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2017-10-19commoncap: move assignment of fs_ns to avoid null pointer dereferenceColin Ian King1-1/+2
The pointer fs_ns is assigned from inode->i_ib->s_user_ns before a null pointer check on inode, hence if inode is actually null we will get a null pointer dereference on this assignment. Fix this by only dereferencing inode after the null pointer check on inode. Detected by CoverityScan CID#1455328 ("Dereference before null check") Fixes: 8db6c34f1dbc ("Introduce v3 namespaced file capabilities") Signed-off-by: Colin Ian King <colin.king@canonical.com> Cc: stable@vger.kernel.org Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-10-19Merge commit 'tags/keys-fixes-20171018' into fixes-v4.14-rc5James Morris14-53/+88
2017-10-18KEYS: load key flags and expiry time atomically in proc_keys_show()Eric Biggers1-10/+14
In proc_keys_show(), the key semaphore is not held, so the key ->flags and ->expiry can be changed concurrently. We therefore should read them atomically just once. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-10-18KEYS: Load key expiry time atomically in keyring_search_iterator()Eric Biggers1-1/+3
Similar to the case for key_validate(), we should load the key ->expiry once atomically in keyring_search_iterator(), since it can be changed concurrently with the flags whenever the key semaphore isn't held. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-10-18KEYS: load key flags and expiry time atomically in key_validate()Eric Biggers1-3/+4
In key_validate(), load the flags and expiry time once atomically, since these can change concurrently if key_validate() is called without the key semaphore held. And we don't want to get inconsistent results if a variable is referenced multiple times. For example, key->expiry was referenced in both 'if (key->expiry)' and in 'if (now.tv_sec >= key->expiry)', making it theoretically possible to see a spurious EKEYEXPIRED while the expiration time was being removed, i.e. set to 0. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-10-18KEYS: don't let add_key() update an uninstantiated keyDavid Howells1-0/+10
Currently, when passed a key that already exists, add_key() will call the key's ->update() method if such exists. But this is heavily broken in the case where the key is uninstantiated because it doesn't call __key_instantiate_and_link(). Consequently, it doesn't do most of the things that are supposed to happen when the key is instantiated, such as setting the instantiation state, clearing KEY_FLAG_USER_CONSTRUCT and awakening tasks waiting on it, and incrementing key->user->nikeys. It also never takes key_construction_mutex, which means that ->instantiate() can run concurrently with ->update() on the same key. In the case of the "user" and "logon" key types this causes a memory leak, at best. Maybe even worse, the ->update() methods of the "encrypted" and "trusted" key types actually just dereference a NULL pointer when passed an uninstantiated key. Change key_create_or_update() to wait interruptibly for the key to finish construction before continuing. This patch only affects *uninstantiated* keys. For now we still allow a negatively instantiated key to be updated (thereby positively instantiating it), although that's broken too (the next patch fixes it) and I'm not sure that anyone actually uses that functionality either. Here is a simple reproducer for the bug using the "encrypted" key type (requires CONFIG_ENCRYPTED_KEYS=y), though as noted above the bug pertained to more than just the "encrypted" key type: #include <stdlib.h> #include <unistd.h> #include <keyutils.h> int main(void) { int ringid = keyctl_join_session_keyring(NULL); if (fork()) { for (;;) { const char payload[] = "update user:foo 32"; usleep(rand() % 10000); add_key("encrypted", "desc", payload, sizeof(payload), ringid); keyctl_clear(ringid); } } else { for (;;) request_key("encrypted", "desc", "callout_info", ringid); } } It causes: BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 IP: encrypted_update+0xb0/0x170 PGD 7a178067 P4D 7a178067 PUD 77269067 PMD 0 PREEMPT SMP CPU: 0 PID: 340 Comm: reproduce Tainted: G D 4.14.0-rc1-00025-g428490e38b2e #796 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff8a467a39a340 task.stack: ffffb15c40770000 RIP: 0010:encrypted_update+0xb0/0x170 RSP: 0018:ffffb15c40773de8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8a467a275b00 RCX: 0000000000000000 RDX: 0000000000000005 RSI: ffff8a467a275b14 RDI: ffffffffb742f303 RBP: ffffb15c40773e20 R08: 0000000000000000 R09: ffff8a467a275b17 R10: 0000000000000020 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffff8a4677057180 R15: ffff8a467a275b0f FS: 00007f5d7fb08700(0000) GS:ffff8a467f200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000018 CR3: 0000000077262005 CR4: 00000000001606f0 Call Trace: key_create_or_update+0x2bc/0x460 SyS_add_key+0x10c/0x1d0 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x7f5d7f211259 RSP: 002b:00007ffed03904c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000f8 RAX: ffffffffffffffda RBX: 000000003b2a7955 RCX: 00007f5d7f211259 RDX: 00000000004009e4 RSI: 00000000004009ff RDI: 0000000000400a04 RBP: 0000000068db8bad R08: 000000003b2a7955 R09: 0000000000000004 R10: 000000000000001a R11: 0000000000000246 R12: 0000000000400868 R13: 00007ffed03905d0 R14: 0000000000000000 R15: 0000000000000000 Code: 77 28 e8 64 34 1f 00 45 31 c0 31 c9 48 8d 55 c8 48 89 df 48 8d 75 d0 e8 ff f9 ff ff 85 c0 41 89 c4 0f 88 84 00 00 00 4c 8b 7d c8 <49> 8b 75 18 4c 89 ff e8 24 f8 ff ff 85 c0 41 89 c4 78 6d 49 8b RIP: encrypted_update+0xb0/0x170 RSP: ffffb15c40773de8 CR2: 0000000000000018 Cc: <stable@vger.kernel.org> # v2.6.12+ Reported-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Eric Biggers <ebiggers@google.com>
2017-10-18KEYS: Fix race between updating and finding a negative keyDavid Howells12-39/+49
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") Cc: stable@vger.kernel.org # v4.4+ Reported-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Eric Biggers <ebiggers@google.com>
2017-10-18security/keys: BIG_KEY requires CONFIG_CRYPTOArnd Bergmann1-0/+1
The recent rework introduced a possible randconfig build failure when CONFIG_CRYPTO configured to only allow modules: security/keys/big_key.o: In function `big_key_crypt': big_key.c:(.text+0x29f): undefined reference to `crypto_aead_setkey' security/keys/big_key.o: In function `big_key_init': big_key.c:(.init.text+0x1a): undefined reference to `crypto_alloc_aead' big_key.c:(.init.text+0x45): undefined reference to `crypto_aead_setauthsize' big_key.c:(.init.text+0x77): undefined reference to `crypto_destroy_tfm' crypto/gcm.o: In function `gcm_hash_crypt_remain_continue': gcm.c:(.text+0x167): undefined reference to `crypto_ahash_finup' crypto/gcm.o: In function `crypto_gcm_exit_tfm': gcm.c:(.text+0x847): undefined reference to `crypto_destroy_tfm' When we 'select CRYPTO' like the other users, we always get a configuration that builds. Fixes: 428490e38b2e ("security/keys: rewrite all of big_key crypto") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David Howells <dhowells@redhat.com>
2017-10-12KEYS: encrypted: fix dereference of NULL user_key_payloadEric Biggers1-0/+7
A key of type "encrypted" references a "master key" which is used to encrypt and decrypt the encrypted key's payload. However, when we accessed the master key's payload, we failed to handle the case where the master key has been revoked, which sets the payload pointer to NULL. Note that request_key() *does* skip revoked keys, but there is still a window where the key can be revoked before we acquire its semaphore. Fix it by checking for a NULL payload, treating it like a key which was already revoked at the time it was requested. This was an issue for master keys of type "user" only. Master keys can also be of type "trusted", but those cannot be revoked. Fixes: 7e70cb497850 ("keys: add new key-type encrypted") Reviewed-by: James Morris <james.l.morris@oracle.com> Cc: <stable@vger.kernel.org> [v2.6.38+] Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: David Safford <safford@us.ibm.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-10-04lsm: fix smack_inode_removexattr and xattr_getsecurity memleakCasey Schaufler1-30/+25
security_inode_getsecurity() provides the text string value of a security attribute. It does not provide a "secctx". The code in xattr_getsecurity() that calls security_inode_getsecurity() and then calls security_release_secctx() happened to work because SElinux and Smack treat the attribute and the secctx the same way. It fails for cap_inode_getsecurity(), because that module has no secctx that ever needs releasing. It turns out that Smack is the one that's doing things wrong by not allocating memory when instructed to do so by the "alloc" parameter. The fix is simple enough. Change the security_release_secctx() to kfree() because it isn't a secctx being returned by security_inode_getsecurity(). Change Smack to allocate the string when told to do so. Note: this also fixes memory leaks for LSMs which implement inode_getsecurity but not release_secctx, such as capabilities. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: stable@vger.kernel.org Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-09-28Merge commit 'keys-fixes-20170927' into fixes-v4.14-rc3James Morris9-152/+137
From David Howells: "There are two sets of patches here: (1) A bunch of core keyrings bug fixes from Eric Biggers. (2) Fixing big_key to use safe crypto from Jason A. Donenfeld."
2017-09-25security/keys: rewrite all of big_key cryptoJason A. Donenfeld2-71/+60
This started out as just replacing the use of crypto/rng with get_random_bytes_wait, so that we wouldn't use bad randomness at boot time. But, upon looking further, it appears that there were even deeper underlying cryptographic problems, and that this seems to have been committed with very little crypto review. So, I rewrote the whole thing, trying to keep to the conventions introduced by the previous author, to fix these cryptographic flaws. It makes no sense to seed crypto/rng at boot time and then keep using it like this, when in fact there's already get_random_bytes_wait, which can ensure there's enough entropy and be a much more standard way of generating keys. Since this sensitive material is being stored untrusted, using ECB and no authentication is simply not okay at all. I find it surprising and a bit horrifying that this code even made it past basic crypto review, which perhaps points to some larger issues. This patch moves from using AES-ECB to using AES-GCM. Since keys are uniquely generated each time, we can set the nonce to zero. There was also a race condition in which the same key would be reused at the same time in different threads. A mutex fixes this issue now. So, to summarize, this commit fixes the following vulnerabilities: * Low entropy key generation, allowing an attacker to potentially guess or predict keys. * Unauthenticated encryption, allowing an attacker to modify the cipher text in particular ways in order to manipulate the plaintext, which is is even more frightening considering the next point. * Use of ECB mode, allowing an attacker to trivially swap blocks or compare identical plaintext blocks. * Key re-use. * Faulty memory zeroing. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Eric Biggers <ebiggers3@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Kirill Marinushkin <k.marinushkin@gmail.com> Cc: security@kernel.org Cc: stable@vger.kernel.org
2017-09-25security/keys: properly zero out sensitive key material in big_keyJason A. Donenfeld1-6/+6
Error paths forgot to zero out sensitive material, so this patch changes some kfrees into a kzfrees. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Eric Biggers <ebiggers3@gmail.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Kirill Marinushkin <k.marinushkin@gmail.com> Cc: security@kernel.org Cc: stable@vger.kernel.org
2017-09-25KEYS: use kmemdup() in request_key_auth_new()Eric Biggers1-3/+2
kmemdup() is preferred to kmalloc() followed by memcpy(). Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-25KEYS: restrict /proc/keys by credentials at open timeEric Biggers1-6/+2
When checking for permission to view keys whilst reading from /proc/keys, we should use the credentials with which the /proc/keys file was opened. This is because, in a classic type of exploit, it can be possible to bypass checks for the *current* credentials by passing the file descriptor to a suid program. Following commit 34dbbcdbf633 ("Make file credentials available to the seqfile interfaces") we can finally fix it. So let's do it. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-25KEYS: reset parent each time before searching key_user_treeEric Biggers1-2/+2
In key_user_lookup(), if there is no key_user for the given uid, we drop key_user_lock, allocate a new key_user, and search the tree again. But we failed to set 'parent' to NULL at the beginning of the second search. If the tree were to be empty for the second search, the insertion would be done with an invalid 'parent', scribbling over freed memory. Fortunately this can't actually happen currently because the tree always contains at least the root_key_user. But it still should be fixed to make the code more robust. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-25KEYS: prevent KEYCTL_READ on negative keyEric Biggers1-0/+5
Because keyctl_read_key() looks up the key with no permissions requested, it may find a negatively instantiated key. If the key is also possessed, we went ahead and called ->read() on the key. But the key payload will actually contain the ->reject_error rather than the normal payload. Thus, the kernel oopses trying to read the user_key_payload from memory address (int)-ENOKEY = 0x00000000ffffff82. Fortunately the payload data is stored inline, so it shouldn't be possible to abuse this as an arbitrary memory read primitive... Reproducer: keyctl new_session keyctl request2 user desc '' @s keyctl read $(keyctl show | awk '/user: desc/ {print $1}') It causes a crash like the following: BUG: unable to handle kernel paging request at 00000000ffffff92 IP: user_read+0x33/0xa0 PGD 36a54067 P4D 36a54067 PUD 0 Oops: 0000 [#1] SMP CPU: 0 PID: 211 Comm: keyctl Not tainted 4.14.0-rc1 #337 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-20170228_101828-anatol 04/01/2014 task: ffff90aa3b74c3c0 task.stack: ffff9878c0478000 RIP: 0010:user_read+0x33/0xa0 RSP: 0018:ffff9878c047bee8 EFLAGS: 00010246 RAX: 0000000000000001 RBX: ffff90aa3d7da340 RCX: 0000000000000017 RDX: 0000000000000000 RSI: 00000000ffffff82 RDI: ffff90aa3d7da340 RBP: ffff9878c047bf00 R08: 00000024f95da94f R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f58ece69740(0000) GS:ffff90aa3e200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000ffffff92 CR3: 0000000036adc001 CR4: 00000000003606f0 Call Trace: keyctl_read_key+0xac/0xe0 SyS_keyctl+0x99/0x120 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x7f58ec787bb9 RSP: 002b:00007ffc8d401678 EFLAGS: 00000206 ORIG_RAX: 00000000000000fa RAX: ffffffffffffffda RBX: 00007ffc8d402800 RCX: 00007f58ec787bb9 RDX: 0000000000000000 RSI: 00000000174a63ac RDI: 000000000000000b RBP: 0000000000000004 R08: 00007ffc8d402809 R09: 0000000000000020 R10: 0000000000000000 R11: 0000000000000206 R12: 00007ffc8d402800 R13: 00007ffc8d4016e0 R14: 0000000000000000 R15: 0000000000000000 Code: e5 41 55 49 89 f5 41 54 49 89 d4 53 48 89 fb e8 a4 b4 ad ff 85 c0 74 09 80 3d b9 4c 96 00 00 74 43 48 8b b3 20 01 00 00 4d 85 ed <0f> b7 5e 10 74 29 4d 85 e4 74 24 4c 39 e3 4c 89 e2 4c 89 ef 48 RIP: user_read+0x33/0xa0 RSP: ffff9878c047bee8 CR2: 00000000ffffff92 Fixes: 61ea0c0ba904 ("KEYS: Skip key state checks when checking for possession") Cc: <stable@vger.kernel.org> [v3.13+] Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-25KEYS: prevent creating a different user's keyringsEric Biggers4-12/+21
It was possible for an unprivileged user to create the user and user session keyrings for another user. For example: sudo -u '#3000' sh -c 'keyctl add keyring _uid.4000 "" @u keyctl add keyring _uid_ses.4000 "" @u sleep 15' & sleep 1 sudo -u '#4000' keyctl describe @u sudo -u '#4000' keyctl describe @us This is problematic because these "fake" keyrings won't have the right permissions. In particular, the user who created them first will own them and will have full access to them via the possessor permissions, which can be used to compromise the security of a user's keys: -4: alswrv-----v------------ 3000 0 keyring: _uid.4000 -5: alswrv-----v------------ 3000 0 keyring: _uid_ses.4000 Fix it by marking user and user session keyrings with a flag KEY_FLAG_UID_KEYRING. Then, when searching for a user or user session keyring by name, skip all keyrings that don't have the flag set. Fixes: 69664cf16af4 ("keys: don't generate user and user session keyrings unless they're accessed") Cc: <stable@vger.kernel.org> [v2.6.26+] Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-25KEYS: fix writing past end of user-supplied buffer in keyring_read()Eric Biggers1-9/+5
Userspace can call keyctl_read() on a keyring to get the list of IDs of keys in the keyring. But if the user-supplied buffer is too small, the kernel would write the full list anyway --- which will corrupt whatever userspace memory happened to be past the end of the buffer. Fix it by only filling the space that is available. Fixes: b2a4df200d57 ("KEYS: Expand the capacity of a keyring") Cc: <stable@vger.kernel.org> [v3.13+] Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-25KEYS: fix key refcount leak in keyctl_read_key()Eric Biggers1-1/+1
In keyctl_read_key(), if key_permission() were to return an error code other than EACCES, we would leak a the reference to the key. This can't actually happen currently because key_permission() can only return an error code other than EACCES if security_key_permission() does, only SELinux and Smack implement that hook, and neither can return an error code other than EACCES. But it should still be fixed, as it is a bug waiting to happen. Fixes: 29db91906340 ("[PATCH] Keys: Add LSM hooks for key management [try #3]") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-25KEYS: fix key refcount leak in keyctl_assume_authority()Eric Biggers1-4/+2
In keyctl_assume_authority(), if keyctl_change_reqkey_auth() were to fail, we would leak the reference to the 'authkey'. Currently this can only happen if prepare_creds() fails to allocate memory. But it still should be fixed, as it is a more severe bug waiting to happen. This patch also moves the read of 'authkey->serial' to before the reference to the authkey is dropped. Doing the read after dropping the reference is very fragile because it assumes we still hold another reference to the key. (Which we do, in current->cred->request_key_auth, but there's no reason not to write it in the "obviously correct" way.) Fixes: d84f4f992cbd ("CRED: Inaugurate COW credentials") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-25KEYS: don't revoke uninstantiated key in request_key_auth_new()Eric Biggers1-1/+0
If key_instantiate_and_link() were to fail (which fortunately isn't possible currently), the call to key_revoke(authkey) would crash with a NULL pointer dereference in request_key_auth_revoke() because the key has not yet been instantiated. Fix this by removing the call to key_revoke(). key_put() is sufficient, as it's not possible for an uninstantiated authkey to have been used for anything yet. Fixes: b5f545c880a2 ("[PATCH] keys: Permit running process to instantiate keys") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-25KEYS: fix cred refcount leak in request_key_auth_new()Eric Biggers1-37/+31
In request_key_auth_new(), if key_alloc() or key_instantiate_and_link() were to fail, we would leak a reference to the 'struct cred'. Currently this can only happen if key_alloc() fails to allocate memory. But it still should be fixed, as it is a more severe bug waiting to happen. Fix it by cleaning things up to use a helper function which frees a 'struct request_key_auth' correctly. Fixes: d84f4f992cbd ("CRED: Inaugurate COW credentials") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-24Merge branch 'next-general' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull misc security layer update from James Morris: "This is the remaining 'general' change in the security tree for v4.14, following the direct merging of SELinux (+ TOMOYO), AppArmor, and seccomp. That's everything now for the security tree except IMA, which will follow shortly (I've been traveling for the past week with patchy internet)" * 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: security: fix description of values returned by cap_inode_need_killpriv
2017-09-23security: fix description of values returned by cap_inode_need_killprivStefan Berger1-3/+3
cap_inode_need_killpriv returns 1 if security.capability exists and has a value and inode_killpriv() is required, 0 otherwise. Fix the description of the return value to reflect this. Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com> Reviewed-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-09-23Merge tag 'apparmor-pr-2017-09-22' of ↵Linus Torvalds24-137/+2088
git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor Pull apparmor updates from John Johansen: "This is the apparmor pull request, similar to SELinux and seccomp. It's the same series that I was sent to James' security tree + one regression fix that was found after the series was sent to James and would have been sent for v4.14-rc2. Features: - in preparation for secid mapping add support for absolute root view based labels - add base infastructure for socket mediation - add mount mediation - add signal mediation minor cleanups and changes: - be defensive, ensure unconfined profiles have dfas initialized - add more debug asserts to apparmorfs - enable policy unpacking to audit different reasons for failure - cleanup conditional check for label in label_print - Redundant condition: prev_ns. in [label.c:1498] Bug Fixes: - fix regression in apparmorfs DAC access permissions - fix build failure on sparc caused by undeclared signals - fix sparse report of incorrect type assignment when freeing label proxies - fix race condition in null profile creation - Fix an error code in aafs_create() - Fix logical error in verify_header() - Fix shadowed local variable in unpack_trans_table()" * tag 'apparmor-pr-2017-09-22' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor: apparmor: fix apparmorfs DAC access permissions apparmor: fix build failure on sparc caused by undeclared signals apparmor: fix incorrect type assignment when freeing proxies apparmor: ensure unconfined profiles have dfas initialized apparmor: fix race condition in null profile creation apparmor: move new_null_profile to after profile lookup fns() apparmor: add base infastructure for socket mediation apparmor: add more debug asserts to apparmorfs apparmor: make policy_unpack able to audit different info messages apparmor: add support for absolute root view based labels apparmor: cleanup conditional check for label in label_print apparmor: add mount mediation apparmor: add the ability to mediate signals apparmor: Redundant condition: prev_ns. in [label.c:1498] apparmor: Fix an error code in aafs_create() apparmor: Fix logical error in verify_header() apparmor: Fix shadowed local variable in unpack_trans_table()
2017-09-22apparmor: fix apparmorfs DAC access permissionsJohn Johansen1-4/+4
The DAC access permissions for several apparmorfs files are wrong. .access - needs to be writable by all tasks to perform queries the others in the set only provide a read fn so should be read only. With policy namespace virtualization all apparmor needs to control the permission and visibility checks directly which means DAC access has to be allowed for all user, group, and other. BugLink: http://bugs.launchpad.net/bugs/1713103 Fixes: c97204baf840b ("apparmor: rename apparmor file fns and data to indicate use") Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-09-22apparmor: fix build failure on sparc caused by undeclared signalsJohn Johansen1-1/+4
In file included from security/apparmor/ipc.c:23:0: security/apparmor/include/sig_names.h:26:3: error: 'SIGSTKFLT' undeclared here (not in a function) [SIGSTKFLT] = 16, /* -, 16, - */ ^ security/apparmor/include/sig_names.h:26:3: error: array index in initializer not of integer type security/apparmor/include/sig_names.h:26:3: note: (near initialization for 'sig_map') security/apparmor/include/sig_names.h:51:3: error: 'SIGUNUSED' undeclared here (not in a function) [SIGUNUSED] = 34, /* -, 31, - */ ^ security/apparmor/include/sig_names.h:51:3: error: array index in initializer not of integer type security/apparmor/include/sig_names.h:51:3: note: (near initialization for 'sig_map') Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Fixes: c6bf1adaecaa ("apparmor: add the ability to mediate signals") Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-09-22apparmor: fix incorrect type assignment when freeing proxiesJohn Johansen1-1/+1
sparse reports poisoning the proxy->label before freeing the struct is resulting in a sparse build warning. ../security/apparmor/label.c:52:30: warning: incorrect type in assignment (different address spaces) ../security/apparmor/label.c:52:30: expected struct aa_label [noderef] <asn:4>*label ../security/apparmor/label.c:52:30: got struct aa_label *<noident> fix with RCU_INIT_POINTER as this is one of those cases where rcu_assign_pointer() is not needed. Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-09-22apparmor: ensure unconfined profiles have dfas initializedJohn Johansen1-0/+2
Generally unconfined has early bailout tests and does not need the dfas initialized, however if an early bailout test is ever missed it will result in an oops. Be defensive and initialize the unconfined profile to have null dfas (no permission) so if an early bailout test is missed we fail closed (no perms granted) instead of oopsing. Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-09-22apparmor: fix race condition in null profile creationJohn Johansen1-3/+11
There is a race when null- profile is being created between the initial lookup/creation of the profile and lock/addition of the profile. This could result in multiple version of a profile being added to the list which need to be removed/replaced. Since these are learning profile their is no affect on mediation. Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-09-22apparmor: move new_null_profile to after profile lookup fns()John Johansen1-79/+79
new_null_profile will need to use some of the profile lookup fns() so move instead of doing forward fn declarations. Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-09-22apparmor: add base infastructure for socket mediationJohn Johansen12-16/+840
Provide a basic mediation of sockets. This is not a full net mediation but just whether a spcific family of socket can be used by an application, along with setting up some basic infrastructure for network mediation to follow. the user space rule hav the basic form of NETWORK RULE = [ QUALIFIERS ] 'network' [ DOMAIN ] [ TYPE | PROTOCOL ] DOMAIN = ( 'inet' | 'ax25' | 'ipx' | 'appletalk' | 'netrom' | 'bridge' | 'atmpvc' | 'x25' | 'inet6' | 'rose' | 'netbeui' | 'security' | 'key' | 'packet' | 'ash' | 'econet' | 'atmsvc' | 'sna' | 'irda' | 'pppox' | 'wanpipe' | 'bluetooth' | 'netlink' | 'unix' | 'rds' | 'llc' | 'can' | 'tipc' | 'iucv' | 'rxrpc' | 'isdn' | 'phonet' | 'ieee802154' | 'caif' | 'alg' | 'nfc' | 'vsock' | 'mpls' | 'ib' | 'kcm' ) ',' TYPE = ( 'stream' | 'dgram' | 'seqpacket' | 'rdm' | 'raw' | 'packet' ) PROTOCOL = ( 'tcp' | 'udp' | 'icmp' ) eg. network, network inet, Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2017-09-22apparmor: add more debug asserts to apparmorfsJohn Johansen1-0/+17
Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2017-09-22apparmor: make policy_unpack able to audit different info messagesJohn Johansen2-16/+40
Switch unpack auditing to using the generic name field in the audit struct and make it so we can start adding new info messages about why an unpack failed. Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2017-09-22apparmor: add support for absolute root view based labelsJohn Johansen2-1/+10
With apparmor policy virtualization based on policy namespace View's we don't generally want/need absolute root based views, however there are cases like debugging and some secid based conversions where using a root based view is important. Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2017-09-22apparmor: cleanup conditional check for label in label_printJohn Johansen1-14/+8
Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2017-09-22apparmor: add mount mediationJohn Johansen9-4/+841
Add basic mount mediation. That allows controlling based on basic mount parameters. It does not include special mount parameters for apparmor, super block labeling, or any triggers for apparmor namespace parameter modifications on pivot root. default userspace policy rules have the form of MOUNT RULE = ( MOUNT | REMOUNT | UMOUNT ) MOUNT = [ QUALIFIERS ] 'mount' [ MOUNT CONDITIONS ] [ SOURCE FILEGLOB ] [ '->' MOUNTPOINT FILEGLOB ] REMOUNT = [ QUALIFIERS ] 'remount' [ MOUNT CONDITIONS ] MOUNTPOINT FILEGLOB UMOUNT = [ QUALIFIERS ] 'umount' [ MOUNT CONDITIONS ] MOUNTPOINT FILEGLOB MOUNT CONDITIONS = [ ( 'fstype' | 'vfstype' ) ( '=' | 'in' ) MOUNT FSTYPE EXPRESSION ] [ 'options' ( '=' | 'in' ) MOUNT FLAGS EXPRESSION ] MOUNT FSTYPE EXPRESSION = ( MOUNT FSTYPE LIST | MOUNT EXPRESSION ) MOUNT FSTYPE LIST = Comma separated list of valid filesystem and virtual filesystem types (eg ext4, debugfs, etc) MOUNT FLAGS EXPRESSION = ( MOUNT FLAGS LIST | MOUNT EXPRESSION ) MOUNT FLAGS LIST = Comma separated list of MOUNT FLAGS. MOUNT FLAGS = ( 'ro' | 'rw' | 'nosuid' | 'suid' | 'nodev' | 'dev' | 'noexec' | 'exec' | 'sync' | 'async' | 'remount' | 'mand' | 'nomand' | 'dirsync' | 'noatime' | 'atime' | 'nodiratime' | 'diratime' | 'bind' | 'rbind' | 'move' | 'verbose' | 'silent' | 'loud' | 'acl' | 'noacl' | 'unbindable' | 'runbindable' | 'private' | 'rprivate' | 'slave' | 'rslave' | 'shared' | 'rshared' | 'relatime' | 'norelatime' | 'iversion' | 'noiversion' | 'strictatime' | 'nouser' | 'user' ) MOUNT EXPRESSION = ( ALPHANUMERIC | AARE ) ... PIVOT ROOT RULE = [ QUALIFIERS ] pivot_root [ oldroot=OLD PUT FILEGLOB ] [ NEW ROOT FILEGLOB ] SOURCE FILEGLOB = FILEGLOB MOUNTPOINT FILEGLOB = FILEGLOB eg. mount, mount /dev/foo, mount options=ro /dev/foo -> /mnt/, mount options in (ro,atime) /dev/foo -> /mnt/, mount options=ro options=atime, Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2017-09-22apparmor: add the ability to mediate signalsJohn Johansen7-0/+231
Add signal mediation where the signal can be mediated based on the signal, direction, or the label or the peer/target. The signal perms are verified on a cross check to ensure policy consistency in the case of incremental policy load/replacement. The optimization of skipping the cross check when policy is guaranteed to be consistent (single compile unit) remains to be done. policy rules have the form of SIGNAL_RULE = [ QUALIFIERS ] 'signal' [ SIGNAL ACCESS PERMISSIONS ] [ SIGNAL SET ] [ SIGNAL PEER ] SIGNAL ACCESS PERMISSIONS = SIGNAL ACCESS | SIGNAL ACCESS LIST SIGNAL ACCESS LIST = '(' Comma or space separated list of SIGNAL ACCESS ')' SIGNAL ACCESS = ( 'r' | 'w' | 'rw' | 'read' | 'write' | 'send' | 'receive' ) SIGNAL SET = 'set' '=' '(' SIGNAL LIST ')' SIGNAL LIST = Comma or space separated list of SIGNALS SIGNALS = ( 'hup' | 'int' | 'quit' | 'ill' | 'trap' | 'abrt' | 'bus' | 'fpe' | 'kill' | 'usr1' | 'segv' | 'usr2' | 'pipe' | 'alrm' | 'term' | 'stkflt' | 'chld' | 'cont' | 'stop' | 'stp' | 'ttin' | 'ttou' | 'urg' | 'xcpu' | 'xfsz' | 'vtalrm' | 'prof' | 'winch' | 'io' | 'pwr' | 'sys' | 'emt' | 'exists' | 'rtmin+0' ... 'rtmin+32' ) SIGNAL PEER = 'peer' '=' AARE eg. signal, # allow all signals signal send set=(hup, kill) peer=foo, Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2017-09-22apparmor: Redundant condition: prev_ns. in [label.c:1498]John Johansen1-1/+1
Reported-by: David Binderman <dcb314@hotmail.com> Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-09-22apparmor: Fix an error code in aafs_create()Dan Carpenter1-1/+3
We accidentally forgot to set the error code on this path. It means we return NULL instead of an error pointer. I looked through a bunch of callers and I don't think it really causes a big issue, but the documentation says we're supposed to return error pointers here. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-09-22apparmor: Fix logical error in verify_header()Christos Gkekas1-1/+1
verify_header() is currently checking whether interface version is less than 5 *and* greater than 7, which always evaluates to false. Instead it should check whether it is less than 5 *or* greater than 7. Signed-off-by: Christos Gkekas <chris.gekas@gmail.com> Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-09-22apparmor: Fix shadowed local variable in unpack_trans_table()Geert Uytterhoeven1-2/+2
with W=2: security/apparmor/policy_unpack.c: In function ‘unpack_trans_table’: security/apparmor/policy_unpack.c:469: warning: declaration of ‘pos’ shadows a previous local security/apparmor/policy_unpack.c:451: warning: shadowed declaration is here Rename the old "pos" to "saved_pos" to fix this. Fixes: 5379a3312024a8be ("apparmor: support v7 transition format compatible with label_parse") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-09-14Merge branch 'work.set_fs' of ↵Linus Torvalds1-2/+4
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more set_fs removal from Al Viro: "Christoph's 'use kernel_read and friends rather than open-coding set_fs()' series" * 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: unexport vfs_readv and vfs_writev fs: unexport vfs_read and vfs_write fs: unexport __vfs_read/__vfs_write lustre: switch to kernel_write gadget/f_mass_storage: stop messing with the address limit mconsole: switch to kernel_read btrfs: switch write_buf to kernel_write net/9p: switch p9_fd_read to kernel_write mm/nommu: switch do_mmap_private to kernel_read serial2002: switch serial2002_tty_write to kernel_{read/write} fs: make the buf argument to __kernel_write a void pointer fs: fix kernel_write prototype fs: fix kernel_read prototype fs: move kernel_read to fs/read_write.c fs: move kernel_write to fs/read_write.c autofs4: switch autofs4_write to __kernel_write ashmem: switch to ->read_iter
2017-09-12Merge tag 'selinux-pr-20170831' of ↵Linus Torvalds28-56/+78
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux updates from Paul Moore: "A relatively quiet period for SELinux, 11 patches with only two/three having any substantive changes. These noteworthy changes include another tweak to the NNP/nosuid handling, per-file labeling for cgroups, and an object class fix for AF_UNIX/SOCK_RAW sockets; the rest of the changes are minor tweaks or administrative updates (Stephen's email update explains the file explosion in the diffstat). Everything passes the selinux-testsuite" [ Also a couple of small patches from the security tree from Tetsuo Handa for Tomoyo and LSM cleanup. The separation of security policy updates wasn't all that clean - Linus ] * tag 'selinux-pr-20170831' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: constify nf_hook_ops selinux: allow per-file labeling for cgroupfs lsm_audit: update my email address selinux: update my email address MAINTAINERS: update the NetLabel and Labeled Networking information selinux: use GFP_NOWAIT in the AVC kmem_caches selinux: Generalize support for NNP/nosuid SELinux domain transitions selinux: genheaders should fail if too many permissions are defined selinux: update the selinux info in MAINTAINERS credits: update Paul Moore's info selinux: Assign proper class to PF_UNIX/SOCK_RAW sockets tomoyo: Update URLs in Documentation/admin-guide/LSM/tomoyo.rst LSM: Remove security_task_create() hook.
2017-09-11Merge branch 'for-linus' of ↵Linus Torvalds1-21/+256
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace updates from Eric Biederman: "Life has been busy and I have not gotten half as much done this round as I would have liked. I delayed it so that a minor conflict resolution with the mips tree could spend a little time in linux-next before I sent this pull request. This includes two long delayed user namespace changes from Kirill Tkhai. It also includes a very useful change from Serge Hallyn that allows the security capability attribute to be used inside of user namespaces. The practical effect of this is people can now untar tarballs and install rpms in user namespaces. It had been suggested to generalize this and encode some of the namespace information information in the xattr name. Upon close inspection that makes the things that should be hard easy and the things that should be easy more expensive. Then there is my bugfix/cleanup for signal injection that removes the magic encoding of the siginfo union member from the kernel internal si_code. The mips folks reported the case where I had used FPE_FIXME me is impossible so I have remove FPE_FIXME from mips, while at the same time including a return statement in that case to keep gcc from complaining about unitialized variables. I almost finished the work to get make copy_siginfo_to_user a trivial copy to user. The code is available at: git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git neuter-copy_siginfo_to_user-v3 But I did not have time/energy to get the code posted and reviewed before the merge window opened. I was able to see that the security excuse for just copying fields that we know are initialized doesn't work in practice there are buggy initializations that don't initialize the proper fields in siginfo. So we still sometimes copy unitialized data to userspace" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: Introduce v3 namespaced file capabilities mips/signal: In force_fcr31_sig return in the impossible case signal: Remove kernel interal si_code magic fcntl: Don't use ambiguous SIG_POLL si_codes prctl: Allow local CAP_SYS_ADMIN changing exe_file security: Use user_namespace::level to avoid redundant iterations in cap_capable() userns,pidns: Verify the userns for new pid namespaces signal/testing: Don't look for __SI_FAULT in userspace signal/mips: Document a conflict with SI_USER with SIGFPE signal/sparc: Document a conflict with SI_USER with SIGFPE signal/ia64: Document a conflict with SI_USER with SIGFPE signal/alpha: Document a conflict with SI_USER for SIGTRAP
2017-09-07Merge tag 'audit-pr-20170907' of ↵Linus Torvalds1-2/+0
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit Pull audit updates from Paul Moore: "A small pull request for audit this time, only four patches and only two with any real code changes. Those two changes are the removal of a pointless SELinux AVC initialization audit event and a fix to improve the audit timestamp overhead. The other two patches are comment cleanup and administrative updates, nothing very exciting. Everything passes our tests" * tag 'audit-pr-20170907' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: audit: update the function comments selinux: remove AVC init audit log message audit: update the audit info in MAINTAINERS audit: Reduce overhead using a coarse clock
2017-09-07Merge tag 'secureexec-v4.14-rc1' of ↵Linus Torvalds9-120/+23
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull secureexec update from Kees Cook: "This series has the ultimate goal of providing a sane stack rlimit when running set*id processes. To do this, the bprm_secureexec LSM hook is collapsed into the bprm_set_creds hook so the secureexec-ness of an exec can be determined early enough to make decisions about rlimits and the resulting memory layouts. Other logic acting on the secureexec-ness of an exec is similarly consolidated. Capabilities needed some special handling, but the refactoring removed other special handling, so that was a wash" * tag 'secureexec-v4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: exec: Consolidate pdeath_signal clearing exec: Use sane stack rlimit under secureexec exec: Consolidate dumpability logic smack: Remove redundant pdeath_signal clearing exec: Use secureexec for clearing pdeath_signal exec: Use secureexec for setting dumpability LSM: drop bprm_secureexec hook commoncap: Move cap_elevated calculation into bprm_set_creds commoncap: Refactor to remove bprm_secureexec hook smack: Refactor to remove bprm_secureexec hook selinux: Refactor to remove bprm_secureexec hook apparmor: Refactor to remove bprm_secureexec hook binfmt: Introduce secureexec flag exec: Correct comments about "point of no return" exec: Rename bprm->cred_prepared to called_set_creds
2017-09-05selinux: remove AVC init audit log messageRichard Guy Briggs1-2/+0
In the process of normalizing audit log messages, it was noticed that the AVC initialization code registered an audit log KERNEL record that didn't fit the standard format. In the process of attempting to normalize it it was determined that this record was not even necessary. Remove it. Ref: http://marc.info/?l=selinux&m=149614868525826&w=2 See: https://github.com/linux-audit/audit-kernel/issues/48 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Steve Grubb <sgrubb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-09-04fs: fix kernel_write prototypeChristoph Hellwig1-1/+2
Make the position an in/out argument like all the other read/write helpers and and make the buf argument a void pointer. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>