksmbd_vfs_set_dos_attrib_xattr+0xcc/0x110 [ksmbd]
[ 8743.393924]        compat_ksmbd_vfs_set_dos_attrib_xattr+0x39/0x50 [ksmbd]
[ 8743.394010]        smb2_open+0x3432/0x3cc0 [ksmbd]
[ 8743.394099]        handle_ksmbd_work+0x2c9/0x7b0 [ksmbd]
[ 8743.394187]        process_one_work+0x65a/0xb30
[ 8743.394198]        worker_thread+0x2cf/0x700
[ 8743.394209]        kthread+0x1ad/0x1f0
[ 8743.394218]        ret_from_fork+0x29/0x50

This patch add mnt_want_write() above parent inode lock and remove
nested mnt_want_write calls in smb2_open().

Fixes: 40b268d384 ("ksmbd: add mnt_want_write to ksmbd vfs functions")
Cc: stable@vger.kernel.org
Reported-by: Marios Makassikis <mmakassikis@freebox.fr>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-11-23 20:50:45 -06:00

238 lines
6.5 KiB
C

/* SPDX-License-Identifier: LGPL-2.1+ */
/*
* Copyright (c) International Business Machines Corp., 2007
* Author(s): Steve French (sfrench@us.ibm.com)
* Modified by Namjae Jeon (linkinjeon@kernel.org)
*/
#ifndef _SMBACL_H
#define _SMBACL_H
#include <linux/fs.h>
#include <linux/namei.h>
#include <linux/posix_acl.h>
#include <linux/mnt_idmapping.h>
#include "mgmt/tree_connect.h"
#define NUM_AUTHS (6) /* number of authority fields */
#define SID_MAX_SUB_AUTHORITIES (15) /* max number of sub authority fields */
/*
* ACE types - see MS-DTYP 2.4.4.1
*/
enum {
ACCESS_ALLOWED,
ACCESS_DENIED,
};
/*
* Security ID types
*/
enum {
SIDOWNER = 1,
SIDGROUP,
SIDCREATOR_OWNER,
SIDCREATOR_GROUP,
SIDUNIX_USER,
SIDUNIX_GROUP,
SIDNFS_USER,
SIDNFS_GROUP,
SIDNFS_MODE,
};
/* Revision for ACLs */
#define SD_REVISION 1
/* Control flags for Security Descriptor */
#define OWNER_DEFAULTED 0x0001
#define GROUP_DEFAULTED 0x0002
#define DACL_PRESENT 0x0004
#define DACL_DEFAULTED 0x0008
#define SACL_PRESENT 0x0010
#define SACL_DEFAULTED 0x0020
#define DACL_TRUSTED 0x0040
#define SERVER_SECURITY 0x0080
#define DACL_AUTO_INHERIT_REQ 0x0100
#define SACL_AUTO_INHERIT_REQ 0x0200
#define DACL_AUTO_INHERITED 0x0400
#define SACL_AUTO_INHERITED 0x0800
#define DACL_PROTECTED 0x1000
#define SACL_PROTECTED 0x2000
#define RM_CONTROL_VALID 0x4000
#define SELF_RELATIVE 0x8000
/* ACE types - see MS-DTYP 2.4.4.1 */
#define ACCESS_ALLOWED_ACE_TYPE 0x00
#define ACCESS_DENIED_ACE_TYPE 0x01
#define SYSTEM_AUDIT_ACE_TYPE 0x02
#define SYSTEM_ALARM_ACE_TYPE 0x03
#define ACCESS_ALLOWED_COMPOUND_ACE_TYPE 0x04
#define ACCESS_ALLOWED_OBJECT_ACE_TYPE 0x05
#define ACCESS_DENIED_OBJECT_ACE_TYPE 0x06
#define SYSTEM_AUDIT_OBJECT_ACE_TYPE 0x07
#define SYSTEM_ALARM_OBJECT_ACE_TYPE 0x08
#define ACCESS_ALLOWED_CALLBACK_ACE_TYPE 0x09
#define ACCESS_DENIED_CALLBACK_ACE_TYPE 0x0A
#define ACCESS_ALLOWED_CALLBACK_OBJECT_ACE_TYPE 0x0B
#define ACCESS_DENIED_CALLBACK_OBJECT_ACE_TYPE 0x0C
#define SYSTEM_AUDIT_CALLBACK_ACE_TYPE 0x0D
#define SYSTEM_ALARM_CALLBACK_ACE_TYPE 0x0E /* Reserved */
#define SYSTEM_AUDIT_CALLBACK_OBJECT_ACE_TYPE 0x0F
#define SYSTEM_ALARM_CALLBACK_OBJECT_ACE_TYPE 0x10 /* reserved */
#define SYSTEM_MANDATORY_LABEL_ACE_TYPE 0x11
#define SYSTEM_RESOURCE_ATTRIBUTE_ACE_TYPE 0x12
#define SYSTEM_SCOPED_POLICY_ID_ACE_TYPE 0x13
/* ACE flags */
#define OBJECT_INHERIT_ACE 0x01
#define CONTAINER_INHERIT_ACE 0x02
#define NO_PROPAGATE_INHERIT_ACE 0x04
#define INHERIT_ONLY_ACE 0x08
#define INHERITED_ACE 0x10
#define SUCCESSFUL_ACCESS_ACE_FLAG 0x40
#define FAILED_ACCESS_ACE_FLAG 0x80
/*
* Maximum size of a string representation of a SID:
*
* The fields are unsigned values in decimal. So:
*
* u8: max 3 bytes in decimal
* u32: max 10 bytes in decimal
*
* "S-" + 3 bytes for version field + 15 for authority field + NULL terminator
*
* For authority field, max is when all 6 values are non-zero and it must be
* represented in hex. So "-0x" + 12 hex digits.
*
* Add 11 bytes for each subauthority field (10 bytes each + 1 for '-')
*/
#define SID_STRING_BASE_SIZE (2 + 3 + 15 + 1)
#define SID_STRING_SUBAUTH_SIZE (11) /* size of a single subauth string */
#define DOMAIN_USER_RID_LE cpu_to_le32(513)
struct ksmbd_conn;
struct smb_ntsd {
__le16 revision; /* revision level */
__le16 type;
__le32 osidoffset;
__le32 gsidoffset;
__le32 sacloffset;
__le32 dacloffset;
} __packed;
struct smb_sid {
__u8 revision; /* revision level */
__u8 num_subauth;
__u8 authority[NUM_AUTHS];
__le32 sub_auth[SID_MAX_SUB_AUTHORITIES]; /* sub_auth[num_subauth] */
} __packed;
/* size of a struct cifs_sid, sans sub_auth array */
#define CIFS_SID_BASE_SIZE (1 + 1 + NUM_AUTHS)
struct smb_acl {
__le16 revision; /* revision level */
__le16 size;
__le32 num_aces;
} __packed;
struct smb_ace {
__u8 type;
__u8 flags;
__le16 size;
__le32 access_req;
struct smb_sid sid; /* ie UUID of user or group who gets these perms */
} __packed;
struct smb_fattr {
kuid_t cf_uid;
kgid_t cf_gid;
umode_t cf_mode;
__le32 daccess;
struct posix_acl *cf_acls;
struct posix_acl *cf_dacls;
};
struct posix_ace_state {
u32 allow;
u32 deny;
};
struct posix_user_ace_state {
union {
kuid_t uid;
kgid_t gid;
};
struct posix_ace_state perms;
};
struct posix_ace_state_array {
int n;
struct posix_user_ace_state aces[];
};
/*
* while processing the nfsv4 ace, this maintains the partial permissions
* calculated so far:
*/
struct posix_acl_state {
struct posix_ace_state owner;
struct posix_ace_state group;
struct posix_ace_state other;
struct posix_ace_state everyone;
struct posix_ace_state mask; /* deny unused in this case */
struct posix_ace_state_array *users;
struct posix_ace_state_array *groups;
};
int parse_sec_desc(struct mnt_idmap *idmap, struct smb_ntsd *pntsd,
int acl_len, struct smb_fattr *fattr);
int build_sec_desc(struct mnt_idmap *idmap, struct smb_ntsd *pntsd,
struct smb_ntsd *ppntsd, int ppntsd_size, int addition_info,
__u32 *secdesclen, struct smb_fattr *fattr);
int init_acl_state(struct posix_acl_state *state, int cnt);
void free_acl_state(struct posix_acl_state *state);
void posix_state_to_acl(struct posix_acl_state *state,
struct posix_acl_entry *pace);
int compare_sids(const struct smb_sid *ctsid, const struct smb_sid *cwsid);
bool smb_inherit_flags(int flags, bool is_dir);
int smb_inherit_dacl(struct ksmbd_conn *conn, const struct path *path,
unsigned int uid, unsigned int gid);
int smb_check_perm_dacl(struct ksmbd_conn *conn, const struct path *path,
__le32 *pdaccess, int uid);
int set_info_sec(struct ksmbd_conn *conn, struct ksmbd_tree_connect *tcon,
const struct path *path, struct smb_ntsd *pntsd, int ntsd_len,
bool type_check, bool get_write);
void id_to_sid(unsigned int cid, uint sidtype, struct smb_sid *ssid);
void ksmbd_init_domain(u32 *sub_auth);
static inline uid_t posix_acl_uid_translate(struct mnt_idmap *idmap,
struct posix_acl_entry *pace)
{
vfsuid_t vfsuid;
/* If this is an idmapped mount, apply the idmapping. */
vfsuid = make_vfsuid(idmap, &init_user_ns, pace->e_uid);
/* Translate the kuid into a userspace id ksmbd would see. */
return from_kuid(&init_user_ns, vfsuid_into_kuid(vfsuid));
}
static inline gid_t posix_acl_gid_translate(struct mnt_idmap *idmap,
struct posix_acl_entry *pace)
{
vfsgid_t vfsgid;
/* If this is an idmapped mount, apply the idmapping. */
vfsgid = make_vfsgid(idmap, &init_user_ns, pace->e_gid);
/* Translate the kgid into a userspace id ksmbd would see. */
return from_kgid(&init_user_ns, vfsgid_into_kgid(vfsgid));
}
#endif /* _SMBACL_H */