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![David Howells](/assets/img/avatar_default.png)
Add support for per-user_namespace registers of persistent per-UID kerberos caches held within the kernel. This allows the kerberos cache to be retained beyond the life of all a user's processes so that the user's cron jobs can work. The kerberos cache is envisioned as a keyring/key tree looking something like: struct user_namespace \___ .krb_cache keyring - The register \___ _krb.0 keyring - Root's Kerberos cache \___ _krb.5000 keyring - User 5000's Kerberos cache \___ _krb.5001 keyring - User 5001's Kerberos cache \___ tkt785 big_key - A ccache blob \___ tkt12345 big_key - Another ccache blob Or possibly: struct user_namespace \___ .krb_cache keyring - The register \___ _krb.0 keyring - Root's Kerberos cache \___ _krb.5000 keyring - User 5000's Kerberos cache \___ _krb.5001 keyring - User 5001's Kerberos cache \___ tkt785 keyring - A ccache \___ krbtgt/REDHAT.COM@REDHAT.COM big_key \___ http/REDHAT.COM@REDHAT.COM user \___ afs/REDHAT.COM@REDHAT.COM user \___ nfs/REDHAT.COM@REDHAT.COM user \___ krbtgt/KERNEL.ORG@KERNEL.ORG big_key \___ http/KERNEL.ORG@KERNEL.ORG big_key What goes into a particular Kerberos cache is entirely up to userspace. Kernel support is limited to giving you the Kerberos cache keyring that you want. The user asks for their Kerberos cache by: krb_cache = keyctl_get_krbcache(uid, dest_keyring); The uid is -1 or the user's own UID for the user's own cache or the uid of some other user's cache (requires CAP_SETUID). This permits rpc.gssd or whatever to mess with the cache. The cache returned is a keyring named "_krb.<uid>" that the possessor can read, search, clear, invalidate, unlink from and add links to. Active LSMs get a chance to rule on whether the caller is permitted to make a link. Each uid's cache keyring is created when it first accessed and is given a timeout that is extended each time this function is called so that the keyring goes away after a while. The timeout is configurable by sysctl but defaults to three days. Each user_namespace struct gets a lazily-created keyring that serves as the register. The cache keyrings are added to it. This means that standard key search and garbage collection facilities are available. The user_namespace struct's register goes away when it does and anything left in it is then automatically gc'd. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Simo Sorce <simo@redhat.com> cc: Serge E. Hallyn <serge.hallyn@ubuntu.com> cc: Eric W. Biederman <ebiederm@xmission.com>
147 lines
3.8 KiB
C
147 lines
3.8 KiB
C
/* 32-bit compatibility syscall for 64-bit systems
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*
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* Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/syscalls.h>
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#include <linux/keyctl.h>
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#include <linux/compat.h>
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#include <linux/slab.h>
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#include "internal.h"
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/*
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* Instantiate a key with the specified compatibility multipart payload and
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* link the key into the destination keyring if one is given.
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*
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* The caller must have the appropriate instantiation permit set for this to
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* work (see keyctl_assume_authority). No other permissions are required.
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*
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* If successful, 0 will be returned.
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*/
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static long compat_keyctl_instantiate_key_iov(
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key_serial_t id,
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const struct compat_iovec __user *_payload_iov,
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unsigned ioc,
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key_serial_t ringid)
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{
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struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
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long ret;
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if (!_payload_iov || !ioc)
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goto no_payload;
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ret = compat_rw_copy_check_uvector(WRITE, _payload_iov, ioc,
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ARRAY_SIZE(iovstack),
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iovstack, &iov);
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if (ret < 0)
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goto err;
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if (ret == 0)
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goto no_payload_free;
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ret = keyctl_instantiate_key_common(id, iov, ioc, ret, ringid);
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err:
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if (iov != iovstack)
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kfree(iov);
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return ret;
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no_payload_free:
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if (iov != iovstack)
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kfree(iov);
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no_payload:
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return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid);
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}
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/*
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* The key control system call, 32-bit compatibility version for 64-bit archs
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*
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* This should only be called if the 64-bit arch uses weird pointers in 32-bit
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* mode or doesn't guarantee that the top 32-bits of the argument registers on
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* taking a 32-bit syscall are zero. If you can, you should call sys_keyctl()
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* directly.
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*/
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asmlinkage long compat_sys_keyctl(u32 option,
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u32 arg2, u32 arg3, u32 arg4, u32 arg5)
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{
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switch (option) {
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case KEYCTL_GET_KEYRING_ID:
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return keyctl_get_keyring_ID(arg2, arg3);
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case KEYCTL_JOIN_SESSION_KEYRING:
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return keyctl_join_session_keyring(compat_ptr(arg2));
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case KEYCTL_UPDATE:
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return keyctl_update_key(arg2, compat_ptr(arg3), arg4);
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case KEYCTL_REVOKE:
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return keyctl_revoke_key(arg2);
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case KEYCTL_DESCRIBE:
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return keyctl_describe_key(arg2, compat_ptr(arg3), arg4);
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case KEYCTL_CLEAR:
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return keyctl_keyring_clear(arg2);
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case KEYCTL_LINK:
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return keyctl_keyring_link(arg2, arg3);
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case KEYCTL_UNLINK:
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return keyctl_keyring_unlink(arg2, arg3);
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case KEYCTL_SEARCH:
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return keyctl_keyring_search(arg2, compat_ptr(arg3),
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compat_ptr(arg4), arg5);
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case KEYCTL_READ:
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return keyctl_read_key(arg2, compat_ptr(arg3), arg4);
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case KEYCTL_CHOWN:
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return keyctl_chown_key(arg2, arg3, arg4);
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case KEYCTL_SETPERM:
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return keyctl_setperm_key(arg2, arg3);
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case KEYCTL_INSTANTIATE:
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return keyctl_instantiate_key(arg2, compat_ptr(arg3), arg4,
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arg5);
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case KEYCTL_NEGATE:
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return keyctl_negate_key(arg2, arg3, arg4);
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case KEYCTL_SET_REQKEY_KEYRING:
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return keyctl_set_reqkey_keyring(arg2);
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case KEYCTL_SET_TIMEOUT:
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return keyctl_set_timeout(arg2, arg3);
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case KEYCTL_ASSUME_AUTHORITY:
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return keyctl_assume_authority(arg2);
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case KEYCTL_GET_SECURITY:
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return keyctl_get_security(arg2, compat_ptr(arg3), arg4);
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case KEYCTL_SESSION_TO_PARENT:
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return keyctl_session_to_parent();
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case KEYCTL_REJECT:
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return keyctl_reject_key(arg2, arg3, arg4, arg5);
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case KEYCTL_INSTANTIATE_IOV:
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return compat_keyctl_instantiate_key_iov(
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arg2, compat_ptr(arg3), arg4, arg5);
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case KEYCTL_INVALIDATE:
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return keyctl_invalidate_key(arg2);
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case KEYCTL_GET_PERSISTENT:
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return keyctl_get_persistent(arg2, arg3);
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default:
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return -EOPNOTSUPP;
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}
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}
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