user/sven/linux.git/security/keys/process_keys.c, branch v3.13.2

KEYS: initialize root uid and session keyrings early

2013-09-25T16:17:01Z

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 Signed-off-by: David Howells

KEYS: Define a __key_get() wrapper to use rather than atomic_inc()

2013-09-24T09:35:16Z

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

KEYS: Introduce a search context structure

2013-09-24T09:35:15Z

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

KEYS: Skip key state checks when checking for possession

2013-09-24T09:35:13Z

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

keys: fix race with concurrent install_user_keyrings()

2013-03-12T05:44:31Z

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 Reported-by: Mateusz Guzik Cc: Signed-off-by: Andrew Morton Signed-off-by: James Morris

userns: Stop oopsing in key_change_session_keyring

2013-03-04T03:35:38Z

Dave Jones writes: > Just hit this on Linus' current tree. > > [ 89.621770] BUG: unable to handle kernel NULL pointer dereference at 00000000000000c8 > [ 89.623111] IP: [] 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:[] [] 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] [] key_change_session_keyring+0xfb/0x140 > [ 89.659845] [] task_work_run+0xa5/0xd0 > [ 89.660698] [] do_notify_resume+0x71/0xb0 > [ 89.661581] [] 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 [] commit_creds+0x250/0x2f0 > [ 89.668733] RSP > [ 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 Tested-by: Dave Jones Acked-by: Serge Hallyn Signed-off-by: "Eric W. Biederman"

KEYS: Revert one application of "Fix unreachable code" patch

2013-02-21T15:56:25Z

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 Cc: Jiri Kosina Cc: Andrew Morton Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds

keys: fix unreachable code

2012-12-21T01:40:21Z

We set ret to NULL then test it. Remove the bogus test Signed-off-by: Alan Cox Signed-off-by: David Howells Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2012-12-16T23:40:50Z

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

Merge branch 'master' into for-next

2012-10-28T18:29:19Z

Sync up with Linus' tree to be able to apply Cesar's patch against newer version of the code. Signed-off-by: Jiri Kosina