ksmbd: fix heap-based overflow in set_ntacl_dacl()
The testcase use SMB2_SET_INFO_HE command to set a malformed file attribute
under the label `security.NTACL`. SMB2_QUERY_INFO_HE command in testcase
trigger the following overflow.
[ 4712.003781] ==================================================================
[ 4712.003790] BUG: KASAN: slab-out-of-bounds in build_sec_desc+0x842/0x1dd0 [ksmbd]
[ 4712.003807] Write of size 1060 at addr ffff88801e34c068 by task kworker/0:0/4190
[ 4712.003813] CPU: 0 PID: 4190 Comm: kworker/0:0 Not tainted 5.19.0-rc5 #1
[ 4712.003850] Workqueue: ksmbd-io handle_ksmbd_work [ksmbd]
[ 4712.003867] Call Trace:
[ 4712.003870] <TASK>
[ 4712.003873] dump_stack_lvl+0x49/0x5f
[ 4712.003935] print_report.cold+0x5e/0x5cf
[ 4712.003972] ? ksmbd_vfs_get_sd_xattr+0x16d/0x500 [ksmbd]
[ 4712.003984] ? cmp_map_id+0x200/0x200
[ 4712.003988] ? build_sec_desc+0x842/0x1dd0 [ksmbd]
[ 4712.004000] kasan_report+0xaa/0x120
[ 4712.004045] ? build_sec_desc+0x842/0x1dd0 [ksmbd]
[ 4712.004056] kasan_check_range+0x100/0x1e0
[ 4712.004060] memcpy+0x3c/0x60
[ 4712.004064] build_sec_desc+0x842/0x1dd0 [ksmbd]
[ 4712.004076] ? parse_sec_desc+0x580/0x580 [ksmbd]
[ 4712.004088] ? ksmbd_acls_fattr+0x281/0x410 [ksmbd]
[ 4712.004099] smb2_query_info+0xa8f/0x6110 [ksmbd]
[ 4712.004111] ? psi_group_change+0x856/0xd70
[ 4712.004148] ? update_load_avg+0x1c3/0x1af0
[ 4712.004152] ? asym_cpu_capacity_scan+0x5d0/0x5d0
[ 4712.004157] ? xas_load+0x23/0x300
[ 4712.004162] ? smb2_query_dir+0x1530/0x1530 [ksmbd]
[ 4712.004173] ? _raw_spin_lock_bh+0xe0/0xe0
[ 4712.004179] handle_ksmbd_work+0x30e/0x1020 [ksmbd]
[ 4712.004192] process_one_work+0x778/0x11c0
[ 4712.004227] ? _raw_spin_lock_irq+0x8e/0xe0
[ 4712.004231] worker_thread+0x544/0x1180
[ 4712.004234] ? __cpuidle_text_end+0x4/0x4
[ 4712.004239] kthread+0x282/0x320
[ 4712.004243] ? process_one_work+0x11c0/0x11c0
[ 4712.004246] ? kthread_complete_and_exit+0x30/0x30
[ 4712.004282] ret_from_fork+0x1f/0x30
This patch add the buffer validation for security descriptor that is
stored by malformed SMB2_SET_INFO_HE command. and allocate large
response buffer about SMB2_O_INFO_SECURITY file info class.
Fixes: e2f34481b2 ("cifsd: add server-side procedures for SMB3")
Cc: stable@vger.kernel.org
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-17771
Reviewed-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Namjae Jeon
Steve French
parent
824d4f64c2
commit
8f0541186e
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@ -535,9 +535,10 @@ int smb2_allocate_rsp_buf(struct ksmbd_work *work)
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struct smb2_query_info_req *req;
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req = smb2_get_msg(work->request_buf);
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if (req->InfoType == SMB2_O_INFO_FILE &&
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(req->FileInfoClass == FILE_FULL_EA_INFORMATION ||
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req->FileInfoClass == FILE_ALL_INFORMATION))
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if ((req->InfoType == SMB2_O_INFO_FILE &&
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(req->FileInfoClass == FILE_FULL_EA_INFORMATION ||
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req->FileInfoClass == FILE_ALL_INFORMATION)) ||
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req->InfoType == SMB2_O_INFO_SECURITY)
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sz = large_sz;
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}
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@ -2988,7 +2989,7 @@ int smb2_open(struct ksmbd_work *work)
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goto err_out;
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rc = build_sec_desc(user_ns,
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pntsd, NULL,
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pntsd, NULL, 0,
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OWNER_SECINFO |
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GROUP_SECINFO |
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DACL_SECINFO,
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@ -3833,6 +3834,15 @@ static int verify_info_level(int info_level)
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return 0;
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}
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static int smb2_resp_buf_len(struct ksmbd_work *work, unsigned short hdr2_len)
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{
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int free_len;
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free_len = (int)(work->response_sz -
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(get_rfc1002_len(work->response_buf) + 4)) - hdr2_len;
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return free_len;
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}
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static int smb2_calc_max_out_buf_len(struct ksmbd_work *work,
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unsigned short hdr2_len,
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unsigned int out_buf_len)
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@ -3842,9 +3852,7 @@ static int smb2_calc_max_out_buf_len(struct ksmbd_work *work,
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if (out_buf_len > work->conn->vals->max_trans_size)
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return -EINVAL;
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free_len = (int)(work->response_sz -
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(get_rfc1002_len(work->response_buf) + 4)) -
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hdr2_len;
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free_len = smb2_resp_buf_len(work, hdr2_len);
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if (free_len < 0)
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return -EINVAL;
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@ -5107,10 +5115,10 @@ static int smb2_get_info_sec(struct ksmbd_work *work,
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struct smb_ntsd *pntsd = (struct smb_ntsd *)rsp->Buffer, *ppntsd = NULL;
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struct smb_fattr fattr = {{0}};
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struct inode *inode;
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__u32 secdesclen;
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__u32 secdesclen = 0;
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unsigned int id = KSMBD_NO_FID, pid = KSMBD_NO_FID;
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int addition_info = le32_to_cpu(req->AdditionalInformation);
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int rc;
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int rc = 0, ppntsd_size = 0;
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if (addition_info & ~(OWNER_SECINFO | GROUP_SECINFO | DACL_SECINFO |
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PROTECTED_DACL_SECINFO |
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@ -5156,11 +5164,14 @@ static int smb2_get_info_sec(struct ksmbd_work *work,
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if (test_share_config_flag(work->tcon->share_conf,
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KSMBD_SHARE_FLAG_ACL_XATTR))
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ksmbd_vfs_get_sd_xattr(work->conn, user_ns,
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fp->filp->f_path.dentry, &ppntsd);
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ppntsd_size = ksmbd_vfs_get_sd_xattr(work->conn, user_ns,
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fp->filp->f_path.dentry,
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&ppntsd);
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rc = build_sec_desc(user_ns, pntsd, ppntsd, addition_info,
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&secdesclen, &fattr);
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/* Check if sd buffer size exceeds response buffer size */
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if (smb2_resp_buf_len(work, 8) > ppntsd_size)
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rc = build_sec_desc(user_ns, pntsd, ppntsd, ppntsd_size,
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addition_info, &secdesclen, &fattr);
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posix_acl_release(fattr.cf_acls);
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posix_acl_release(fattr.cf_dacls);
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kfree(ppntsd);
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@ -690,6 +690,7 @@ posix_default_acl:
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static void set_ntacl_dacl(struct user_namespace *user_ns,
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struct smb_acl *pndacl,
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struct smb_acl *nt_dacl,
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unsigned int aces_size,
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const struct smb_sid *pownersid,
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const struct smb_sid *pgrpsid,
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struct smb_fattr *fattr)
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@ -703,9 +704,19 @@ static void set_ntacl_dacl(struct user_namespace *user_ns,
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if (nt_num_aces) {
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ntace = (struct smb_ace *)((char *)nt_dacl + sizeof(struct smb_acl));
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for (i = 0; i < nt_num_aces; i++) {
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memcpy((char *)pndace + size, ntace, le16_to_cpu(ntace->size));
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size += le16_to_cpu(ntace->size);
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ntace = (struct smb_ace *)((char *)ntace + le16_to_cpu(ntace->size));
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unsigned short nt_ace_size;
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if (offsetof(struct smb_ace, access_req) > aces_size)
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break;
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nt_ace_size = le16_to_cpu(ntace->size);
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if (nt_ace_size > aces_size)
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break;
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memcpy((char *)pndace + size, ntace, nt_ace_size);
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size += nt_ace_size;
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aces_size -= nt_ace_size;
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ntace = (struct smb_ace *)((char *)ntace + nt_ace_size);
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num_aces++;
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}
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}
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@ -878,7 +889,7 @@ int parse_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd,
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/* Convert permission bits from mode to equivalent CIFS ACL */
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int build_sec_desc(struct user_namespace *user_ns,
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struct smb_ntsd *pntsd, struct smb_ntsd *ppntsd,
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int addition_info, __u32 *secdesclen,
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int ppntsd_size, int addition_info, __u32 *secdesclen,
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struct smb_fattr *fattr)
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{
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int rc = 0;
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@ -938,15 +949,25 @@ int build_sec_desc(struct user_namespace *user_ns,
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if (!ppntsd) {
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set_mode_dacl(user_ns, dacl_ptr, fattr);
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} else if (!ppntsd->dacloffset) {
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goto out;
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} else {
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struct smb_acl *ppdacl_ptr;
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unsigned int dacl_offset = le32_to_cpu(ppntsd->dacloffset);
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int ppdacl_size, ntacl_size = ppntsd_size - dacl_offset;
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if (!dacl_offset ||
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(dacl_offset + sizeof(struct smb_acl) > ppntsd_size))
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goto out;
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ppdacl_ptr = (struct smb_acl *)((char *)ppntsd + dacl_offset);
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ppdacl_size = le16_to_cpu(ppdacl_ptr->size);
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if (ppdacl_size > ntacl_size ||
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ppdacl_size < sizeof(struct smb_acl))
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goto out;
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ppdacl_ptr = (struct smb_acl *)((char *)ppntsd +
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le32_to_cpu(ppntsd->dacloffset));
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set_ntacl_dacl(user_ns, dacl_ptr, ppdacl_ptr,
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nowner_sid_ptr, ngroup_sid_ptr, fattr);
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ntacl_size - sizeof(struct smb_acl),
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nowner_sid_ptr, ngroup_sid_ptr,
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fattr);
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}
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pntsd->dacloffset = cpu_to_le32(offset);
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offset += le16_to_cpu(dacl_ptr->size);
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@ -980,24 +1001,31 @@ int smb_inherit_dacl(struct ksmbd_conn *conn,
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struct smb_sid owner_sid, group_sid;
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struct dentry *parent = path->dentry->d_parent;
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struct user_namespace *user_ns = mnt_user_ns(path->mnt);
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int inherited_flags = 0, flags = 0, i, ace_cnt = 0, nt_size = 0;
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int rc = 0, num_aces, dacloffset, pntsd_type, acl_len;
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int inherited_flags = 0, flags = 0, i, ace_cnt = 0, nt_size = 0, pdacl_size;
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int rc = 0, num_aces, dacloffset, pntsd_type, pntsd_size, acl_len, aces_size;
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char *aces_base;
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bool is_dir = S_ISDIR(d_inode(path->dentry)->i_mode);
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acl_len = ksmbd_vfs_get_sd_xattr(conn, user_ns,
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parent, &parent_pntsd);
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if (acl_len <= 0)
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pntsd_size = ksmbd_vfs_get_sd_xattr(conn, user_ns,
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parent, &parent_pntsd);
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if (pntsd_size <= 0)
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return -ENOENT;
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dacloffset = le32_to_cpu(parent_pntsd->dacloffset);
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if (!dacloffset) {
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if (!dacloffset || (dacloffset + sizeof(struct smb_acl) > pntsd_size)) {
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rc = -EINVAL;
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goto free_parent_pntsd;
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}
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parent_pdacl = (struct smb_acl *)((char *)parent_pntsd + dacloffset);
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acl_len = pntsd_size - dacloffset;
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num_aces = le32_to_cpu(parent_pdacl->num_aces);
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pntsd_type = le16_to_cpu(parent_pntsd->type);
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pdacl_size = le16_to_cpu(parent_pdacl->size);
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if (pdacl_size > acl_len || pdacl_size < sizeof(struct smb_acl)) {
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rc = -EINVAL;
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goto free_parent_pntsd;
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}
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aces_base = kmalloc(sizeof(struct smb_ace) * num_aces * 2, GFP_KERNEL);
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if (!aces_base) {
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@ -1008,11 +1036,23 @@ int smb_inherit_dacl(struct ksmbd_conn *conn,
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aces = (struct smb_ace *)aces_base;
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parent_aces = (struct smb_ace *)((char *)parent_pdacl +
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sizeof(struct smb_acl));
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aces_size = acl_len - sizeof(struct smb_acl);
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if (pntsd_type & DACL_AUTO_INHERITED)
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inherited_flags = INHERITED_ACE;
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for (i = 0; i < num_aces; i++) {
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int pace_size;
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if (offsetof(struct smb_ace, access_req) > aces_size)
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break;
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pace_size = le16_to_cpu(parent_aces->size);
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if (pace_size > aces_size)
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break;
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aces_size -= pace_size;
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flags = parent_aces->flags;
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if (!smb_inherit_flags(flags, is_dir))
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goto pass;
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@ -1057,8 +1097,7 @@ int smb_inherit_dacl(struct ksmbd_conn *conn,
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aces = (struct smb_ace *)((char *)aces + le16_to_cpu(aces->size));
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ace_cnt++;
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pass:
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parent_aces =
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(struct smb_ace *)((char *)parent_aces + le16_to_cpu(parent_aces->size));
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parent_aces = (struct smb_ace *)((char *)parent_aces + pace_size);
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}
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if (nt_size > 0) {
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@ -1153,7 +1192,7 @@ int smb_check_perm_dacl(struct ksmbd_conn *conn, struct path *path,
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struct smb_ntsd *pntsd = NULL;
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struct smb_acl *pdacl;
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struct posix_acl *posix_acls;
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int rc = 0, acl_size;
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int rc = 0, pntsd_size, acl_size, aces_size, pdacl_size, dacl_offset;
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struct smb_sid sid;
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int granted = le32_to_cpu(*pdaccess & ~FILE_MAXIMAL_ACCESS_LE);
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struct smb_ace *ace;
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@ -1162,37 +1201,33 @@ int smb_check_perm_dacl(struct ksmbd_conn *conn, struct path *path,
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struct smb_ace *others_ace = NULL;
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struct posix_acl_entry *pa_entry;
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unsigned int sid_type = SIDOWNER;
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char *end_of_acl;
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unsigned short ace_size;
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ksmbd_debug(SMB, "check permission using windows acl\n");
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acl_size = ksmbd_vfs_get_sd_xattr(conn, user_ns,
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path->dentry, &pntsd);
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if (acl_size <= 0 || !pntsd || !pntsd->dacloffset) {
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kfree(pntsd);
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return 0;
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}
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pntsd_size = ksmbd_vfs_get_sd_xattr(conn, user_ns,
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path->dentry, &pntsd);
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if (pntsd_size <= 0 || !pntsd)
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goto err_out;
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dacl_offset = le32_to_cpu(pntsd->dacloffset);
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if (!dacl_offset ||
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(dacl_offset + sizeof(struct smb_acl) > pntsd_size))
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goto err_out;
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pdacl = (struct smb_acl *)((char *)pntsd + le32_to_cpu(pntsd->dacloffset));
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end_of_acl = ((char *)pntsd) + acl_size;
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if (end_of_acl <= (char *)pdacl) {
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kfree(pntsd);
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return 0;
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}
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acl_size = pntsd_size - dacl_offset;
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pdacl_size = le16_to_cpu(pdacl->size);
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if (end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size) ||
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le16_to_cpu(pdacl->size) < sizeof(struct smb_acl)) {
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kfree(pntsd);
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return 0;
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}
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if (pdacl_size > acl_size || pdacl_size < sizeof(struct smb_acl))
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goto err_out;
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if (!pdacl->num_aces) {
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if (!(le16_to_cpu(pdacl->size) - sizeof(struct smb_acl)) &&
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if (!(pdacl_size - sizeof(struct smb_acl)) &&
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*pdaccess & ~(FILE_READ_CONTROL_LE | FILE_WRITE_DAC_LE)) {
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rc = -EACCES;
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goto err_out;
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}
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kfree(pntsd);
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return 0;
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goto err_out;
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}
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if (*pdaccess & FILE_MAXIMAL_ACCESS_LE) {
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@ -1200,11 +1235,16 @@ int smb_check_perm_dacl(struct ksmbd_conn *conn, struct path *path,
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DELETE;
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ace = (struct smb_ace *)((char *)pdacl + sizeof(struct smb_acl));
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aces_size = acl_size - sizeof(struct smb_acl);
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for (i = 0; i < le32_to_cpu(pdacl->num_aces); i++) {
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if (offsetof(struct smb_ace, access_req) > aces_size)
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break;
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ace_size = le16_to_cpu(ace->size);
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if (ace_size > aces_size)
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break;
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aces_size -= ace_size;
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granted |= le32_to_cpu(ace->access_req);
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ace = (struct smb_ace *)((char *)ace + le16_to_cpu(ace->size));
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if (end_of_acl < (char *)ace)
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goto err_out;
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}
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if (!pdacl->num_aces)
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@ -1216,7 +1256,15 @@ int smb_check_perm_dacl(struct ksmbd_conn *conn, struct path *path,
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id_to_sid(uid, sid_type, &sid);
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ace = (struct smb_ace *)((char *)pdacl + sizeof(struct smb_acl));
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aces_size = acl_size - sizeof(struct smb_acl);
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for (i = 0; i < le32_to_cpu(pdacl->num_aces); i++) {
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if (offsetof(struct smb_ace, access_req) > aces_size)
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break;
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ace_size = le16_to_cpu(ace->size);
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if (ace_size > aces_size)
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break;
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aces_size -= ace_size;
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if (!compare_sids(&sid, &ace->sid) ||
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!compare_sids(&sid_unix_NFS_mode, &ace->sid)) {
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found = 1;
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|
|
@ -1226,8 +1274,6 @@ int smb_check_perm_dacl(struct ksmbd_conn *conn, struct path *path,
|
|||
others_ace = ace;
|
||||
|
||||
ace = (struct smb_ace *)((char *)ace + le16_to_cpu(ace->size));
|
||||
if (end_of_acl < (char *)ace)
|
||||
goto err_out;
|
||||
}
|
||||
|
||||
if (*pdaccess & FILE_MAXIMAL_ACCESS_LE && found) {
|
||||
|
|
|
|||
|
|
@ -193,7 +193,7 @@ struct posix_acl_state {
|
|||
int parse_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd,
|
||||
int acl_len, struct smb_fattr *fattr);
|
||||
int build_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd,
|
||||
struct smb_ntsd *ppntsd, int addition_info,
|
||||
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);
|
||||
|
|
|
|||
|
|
@ -1539,6 +1539,11 @@ int ksmbd_vfs_get_sd_xattr(struct ksmbd_conn *conn,
|
|||
}
|
||||
|
||||
*pntsd = acl.sd_buf;
|
||||
if (acl.sd_size < sizeof(struct smb_ntsd)) {
|
||||
pr_err("sd size is invalid\n");
|
||||
goto out_free;
|
||||
}
|
||||
|
||||
(*pntsd)->osidoffset = cpu_to_le32(le32_to_cpu((*pntsd)->osidoffset) -
|
||||
NDR_NTSD_OFFSETOF);
|
||||
(*pntsd)->gsidoffset = cpu_to_le32(le32_to_cpu((*pntsd)->gsidoffset) -
|
||||
|
|
|
|||
Loading…
Reference in New Issue