linux-stable.git/crypto, branch v3.18.40 Linux kernel stable tree crypto: scatterwalk - Fix test in scatterwalk_done 2016-08-22T16:23:12+00:00 Herbert Xu herbert@gondor.apana.org.au 2016-07-12T05:17:57+00:00 57eed939b9b93fab2533a27659c723d6e691e684 [ Upstream commit 5f070e81bee35f1b7bd1477bb223a873ff657803 ] When there is more data to be processed, the current test in scatterwalk_done may prevent us from calling pagedone even when we should. In particular, if we're on an SG entry spanning multiple pages where the last page is not a full page, we will incorrectly skip calling pagedone on the second last page. This patch fixes this by adding a separate test for whether we've reached the end of a page. Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> 
[ Upstream commit 5f070e81bee35f1b7bd1477bb223a873ff657803 ]

When there is more data to be processed, the current test in
scatterwalk_done may prevent us from calling pagedone even when
we should.

In particular, if we're on an SG entry spanning multiple pages
where the last page is not a full page, we will incorrectly skip
calling pagedone on the second last page.

This patch fixes this by adding a separate test for whether we've
reached the end of a page.

Cc: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
crypto: gcm - Filter out async ghash if necessary 2016-08-22T16:23:00+00:00 Herbert Xu herbert@gondor.apana.org.au 2016-06-15T14:27:05+00:00 8acc67b372ac0c3607ccd3a898ca8fd75455a8fa [ Upstream commit b30bdfa86431afbafe15284a3ad5ac19b49b88e3 ] As it is if you ask for a sync gcm you may actually end up with an async one because it does not filter out async implementations of ghash. This patch fixes this by adding the necessary filter when looking for ghash. Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> 
[ Upstream commit b30bdfa86431afbafe15284a3ad5ac19b49b88e3 ]

As it is if you ask for a sync gcm you may actually end up with
an async one because it does not filter out async implementations
of ghash.

This patch fixes this by adding the necessary filter when looking
for ghash.

Cc: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
PKCS#7: pkcs7_validate_trust(): initialize the _trusted output argument 2016-07-12T12:47:23+00:00 Nicolai Stange nicstange@gmail.com 2016-03-20T22:23:46+00:00 772935dac761d186dee3ed7e713e48ed710eff46 [ Upstream commit e54358915d0a00399c11c2c23ae1be674cba188a ] Despite what the DocBook comment to pkcs7_validate_trust() says, the *_trusted argument is never set to false. pkcs7_validate_trust() only positively sets *_trusted upon encountering a trusted PKCS#7 SignedInfo block. This is quite unfortunate since its callers, system_verify_data() for example, depend on pkcs7_validate_trust() clearing *_trusted on non-trust. Indeed, UBSAN splats when attempting to load the uninitialized local variable 'trusted' from system_verify_data() in pkcs7_validate_trust(): UBSAN: Undefined behaviour in crypto/asymmetric_keys/pkcs7_trust.c:194:14 load of value 82 is not a valid value for type '_Bool' [...] Call Trace: [<ffffffff818c4d35>] dump_stack+0xbc/0x117 [<ffffffff818c4c79>] ? _atomic_dec_and_lock+0x169/0x169 [<ffffffff8194113b>] ubsan_epilogue+0xd/0x4e [<ffffffff819419fa>] __ubsan_handle_load_invalid_value+0x111/0x158 [<ffffffff819418e9>] ? val_to_string.constprop.12+0xcf/0xcf [<ffffffff818334a4>] ? x509_request_asymmetric_key+0x114/0x370 [<ffffffff814b83f0>] ? kfree+0x220/0x370 [<ffffffff818312c2>] ? public_key_verify_signature_2+0x32/0x50 [<ffffffff81835e04>] pkcs7_validate_trust+0x524/0x5f0 [<ffffffff813c391a>] system_verify_data+0xca/0x170 [<ffffffff813c3850>] ? top_trace_array+0x9b/0x9b [<ffffffff81510b29>] ? __vfs_read+0x279/0x3d0 [<ffffffff8129372f>] mod_verify_sig+0x1ff/0x290 [...] The implication is that pkcs7_validate_trust() effectively grants trust when it really shouldn't have. Fix this by explicitly setting *_trusted to false at the very beginning of pkcs7_validate_trust(). Cc: <stable@vger.kernel.org> Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> 
[ Upstream commit e54358915d0a00399c11c2c23ae1be674cba188a ]

Despite what the DocBook comment to pkcs7_validate_trust() says, the
*_trusted argument is never set to false.

pkcs7_validate_trust() only positively sets *_trusted upon encountering
a trusted PKCS#7 SignedInfo block.

This is quite unfortunate since its callers, system_verify_data() for
example, depend on pkcs7_validate_trust() clearing *_trusted on non-trust.

Indeed, UBSAN splats when attempting to load the uninitialized local
variable 'trusted' from system_verify_data() in pkcs7_validate_trust():

  UBSAN: Undefined behaviour in crypto/asymmetric_keys/pkcs7_trust.c:194:14
  load of value 82 is not a valid value for type '_Bool'
  [...]
  Call Trace:
    [<ffffffff818c4d35>] dump_stack+0xbc/0x117
    [<ffffffff818c4c79>] ? _atomic_dec_and_lock+0x169/0x169
    [<ffffffff8194113b>] ubsan_epilogue+0xd/0x4e
    [<ffffffff819419fa>] __ubsan_handle_load_invalid_value+0x111/0x158
    [<ffffffff819418e9>] ? val_to_string.constprop.12+0xcf/0xcf
    [<ffffffff818334a4>] ? x509_request_asymmetric_key+0x114/0x370
    [<ffffffff814b83f0>] ? kfree+0x220/0x370
    [<ffffffff818312c2>] ? public_key_verify_signature_2+0x32/0x50
    [<ffffffff81835e04>] pkcs7_validate_trust+0x524/0x5f0
    [<ffffffff813c391a>] system_verify_data+0xca/0x170
    [<ffffffff813c3850>] ? top_trace_array+0x9b/0x9b
    [<ffffffff81510b29>] ? __vfs_read+0x279/0x3d0
    [<ffffffff8129372f>] mod_verify_sig+0x1ff/0x290
    [...]

The implication is that pkcs7_validate_trust() effectively grants trust
when it really shouldn't have.

Fix this by explicitly setting *_trusted to false at the very beginning
of pkcs7_validate_trust().

Cc: <stable@vger.kernel.org>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
crypto: public_key: select CRYPTO_AKCIPHER 2016-06-18T20:52:40+00:00 Arnd Bergmann arnd@arndb.de 2016-05-18T14:55:56+00:00 008656835a1bfafe37771d2ba2249a8eaeb4eab6 [ Upstream commit bad6a185b4d6f81d0ed2b6e4c16307969f160b95 ] In some rare randconfig builds, we can end up with ASYMMETRIC_PUBLIC_KEY_SUBTYPE enabled but CRYPTO_AKCIPHER disabled, which fails to link because of the reference to crypto_alloc_akcipher: crypto/built-in.o: In function `public_key_verify_signature': :(.text+0x110e4): undefined reference to `crypto_alloc_akcipher' This adds a Kconfig 'select' statement to ensure the dependency is always there. Cc: <stable@vger.kernel.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> 
[ Upstream commit bad6a185b4d6f81d0ed2b6e4c16307969f160b95 ]

In some rare randconfig builds, we can end up with
ASYMMETRIC_PUBLIC_KEY_SUBTYPE enabled but CRYPTO_AKCIPHER disabled,
which fails to link because of the reference to crypto_alloc_akcipher:

crypto/built-in.o: In function `public_key_verify_signature':
:(.text+0x110e4): undefined reference to `crypto_alloc_akcipher'

This adds a Kconfig 'select' statement to ensure the dependency
is always there.

Cc: <stable@vger.kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
crypto: hash - Fix page length clamping in hash walk 2016-05-17T21:30:20+00:00 Herbert Xu herbert@gondor.apana.org.au 2016-05-04T09:52:56+00:00 82b612eb124f25fa66a35ad8675a4320520028fa [ Upstream commit 13f4bb78cf6a312bbdec367ba3da044b09bf0e29 ] The crypto hash walk code is broken when supplied with an offset greater than or equal to PAGE_SIZE. This patch fixes it by adjusting walk->pg and walk->offset when this happens. Cc: <stable@vger.kernel.org> Reported-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> 
[ Upstream commit 13f4bb78cf6a312bbdec367ba3da044b09bf0e29 ]

The crypto hash walk code is broken when supplied with an offset
greater than or equal to PAGE_SIZE.  This patch fixes it by adjusting
walk->pg and walk->offset when this happens.

Cc: <stable@vger.kernel.org>
Reported-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
crypto: algif_skcipher - Fix race condition in skcipher_check_key 2016-04-19T11:57:03+00:00 Herbert Xu herbert@gondor.apana.org.au 2016-02-26T11:44:11+00:00 7855e916590ab8d97abcba3d0dc735bcfa55561d commit 1822793a523e5d5730b19cc21160ff1717421bc8 upstream. We need to lock the child socket in skcipher_check_key as otherwise two simultaneous calls can cause the parent socket to be freed. Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> 
    commit 1822793a523e5d5730b19cc21160ff1717421bc8 upstream.

    We need to lock the child socket in skcipher_check_key as otherwise
    two simultaneous calls can cause the parent socket to be freed.

    Cc: stable@vger.kernel.org
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
crypto: algif_skcipher - Remove custom release parent function 2016-04-19T11:57:03+00:00 Herbert Xu herbert@gondor.apana.org.au 2016-02-26T11:44:10+00:00 801492e27fb9f24b4e05bc79047301408d5a6a0d commit d7b65aee1e7b4c87922b0232eaba56a8a143a4a0 upstream. This patch removes the custom release parent function as the generic af_alg_release_parent now works for nokey sockets too. Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> 
    commit d7b65aee1e7b4c87922b0232eaba56a8a143a4a0 upstream.

    This patch removes the custom release parent function as the
    generic af_alg_release_parent now works for nokey sockets too.

    Cc: stable@vger.kernel.org
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
crypto: algif_skcipher - Add nokey compatibility path 2016-04-19T11:57:02+00:00 Herbert Xu herbert@gondor.apana.org.au 2016-02-26T11:44:09+00:00 50d7bf3d3dc47b13de6aefc397bd75ce145b9ef4 commit a0fa2d037129a9849918a92d91b79ed6c7bd2818 upstream. This patch adds a compatibility path to support old applications that do acept(2) before setkey. Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> [backported to 3.18 by Milan Broz <gmazyland@gmail.com>] Signed-off-by: Sasha Levin <sasha.levin@oracle.com> 
    commit a0fa2d037129a9849918a92d91b79ed6c7bd2818 upstream.

    This patch adds a compatibility path to support old applications
    that do acept(2) before setkey.

    Cc: stable@vger.kernel.org
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
    [backported to 3.18 by Milan Broz <gmazyland@gmail.com>]

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
crypto: algif_skcipher - Require setkey before accept(2) 2016-04-19T11:57:02+00:00 Herbert Xu herbert@gondor.apana.org.au 2016-02-26T11:44:08+00:00 1f45c38917129af49a187aae8f2ef76d098d66ca commit dd504589577d8e8e70f51f997ad487a4cb6c026f upstream. Some cipher implementations will crash if you try to use them without calling setkey first. This patch adds a check so that the accept(2) call will fail with -ENOKEY if setkey hasn't been done on the socket yet. Cc: stable@vger.kernel.org Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Tested-by: Dmitry Vyukov <dvyukov@google.com> [backported to 3.18 by Milan Broz <gmazyland@gmail.com>] Signed-off-by: Sasha Levin <sasha.levin@oracle.com> 
    commit dd504589577d8e8e70f51f997ad487a4cb6c026f upstream.

    Some cipher implementations will crash if you try to use them
    without calling setkey first.  This patch adds a check so that
    the accept(2) call will fail with -ENOKEY if setkey hasn't been
    done on the socket yet.

    Cc: stable@vger.kernel.org
    Reported-by: Dmitry Vyukov <dvyukov@google.com>
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
    Tested-by: Dmitry Vyukov <dvyukov@google.com>
    [backported to 3.18 by Milan Broz <gmazyland@gmail.com>]

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
crypto: user - lock crypto_alg_list on alg dump 2016-03-02T20:18:58+00:00 Mathias Krause minipli@googlemail.com 2016-02-01T13:27:30+00:00 6125fee1e8e1aba5e580124eb7d9d1268380de1c [ Upstream commit 63e41ebc6630f39422d87f8a4bade1e793f37a01 ] We miss to take the crypto_alg_sem semaphore when traversing the crypto_alg_list for CRYPTO_MSG_GETALG dumps. This allows a race with crypto_unregister_alg() removing algorithms from the list while we're still traversing it, thereby leading to a use-after-free as show below: [ 3482.071639] general protection fault: 0000 [#1] SMP [ 3482.075639] Modules linked in: aes_x86_64 glue_helper lrw ablk_helper cryptd gf128mul ipv6 pcspkr serio_raw virtio_net microcode virtio_pci virtio_ring virtio sr_mod cdrom [last unloaded: aesni_intel] [ 3482.075639] CPU: 1 PID: 11065 Comm: crconf Not tainted 4.3.4-grsec+ #126 [ 3482.075639] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [ 3482.075639] task: ffff88001cd41a40 ti: ffff88001cd422c8 task.ti: ffff88001cd422c8 [ 3482.075639] RIP: 0010:[<ffffffff93722bd3>] [<ffffffff93722bd3>] strncpy+0x13/0x30 [ 3482.075639] RSP: 0018:ffff88001f713b60 EFLAGS: 00010202 [ 3482.075639] RAX: ffff88001f6c4430 RBX: ffff88001f6c43a0 RCX: ffff88001f6c4430 [ 3482.075639] RDX: 0000000000000040 RSI: fefefefefefeff16 RDI: ffff88001f6c4430 [ 3482.075639] RBP: ffff88001f713b60 R08: ffff88001f6c4470 R09: ffff88001f6c4480 [ 3482.075639] R10: 0000000000000002 R11: 0000000000000246 R12: ffff88001ce2aa28 [ 3482.075639] R13: ffff880000093700 R14: ffff88001f5e4bf8 R15: 0000000000003b20 [ 3482.075639] FS: 0000033826fa2700(0000) GS:ffff88001e900000(0000) knlGS:0000000000000000 [ 3482.075639] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 3482.075639] CR2: ffffffffff600400 CR3: 00000000139ec000 CR4: 00000000001606f0 [ 3482.075639] Stack: [ 3482.075639] ffff88001f713bd8 ffffffff936ccd00 ffff88001e5c4200 ffff880000093700 [ 3482.075639] ffff88001f713bd0 ffffffff938ef4bf 0000000000000000 0000000000003b20 [ 3482.075639] ffff88001f5e4bf8 ffff88001f5e4848 0000000000000000 0000000000003b20 [ 3482.075639] Call Trace: [ 3482.075639] [<ffffffff936ccd00>] crypto_report_alg+0xc0/0x3e0 [ 3482.075639] [<ffffffff938ef4bf>] ? __alloc_skb+0x16f/0x300 [ 3482.075639] [<ffffffff936cd08a>] crypto_dump_report+0x6a/0x90 [ 3482.075639] [<ffffffff93935707>] netlink_dump+0x147/0x2e0 [ 3482.075639] [<ffffffff93935f99>] __netlink_dump_start+0x159/0x190 [ 3482.075639] [<ffffffff936ccb13>] crypto_user_rcv_msg+0xc3/0x130 [ 3482.075639] [<ffffffff936cd020>] ? crypto_report_alg+0x3e0/0x3e0 [ 3482.075639] [<ffffffff936cc4b0>] ? alg_test_crc32c+0x120/0x120 [ 3482.075639] [<ffffffff93933145>] ? __netlink_lookup+0xd5/0x120 [ 3482.075639] [<ffffffff936cca50>] ? crypto_add_alg+0x1d0/0x1d0 [ 3482.075639] [<ffffffff93938141>] netlink_rcv_skb+0xe1/0x130 [ 3482.075639] [<ffffffff936cc4f8>] crypto_netlink_rcv+0x28/0x40 [ 3482.075639] [<ffffffff939375a8>] netlink_unicast+0x108/0x180 [ 3482.075639] [<ffffffff93937c21>] netlink_sendmsg+0x541/0x770 [ 3482.075639] [<ffffffff938e31e1>] sock_sendmsg+0x21/0x40 [ 3482.075639] [<ffffffff938e4763>] SyS_sendto+0xf3/0x130 [ 3482.075639] [<ffffffff93444203>] ? bad_area_nosemaphore+0x13/0x20 [ 3482.075639] [<ffffffff93444470>] ? __do_page_fault+0x80/0x3a0 [ 3482.075639] [<ffffffff939d80cb>] entry_SYSCALL_64_fastpath+0x12/0x6e [ 3482.075639] Code: 88 4a ff 75 ed 5d 48 0f ba 2c 24 3f c3 66 66 2e 0f 1f 84 00 00 00 00 00 55 48 85 d2 48 89 f8 48 89 f9 4c 8d 04 17 48 89 e5 74 15 <0f> b6 16 80 fa 01 88 11 48 83 de ff 48 83 c1 01 4c 39 c1 75 eb [ 3482.075639] RIP [<ffffffff93722bd3>] strncpy+0x13/0x30 To trigger the race run the following loops simultaneously for a while: $ while : ; do modprobe aesni-intel; rmmod aesni-intel; done $ while : ; do crconf show all > /dev/null; done Fix the race by taking the crypto_alg_sem read lock, thereby preventing crypto_unregister_alg() from modifying the algorithm list during the dump. This bug has been detected by the PaX memory sanitize feature. Cc: stable@vger.kernel.org Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: PaX Team <pageexec@freemail.hu> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> 
[ Upstream commit 63e41ebc6630f39422d87f8a4bade1e793f37a01 ]

We miss to take the crypto_alg_sem semaphore when traversing the
crypto_alg_list for CRYPTO_MSG_GETALG dumps. This allows a race with
crypto_unregister_alg() removing algorithms from the list while we're
still traversing it, thereby leading to a use-after-free as show below:

[ 3482.071639] general protection fault: 0000 [#1] SMP
[ 3482.075639] Modules linked in: aes_x86_64 glue_helper lrw ablk_helper cryptd gf128mul ipv6 pcspkr serio_raw virtio_net microcode virtio_pci virtio_ring virtio sr_mod cdrom [last unloaded: aesni_intel]
[ 3482.075639] CPU: 1 PID: 11065 Comm: crconf Not tainted 4.3.4-grsec+ #126
[ 3482.075639] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
[ 3482.075639] task: ffff88001cd41a40 ti: ffff88001cd422c8 task.ti: ffff88001cd422c8
[ 3482.075639] RIP: 0010:[<ffffffff93722bd3>]  [<ffffffff93722bd3>] strncpy+0x13/0x30
[ 3482.075639] RSP: 0018:ffff88001f713b60  EFLAGS: 00010202
[ 3482.075639] RAX: ffff88001f6c4430 RBX: ffff88001f6c43a0 RCX: ffff88001f6c4430
[ 3482.075639] RDX: 0000000000000040 RSI: fefefefefefeff16 RDI: ffff88001f6c4430
[ 3482.075639] RBP: ffff88001f713b60 R08: ffff88001f6c4470 R09: ffff88001f6c4480
[ 3482.075639] R10: 0000000000000002 R11: 0000000000000246 R12: ffff88001ce2aa28
[ 3482.075639] R13: ffff880000093700 R14: ffff88001f5e4bf8 R15: 0000000000003b20
[ 3482.075639] FS:  0000033826fa2700(0000) GS:ffff88001e900000(0000) knlGS:0000000000000000
[ 3482.075639] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 3482.075639] CR2: ffffffffff600400 CR3: 00000000139ec000 CR4: 00000000001606f0
[ 3482.075639] Stack:
[ 3482.075639]  ffff88001f713bd8 ffffffff936ccd00 ffff88001e5c4200 ffff880000093700
[ 3482.075639]  ffff88001f713bd0 ffffffff938ef4bf 0000000000000000 0000000000003b20
[ 3482.075639]  ffff88001f5e4bf8 ffff88001f5e4848 0000000000000000 0000000000003b20
[ 3482.075639] Call Trace:
[ 3482.075639]  [<ffffffff936ccd00>] crypto_report_alg+0xc0/0x3e0
[ 3482.075639]  [<ffffffff938ef4bf>] ? __alloc_skb+0x16f/0x300
[ 3482.075639]  [<ffffffff936cd08a>] crypto_dump_report+0x6a/0x90
[ 3482.075639]  [<ffffffff93935707>] netlink_dump+0x147/0x2e0
[ 3482.075639]  [<ffffffff93935f99>] __netlink_dump_start+0x159/0x190
[ 3482.075639]  [<ffffffff936ccb13>] crypto_user_rcv_msg+0xc3/0x130
[ 3482.075639]  [<ffffffff936cd020>] ? crypto_report_alg+0x3e0/0x3e0
[ 3482.075639]  [<ffffffff936cc4b0>] ? alg_test_crc32c+0x120/0x120
[ 3482.075639]  [<ffffffff93933145>] ? __netlink_lookup+0xd5/0x120
[ 3482.075639]  [<ffffffff936cca50>] ? crypto_add_alg+0x1d0/0x1d0
[ 3482.075639]  [<ffffffff93938141>] netlink_rcv_skb+0xe1/0x130
[ 3482.075639]  [<ffffffff936cc4f8>] crypto_netlink_rcv+0x28/0x40
[ 3482.075639]  [<ffffffff939375a8>] netlink_unicast+0x108/0x180
[ 3482.075639]  [<ffffffff93937c21>] netlink_sendmsg+0x541/0x770
[ 3482.075639]  [<ffffffff938e31e1>] sock_sendmsg+0x21/0x40
[ 3482.075639]  [<ffffffff938e4763>] SyS_sendto+0xf3/0x130
[ 3482.075639]  [<ffffffff93444203>] ? bad_area_nosemaphore+0x13/0x20
[ 3482.075639]  [<ffffffff93444470>] ? __do_page_fault+0x80/0x3a0
[ 3482.075639]  [<ffffffff939d80cb>] entry_SYSCALL_64_fastpath+0x12/0x6e
[ 3482.075639] Code: 88 4a ff 75 ed 5d 48 0f ba 2c 24 3f c3 66 66 2e 0f 1f 84 00 00 00 00 00 55 48 85 d2 48 89 f8 48 89 f9 4c 8d 04 17 48 89 e5 74 15 <0f> b6 16 80 fa 01 88 11 48 83 de ff 48 83 c1 01 4c 39 c1 75 eb
[ 3482.075639] RIP  [<ffffffff93722bd3>] strncpy+0x13/0x30

To trigger the race run the following loops simultaneously for a while:
  $ while : ; do modprobe aesni-intel; rmmod aesni-intel; done
  $ while : ; do crconf show all > /dev/null; done

Fix the race by taking the crypto_alg_sem read lock, thereby preventing
crypto_unregister_alg() from modifying the algorithm list during the
dump.

This bug has been detected by the PaX memory sanitize feature.

Cc: stable@vger.kernel.org
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: PaX Team <pageexec@freemail.hu>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>