linux-stable.git/security/keys, branch linux-5.10.y

KEYS: trusted_tpm1: Compare HMAC values in constant time

2025-10-29T13:01:24+00:00

[ Upstream commit eed0e3d305530066b4fc5370107cff8ef1a0d229 ]

To prevent timing attacks, HMAC value comparison needs to be constant
time.  Replace the memcmp() with the correct function, crypto_memneq().

[For the Fixes commit I used the commit that introduced the memcmp().
It predates the introduction of crypto_memneq(), but it was still a bug
at the time even though a helper function didn't exist yet.]

Fixes: d00a1c72f7f4 ("keys: add new trusted key-type")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers 
Reviewed-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen 
[ replaced crypto/utils.h include with crypto/algapi.h ]
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

security/keys: fix slab-out-of-bounds in key_task_permission

2024-11-17T13:59:35+00:00

[ Upstream commit 4a74da044ec9ec8679e6beccc4306b936b62873f ]

KASAN reports an out of bounds read:
BUG: KASAN: slab-out-of-bounds in __kuid_val include/linux/uidgid.h:36
BUG: KASAN: slab-out-of-bounds in uid_eq include/linux/uidgid.h:63 [inline]
BUG: KASAN: slab-out-of-bounds in key_task_permission+0x394/0x410
security/keys/permission.c:54
Read of size 4 at addr ffff88813c3ab618 by task stress-ng/4362

CPU: 2 PID: 4362 Comm: stress-ng Not tainted 5.10.0-14930-gafbffd6c3ede #15
Call Trace:
 __dump_stack lib/dump_stack.c:82 [inline]
 dump_stack+0x107/0x167 lib/dump_stack.c:123
 print_address_description.constprop.0+0x19/0x170 mm/kasan/report.c:400
 __kasan_report.cold+0x6c/0x84 mm/kasan/report.c:560
 kasan_report+0x3a/0x50 mm/kasan/report.c:585
 __kuid_val include/linux/uidgid.h:36 [inline]
 uid_eq include/linux/uidgid.h:63 [inline]
 key_task_permission+0x394/0x410 security/keys/permission.c:54
 search_nested_keyrings+0x90e/0xe90 security/keys/keyring.c:793

This issue was also reported by syzbot.

It can be reproduced by following these steps(more details [1]):
1. Obtain more than 32 inputs that have similar hashes, which ends with the
   pattern '0xxxxxxxe6'.
2. Reboot and add the keys obtained in step 1.

The reproducer demonstrates how this issue happened:
1. In the search_nested_keyrings function, when it iterates through the
   slots in a node(below tag ascend_to_node), if the slot pointer is meta
   and node->back_pointer != NULL(it means a root), it will proceed to
   descend_to_node. However, there is an exception. If node is the root,
   and one of the slots points to a shortcut, it will be treated as a
   keyring.
2. Whether the ptr is keyring decided by keyring_ptr_is_keyring function.
   However, KEYRING_PTR_SUBTYPE is 0x2UL, the same as
   ASSOC_ARRAY_PTR_SUBTYPE_MASK.
3. When 32 keys with the similar hashes are added to the tree, the ROOT
   has keys with hashes that are not similar (e.g. slot 0) and it splits
   NODE A without using a shortcut. When NODE A is filled with keys that
   all hashes are xxe6, the keys are similar, NODE A will split with a
   shortcut. Finally, it forms the tree as shown below, where slot 6 points
   to a shortcut.

                      NODE A
              +------>+---+
      ROOT    |       | 0 | xxe6
      +---+   |       +---+
 xxxx | 0 | shortcut  :   : xxe6
      +---+   |       +---+
 xxe6 :   :   |       |   | xxe6
      +---+   |       +---+
      | 6 |---+       :   : xxe6
      +---+           +---+
 xxe6 :   :           | f | xxe6
      +---+           +---+
 xxe6 | f |
      +---+

4. As mentioned above, If a slot(slot 6) of the root points to a shortcut,
   it may be mistakenly transferred to a key*, leading to a read
   out-of-bounds read.

To fix this issue, one should jump to descend_to_node if the ptr is a
shortcut, regardless of whether the node is root or not.

[1] https://lore.kernel.org/linux-kernel/1cfa878e-8c7b-4570-8606-21daf5e13ce7@huaweicloud.com/

[jarkko: tweaked the commit message a bit to have an appropriate closes
 tag.]
Fixes: b2a4df200d57 ("KEYS: Expand the capacity of a keyring")
Reported-by: syzbot+5b415c07907a2990d1a3@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000cbb7860611f61147@google.com/T/
Signed-off-by: Chen Ridong 
Reviewed-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Sasha Levin

task_work: s/task_work_cancel()/task_work_cancel_func()/

2024-08-19T03:40:57+00:00

commit 68cbd415dd4b9c5b9df69f0f091879e56bf5907a upstream.

A proper task_work_cancel() API that actually cancels a callback and not
*any* callback pointing to a given function is going to be needed for
perf events event freeing. Do the appropriate rename to prepare for
that.

Signed-off-by: Frederic Weisbecker 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240621091601.18227-2-frederic@kernel.org
Signed-off-by: Greg Kroah-Hartman

keys: Fix overwrite of key expiration on instantiation

2024-05-17T09:48:11+00:00

commit 9da27fb65a14c18efd4473e2e82b76b53ba60252 upstream.

The expiry time of a key is unconditionally overwritten during
instantiation, defaulting to turn it permanent. This causes a problem
for DNS resolution as the expiration set by user-space is overwritten to
TIME64_MAX, disabling further DNS updates. Fix this by restoring the
condition that key_set_expiry is only called when the pre-parser sets a
specific expiry.

Fixes: 39299bdd2546 ("keys, dns: Allow key types (eg. DNS) to be reclaimed immediately on expiry")
Signed-off-by: Silvio Gissi 
cc: David Howells 
cc: Hazem Mohamed Abuelfotoh 
cc: linux-afs@lists.infradead.org
cc: linux-cifs@vger.kernel.org
cc: keyrings@vger.kernel.org
cc: netdev@vger.kernel.org
cc: stable@vger.kernel.org
Reviewed-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Greg Kroah-Hartman

keys, dns: Allow key types (eg. DNS) to be reclaimed immediately on expiry

2024-01-05T14:12:25+00:00

[ Upstream commit 39299bdd2546688d92ed9db4948f6219ca1b9542 ]

If a key has an expiration time, then when that time passes, the key is
left around for a certain amount of time before being collected (5 mins by
default) so that EKEYEXPIRED can be returned instead of ENOKEY.  This is a
problem for DNS keys because we want to redo the DNS lookup immediately at
that point.

Fix this by allowing key types to be marked such that keys of that type
don't have this extra period, but are reclaimed as soon as they expire and
turn this on for dns_resolver-type keys.  To make this easier to handle,
key->expiry is changed to be permanent if TIME64_MAX rather than 0.

Furthermore, give such new-style negative DNS results a 1s default expiry
if no other expiry time is set rather than allowing it to stick around
indefinitely.  This shouldn't be zero as ls will follow a failing stat call
immediately with a second with AT_SYMLINK_NOFOLLOW added.

Fixes: 1a4240f4764a ("DNS: Separate out CIFS DNS Resolver code")
Signed-off-by: David Howells 
Tested-by: Markus Suvanto 
cc: Wang Lei 
cc: Jeff Layton 
cc: Steve French 
cc: Marc Dionne 
cc: Jarkko Sakkinen 
cc: "David S. Miller" 
cc: Eric Dumazet 
cc: Jakub Kicinski 
cc: Paolo Abeni 
cc: linux-afs@lists.infradead.org
cc: linux-cifs@vger.kernel.org
cc: linux-nfs@vger.kernel.org
cc: ceph-devel@vger.kernel.org
cc: keyrings@vger.kernel.org
cc: netdev@vger.kernel.org
Signed-off-by: Sasha Levin

security: keys: perform capable check only on privileged operations

2023-09-19T10:20:05+00:00

[ Upstream commit 2d7f105edbb3b2be5ffa4d833abbf9b6965e9ce7 ]

If the current task fails the check for the queried capability via
`capable(CAP_SYS_ADMIN)` LSMs like SELinux generate a denial message.
Issuing such denial messages unnecessarily can lead to a policy author
granting more privileges to a subject than needed to silence them.

Reorder CAP_SYS_ADMIN checks after the check whether the operation is
actually privileged.

Signed-off-by: Christian Göttsche 
Reviewed-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Sasha Levin

security: keys: Modify mismatched function name

2023-07-27T06:44:39+00:00

[ Upstream commit 2a4152742025c5f21482e8cebc581702a0fa5b01 ]

No functional modification involved.

security/keys/trusted-keys/trusted_tpm2.c:203: warning: expecting prototype for tpm_buf_append_auth(). Prototype was for tpm2_buf_append_auth() instead.

Fixes: 2e19e10131a0 ("KEYS: trusted: Move TPM2 trusted keys code")
Reported-by: Abaci Robot 
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=5524
Signed-off-by: Jiapeng Chong 
Reviewed-by: Paul Moore 
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Sasha Levin

keys: Fix linking a duplicate key to a keyring's assoc_array

2023-07-27T06:44:34+00:00

commit d55901522f96082a43b9842d34867363c0cdbac5 upstream.

When making a DNS query inside the kernel using dns_query(), the request
code can in rare cases end up creating a duplicate index key in the
assoc_array of the destination keyring. It is eventually found by
a BUG_ON() check in the assoc_array implementation and results in
a crash.

Example report:
[2158499.700025] kernel BUG at ../lib/assoc_array.c:652!
[2158499.700039] invalid opcode: 0000 [#1] SMP PTI
[2158499.700065] CPU: 3 PID: 31985 Comm: kworker/3:1 Kdump: loaded Not tainted 5.3.18-150300.59.90-default #1 SLE15-SP3
[2158499.700096] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020
[2158499.700351] Workqueue: cifsiod cifs_resolve_server [cifs]
[2158499.700380] RIP: 0010:assoc_array_insert+0x85f/0xa40
[2158499.700401] Code: ff 74 2b 48 8b 3b 49 8b 45 18 4c 89 e6 48 83 e7 fe e8 95 ec 74 00 3b 45 88 7d db 85 c0 79 d4 0f 0b 0f 0b 0f 0b e8 41 f2 be ff <0f> 0b 0f 0b 81 7d 88 ff ff ff 7f 4c 89 eb 4c 8b ad 58 ff ff ff 0f
[2158499.700448] RSP: 0018:ffffc0bd6187faf0 EFLAGS: 00010282
[2158499.700470] RAX: ffff9f1ea7da2fe8 RBX: ffff9f1ea7da2fc1 RCX: 0000000000000005
[2158499.700492] RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000000
[2158499.700515] RBP: ffffc0bd6187fbb0 R08: ffff9f185faf1100 R09: 0000000000000000
[2158499.700538] R10: ffff9f1ea7da2cc0 R11: 000000005ed8cec8 R12: ffffc0bd6187fc28
[2158499.700561] R13: ffff9f15feb8d000 R14: ffff9f1ea7da2fc0 R15: ffff9f168dc0d740
[2158499.700585] FS:  0000000000000000(0000) GS:ffff9f185fac0000(0000) knlGS:0000000000000000
[2158499.700610] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[2158499.700630] CR2: 00007fdd94fca238 CR3: 0000000809d8c006 CR4: 00000000003706e0
[2158499.700702] Call Trace:
[2158499.700741]  ? key_alloc+0x447/0x4b0
[2158499.700768]  ? __key_link_begin+0x43/0xa0
[2158499.700790]  __key_link_begin+0x43/0xa0
[2158499.700814]  request_key_and_link+0x2c7/0x730
[2158499.700847]  ? dns_resolver_read+0x20/0x20 [dns_resolver]
[2158499.700873]  ? key_default_cmp+0x20/0x20
[2158499.700898]  request_key_tag+0x43/0xa0
[2158499.700926]  dns_query+0x114/0x2ca [dns_resolver]
[2158499.701127]  dns_resolve_server_name_to_ip+0x194/0x310 [cifs]
[2158499.701164]  ? scnprintf+0x49/0x90
[2158499.701190]  ? __switch_to_asm+0x40/0x70
[2158499.701211]  ? __switch_to_asm+0x34/0x70
[2158499.701405]  reconn_set_ipaddr_from_hostname+0x81/0x2a0 [cifs]
[2158499.701603]  cifs_resolve_server+0x4b/0xd0 [cifs]
[2158499.701632]  process_one_work+0x1f8/0x3e0
[2158499.701658]  worker_thread+0x2d/0x3f0
[2158499.701682]  ? process_one_work+0x3e0/0x3e0
[2158499.701703]  kthread+0x10d/0x130
[2158499.701723]  ? kthread_park+0xb0/0xb0
[2158499.701746]  ret_from_fork+0x1f/0x40

The situation occurs as follows:
* Some kernel facility invokes dns_query() to resolve a hostname, for
  example, "abcdef". The function registers its global DNS resolver
  cache as current->cred.thread_keyring and passes the query to
  request_key_net() -> request_key_tag() -> request_key_and_link().
* Function request_key_and_link() creates a keyring_search_context
  object. Its match_data.cmp method gets set via a call to
  type->match_preparse() (resolves to dns_resolver_match_preparse()) to
  dns_resolver_cmp().
* Function request_key_and_link() continues and invokes
  search_process_keyrings_rcu() which returns that a given key was not
  found. The control is then passed to request_key_and_link() ->
  construct_alloc_key().
* Concurrently to that, a second task similarly makes a DNS query for
  "abcdef." and its result gets inserted into the DNS resolver cache.
* Back on the first task, function construct_alloc_key() first runs
  __key_link_begin() to determine an assoc_array_edit operation to
  insert a new key. Index keys in the array are compared exactly as-is,
  using keyring_compare_object(). The operation finds that "abcdef" is
  not yet present in the destination keyring.
* Function construct_alloc_key() continues and checks if a given key is
  already present on some keyring by again calling
  search_process_keyrings_rcu(). This search is done using
  dns_resolver_cmp() and "abcdef" gets matched with now present key
  "abcdef.".
* The found key is linked on the destination keyring by calling
  __key_link() and using the previously calculated assoc_array_edit
  operation. This inserts the "abcdef." key in the array but creates
  a duplicity because the same index key is already present.

Fix the problem by postponing __key_link_begin() in
construct_alloc_key() until an actual key which should be linked into
the destination keyring is determined.

[jarkko@kernel.org: added a fixes tag and cc to stable]
Cc: stable@vger.kernel.org # v5.3+
Fixes: df593ee23e05 ("keys: Hoist locking out of __key_link_begin()")
Signed-off-by: Petr Pavlu 
Reviewed-by: Joey Lee 
Reviewed-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Greg Kroah-Hartman

keys: Do not cache key in task struct if key is requested from kernel thread

2023-04-05T09:23:34+00:00

[ Upstream commit 47f9e4c924025c5be87959d3335e66fcbb7f6b5c ]

The key which gets cached in task structure from a kernel thread does not
get invalidated even after expiry.  Due to which, a new key request from
kernel thread will be served with the cached key if it's present in task
struct irrespective of the key validity.  The change is to not cache key in
task_struct when key requested from kernel thread so that kernel thread
gets a valid key on every key request.

The problem has been seen with the cifs module doing DNS lookups from a
kernel thread and the results getting pinned by being attached to that
kernel thread's cache - and thus not something that can be easily got rid
of.  The cache would ordinarily be cleared by notify-resume, but kernel
threads don't do that.

This isn't seen with AFS because AFS is doing request_key() within the
kernel half of a user thread - which will do notify-resume.

Fixes: 7743c48e54ee ("keys: Cache result of request_key*() temporarily in task_struct")
Signed-off-by: Bharath SM 
Signed-off-by: David Howells 
Reviewed-by: Jarkko Sakkinen 
cc: Shyam Prasad N 
cc: Steve French 
cc: keyrings@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/CAGypqWw951d=zYRbdgNR4snUDvJhWL=q3=WOyh7HhSJupjz2vA@mail.gmail.com/
Signed-off-by: Sasha Levin

KEYS: fix length validation in keyctl_pkey_params_get_2()

2022-04-08T12:39:50+00:00

commit c51abd96837f600d8fd940b6ab8e2da578575504 upstream.

In many cases, keyctl_pkey_params_get_2() is validating the user buffer
lengths against the wrong algorithm properties.  Fix it to check against
the correct properties.

Probably this wasn't noticed before because for all asymmetric keys of
the "public_key" subtype, max_data_size == max_sig_size == max_enc_size
== max_dec_size.  However, this isn't necessarily true for the
"asym_tpm" subtype (it should be, but it's not strictly validated).  Of
course, future key types could have different values as well.

Fixes: 00d60fd3b932 ("KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver #2]")
Cc:  # v4.20+
Signed-off-by: Eric Biggers 
Reviewed-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Greg Kroah-Hartman