25 Feb, 2018
3 commits
-
commit 3cd18d1981731d5f74b8e437009124ac99905d14 upstream.
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
Signed-off-by: David Howells
Signed-off-by: Greg Kroah-Hartman -
commit 4b14752ec4e0d87126e636384cf37c8dd9df157c upstream.
We can't do anything reasonable in security_bounded_transition() if we
don't have a policy loaded, and in fact we could run into problems
with some of the code inside expecting a policy. Fix these problems
like we do many others in security/selinux/ss/services.c by checking
to see if the policy is loaded (ss_initialized) and returning quickly
if it isn't.Reported-by: syzbot
Signed-off-by: Paul Moore
Acked-by: Stephen Smalley
Reviewed-by: James Morris
Signed-off-by: Greg Kroah-Hartman -
commit ef28df55ac27e1e5cd122e19fa311d886d47a756 upstream.
The syzbot/syzkaller automated tests found a problem in
security_context_to_sid_core() during early boot (before we load the
SELinux policy) where we could potentially feed context strings without
NUL terminators into the strcmp() function.We already guard against this during normal operation (after the SELinux
policy has been loaded) by making a copy of the context strings and
explicitly adding a NUL terminator to the end. The patch extends this
protection to the early boot case (no loaded policy) by moving the context
copy earlier in security_context_to_sid_core().Reported-by: syzbot
Signed-off-by: Paul Moore
Reviewed-By: William Roberts
Signed-off-by: Greg Kroah-Hartman
13 Feb, 2018
1 commit
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commit 794b4bc292f5d31739d89c0202c54e7dc9bc3add upstream.
With the 'encrypted' key type it was possible for userspace to provide a
data blob ending with a master key description shorter than expected,
e.g. 'keyctl add encrypted desc "new x" @s'. When validating such a
master key description, validate_master_desc() could read beyond the end
of the buffer. Fix this by using strncmp() instead of memcmp(). [Also
clean up the code to deduplicate some logic.]Cc: Mimi Zohar
Signed-off-by: Eric Biggers
Signed-off-by: David Howells
Signed-off-by: James Morris
Signed-off-by: Jin Qian
Signed-off-by: Greg Kroah-Hartman
05 Jan, 2018
6 commits
-
This renames CONFIG_KAISER to CONFIG_PAGE_TABLE_ISOLATION.
Signed-off-by: Kees Cook
Signed-off-by: Greg Kroah-Hartman -
Now that the required bits have been addressed, reenable
PARAVIRT.Signed-off-by: Borislav Petkov
Signed-off-by: Greg Kroah-Hartman -
We fail to see what CONFIG_KAISER_REAL_SWITCH is for: it seems to be
left over from early development, and now just obscures tricky parts
of the code. Delete it before adding PCIDs, or nokaiser boot option.(Or if there is some good reason to keep the option, then it needs
a help text - and a "depends on KAISER", so that all those without
KAISER are not asked the question. But we'd much rather delete it.)Signed-off-by: Hugh Dickins
Signed-off-by: Greg Kroah-Hartman -
It is absurd that KAISER should depend on SMP, but apparently nobody
has tried a UP build before: which breaks on implicit declaration of
function 'per_cpu_offset' in arch/x86/mm/kaiser.c.Now, you would expect that to be trivially fixed up; but looking at
the System.map when that block is #ifdef'ed out of kaiser_init(),
I see that in a UP build __per_cpu_user_mapped_end is precisely at
__per_cpu_user_mapped_start, and the items carefully gathered into
that section for user-mapping on SMP, dispersed elsewhere on UP.So, some other kind of section assignment will be needed on UP,
but implementing that is not a priority: just make KAISER depend
on SMP for now.Also inserted a blank line before the option, tidied up the
brief Kconfig help message, and added an "If unsure, Y".Signed-off-by: Hugh Dickins
Signed-off-by: Greg Kroah-Hartman -
Merged fixes and cleanups, rebased to 4.9.51 tree (no 5-level paging).
Signed-off-by: Dave Hansen
Signed-off-by: Hugh Dickins
Signed-off-by: Greg Kroah-Hartman -
This patch introduces our implementation of KAISER (Kernel Address Isolation to
have Side-channels Efficiently Removed), a kernel isolation technique to close
hardware side channels on kernel address information.More information about the patch can be found on:
https://github.com/IAIK/KAISER
From: Richard Fellner
From: Daniel Gruss
Subject: [RFC, PATCH] x86_64: KAISER - do not map kernel in user mode
Date: Thu, 4 May 2017 14:26:50 +0200
Link: http://marc.info/?l=linux-kernel&m=149390087310405&w=2
Kaiser-4.10-SHA1: c4b1831d44c6144d3762ccc72f0c4e71a0c713e5To:
To:
Cc:
Cc:
Cc: Michael Schwarz
Cc: Richard Fellner
Cc: Ingo Molnar
Cc:
Cc:After several recent works [1,2,3] KASLR on x86_64 was basically
considered dead by many researchers. We have been working on an
efficient but effective fix for this problem and found that not mapping
the kernel space when running in user mode is the solution to this
problem [4] (the corresponding paper [5] will be presented at ESSoS17).With this RFC patch we allow anybody to configure their kernel with the
flag CONFIG_KAISER to add our defense mechanism.If there are any questions we would love to answer them.
We also appreciate any comments!Cheers,
Daniel (+ the KAISER team from Graz University of Technology)[1] http://www.ieee-security.org/TC/SP2013/papers/4977a191.pdf
[2] https://www.blackhat.com/docs/us-16/materials/us-16-Fogh-Using-Undocumented-CPU-Behaviour-To-See-Into-Kernel-Mode-And-Break-KASLR-In-The-Process.pdf
[3] https://www.blackhat.com/docs/us-16/materials/us-16-Jang-Breaking-Kernel-Address-Space-Layout-Randomization-KASLR-With-Intel-TSX.pdf
[4] https://github.com/IAIK/KAISER
[5] https://gruss.cc/files/kaiser.pdf[patch based also on
https://raw.githubusercontent.com/IAIK/KAISER/master/KAISER/0001-KAISER-Kernel-Address-Isolation.patch]Signed-off-by: Richard Fellner
Signed-off-by: Moritz Lipp
Signed-off-by: Daniel Gruss
Signed-off-by: Michael Schwarz
Acked-by: Jiri Kosina
Signed-off-by: Hugh Dickins
Signed-off-by: Greg Kroah-Hartman
14 Dec, 2017
1 commit
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commit 4dca6ea1d9432052afb06baf2e3ae78188a4410b upstream.
When the request_key() syscall is not passed a destination keyring, it
links the requested key (if constructed) into the "default" request-key
keyring. This should require Write permission to the keyring. However,
there is actually no permission check.This can be abused to add keys to any keyring to which only Search
permission is granted. This is because Search permission allows joining
the keyring. keyctl_set_reqkey_keyring(KEY_REQKEY_DEFL_SESSION_KEYRING)
then will set the default request-key keyring to the session keyring.
Then, request_key() can be used to add keys to the keyring.Both negatively and positively instantiated keys can be added using this
method. Adding negative keys is trivial. Adding a positive key is a
bit trickier. It requires that either /sbin/request-key positively
instantiates the key, or that another thread adds the key to the process
keyring at just the right time, such that request_key() misses it
initially but then finds it in construct_alloc_key().Fix this bug by checking for Write permission to the keyring in
construct_get_dest_keyring() when the default keyring is being used.We don't do the permission check for non-default keyrings because that
was already done by the earlier call to lookup_user_key(). Also,
request_key_and_link() is currently passed a 'struct key *' rather than
a key_ref_t, so the "possessed" bit is unavailable.We also don't do the permission check for the "requestor keyring", to
continue to support the use case described by commit 8bbf4976b59f
("KEYS: Alter use of key instantiation link-to-keyring argument") where
/sbin/request-key recursively calls request_key() to add keys to the
original requestor's destination keyring. (I don't know of any users
who actually do that, though...)Fixes: 3e30148c3d52 ("[PATCH] Keys: Make request-key create an authorisation key")
Signed-off-by: Eric Biggers
Signed-off-by: David Howells
Signed-off-by: Greg Kroah-Hartman
10 Dec, 2017
1 commit
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[ Upstream commit ebe7c0a7be92bbd34c6ff5b55810546a0ee05bee ]
The hash_setup function always sets the hash_setup_done flag, even
when the hash algorithm is invalid. This prevents the default hash
algorithm defined as CONFIG_IMA_DEFAULT_HASH from being used.This patch sets hash_setup_done flag only for valid hash algorithms.
Fixes: e7a2ad7eb6f4 "ima: enable support for larger default filedata hash algorithms"
Signed-off-by: Boshi Wang
Signed-off-by: Mimi Zohar
Signed-off-by: Sasha Levin
Signed-off-by: Greg Kroah-Hartman
24 Nov, 2017
1 commit
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commit 020aae3ee58c1af0e7ffc4e2cc9fe4dc630338cb upstream.
Commit b65a9cfc2c38 ("Untangling ima mess, part 2: deal with counters")
moved the call of ima_file_check() from may_open() to do_filp_open() at a
point where the file descriptor is already opened.This breaks the assumption made by IMA that file descriptors being closed
belong to files whose access was granted by ima_file_check(). The
consequence is that security.ima and security.evm are updated with good
values, regardless of the current appraisal status.For example, if a file does not have security.ima, IMA will create it after
opening the file for writing, even if access is denied. Access to the file
will be allowed afterwards.Avoid this issue by checking the appraisal status before updating
security.ima.Signed-off-by: Roberto Sassu
Signed-off-by: Mimi Zohar
Signed-off-by: James Morris
Signed-off-by: Greg Kroah-Hartman
18 Nov, 2017
1 commit
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commit 47b2c3fff4932e6fc17ce13d51a43c6969714e20 upstream.
CONFIG_KEYS_COMPAT is defined in arch-specific Kconfigs and is missing for
several 64-bit architectures : mips, parisc, tile.At the moment and for those architectures, calling in 32-bit userspace the
keyctl syscall would return an ENOSYS error.This patch moves the CONFIG_KEYS_COMPAT option to security/keys/Kconfig, to
make sure the compatibility wrapper is registered by default for any 64-bit
architecture as long as it is configured with CONFIG_COMPAT.[DH: Modified to remove arm64 compat enablement also as requested by Eric
Biggers]Signed-off-by: Bilal Amarni
Signed-off-by: David Howells
Reviewed-by: Arnd Bergmann
cc: Eric Biggers
Signed-off-by: James Morris
Cc: James Cowgill
Signed-off-by: Greg Kroah-Hartman
15 Nov, 2017
3 commits
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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 -
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 -
[ Upstream commit 3ccb76c5dfe0d25c1d0168d5b726d0b43d19a485 ]
The kernel build bot turned up a bad config combination when
CONFIG_SECURITY_APPARMOR is y and CONFIG_SECURITY_APPARMOR_HASH is n,
resulting in the build error
security/built-in.o: In function `aa_unpack':
(.text+0x841e2): undefined reference to `aa_g_hash_policy'Signed-off-by: John Johansen
Signed-off-by: Sasha Levin
Signed-off-by: Greg Kroah-Hartman
08 Nov, 2017
1 commit
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commit 3239b6f29bdfb4b0a2ba59df995fc9e6f4df7f1f upstream.
Commit e645016abc80 ("KEYS: fix writing past end of user-supplied buffer
in keyring_read()") made keyring_read() stop corrupting userspace memory
when the user-supplied buffer is too small. However it also made the
return value in that case be the short buffer size rather than the size
required, yet keyctl_read() is actually documented to return the size
required. Therefore, switch it over to the documented behavior.Note that for now we continue to have it fill the short buffer, since it
did that before (pre-v3.13) and dump_key_tree_aux() in keyutils arguably
relies on it.Fixes: e645016abc80 ("KEYS: fix writing past end of user-supplied buffer in keyring_read()")
Reported-by: Ben Hutchings
Signed-off-by: Eric Biggers
Signed-off-by: David Howells
Reviewed-by: James Morris
Signed-off-by: James Morris
Signed-off-by: Greg Kroah-Hartman
27 Oct, 2017
3 commits
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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 -
commit 60ff5b2f547af3828aebafd54daded44cfb0807a upstream.
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
#include
#includeint 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 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: 0000000000000018Reported-by: Eric Biggers
Signed-off-by: David Howells
cc: Eric Biggers
Signed-off-by: Greg Kroah-Hartman -
commit 13923d0865ca96312197962522e88bc0aedccd74 upstream.
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
Cc: Mimi Zohar
Cc: David Safford
Signed-off-by: Eric Biggers
Signed-off-by: David Howells
Signed-off-by: Greg Kroah-Hartman
12 Oct, 2017
1 commit
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commit 57e7ba04d422c3d41c8426380303ec9b7533ded9 upstream.
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
Reported-by: Konstantin Khlebnikov
Signed-off-by: James Morris
Signed-off-by: Greg Kroah-Hartman
05 Oct, 2017
5 commits
-
commit 37863c43b2c6464f252862bf2e9768264e961678 upstream.
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 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: 00000000ffffff92Fixes: 61ea0c0ba904 ("KEYS: Skip key state checks when checking for possession")
Signed-off-by: Eric Biggers
Signed-off-by: David Howells
Signed-off-by: Greg Kroah-Hartman -
commit 237bbd29f7a049d310d907f4b2716a7feef9abf3 upstream.
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 @usThis 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.4000Fix 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")
Signed-off-by: Eric Biggers
Signed-off-by: David Howells
Signed-off-by: Greg Kroah-Hartman -
commit e645016abc803dafc75e4b8f6e4118f088900ffb upstream.
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")
Signed-off-by: Eric Biggers
Signed-off-by: David Howells
Signed-off-by: Greg Kroah-Hartman -
commit 428490e38b2e352812e0b765d8bceafab0ec441d upstream.
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.[Note that in backporting this commit to 4.9, get_random_bytes_wait was
replaced with get_random_bytes, since 4.9 does not have the former
function. This might result in slightly worse entropy in key generation,
but common use cases of big_keys makes that likely not a huge deal. And,
this is the best we can do with this old kernel. Alas.]Signed-off-by: Jason A. Donenfeld
Reviewed-by: Eric Biggers
Signed-off-by: David Howells
Cc: Herbert Xu
Cc: Kirill Marinushkin
Cc: security@kernel.org
Signed-off-by: Greg Kroah-Hartman -
commit 910801809b2e40a4baedd080ef5d80b4a180e70e upstream.
Error paths forgot to zero out sensitive material, so this patch changes
some kfrees into a kzfrees.Signed-off-by: Jason A. Donenfeld
Signed-off-by: David Howells
Reviewed-by: Eric Biggers
Cc: Herbert Xu
Cc: Kirill Marinushkin
Cc: security@kernel.org
Signed-off-by: Greg Kroah-Hartman
12 Jul, 2017
1 commit
-
commit 57cb17e764ba0aaa169d07796acce54ccfbc6cae upstream.
This function has two callers and neither are able to handle a NULL
return. Really, -EINVAL is the correct thing return here anyway. This
fixes some static checker warnings like:security/keys/encrypted-keys/encrypted.c:709 encrypted_key_decrypt()
error: uninitialized symbol 'master_key'.Fixes: 7e70cb497850 ("keys: add new key-type encrypted")
Signed-off-by: Dan Carpenter
Acked-by: Mimi Zohar
Signed-off-by: James Morris
Signed-off-by: Greg Kroah-Hartman
14 Jun, 2017
3 commits
-
commit e9ff56ac352446f55141aaef1553cee662b2e310 upstream.
Since v4.9, the crypto API cannot (normally) be used to encrypt/decrypt
stack buffers because the stack may be virtually mapped. Fix this for
the padding buffers in encrypted-keys by using ZERO_PAGE for the
encryption padding and by allocating a temporary heap buffer for the
decryption padding.Tested with CONFIG_DEBUG_SG=y:
keyctl new_session
keyctl add user master "abcdefghijklmnop" @s
keyid=$(keyctl add encrypted desc "new user:master 25" @s)
datablob="$(keyctl pipe $keyid)"
keyctl unlink $keyid
keyid=$(keyctl add encrypted desc "load $datablob" @s)
datablob2="$(keyctl pipe $keyid)"
[ "$datablob" = "$datablob2" ] && echo "Success!"Cc: Andy Lutomirski
Cc: Herbert Xu
Cc: Mimi Zohar
Signed-off-by: Eric Biggers
Signed-off-by: David Howells
Signed-off-by: James Morris
Signed-off-by: Greg Kroah-Hartman -
commit 63a0b0509e700717a59f049ec6e4e04e903c7fe2 upstream.
key_update() freed the key_preparsed_payload even if it was not
initialized first. This would cause a crash if userspace called
keyctl_update() on a key with type like "asymmetric" that has a
->preparse() method but not an ->update() method. Possibly it could
even be triggered for other key types by racing with keyctl_setperm() to
make the KEY_NEED_WRITE check fail (the permission was already checked,
so normally it wouldn't fail there).Reproducer with key type "asymmetric", given a valid cert.der:
keyctl new_session
keyid=$(keyctl padd asymmetric desc @s < cert.der)
keyctl setperm $keyid 0x3f000000
keyctl update $keyid data[ 150.686666] BUG: unable to handle kernel NULL pointer dereference at 0000000000000001
[ 150.687601] IP: asymmetric_key_free_kids+0x12/0x30
[ 150.688139] PGD 38a3d067
[ 150.688141] PUD 3b3de067
[ 150.688447] PMD 0
[ 150.688745]
[ 150.689160] Oops: 0000 [#1] SMP
[ 150.689455] Modules linked in:
[ 150.689769] CPU: 1 PID: 2478 Comm: keyctl Not tainted 4.11.0-rc4-xfstests-00187-ga9f6b6b8cd2f #742
[ 150.690916] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-20170228_101828-anatol 04/01/2014
[ 150.692199] task: ffff88003b30c480 task.stack: ffffc90000350000
[ 150.692952] RIP: 0010:asymmetric_key_free_kids+0x12/0x30
[ 150.693556] RSP: 0018:ffffc90000353e58 EFLAGS: 00010202
[ 150.694142] RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000004
[ 150.694845] RDX: ffffffff81ee3920 RSI: ffff88003d4b0700 RDI: 0000000000000001
[ 150.697569] RBP: ffffc90000353e60 R08: ffff88003d5d2140 R09: 0000000000000000
[ 150.702483] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
[ 150.707393] R13: 0000000000000004 R14: ffff880038a4d2d8 R15: 000000000040411f
[ 150.709720] FS: 00007fcbcee35700(0000) GS:ffff88003fd00000(0000) knlGS:0000000000000000
[ 150.711504] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 150.712733] CR2: 0000000000000001 CR3: 0000000039eab000 CR4: 00000000003406e0
[ 150.714487] Call Trace:
[ 150.714975] asymmetric_key_free_preparse+0x2f/0x40
[ 150.715907] key_update+0xf7/0x140
[ 150.716560] ? key_default_cmp+0x20/0x20
[ 150.717319] keyctl_update_key+0xb0/0xe0
[ 150.718066] SyS_keyctl+0x109/0x130
[ 150.718663] entry_SYSCALL_64_fastpath+0x1f/0xc2
[ 150.719440] RIP: 0033:0x7fcbce75ff19
[ 150.719926] RSP: 002b:00007ffd5d167088 EFLAGS: 00000206 ORIG_RAX: 00000000000000fa
[ 150.720918] RAX: ffffffffffffffda RBX: 0000000000404d80 RCX: 00007fcbce75ff19
[ 150.721874] RDX: 00007ffd5d16785e RSI: 000000002866cd36 RDI: 0000000000000002
[ 150.722827] RBP: 0000000000000006 R08: 000000002866cd36 R09: 00007ffd5d16785e
[ 150.723781] R10: 0000000000000004 R11: 0000000000000206 R12: 0000000000404d80
[ 150.724650] R13: 00007ffd5d16784d R14: 00007ffd5d167238 R15: 000000000040411f
[ 150.725447] Code: 83 c4 08 31 c0 5b 41 5c 41 5d 41 5e 41 5f 5d c3 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 85 ff 74 23 55 48 89 e5 53 48 89 fb 8b 3f e8 06 21 c5 ff 48 8b 7b 08 e8 fd 20 c5 ff 48 89 df e8
[ 150.727489] RIP: asymmetric_key_free_kids+0x12/0x30 RSP: ffffc90000353e58
[ 150.728117] CR2: 0000000000000001
[ 150.728430] ---[ end trace f7f8fe1da2d5ae8d ]---Fixes: 4d8c0250b841 ("KEYS: Call ->free_preparse() even after ->preparse() returns an error")
Signed-off-by: Eric Biggers
Signed-off-by: David Howells
Signed-off-by: James Morris
Signed-off-by: Greg Kroah-Hartman -
commit 5649645d725c73df4302428ee4e02c869248b4c5 upstream.
sys_add_key() and the KEYCTL_UPDATE operation of sys_keyctl() allowed a
NULL payload with nonzero length to be passed to the key type's
->preparse(), ->instantiate(), and/or ->update() methods. Various key
types including asymmetric, cifs.idmap, cifs.spnego, and pkcs7_test did
not handle this case, allowing an unprivileged user to trivially cause a
NULL pointer dereference (kernel oops) if one of these key types was
present. Fix it by doing the copy_from_user() when 'plen' is nonzero
rather than when '_payload' is non-NULL, causing the syscall to fail
with EFAULT as expected when an invalid buffer is specified.Signed-off-by: Eric Biggers
Signed-off-by: David Howells
Signed-off-by: James Morris
Signed-off-by: Greg Kroah-Hartman
25 May, 2017
1 commit
-
commit 1ac202e978e18f045006d75bd549612620c6ec3a upstream.
Modifying the attributes of a file makes ima_inode_post_setattr reset
the IMA cache flags. So if the file, which has just been created,
is opened a second time before the first file descriptor is closed,
verification fails since the security.ima xattr has not been written
yet. We therefore have to look at the IMA_NEW_FILE even if the file
already existed.With this patch there should no longer be an error when cat tries to
open testfile:$ rm -f testfile
$ ( echo test >&3 ; touch testfile ; cat testfile ) 3>testfileA file being new is no reason to accept that it is missing a digital
signature demanded by the policy.Signed-off-by: Daniel Glöckner
Signed-off-by: Mimi Zohar
Signed-off-by: Greg Kroah-Hartman
27 Apr, 2017
3 commits
-
commit c9f838d104fed6f2f61d68164712e3204bf5271b upstream.
This fixes CVE-2017-7472.
Running the following program as an unprivileged user exhausts kernel
memory by leaking thread keyrings:#include
int main()
{
for (;;)
keyctl_set_reqkey_keyring(KEY_REQKEY_DEFL_THREAD_KEYRING);
}Fix it by only creating a new thread keyring if there wasn't one before.
To make things more consistent, make install_thread_keyring_to_cred()
and install_process_keyring_to_cred() both return 0 if the corresponding
keyring is already present.Fixes: d84f4f992cbd ("CRED: Inaugurate COW credentials")
Signed-off-by: Eric Biggers
Signed-off-by: David Howells
Signed-off-by: Greg Kroah-Hartman -
commit c1644fe041ebaf6519f6809146a77c3ead9193af upstream.
This fixes CVE-2017-6951.
Userspace should not be able to do things with the "dead" key type as it
doesn't have some of the helper functions set upon it that the kernel
needs. Attempting to use it may cause the kernel to crash.Fix this by changing the name of the type to ".dead" so that it's rejected
up front on userspace syscalls by key_get_type_from_user().Though this doesn't seem to affect recent kernels, it does affect older
ones, certainly those prior to:commit c06cfb08b88dfbe13be44a69ae2fdc3a7c902d81
Author: David Howells
Date: Tue Sep 16 17:36:06 2014 +0100
KEYS: Remove key_type::match in favour of overriding default by match_preparsewhich went in before 3.18-rc1.
Signed-off-by: David Howells
Signed-off-by: Greg Kroah-Hartman -
commit ee8f844e3c5a73b999edf733df1c529d6503ec2f upstream.
This fixes CVE-2016-9604.
Keyrings whose name begin with a '.' are special internal keyrings and so
userspace isn't allowed to create keyrings by this name to prevent
shadowing. However, the patch that added the guard didn't fix
KEYCTL_JOIN_SESSION_KEYRING. Not only can that create dot-named keyrings,
it can also subscribe to them as a session keyring if they grant SEARCH
permission to the user.This, for example, allows a root process to set .builtin_trusted_keys as
its session keyring, at which point it has full access because now the
possessor permissions are added. This permits root to add extra public
keys, thereby bypassing module verification.This also affects kexec and IMA.
This can be tested by (as root):
keyctl session .builtin_trusted_keys
keyctl add user a a @s
keyctl list @swhich on my test box gives me:
2 keys in keyring:
180010936: ---lswrv 0 0 asymmetric: Build time autogenerated kernel key: ae3d4a31b82daa8e1a75b49dc2bba949fd992a05
801382539: --alswrv 0 0 user: aFix this by rejecting names beginning with a '.' in the keyctl.
Signed-off-by: David Howells
Acked-by: Mimi Zohar
cc: linux-ima-devel@lists.sourceforge.net
Signed-off-by: Greg Kroah-Hartman
12 Mar, 2017
1 commit
-
commit bc15ed663e7e53ee4dc3e60f8d09c93a0528c694 upstream.
On failure to return a pathname from ima_d_path(), a pointer to
dname is returned, which is subsequently used in the IMA measurement
list, the IMA audit records, and other audit logging. Saving the
pointer to dname for later use has the potential to race with rename.Intead of returning a pointer to dname on failure, this patch returns
a pointer to a copy of the filename.Reported-by: Al Viro
Signed-off-by: Mimi Zohar
Signed-off-by: Greg Kroah-Hartman
15 Feb, 2017
1 commit
-
commit 0c461cb727d146c9ef2d3e86214f498b78b7d125 upstream.
SELinux tries to support setting/clearing of /proc/pid/attr attributes
from the shell by ignoring terminating newlines and treating an
attribute value that begins with a NUL or newline as an attempt to
clear the attribute. However, the test for clearing attributes has
always been wrong; it has an off-by-one error, and this could further
lead to reading past the end of the allocated buffer since commit
bb646cdb12e75d82258c2f2e7746d5952d3e321a ("proc_pid_attr_write():
switch to memdup_user()"). Fix the off-by-one error.Even with this fix, setting and clearing /proc/pid/attr attributes
from the shell is not straightforward since the interface does not
support multiple write() calls (so shells that write the value and
newline separately will set and then immediately clear the attribute,
requiring use of echo -n to set the attribute), whereas trying to use
echo -n "" to clear the attribute causes the shell to skip the
write() call altogether since POSIX says that a zero-length write
causes no side effects. Thus, one must use echo -n to set and echo
without -n to clear, as in the following example:
$ echo -n unconfined_u:object_r:user_home_t:s0 > /proc/$$/attr/fscreate
$ cat /proc/$$/attr/fscreate
unconfined_u:object_r:user_home_t:s0
$ echo "" > /proc/$$/attr/fscreate
$ cat /proc/$$/attr/fscreateNote the use of /proc/$$ rather than /proc/self, as otherwise
the cat command will read its own attribute value, not that of the shell.There are no users of this facility to my knowledge; possibly we
should just get rid of it.UPDATE: Upon further investigation it appears that a local process
with the process:setfscreate permission can cause a kernel panic as a
result of this bug. This patch fixes CVE-2017-2618.Signed-off-by: Stephen Smalley
[PM: added the update about CVE-2017-2618 to the commit description]
Signed-off-by: Paul Moore
Signed-off-by: Greg Kroah-HartmanSigned-off-by: James Morris
12 Jan, 2017
1 commit
-
commit 9a11a18902bc3b904353063763d06480620245a6 upstream.
When the "policy" securityfs file is opened for read, it is opened as a
sequential file. However, when it is eventually released, there is no
cleanup for the sequential file, therefore some memory is leaked.This patch adds a call to seq_release() in ima_release_policy() to clean up
the memory when the file is opened for read.Fixes: 80eae209d63a IMA: allow reading back the current policy
Reported-by: Colin Ian King
Signed-off-by: Eric Richter
Tested-by: Colin Ian King
Signed-off-by: Mimi Zohar
Signed-off-by: Greg Kroah-Hartman
21 Nov, 2016
1 commit
-
After a policy replacement, the task cred may be out of date and need
to be updated. However change_hat is using the stale profiles from
the out of date cred resulting in either: a stale profile being applied
or, incorrect failure when searching for a hat profile as it has been
migrated to the new parent profile.Fixes: 01e2b670aa898a39259bc85c78e3d74820f4d3b6 (failure to find hat)
Fixes: 898127c34ec03291c86f4ff3856d79e9e18952bc (stale policy being applied)
Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1000287
Cc: stable@vger.kernel.org
Signed-off-by: John Johansen
Signed-off-by: James Morris
27 Oct, 2016
1 commit
-
Since BIG_KEYS can't be compiled as module it requires one of the "stdrng"
providers to be compiled into kernel. Otherwise big_key_crypto_init() fails
on crypto_alloc_rng step and next dereference of big_key_skcipher (e.g. in
big_key_preparse()) results in a NULL pointer dereference.Fixes: 13100a72f40f5748a04017e0ab3df4cf27c809ef ('Security: Keys: Big keys stored encrypted')
Signed-off-by: Artem Savkov
Signed-off-by: David Howells
cc: Stephan Mueller
cc: Kirill Marinushkin
cc: stable@vger.kernel.org
Signed-off-by: James Morris
