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2013-12-02security: shmem: implement kernel private shmem inodesEric Paris1-1/+1
We have a problem where the big_key key storage implementation uses a shmem backed inode to hold the key contents. Because of this detail of implementation LSM checks are being done between processes trying to read the keys and the tmpfs backed inode. The LSM checks are already being handled on the key interface level and should not be enforced at the inode level (since the inode is an implementation detail, not a part of the security model) This patch implements a new function shmem_kernel_file_setup() which returns the equivalent to shmem_file_setup() only the underlying inode has S_PRIVATE set. This means that all LSM checks for the inode in question are skipped. It should only be used for kernel internal operations where the inode is not exposed to userspace without proper LSM checking. It is possible that some other users of shmem_file_setup() should use the new interface, but this has not been explored. Reproducing this bug is a little bit difficult. The steps I used on Fedora are: (1) Turn off selinux enforcing: setenforce 0 (2) Create a huge key k=`dd if=/dev/zero bs=8192 count=1 | keyctl padd big_key test-key @s` (3) Access the key in another context: runcon system_u:system_r:httpd_t:s0-s0:c0.c1023 keyctl print $k >/dev/null (4) Examine the audit logs: ausearch -m AVC -i --subject httpd_t | audit2allow If the last command's output includes a line that looks like: allow httpd_t user_tmpfs_t:file { open read }; There was an inode check between httpd and the tmpfs filesystem. With this patch no such denial will be seen. (NOTE! you should clear your audit log if you have tested for this previously) (Please return you box to enforcing) Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Hugh Dickins <hughd@google.com> cc: linux-mm@kvack.org
2013-12-02KEYS: Fix searching of nested keyringsDavid Howells1-1/+1
If a keyring contains more than 16 keyrings (the capacity of a single node in the associative array) then those keyrings are split over multiple nodes arranged as a tree. If search_nested_keyrings() is called to search the keyring then it will attempt to manually walk over just the 0 branch of the associative array tree where all the keyring links are stored. This works provided the key is found before the algorithm steps from one node containing keyrings to a child node or if there are sufficiently few keyring links that the keyrings are all in one node. However, if the algorithm does need to step from a node to a child node, it doesn't change the node pointer unless a shortcut also gets transited. This means that the algorithm will keep scanning the same node over and over again without terminating and without returning. To fix this, move the internal-pointer-to-node translation from inside the shortcut transit handler so that it applies it to node arrival as well. This can be tested by: r=`keyctl newring sandbox @s` for ((i=0; i<=16; i++)); do keyctl newring ring$i $r; done for ((i=0; i<=16; i++)); do keyctl add user a$i a %:ring$i; done for ((i=0; i<=16; i++)); do keyctl search $r user a$i; done for ((i=17; i<=20; i++)); do keyctl search $r user a$i; done The searches should all complete successfully (or with an error for 17-20), but instead one or more of them will hang. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Stephen Gallagher <sgallagh@redhat.com>
2013-12-02KEYS: Fix multiple key add into associative arrayDavid Howells1-4/+3
If sufficient keys (or keyrings) are added into a keyring such that a node in the associative array's tree overflows (each node has a capacity N, currently 16) and such that all N+1 keys have the same index key segment for that level of the tree (the level'th nibble of the index key), then assoc_array_insert() calls ops->diff_objects() to indicate at which bit position the two index keys vary. However, __key_link_begin() passes a NULL object to assoc_array_insert() with the intention of supplying the correct pointer later before we commit the change. This means that keyring_diff_objects() is given a NULL pointer as one of its arguments which it does not expect. This results in an oops like the attached. With the previous patch to fix the keyring hash function, this can be forced much more easily by creating a keyring and only adding keyrings to it. Add any other sort of key and a different insertion path is taken - all 16+1 objects must want to cluster in the same node slot. This can be tested by: r=`keyctl newring sandbox @s` for ((i=0; i<=16; i++)); do keyctl newring ring$i $r; done This should work fine, but oopses when the 17th keyring is added. Since ops->diff_objects() is always called with the first pointer pointing to the object to be inserted (ie. the NULL pointer), we can fix the problem by changing the to-be-inserted object pointer to point to the index key passed into assoc_array_insert() instead. Whilst we're at it, we also switch the arguments so that they are the same as for ->compare_object(). BUG: unable to handle kernel NULL pointer dereference at 0000000000000088 IP: [<ffffffff81191ee4>] hash_key_type_and_desc+0x18/0xb0 ... RIP: 0010:[<ffffffff81191ee4>] hash_key_type_and_desc+0x18/0xb0 ... Call Trace: [<ffffffff81191f9d>] keyring_diff_objects+0x21/0xd2 [<ffffffff811f09ef>] assoc_array_insert+0x3b6/0x908 [<ffffffff811929a7>] __key_link_begin+0x78/0xe5 [<ffffffff81191a2e>] key_create_or_update+0x17d/0x36a [<ffffffff81192e0a>] SyS_add_key+0x123/0x183 [<ffffffff81400ddb>] tracesys+0xdd/0xe2 Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Stephen Gallagher <sgallagh@redhat.com>
2013-12-02KEYS: Fix the keyring hash functionDavid Howells1-4/+4
The keyring hash function (used by the associative array) is supposed to clear the bottommost nibble of the index key (where the hash value resides) for keyrings and make sure it is non-zero for non-keyrings. This is done to make keyrings cluster together on one branch of the tree separately to other keys. Unfortunately, the wrong mask is used, so only the bottom two bits are examined and cleared and not the whole bottom nibble. This means that keys and keyrings can still be successfully searched for under most circumstances as the hash is consistent in its miscalculation, but if a keyring's associative array bottom node gets filled up then approx 75% of the keyrings will not be put into the 0 branch. The consequence of this is that a key in a keyring linked to by another keyring, ie. keyring A -> keyring B -> key may not be found if the search starts at keyring A and then descends into keyring B because search_nested_keyrings() only searches up the 0 branch (as it "knows" all keyrings must be there and not elsewhere in the tree). The fix is to use the right mask. This can be tested with: r=`keyctl newring sandbox @s` for ((i=0; i<=16; i++)); do keyctl newring ring$i $r; done for ((i=0; i<=16; i++)); do keyctl add user a$i a %:ring$i; done for ((i=0; i<=16; i++)); do keyctl search $r user a$i; done This creates a sandbox keyring, then creates 17 keyrings therein (labelled ring0..ring16). This causes the root node of the sandbox's associative array to overflow and for the tree to have extra nodes inserted. Each keyring then is given a user key (labelled aN for ringN) for us to search for. We then search for the user keys we added, starting from the sandbox. If working correctly, it should return the same ordered list of key IDs as for...keyctl add... did. Without this patch, it reports ENOKEY "Required key not available" for some of the keys. Just which keys get this depends as the kernel pointer to the key type forms part of the hash function. Reported-by: Nalin Dahyabhai <nalin@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Stephen Gallagher <sgallagh@redhat.com>
2013-12-02KEYS: Pre-clear struct key on allocationDavid Howells1-7/+1
The second word of key->payload does not get initialised in key_alloc(), but the big_key type is relying on it having been cleared. The problem comes when big_key fails to instantiate a large key and doesn't then set the payload. The big_key_destroy() op is called from the garbage collector and this assumes that the dentry pointer stored in the second word will be NULL if instantiation did not complete. Therefore just pre-clear the entire struct key on allocation rather than trying to be clever and only initialising to 0 only those bits that aren't otherwise initialised. The lack of initialisation can lead to a bug report like the following if big_key failed to initialise its file: general protection fault: 0000 [#1] SMP Modules linked in: ... CPU: 0 PID: 51 Comm: kworker/0:1 Not tainted 3.10.0-53.el7.x86_64 #1 Hardware name: Dell Inc. PowerEdge 1955/0HC513, BIOS 1.4.4 12/09/2008 Workqueue: events key_garbage_collector task: ffff8801294f5680 ti: ffff8801296e2000 task.ti: ffff8801296e2000 RIP: 0010:[<ffffffff811b4a51>] dput+0x21/0x2d0 ... Call Trace: [<ffffffff811a7b06>] path_put+0x16/0x30 [<ffffffff81235604>] big_key_destroy+0x44/0x60 [<ffffffff8122dc4b>] key_gc_unused_keys.constprop.2+0x5b/0xe0 [<ffffffff8122df2f>] key_garbage_collector+0x1df/0x3c0 [<ffffffff8107759b>] process_one_work+0x17b/0x460 [<ffffffff8107834b>] worker_thread+0x11b/0x400 [<ffffffff81078230>] ? rescuer_thread+0x3e0/0x3e0 [<ffffffff8107eb00>] kthread+0xc0/0xd0 [<ffffffff8107ea40>] ? kthread_create_on_node+0x110/0x110 [<ffffffff815c4bec>] ret_from_fork+0x7c/0xb0 [<ffffffff8107ea40>] ? kthread_create_on_node+0x110/0x110 Reported-by: Patrik Kis <pkis@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Stephen Gallagher <sgallagh@redhat.com>
2013-11-14KEYS: Fix keyring content gc scannerDavid Howells2-51/+36
Key pointers stored in the keyring are marked in bit 1 to indicate if they point to a keyring. We need to strip off this bit before using the pointer when iterating over the keyring for the purpose of looking for links to garbage collect. This means that expirable keyrings aren't correctly expiring because the checker is seeing their key pointer with 2 added to it. Since the fix for this involves knowing about the internals of the keyring, key_gc_keyring() is moved to keyring.c and merged into keyring_gc(). This can be tested by: echo 2 >/proc/sys/kernel/keys/gc_delay keyctl timeout `keyctl add keyring qwerty "" @s` 2 cat /proc/keys sleep 5; cat /proc/keys which should see a keyring called "qwerty" appear in the session keyring and then disappear after it expires, and: echo 2 >/proc/sys/kernel/keys/gc_delay a=`keyctl get_persistent @s` b=`keyctl add keyring 0 "" $a` keyctl add user a a $b keyctl timeout $b 2 cat /proc/keys sleep 5; cat /proc/keys which should see a keyring called "0" with a key called "a" in it appear in the user's persistent keyring (which will be attached to the session keyring) and then both the "0" keyring and the "a" key should disappear when the "0" keyring expires. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Simo Sorce <simo@redhat.com>
2013-11-13KEYS: Fix error handling in big_key instantiationDavid Howells1-0/+1
In the big_key_instantiate() function we return 0 if kernel_write() returns us an error rather than returning an error. This can potentially lead to dentry_open() giving a BUG when called from big_key_read() with an unset tmpfile path. ------------[ cut here ]------------ kernel BUG at fs/open.c:798! ... RIP: 0010:[<ffffffff8119bbd1>] dentry_open+0xd1/0xe0 ... Call Trace: [<ffffffff812350c5>] big_key_read+0x55/0x100 [<ffffffff81231084>] keyctl_read_key+0xb4/0xe0 [<ffffffff81231e58>] SyS_keyctl+0xf8/0x1d0 [<ffffffff815bb799>] system_call_fastpath+0x16/0x1b Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Stephen Gallagher <sgallagh@redhat.com>
2013-11-06KEYS: Fix UID check in keyctl_get_persistent()David Howells1-4/+2
If the UID is specified by userspace when calling the KEYCTL_GET_PERSISTENT function and the process does not have the CAP_SETUID capability, then the function will return -EPERM if the current process's uid, suid, euid and fsuid all match the requested UID. This is incorrect. Fix it such that when a non-privileged caller requests a persistent keyring by a specific UID they can only request their own (ie. the specified UID matches either then process's UID or the process's EUID). This can be tested by logging in as the user and doing: keyctl get_persistent @p keyctl get_persistent @p `id -u` keyctl get_persistent @p 0 The first two should successfully print the same key ID. The third should do the same if called by UID 0 or indicate Operation Not Permitted otherwise. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Stephen Gallagher <sgallagh@redhat.com>
2013-10-30KEYS: fix error return code in big_key_instantiate()Wei Yongjun1-1/+3
Fix to return a negative error code from the error handling case instead of 0, as done elsewhere in this function. Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: David Howells <dhowells@redhat.com>
2013-10-30KEYS: Fix keyring quota misaccounting on key replacement and unlinkDavid Howells1-12/+15
If a key is displaced from a keyring by a matching one, then four more bytes of quota are allocated to the keyring - despite the fact that the keyring does not change in size. Further, when a key is unlinked from a keyring, the four bytes of quota allocated the link isn't recovered and returned to the user's pool. The first can be tested by repeating: keyctl add big_key a fred @s cat /proc/key-users (Don't put it in a shell loop otherwise the garbage collector won't have time to clear the displaced keys, thus affecting the result). This was causing the kerberos keyring to run out of room fairly quickly. The second can be tested by: cat /proc/key-users a=`keyctl add user a a @s` cat /proc/key-users keyctl unlink $a sleep 1 # Give RCU a chance to delete the key cat /proc/key-users assuming no system activity that otherwise adds/removes keys, the amount of key data allocated should go up (say 40/20000 -> 47/20000) and then return to the original value at the end. Reported-by: Stephen Gallagher <sgallagh@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com>
2013-10-30KEYS: Fix a race between negating a key and reading the error setDavid Howells3-2/+6
key_reject_and_link() marking a key as negative and setting the error with which it was negated races with keyring searches and other things that read that error. The fix is to switch the order in which the assignments are done in key_reject_and_link() and to use memory barriers. Kudos to Dave Wysochanski <dwysocha@redhat.com> and Scott Mayhew <smayhew@redhat.com> for tracking this down. This may be the cause of: BUG: unable to handle kernel NULL pointer dereference at 0000000000000070 IP: [<ffffffff81219011>] wait_for_key_construction+0x31/0x80 PGD c6b2c3067 PUD c59879067 PMD 0 Oops: 0000 [#1] SMP last sysfs file: /sys/devices/system/cpu/cpu3/cache/index2/shared_cpu_map CPU 0 Modules linked in: ... Pid: 13359, comm: amqzxma0 Not tainted 2.6.32-358.20.1.el6.x86_64 #1 IBM System x3650 M3 -[7945PSJ]-/00J6159 RIP: 0010:[<ffffffff81219011>] wait_for_key_construction+0x31/0x80 RSP: 0018:ffff880c6ab33758 EFLAGS: 00010246 RAX: ffffffff81219080 RBX: 0000000000000000 RCX: 0000000000000002 RDX: ffffffff81219060 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff880c6ab33768 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff880adfcbce40 R13: ffffffffa03afb84 R14: ffff880adfcbce40 R15: ffff880adfcbce43 FS: 00007f29b8042700(0000) GS:ffff880028200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000070 CR3: 0000000c613dc000 CR4: 00000000000007f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process amqzxma0 (pid: 13359, threadinfo ffff880c6ab32000, task ffff880c610deae0) Stack: ffff880adfcbce40 0000000000000000 ffff880c6ab337b8 ffffffff81219695 <d> 0000000000000000 ffff880a000000d0 ffff880c6ab337a8 000000000000000f <d> ffffffffa03afb93 000000000000000f ffff88186c7882c0 0000000000000014 Call Trace: [<ffffffff81219695>] request_key+0x65/0xa0 [<ffffffffa03a0885>] nfs_idmap_request_key+0xc5/0x170 [nfs] [<ffffffffa03a0eb4>] nfs_idmap_lookup_id+0x34/0x80 [nfs] [<ffffffffa03a1255>] nfs_map_group_to_gid+0x75/0xa0 [nfs] [<ffffffffa039a9ad>] decode_getfattr_attrs+0xbdd/0xfb0 [nfs] [<ffffffff81057310>] ? __dequeue_entity+0x30/0x50 [<ffffffff8100988e>] ? __switch_to+0x26e/0x320 [<ffffffffa039ae03>] decode_getfattr+0x83/0xe0 [nfs] [<ffffffffa039b610>] ? nfs4_xdr_dec_getattr+0x0/0xa0 [nfs] [<ffffffffa039b69f>] nfs4_xdr_dec_getattr+0x8f/0xa0 [nfs] [<ffffffffa02dada4>] rpcauth_unwrap_resp+0x84/0xb0 [sunrpc] [<ffffffffa039b610>] ? nfs4_xdr_dec_getattr+0x0/0xa0 [nfs] [<ffffffffa02cf923>] call_decode+0x1b3/0x800 [sunrpc] [<ffffffff81096de0>] ? wake_bit_function+0x0/0x50 [<ffffffffa02cf770>] ? call_decode+0x0/0x800 [sunrpc] [<ffffffffa02d99a7>] __rpc_execute+0x77/0x350 [sunrpc] [<ffffffff81096c67>] ? bit_waitqueue+0x17/0xd0 [<ffffffffa02d9ce1>] rpc_execute+0x61/0xa0 [sunrpc] [<ffffffffa02d03a5>] rpc_run_task+0x75/0x90 [sunrpc] [<ffffffffa02d04c2>] rpc_call_sync+0x42/0x70 [sunrpc] [<ffffffffa038ff80>] _nfs4_call_sync+0x30/0x40 [nfs] [<ffffffffa038836c>] _nfs4_proc_getattr+0xac/0xc0 [nfs] [<ffffffff810aac87>] ? futex_wait+0x227/0x380 [<ffffffffa038b856>] nfs4_proc_getattr+0x56/0x80 [nfs] [<ffffffffa0371403>] __nfs_revalidate_inode+0xe3/0x220 [nfs] [<ffffffffa037158e>] nfs_revalidate_mapping+0x4e/0x170 [nfs] [<ffffffffa036f147>] nfs_file_read+0x77/0x130 [nfs] [<ffffffff811811aa>] do_sync_read+0xfa/0x140 [<ffffffff81096da0>] ? autoremove_wake_function+0x0/0x40 [<ffffffff8100bb8e>] ? apic_timer_interrupt+0xe/0x20 [<ffffffff8100b9ce>] ? common_interrupt+0xe/0x13 [<ffffffff81228ffb>] ? selinux_file_permission+0xfb/0x150 [<ffffffff8121bed6>] ? security_file_permission+0x16/0x20 [<ffffffff81181a95>] vfs_read+0xb5/0x1a0 [<ffffffff81181bd1>] sys_read+0x51/0x90 [<ffffffff810dc685>] ? __audit_syscall_exit+0x265/0x290 [<ffffffff8100b072>] system_call_fastpath+0x16/0x1b Signed-off-by: David Howells <dhowells@redhat.com> cc: Dave Wysochanski <dwysocha@redhat.com> cc: Scott Mayhew <smayhew@redhat.com>
2013-10-30KEYS: Make BIG_KEYS booleanJosh Boyer1-1/+1
Having the big_keys functionality as a module is very marginally useful. The userspace code that would use this functionality will get odd error messages from the keys layer if the module isn't loaded. The code itself is fairly small, so just have this as a boolean option and not a tristate. Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org> Signed-off-by: David Howells <dhowells@redhat.com>
2013-09-25KEYS: initialize root uid and session keyrings earlyMimi Zohar1-0/+10
In order to create the integrity keyrings (eg. _evm, _ima), root's uid and session keyrings need to be initialized early. Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: David Howells <dhowells@redhat.com>
2013-09-25KEYS: Add a 'trusted' flag and a 'trusted only' flagDavid Howells2-0/+12
Add KEY_FLAG_TRUSTED to indicate that a key either comes from a trusted source or had a cryptographic signature chain that led back to a trusted key the kernel already possessed. Add KEY_FLAGS_TRUSTED_ONLY to indicate that a keyring will only accept links to keys marked with KEY_FLAGS_TRUSTED. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Kees Cook <keescook@chromium.org>
2013-09-24KEYS: Add per-user_namespace registers for persistent per-UID kerberos cachesDavid Howells7-0/+213
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>
2013-09-24KEYS: Implement a big key type that can save to tmpfsDavid Howells3-0/+216
Implement a big key type that can save its contents to tmpfs and thus swapspace when memory is tight. This is useful for Kerberos ticket caches. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Simo Sorce <simo@redhat.com>
2013-09-24KEYS: Expand the capacity of a keyringDavid Howells6-742/+792
Expand the capacity of a keyring to be able to hold a lot more keys by using the previously added associative array implementation. Currently the maximum capacity is: (PAGE_SIZE - sizeof(header)) / sizeof(struct key *) which, on a 64-bit system, is a little more 500. However, since this is being used for the NFS uid mapper, we need more than that. The new implementation gives us effectively unlimited capacity. With some alterations, the keyutils testsuite runs successfully to completion after this patch is applied. The alterations are because (a) keyrings that are simply added to no longer appear ordered and (b) some of the errors have changed a bit. Signed-off-by: David Howells <dhowells@redhat.com>
2013-09-24KEYS: Drop the permissions argument from __keyring_search_one()David Howells3-9/+5
Drop the permissions argument from __keyring_search_one() as the only caller passes 0 here - which causes all checks to be skipped. Signed-off-by: David Howells <dhowells@redhat.com>
2013-09-24KEYS: Define a __key_get() wrapper to use rather than atomic_inc()David Howells3-12/+12
Define a __key_get() wrapper to use rather than atomic_inc() on the key usage count as this makes it easier to hook in refcount error debugging. Signed-off-by: David Howells <dhowells@redhat.com>
2013-09-24KEYS: Search for auth-key by name rather than target key IDDavid Howells1-14/+7
Search for auth-key by name rather than by target key ID as, in a future patch, we'll by searching directly by index key in preference to iteration over all keys. Signed-off-by: David Howells <dhowells@redhat.com>
2013-09-24KEYS: Introduce a search context structureDavid Howells7-158/+174
Search functions pass around a bunch of arguments, each of which gets copied with each call. Introduce a search context structure to hold these. Whilst we're at it, create a search flag that indicates whether the search should be directly to the description or whether it should iterate through all keys looking for a non-description match. This will be useful when keyrings use a generic data struct with generic routines to manage their content as the search terms can just be passed through to the iterator callback function. Also, for future use, the data to be supplied to the match function is separated from the description pointer in the search context. This makes it clear which is being supplied. Signed-off-by: David Howells <dhowells@redhat.com>
2013-09-24KEYS: Consolidate the concept of an 'index key' for key accessDavid Howells4-62/+67
Consolidate the concept of an 'index key' for accessing keys. The index key is the search term needed to find a key directly - basically the key type and the key description. We can add to that the description length. This will be useful when turning a keyring into an associative array rather than just a pointer block. Signed-off-by: David Howells <dhowells@redhat.com>
2013-09-24KEYS: key_is_dead() should take a const key pointer argumentDavid Howells1-1/+1
key_is_dead() should take a const key pointer argument as it doesn't modify what it points to. Signed-off-by: David Howells <dhowells@redhat.com>
2013-09-24KEYS: Use bool in make_key_ref() and is_key_possessed()David Howells1-2/+3
Make make_key_ref() take a bool possession parameter and make is_key_possessed() return a bool. Signed-off-by: David Howells <dhowells@redhat.com>
2013-09-24KEYS: Skip key state checks when checking for possessionDavid Howells4-6/+11
Skip key state checks (invalidation, revocation and expiration) when checking for possession. Without this, keys that have been marked invalid, revoked keys and expired keys are not given a possession attribute - which means the possessor is not granted any possession permits and cannot do anything with them unless they also have one a user, group or other permit. This causes failures in the keyutils test suite's revocation and expiration tests now that commit 96b5c8fea6c0861621051290d705ec2e971963f1 reduced the initial permissions granted to a key. The failures are due to accesses to revoked and expired keys being given EACCES instead of EKEYREVOKED or EKEYEXPIRED. Signed-off-by: David Howells <dhowells@redhat.com>
2013-05-07aio: don't include aio.h in sched.hKent Overstreet2-0/+3
Faster kernel compiles by way of fewer unnecessary includes. [akpm@linux-foundation.org: fix fallout] [akpm@linux-foundation.org: fix build] Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Reviewed-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30KEYS: split call to call_usermodehelper_fns()Lucas De Marchi1-3/+10
Use call_usermodehelper_setup() + call_usermodehelper_exec() instead of calling call_usermodehelper_fns(). In case there's an OOM in this last function the cleanup function may not be called - in this case we would miss a call to key_put(). Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi> Cc: Oleg Nesterov <oleg@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <james.l.morris@oracle.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Tejun Heo <tj@kernel.org> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-12Fix: compat_rw_copy_check_uvector() misuse in aio, readv, writev, and ↵Mathieu Desnoyers1-2/+2
security keys Looking at mm/process_vm_access.c:process_vm_rw() and comparing it to compat_process_vm_rw() shows that the compatibility code requires an explicit "access_ok()" check before calling compat_rw_copy_check_uvector(). The same difference seems to appear when we compare fs/read_write.c:do_readv_writev() to fs/compat.c:compat_do_readv_writev(). This subtle difference between the compat and non-compat requirements should probably be debated, as it seems to be error-prone. In fact, there are two others sites that use this function in the Linux kernel, and they both seem to get it wrong: Now shifting our attention to fs/aio.c, we see that aio_setup_iocb() also ends up calling compat_rw_copy_check_uvector() through aio_setup_vectored_rw(). Unfortunately, the access_ok() check appears to be missing. Same situation for security/keys/compat.c:compat_keyctl_instantiate_key_iov(). I propose that we add the access_ok() check directly into compat_rw_copy_check_uvector(), so callers don't have to worry about it, and it therefore makes the compat call code similar to its non-compat counterpart. Place the access_ok() check in the same location where copy_from_user() can trigger a -EFAULT error in the non-compat code, so the ABI behaviors are alike on both compat and non-compat. While we are here, fix compat_do_readv_writev() so it checks for compat_rw_copy_check_uvector() negative return values. And also, fix a memory leak in compat_keyctl_instantiate_key_iov() error handling. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-12keys: fix race with concurrent install_user_keyrings()David Howells1-1/+1
This fixes CVE-2013-1792. There is a race in install_user_keyrings() that can cause a NULL pointer dereference when called concurrently for the same user if the uid and uid-session keyrings are not yet created. It might be possible for an unprivileged user to trigger this by calling keyctl() from userspace in parallel immediately after logging in. Assume that we have two threads both executing lookup_user_key(), both looking for KEY_SPEC_USER_SESSION_KEYRING. THREAD A THREAD B =============================== =============================== ==>call install_user_keyrings(); if (!cred->user->session_keyring) ==>call install_user_keyrings() ... user->uid_keyring = uid_keyring; if (user->uid_keyring) return 0; <== key = cred->user->session_keyring [== NULL] user->session_keyring = session_keyring; atomic_inc(&key->usage); [oops] At the point thread A dereferences cred->user->session_keyring, thread B hasn't updated user->session_keyring yet, but thread A assumes it is populated because install_user_keyrings() returned ok. The race window is really small but can be exploited if, for example, thread B is interrupted or preempted after initializing uid_keyring, but before doing setting session_keyring. This couldn't be reproduced on a stock kernel. However, after placing systemtap probe on 'user->session_keyring = session_keyring;' that introduced some delay, the kernel could be crashed reliably. Fix this by checking both pointers before deciding whether to return. Alternatively, the test could be done away with entirely as it is checked inside the mutex - but since the mutex is global, that may not be the best way. Signed-off-by: David Howells <dhowells@redhat.com> Reported-by: Mateusz Guzik <mguzik@redhat.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: James Morris <james.l.morris@oracle.com>
2013-03-03userns: Stop oopsing in key_change_session_keyringEric W. Biederman1-1/+1
Dave Jones <davej@redhat.com> writes: > Just hit this on Linus' current tree. > > [ 89.621770] BUG: unable to handle kernel NULL pointer dereference at 00000000000000c8 > [ 89.623111] IP: [<ffffffff810784b0>] commit_creds+0x250/0x2f0 > [ 89.624062] PGD 122bfd067 PUD 122bfe067 PMD 0 > [ 89.624901] Oops: 0000 [#1] PREEMPT SMP > [ 89.625678] Modules linked in: caif_socket caif netrom bridge hidp 8021q garp stp mrp rose llc2 af_rxrpc phonet af_key binfmt_misc bnep l2tp_ppp can_bcm l2tp_core pppoe pppox can_raw scsi_transport_iscsi ppp_generic slhc nfnetlink can ipt_ULOG ax25 decnet irda nfc rds x25 crc_ccitt appletalk atm ipx p8023 psnap p8022 llc lockd sunrpc ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_conntrack nf_conntrack ip6table_filter ip6_tables btusb bluetooth snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_pcm vhost_net snd_page_alloc snd_timer tun macvtap usb_debug snd rfkill microcode macvlan edac_core pcspkr serio_raw kvm_amd soundcore kvm r8169 mii > [ 89.637846] CPU 2 > [ 89.638175] Pid: 782, comm: trinity-main Not tainted 3.8.0+ #63 Gigabyte Technology Co., Ltd. GA-MA78GM-S2H/GA-MA78GM-S2H > [ 89.639850] RIP: 0010:[<ffffffff810784b0>] [<ffffffff810784b0>] commit_creds+0x250/0x2f0 > [ 89.641161] RSP: 0018:ffff880115657eb8 EFLAGS: 00010207 > [ 89.641984] RAX: 00000000000003e8 RBX: ffff88012688b000 RCX: 0000000000000000 > [ 89.643069] RDX: 0000000000000000 RSI: ffffffff81c32960 RDI: ffff880105839600 > [ 89.644167] RBP: ffff880115657ed8 R08: 0000000000000000 R09: 0000000000000000 > [ 89.645254] R10: 0000000000000001 R11: 0000000000000246 R12: ffff880105839600 > [ 89.646340] R13: ffff88011beea490 R14: ffff88011beea490 R15: 0000000000000000 > [ 89.647431] FS: 00007f3ac063b740(0000) GS:ffff88012b200000(0000) knlGS:0000000000000000 > [ 89.648660] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > [ 89.649548] CR2: 00000000000000c8 CR3: 0000000122bfc000 CR4: 00000000000007e0 > [ 89.650635] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 89.651723] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > [ 89.652812] Process trinity-main (pid: 782, threadinfo ffff880115656000, task ffff88011beea490) > [ 89.654128] Stack: > [ 89.654433] 0000000000000000 ffff8801058396a0 ffff880105839600 ffff88011beeaa78 > [ 89.655769] ffff880115657ef8 ffffffff812c7d9b ffffffff82079be0 0000000000000000 > [ 89.657073] ffff880115657f28 ffffffff8106c665 0000000000000002 ffff880115657f58 > [ 89.658399] Call Trace: > [ 89.658822] [<ffffffff812c7d9b>] key_change_session_keyring+0xfb/0x140 > [ 89.659845] [<ffffffff8106c665>] task_work_run+0xa5/0xd0 > [ 89.660698] [<ffffffff81002911>] do_notify_resume+0x71/0xb0 > [ 89.661581] [<ffffffff816c9a4a>] int_signal+0x12/0x17 > [ 89.662385] Code: 24 90 00 00 00 48 8b b3 90 00 00 00 49 8b 4c 24 40 48 39 f2 75 08 e9 83 00 00 00 48 89 ca 48 81 fa 60 29 c3 81 0f 84 41 fe ff ff <48> 8b 8a c8 00 00 00 48 39 ce 75 e4 3b 82 d0 00 00 00 0f 84 4b > [ 89.667778] RIP [<ffffffff810784b0>] commit_creds+0x250/0x2f0 > [ 89.668733] RSP <ffff880115657eb8> > [ 89.669301] CR2: 00000000000000c8 > > My fastest trinity induced oops yet! > > > Appears to be.. > > if ((set_ns == subset_ns->parent) && > 850: 48 8b 8a c8 00 00 00 mov 0xc8(%rdx),%rcx > > from the inlined cred_cap_issubset By historical accident we have been reading trying to set new->user_ns from new->user_ns. Which is totally silly as new->user_ns is NULL (as is every other field in new except session_keyring at that point). The intent is clearly to copy all of the fields from old to new so copy old->user_ns into into new->user_ns. Cc: stable@vger.kernel.org Reported-by: Dave Jones <davej@redhat.com> Tested-by: Dave Jones <davej@redhat.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-02-21KEYS: Revert one application of "Fix unreachable code" patchDavid Howells1-0/+2
A patch to fix some unreachable code in search_my_process_keyrings() got applied twice by two different routes upstream as commits e67eab39bee2 and b010520ab3d2 (both "fix unreachable code"). Unfortunately, the second application removed something it shouldn't have and this wasn't detected by GIT. This is due to the patch not having sufficient lines of context to distinguish the two places of application. The effect of this is relatively minor: inside the kernel, the keyring search routines may search multiple keyrings and then prioritise the errors if no keys or negative keys are found in any of them. With the extra deletion, the presence of a negative key in the thread keyring (causing ENOKEY) is incorrectly overridden by an error searching the process keyring. So revert the second application of the patch. Signed-off-by: David Howells <dhowells@redhat.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-20keys: fix unreachable codeAlan Cox1-2/+0
We set ret to NULL then test it. Remove the bogus test Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-16Merge branch 'for-linus' of ↵Linus Torvalds5-75/+69
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: "A quiet cycle for the security subsystem with just a few maintenance updates." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: Smack: create a sysfs mount point for smackfs Smack: use select not depends in Kconfig Yama: remove locking from delete path Yama: add RCU to drop read locking drivers/char/tpm: remove tasklet and cleanup KEYS: Use keyring_alloc() to create special keyrings KEYS: Reduce initial permissions on keys KEYS: Make the session and process keyrings per-thread seccomp: Make syscall skipping and nr changes more consistent key: Fix resource leak keys: Fix unreachable code KEYS: Add payload preparsing opportunity prior to key instantiate or update
2012-10-28Merge branch 'master' into for-nextJiri Kosina13-195/+225
Sync up with Linus' tree to be able to apply Cesar's patch against newer version of the code. Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-10-25keys: Fix unreachable codeAlan Cox1-2/+0
We set ret to NULL then test it. Remove the bogus test Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-10-14Merge branch 'modules-next' of ↵Linus Torvalds7-63/+129
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module signing support from Rusty Russell: "module signing is the highlight, but it's an all-over David Howells frenzy..." Hmm "Magrathea: Glacier signing key". Somebody has been reading too much HHGTTG. * 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (37 commits) X.509: Fix indefinite length element skip error handling X.509: Convert some printk calls to pr_devel asymmetric keys: fix printk format warning MODSIGN: Fix 32-bit overflow in X.509 certificate validity date checking MODSIGN: Make mrproper should remove generated files. MODSIGN: Use utf8 strings in signer's name in autogenerated X.509 certs MODSIGN: Use the same digest for the autogen key sig as for the module sig MODSIGN: Sign modules during the build process MODSIGN: Provide a script for generating a key ID from an X.509 cert MODSIGN: Implement module signature checking MODSIGN: Provide module signing public keys to the kernel MODSIGN: Automatically generate module signing keys if missing MODSIGN: Provide Kconfig options MODSIGN: Provide gitignore and make clean rules for extra files MODSIGN: Add FIPS policy module: signature checking hook X.509: Add a crypto key parser for binary (DER) X.509 certificates MPILIB: Provide a function to read raw data into an MPI X.509: Add an ASN.1 decoder X.509: Add simple ASN.1 grammar compiler ...
2012-10-08KEYS: Add payload preparsing opportunity prior to key instantiate or updateDavid Howells7-63/+129
Give the key type the opportunity to preparse the payload prior to the instantiation and update routines being called. This is done with the provision of two new key type operations: int (*preparse)(struct key_preparsed_payload *prep); void (*free_preparse)(struct key_preparsed_payload *prep); If the first operation is present, then it is called before key creation (in the add/update case) or before the key semaphore is taken (in the update and instantiate cases). The second operation is called to clean up if the first was called. preparse() is given the opportunity to fill in the following structure: struct key_preparsed_payload { char *description; void *type_data[2]; void *payload; const void *data; size_t datalen; size_t quotalen; }; Before the preparser is called, the first three fields will have been cleared, the payload pointer and size will be stored in data and datalen and the default quota size from the key_type struct will be stored into quotalen. The preparser may parse the payload in any way it likes and may store data in the type_data[] and payload fields for use by the instantiate() and update() ops. The preparser may also propose a description for the key by attaching it as a string to the description field. This can be used by passing a NULL or "" description to the add_key() system call or the key_create_or_update() function. This cannot work with request_key() as that required the description to tell the upcall about the key to be created. This, for example permits keys that store PGP public keys to generate their own name from the user ID and public key fingerprint in the key. The instantiate() and update() operations are then modified to look like this: int (*instantiate)(struct key *key, struct key_preparsed_payload *prep); int (*update)(struct key *key, struct key_preparsed_payload *prep); and the new payload data is passed in *prep, whether or not it was preparsed. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-02Merge branch 'next' of ↵Linus Torvalds1-42/+12
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: "Highlights: - Integrity: add local fs integrity verification to detect offline attacks - Integrity: add digital signature verification - Simple stacking of Yama with other LSMs (per LSS discussions) - IBM vTPM support on ppc64 - Add new driver for Infineon I2C TIS TPM - Smack: add rule revocation for subject labels" Fixed conflicts with the user namespace support in kernel/auditsc.c and security/integrity/ima/ima_policy.c. * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (39 commits) Documentation: Update git repository URL for Smack userland tools ima: change flags container data type Smack: setprocattr memory leak fix Smack: implement revoking all rules for a subject label Smack: remove task_wait() hook. ima: audit log hashes ima: generic IMA action flag handling ima: rename ima_must_appraise_or_measure audit: export audit_log_task_info tpm: fix tpm_acpi sparse warning on different address spaces samples/seccomp: fix 31 bit build on s390 ima: digital signature verification support ima: add support for different security.ima data types ima: add ima_inode_setxattr/removexattr function and calls ima: add inode_post_setattr call ima: replace iint spinblock with rwlock/read_lock ima: allocating iint improvements ima: add appraise action keywords and default rules ima: integrity appraisal extension vfs: move ima_file_free before releasing the file ...
2012-10-02Merge branch 'modsign-keys-devel' into security-next-keysDavid Howells7-63/+129
Signed-off-by: David Howells <dhowells@redhat.com>
2012-10-02KEYS: Use keyring_alloc() to create special keyringsDavid Howells1-0/+1
Use keyring_alloc() to create special keyrings now that it has a permissions parameter rather than using key_alloc() + key_instantiate_and_link(). Also document and export keyring_alloc() so that modules can use it too. Signed-off-by: David Howells <dhowells@redhat.com>
2012-10-02KEYS: Reduce initial permissions on keysDavid Howells4-19/+33
Reduce the initial permissions on new keys to grant the possessor everything, view permission only to the user (so the keys can be seen in /proc/keys) and nothing else. This gives the creator a chance to adjust the permissions mask before other processes can access the new key or create a link to it. To aid with this, keyring_alloc() now takes a permission argument rather than setting the permissions itself. The following permissions are now set: (1) The user and user-session keyrings grant the user that owns them full permissions and grant a possessor everything bar SETATTR. (2) The process and thread keyrings grant the possessor full permissions but only grant the user VIEW. This permits the user to see them in /proc/keys, but not to do anything with them. (3) Anonymous session keyrings grant the possessor full permissions, but only grant the user VIEW and READ. This means that the user can see them in /proc/keys and can list them, but nothing else. Possibly READ shouldn't be provided either. (4) Named session keyrings grant everything an anonymous session keyring does, plus they grant the user LINK permission. The whole point of named session keyrings is that others can also subscribe to them. Possibly this should be a separate permission to LINK. (5) The temporary session keyring created by call_sbin_request_key() gets the same permissions as an anonymous session keyring. (6) Keys created by add_key() get VIEW, SEARCH, LINK and SETATTR for the possessor, plus READ and/or WRITE if the key type supports them. The used only gets VIEW now. (7) Keys created by request_key() now get the same as those created by add_key(). Reported-by: Lennart Poettering <lennart@poettering.net> Reported-by: Stef Walter <stefw@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com>
2012-10-02KEYS: Make the session and process keyrings per-threadDavid Howells3-54/+33
Make the session keyring per-thread rather than per-process, but still inherited from the parent thread to solve a problem with PAM and gdm. The problem is that join_session_keyring() will reject attempts to change the session keyring of a multithreaded program but gdm is now multithreaded before it gets to the point of starting PAM and running pam_keyinit to create the session keyring. See: https://bugs.freedesktop.org/show_bug.cgi?id=49211 The reason that join_session_keyring() will only change the session keyring under a single-threaded environment is that it's hard to alter the other thread's credentials to effect the change in a multi-threaded program. The problems are such as: (1) How to prevent two threads both running join_session_keyring() from racing. (2) Another thread's credentials may not be modified directly by this process. (3) The number of threads is uncertain whilst we're not holding the appropriate spinlock, making preallocation slightly tricky. (4) We could use TIF_NOTIFY_RESUME and key_replace_session_keyring() to get another thread to replace its keyring, but that means preallocating for each thread. A reasonable way around this is to make the session keyring per-thread rather than per-process and just document that if you want a common session keyring, you must get it before you spawn any threads - which is the current situation anyway. Whilst we're at it, we can the process keyring behave in the same way. This means we can clean up some of the ickyness in the creds code. Basically, after this patch, the session, process and thread keyrings are about inheritance rules only and not about sharing changes of keyring. Reported-by: Mantas M. <grawity@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Ray Strode <rstrode@redhat.com>
2012-10-02Merge branch 'for-linus' of ↵Linus Torvalds8-83/+79
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull user namespace changes from Eric Biederman: "This is a mostly modest set of changes to enable basic user namespace support. This allows the code to code to compile with user namespaces enabled and removes the assumption there is only the initial user namespace. Everything is converted except for the most complex of the filesystems: autofs4, 9p, afs, ceph, cifs, coda, fuse, gfs2, ncpfs, nfs, ocfs2 and xfs as those patches need a bit more review. The strategy is to push kuid_t and kgid_t values are far down into subsystems and filesystems as reasonable. Leaving the make_kuid and from_kuid operations to happen at the edge of userspace, as the values come off the disk, and as the values come in from the network. Letting compile type incompatible compile errors (present when user namespaces are enabled) guide me to find the issues. The most tricky areas have been the places where we had an implicit union of uid and gid values and were storing them in an unsigned int. Those places were converted into explicit unions. I made certain to handle those places with simple trivial patches. Out of that work I discovered we have generic interfaces for storing quota by projid. I had never heard of the project identifiers before. Adding full user namespace support for project identifiers accounts for most of the code size growth in my git tree. Ultimately there will be work to relax privlige checks from "capable(FOO)" to "ns_capable(user_ns, FOO)" where it is safe allowing root in a user names to do those things that today we only forbid to non-root users because it will confuse suid root applications. While I was pushing kuid_t and kgid_t changes deep into the audit code I made a few other cleanups. I capitalized on the fact we process netlink messages in the context of the message sender. I removed usage of NETLINK_CRED, and started directly using current->tty. Some of these patches have also made it into maintainer trees, with no problems from identical code from different trees showing up in linux-next. After reading through all of this code I feel like I might be able to win a game of kernel trivial pursuit." Fix up some fairly trivial conflicts in netfilter uid/git logging code. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (107 commits) userns: Convert the ufs filesystem to use kuid/kgid where appropriate userns: Convert the udf filesystem to use kuid/kgid where appropriate userns: Convert ubifs to use kuid/kgid userns: Convert squashfs to use kuid/kgid where appropriate userns: Convert reiserfs to use kuid and kgid where appropriate userns: Convert jfs to use kuid/kgid where appropriate userns: Convert jffs2 to use kuid and kgid where appropriate userns: Convert hpfs to use kuid and kgid where appropriate userns: Convert btrfs to use kuid/kgid where appropriate userns: Convert bfs to use kuid/kgid where appropriate userns: Convert affs to use kuid/kgid wherwe appropriate userns: On alpha modify linux_to_osf_stat to use convert from kuids and kgids userns: On ia64 deal with current_uid and current_gid being kuid and kgid userns: On ppc convert current_uid from a kuid before printing. userns: Convert s390 getting uid and gid system calls to use kuid and kgid userns: Convert s390 hypfs to use kuid and kgid where appropriate userns: Convert binder ipc to use kuids userns: Teach security_path_chown to take kuids and kgids userns: Add user namespace support to IMA userns: Convert EVM to deal with kuids and kgids in it's hmac computation ...
2012-10-02Merge branch 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds2-5/+5
Pull workqueue changes from Tejun Heo: "This is workqueue updates for v3.7-rc1. A lot of activities this round including considerable API and behavior cleanups. * delayed_work combines a timer and a work item. The handling of the timer part has always been a bit clunky leading to confusing cancelation API with weird corner-case behaviors. delayed_work is updated to use new IRQ safe timer and cancelation now works as expected. * Another deficiency of delayed_work was lack of the counterpart of mod_timer() which led to cancel+queue combinations or open-coded timer+work usages. mod_delayed_work[_on]() are added. These two delayed_work changes make delayed_work provide interface and behave like timer which is executed with process context. * A work item could be executed concurrently on multiple CPUs, which is rather unintuitive and made flush_work() behavior confusing and half-broken under certain circumstances. This problem doesn't exist for non-reentrant workqueues. While non-reentrancy check isn't free, the overhead is incurred only when a work item bounces across different CPUs and even in simulated pathological scenario the overhead isn't too high. All workqueues are made non-reentrant. This removes the distinction between flush_[delayed_]work() and flush_[delayed_]_work_sync(). The former is now as strong as the latter and the specified work item is guaranteed to have finished execution of any previous queueing on return. * In addition to the various bug fixes, Lai redid and simplified CPU hotplug handling significantly. * Joonsoo introduced system_highpri_wq and used it during CPU hotplug. There are two merge commits - one to pull in IRQ safe timer from tip/timers/core and the other to pull in CPU hotplug fixes from wq/for-3.6-fixes as Lai's hotplug restructuring depended on them." Fixed a number of trivial conflicts, but the more interesting conflicts were silent ones where the deprecated interfaces had been used by new code in the merge window, and thus didn't cause any real data conflicts. Tejun pointed out a few of them, I fixed a couple more. * 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (46 commits) workqueue: remove spurious WARN_ON_ONCE(in_irq()) from try_to_grab_pending() workqueue: use cwq_set_max_active() helper for workqueue_set_max_active() workqueue: introduce cwq_set_max_active() helper for thaw_workqueues() workqueue: remove @delayed from cwq_dec_nr_in_flight() workqueue: fix possible stall on try_to_grab_pending() of a delayed work item workqueue: use hotcpu_notifier() for workqueue_cpu_down_callback() workqueue: use __cpuinit instead of __devinit for cpu callbacks workqueue: rename manager_mutex to assoc_mutex workqueue: WORKER_REBIND is no longer necessary for idle rebinding workqueue: WORKER_REBIND is no longer necessary for busy rebinding workqueue: reimplement idle worker rebinding workqueue: deprecate __cancel_delayed_work() workqueue: reimplement cancel_delayed_work() using try_to_grab_pending() workqueue: use mod_delayed_work() instead of __cancel + queue workqueue: use irqsafe timer for delayed_work workqueue: clean up delayed_work initializers and add missing one workqueue: make deferrable delayed_work initializer names consistent workqueue: cosmetic whitespace updates for macro definitions workqueue: deprecate system_nrt[_freezable]_wq workqueue: deprecate flush[_delayed]_work_sync() ...
2012-09-28key: Fix resource leakAlan Cox1-2/+2
On an error iov may still have been reallocated and need freeing Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: David Howells <dhowells@redhat.com>
2012-09-28keys: Fix unreachable codeAlan Cox1-2/+0
We set ret to NULL then test it. Remove the bogus test Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: David Howells <dhowells@redhat.com>
2012-09-13userns: Convert security/keys to the new userns infrastructureEric W. Biederman8-83/+79
- Replace key_user ->user_ns equality checks with kuid_has_mapping checks. - Use from_kuid to generate key descriptions - Use kuid_t and kgid_t and the associated helpers instead of uid_t and gid_t - Avoid potential problems with file descriptor passing by displaying keys in the user namespace of the opener of key status proc files. Cc: linux-security-module@vger.kernel.org Cc: keyrings@linux-nfs.org Cc: David Howells <dhowells@redhat.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-09-13task_work: Revert "hold task_lock around checks in keyctl"Oleg Nesterov1-2/+0
This reverts commit d35abdb28824cf74f0a106a0f9c6f3ff700a35bf. task_lock() was added to ensure exit_mm() and thus exit_task_work() is not possible before task_work_add(). This is wrong, task_lock() must not be nested with write_lock(tasklist). And this is no longer needed, task_work_add() now fails if it is called after exit_task_work(). Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20120826191214.GA4231@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-09-13KEYS: Add payload preparsing opportunity prior to key instantiate or updateDavid Howells7-63/+129
Give the key type the opportunity to preparse the payload prior to the instantiation and update routines being called. This is done with the provision of two new key type operations: int (*preparse)(struct key_preparsed_payload *prep); void (*free_preparse)(struct key_preparsed_payload *prep); If the first operation is present, then it is called before key creation (in the add/update case) or before the key semaphore is taken (in the update and instantiate cases). The second operation is called to clean up if the first was called. preparse() is given the opportunity to fill in the following structure: struct key_preparsed_payload { char *description; void *type_data[2]; void *payload; const void *data; size_t datalen; size_t quotalen; }; Before the preparser is called, the first three fields will have been cleared, the payload pointer and size will be stored in data and datalen and the default quota size from the key_type struct will be stored into quotalen. The preparser may parse the payload in any way it likes and may store data in the type_data[] and payload fields for use by the instantiate() and update() ops. The preparser may also propose a description for the key by attaching it as a string to the description field. This can be used by passing a NULL or "" description to the add_key() system call or the key_create_or_update() function. This cannot work with request_key() as that required the description to tell the upcall about the key to be created. This, for example permits keys that store PGP public keys to generate their own name from the user ID and public key fingerprint in the key. The instantiate() and update() operations are then modified to look like this: int (*instantiate)(struct key *key, struct key_preparsed_payload *prep); int (*update)(struct key *key, struct key_preparsed_payload *prep); and the new payload data is passed in *prep, whether or not it was preparsed. Signed-off-by: David Howells <dhowells@redhat.com>
2012-08-22tpm: Move tpm_get_random api into the TPM device driverKent Yoder1-42/+12
Move the tpm_get_random api from the trusted keys code into the TPM device driver itself so that other callers can make use of it. Also, change the api slightly so that the number of bytes read is returned in the call, since the TPM command can potentially return fewer bytes than requested. Acked-by: David Safford <safford@linux.vnet.ibm.com> Reviewed-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>