kernel/linux.git/security/keys/trusted.c, branch v4.9.223

KEYS: trusted: fix writing past end of buffer in trusted_read()

2017-11-15T14:53:17+00:00

commit a3c812f7cfd80cf51e8f5b7034f7418f6beb56c1 upstream. When calling keyctl_read() on a key of type "trusted", if the user-supplied buffer was too small, the kernel ignored the buffer length and just wrote past the end of the buffer, potentially corrupting userspace memory. Fix it by instead returning the size required, as per the documentation for keyctl_read(). We also don't even fill the buffer at all in this case, as this is slightly easier to implement than doing a short read, and either behavior appears to be permitted. It also makes it match the behavior of the "encrypted" key type. Fixes: d00a1c72f7f4 ("keys: add new trusted key-type") Reported-by: Ben Hutchings Signed-off-by: Eric Biggers Signed-off-by: David Howells Reviewed-by: Mimi Zohar Reviewed-by: James Morris Signed-off-by: James Morris Signed-off-by: Greg Kroah-Hartman

KEYS: trusted: sanitize all key material

2017-11-15T14:53:17+00:00

commit ee618b4619b72527aaed765f0f0b74072b281159 upstream. As the previous patch did for encrypted-keys, zero sensitive any potentially sensitive data related to the "trusted" key type before it is freed. Notably, we were not zeroing the tpm_buf structures in which the actual key is stored for TPM seal and unseal, nor were we zeroing the trusted_key_payload in certain error paths. Cc: Mimi Zohar Cc: David Safford Signed-off-by: Eric Biggers Signed-off-by: David Howells Signed-off-by: James Morris Signed-off-by: Greg Kroah-Hartman

KEYS: Fix race between updating and finding a negative key

2017-10-27T08:38:11+00:00

commit 363b02dab09b3226f3bd1420dad9c72b79a42a76 upstream. Consolidate KEY_FLAG_INSTANTIATED, KEY_FLAG_NEGATIVE and the rejection error into one field such that: (1) The instantiation state can be modified/read atomically. (2) The error can be accessed atomically with the state. (3) The error isn't stored unioned with the payload pointers. This deals with the problem that the state is spread over three different objects (two bits and a separate variable) and reading or updating them atomically isn't practical, given that not only can uninstantiated keys change into instantiated or rejected keys, but rejected keys can also turn into instantiated keys - and someone accessing the key might not be using any locking. The main side effect of this problem is that what was held in the payload may change, depending on the state. For instance, you might observe the key to be in the rejected state. You then read the cached error, but if the key semaphore wasn't locked, the key might've become instantiated between the two reads - and you might now have something in hand that isn't actually an error code. The state is now KEY_IS_UNINSTANTIATED, KEY_IS_POSITIVE or a negative error code if the key is negatively instantiated. The key_is_instantiated() function is replaced with key_is_positive() to avoid confusion as negative keys are also 'instantiated'. Additionally, barriering is included: (1) Order payload-set before state-set during instantiation. (2) Order state-read before payload-read when using the key. Further separate barriering is necessary if RCU is being used to access the payload content after reading the payload pointers. Fixes: 146aa8b1453b ("KEYS: Merge the type-specific data with the payload data") Reported-by: Eric Biggers Signed-off-by: David Howells Reviewed-by: Eric Biggers Signed-off-by: Greg Kroah-Hartman

tpm: fix checks for policy digest existence in tpm2_seal_trusted()

2016-02-10T02:10:55+00:00

In my original patch sealing with policy was done with dynamically allocated buffer that I changed later into an array so the checks in tpm2-cmd.c became invalid. This patch fixes the issue. Fixes: 5beb0c435bdd ("keys, trusted: seal with a TPM2 authorization policy") Reported-by: Dan Carpenter Signed-off-by: Jarkko Sakkinen Acked-by: Peter Huewe

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

2016-01-18T03:13:15+00:00

Pull security subsystem updates from James Morris: - EVM gains support for loading an x509 cert from the kernel (EVM_LOAD_X509), into the EVM trusted kernel keyring. - Smack implements 'file receive' process-based permission checking for sockets, rather than just depending on inode checks. - Misc enhancments for TPM & TPM2. - Cleanups and bugfixes for SELinux, Keys, and IMA. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (41 commits) selinux: Inode label revalidation performance fix KEYS: refcount bug fix ima: ima_write_policy() limit locking IMA: policy can be updated zero times selinux: rate-limit netlink message warnings in selinux_nlmsg_perm() selinux: export validatetrans decisions gfs2: Invalid security labels of inodes when they go invalid selinux: Revalidate invalid inode security labels security: Add hook to invalidate inode security labels selinux: Add accessor functions for inode->i_security security: Make inode argument of inode_getsecid non-const security: Make inode argument of inode_getsecurity non-const selinux: Remove unused variable in selinux_inode_init_security keys, trusted: seal with a TPM2 authorization policy keys, trusted: select hash algorithm for TPM2 chips keys, trusted: fix: *do not* allow duplicate key options tpm_ibmvtpm: properly handle interrupted packet receptions tpm_tis: Tighten IRQ auto-probing tpm_tis: Refactor the interrupt setup tpm_tis: Get rid of the duplicate IRQ probing code ...

keys, trusted: seal with a TPM2 authorization policy

2015-12-20T13:27:13+00:00

TPM2 supports authorization policies, which are essentially combinational logic statements repsenting the conditions where the data can be unsealed based on the TPM state. This patch enables to use authorization policies to seal trusted keys. Two following new options have been added for trusted keys: * 'policydigest=': provide an auth policy digest for sealing. * 'policyhandle=': provide a policy session handle for unsealing. If 'hash=' option is supplied after 'policydigest=' option, this will result an error because the state of the option would become mixed. Signed-off-by: Jarkko Sakkinen Tested-by: Colin Ian King Reviewed-by: Mimi Zohar Acked-by: Peter Huewe

keys, trusted: select hash algorithm for TPM2 chips

2015-12-20T13:27:12+00:00

Added 'hash=' option for selecting the hash algorithm for add_key() syscall and documentation for it. Added entry for sm3-256 to the following tables in order to support TPM_ALG_SM3_256: * hash_algo_name * hash_digest_size Includes support for the following hash algorithms: * sha1 * sha256 * sha384 * sha512 * sm3-256 Signed-off-by: Jarkko Sakkinen Tested-by: Colin Ian King Reviewed-by: James Morris Reviewed-by: Mimi Zohar Acked-by: Peter Huewe

keys, trusted: fix: do not allow duplicate key options

2015-12-20T13:27:12+00:00

The trusted keys option parsing allows specifying the same option multiple times. The last option value specified is used. This is problematic because: * No gain. * This makes complicated to specify options that are dependent on other options. This patch changes the behavior in a way that option can be specified only once. Reported-by: James Morris James Morris Reviewed-by: Mimi Zohar Signed-off-by: Jarkko Sakkinen Acked-by: Peter Huewe

KEYS: Fix handling of stored error in a negatively instantiated user key

2015-11-25T03:19:47+00:00

If a user key gets negatively instantiated, an error code is cached in the payload area. A negatively instantiated key may be then be positively instantiated by updating it with valid data. However, the ->update key type method must be aware that the error code may be there. The following may be used to trigger the bug in the user key type: keyctl request2 user user "" @u keyctl add user user "a" @u which manifests itself as: BUG: unable to handle kernel paging request at 00000000ffffff8a IP: [] __call_rcu.constprop.76+0x1f/0x280 kernel/rcu/tree.c:3046 PGD 7cc30067 PUD 0 Oops: 0002 [#1] SMP Modules linked in: CPU: 3 PID: 2644 Comm: a.out Not tainted 4.3.0+ #49 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88003ddea700 ti: ffff88003dd88000 task.ti: ffff88003dd88000 RIP: 0010:[] [] __call_rcu.constprop.76+0x1f/0x280 [] __call_rcu.constprop.76+0x1f/0x280 kernel/rcu/tree.c:3046 RSP: 0018:ffff88003dd8bdb0 EFLAGS: 00010246 RAX: 00000000ffffff82 RBX: 0000000000000000 RCX: 0000000000000001 RDX: ffffffff81e3fe40 RSI: 0000000000000000 RDI: 00000000ffffff82 RBP: ffff88003dd8bde0 R08: ffff88007d2d2da0 R09: 0000000000000000 R10: 0000000000000000 R11: ffff88003e8073c0 R12: 00000000ffffff82 R13: ffff88003dd8be68 R14: ffff88007d027600 R15: ffff88003ddea700 FS: 0000000000b92880(0063) GS:ffff88007fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00000000ffffff8a CR3: 000000007cc5f000 CR4: 00000000000006e0 Stack: ffff88003dd8bdf0 ffffffff81160a8a 0000000000000000 00000000ffffff82 ffff88003dd8be68 ffff88007d027600 ffff88003dd8bdf0 ffffffff810a39e5 ffff88003dd8be20 ffffffff812a31ab ffff88007d027600 ffff88007d027620 Call Trace: [] kfree_call_rcu+0x15/0x20 kernel/rcu/tree.c:3136 [] user_update+0x8b/0xb0 security/keys/user_defined.c:129 [< inline >] __key_update security/keys/key.c:730 [] key_create_or_update+0x291/0x440 security/keys/key.c:908 [< inline >] SYSC_add_key security/keys/keyctl.c:125 [] SyS_add_key+0x101/0x1e0 security/keys/keyctl.c:60 [] entry_SYSCALL_64_fastpath+0x12/0x6a arch/x86/entry/entry_64.S:185 Note the error code (-ENOKEY) in EDX. A similar bug can be tripped by: keyctl request2 trusted user "" @u keyctl add trusted user "a" @u This should also affect encrypted keys - but that has to be correctly parameterised or it will fail with EINVAL before getting to the bit that will crashes. Reported-by: Dmitry Vyukov Signed-off-by: David Howells Acked-by: Mimi Zohar Signed-off-by: James Morris

KEYS: Merge the type-specific data with the payload data

2015-10-21T14:18:36+00:00

Merge the type-specific data with the payload data into one four-word chunk as it seems pointless to keep them separate. Use user_key_payload() for accessing the payloads of overloaded user-defined keys. Signed-off-by: David Howells cc: linux-cifs@vger.kernel.org cc: ecryptfs@vger.kernel.org cc: linux-ext4@vger.kernel.org cc: linux-f2fs-devel@lists.sourceforge.net cc: linux-nfs@vger.kernel.org cc: ceph-devel@vger.kernel.org cc: linux-ima-devel@lists.sourceforge.net