Pull crypto fixes from Herbert Xu:
"This push fixes the following issues:
- buffer overread in RSA
- potential use after free in algif_aead.
- error path null pointer dereference in af_alg
- forbid combinations such as hmac(hmac(sha3)) which may crash
- crash in salsa20 due to incorrect API usage"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: salsa20 - fix blkcipher_walk API usage
crypto: hmac - require that the underlying hash algorithm is unkeyed
crypto: af_alg - fix NULL pointer dereference in
crypto: algif_aead - fix reference counting of null skcipher
crypto: rsa - fix buffer overread when stripping leading zeroes
->pkey_algo used to be an enum, but was changed to a string by commit
4e8ae72a75 ("X.509: Make algo identifiers text instead of enum"). But
two comparisons were not updated. Fix them to use strcmp().
This bug broke signature verification in certain configurations,
depending on whether the string constants were deduplicated or not.
Fixes: 4e8ae72a75 ("X.509: Make algo identifiers text instead of enum")
Cc: <stable@vger.kernel.org> # v4.6+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Use crypto_shash_digest() instead of crypto_shash_init() followed by
crypto_shash_finup(). (For simplicity only; they are equivalent.)
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
In public_key_verify_signature(), if akcipher_request_alloc() fails, we
return -ENOMEM. But that error code was set 25 lines above, and by
accident someone could easily insert new code in between that assigns to
'ret', which would introduce a signature verification bypass. Make the
code clearer by moving the -ENOMEM down to where it is used.
Additionally, the callers of public_key_verify_signature() only consider
a negative return value to be an error. This means that if any positive
return value is accidentally introduced deeper in the call stack (e.g.
'return EBADMSG' instead of 'return -EBADMSG' somewhere in RSA),
signature verification will be bypassed. Make things more robust by
having public_key_verify_signature() warn about positive errors and
translate them into -EINVAL.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Use crypto_shash_digest() instead of crypto_shash_init() followed by
crypto_shash_finup(). (For simplicity only; they are equivalent.)
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
pkcs7_validate_trust_one() used 'x509->next == x509' to identify a
self-signed certificate. That's wrong; ->next is simply the link in the
linked list of certificates in the PKCS#7 message. It should be
checking ->signer instead. Fix it.
Fortunately this didn't actually matter because when we re-visited
'x509' on the next iteration via 'x509->signer', it was already seen and
not verified, so we returned -ENOKEY anyway.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
If pkcs7_check_authattrs() returns an error code, we should pass that
error code on, rather than using ENOMEM.
Fixes: 99db443506 ("PKCS#7: Appropriately restrict authenticated attributes and content type")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Adding a specially crafted X.509 certificate whose subjectPublicKey
ASN.1 value is zero-length caused x509_extract_key_data() to set the
public key size to SIZE_MAX, as it subtracted the nonexistent BIT STRING
metadata byte. Then, x509_cert_parse() called kmemdup() with that bogus
size, triggering the WARN_ON_ONCE() in kmalloc_slab().
This appears to be harmless, but it still must be fixed since WARNs are
never supposed to be user-triggerable.
Fix it by updating x509_cert_parse() to validate that the value has a
BIT STRING metadata byte, and that the byte is 0 which indicates that
the number of bits in the bitstring is a multiple of 8.
It would be nice to handle the metadata byte in asn1_ber_decoder()
instead. But that would be tricky because in the general case a BIT
STRING could be implicitly tagged, and/or could legitimately have a
length that is not a whole number of bytes.
Here was the WARN (cleaned up slightly):
WARNING: CPU: 1 PID: 202 at mm/slab_common.c:971 kmalloc_slab+0x5d/0x70 mm/slab_common.c:971
Modules linked in:
CPU: 1 PID: 202 Comm: keyctl Tainted: G B 4.14.0-09238-g1d3b78bbc6e9 #26
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-20171110_100015-anatol 04/01/2014
task: ffff880033014180 task.stack: ffff8800305c8000
Call Trace:
__do_kmalloc mm/slab.c:3706 [inline]
__kmalloc_track_caller+0x22/0x2e0 mm/slab.c:3726
kmemdup+0x17/0x40 mm/util.c:118
kmemdup include/linux/string.h:414 [inline]
x509_cert_parse+0x2cb/0x620 crypto/asymmetric_keys/x509_cert_parser.c:106
x509_key_preparse+0x61/0x750 crypto/asymmetric_keys/x509_public_key.c:174
asymmetric_key_preparse+0xa4/0x150 crypto/asymmetric_keys/asymmetric_type.c:388
key_create_or_update+0x4d4/0x10a0 security/keys/key.c:850
SYSC_add_key security/keys/keyctl.c:122 [inline]
SyS_add_key+0xe8/0x290 security/keys/keyctl.c:62
entry_SYSCALL_64_fastpath+0x1f/0x96
Fixes: 42d5ec27f8 ("X.509: Add an ASN.1 decoder")
Cc: <stable@vger.kernel.org> # v3.7+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
When asked to encrypt or decrypt 0 bytes, both the generic and x86
implementations of Salsa20 crash in blkcipher_walk_done(), either when
doing 'kfree(walk->buffer)' or 'free_page((unsigned long)walk->page)',
because walk->buffer and walk->page have not been initialized.
The bug is that Salsa20 is calling blkcipher_walk_done() even when
nothing is in 'walk.nbytes'. But blkcipher_walk_done() is only meant to
be called when a nonzero number of bytes have been provided.
The broken code is part of an optimization that tries to make only one
call to salsa20_encrypt_bytes() to process inputs that are not evenly
divisible by 64 bytes. To fix the bug, just remove this "optimization"
and use the blkcipher_walk API the same way all the other users do.
Reproducer:
#include <linux/if_alg.h>
#include <sys/socket.h>
#include <unistd.h>
int main()
{
int algfd, reqfd;
struct sockaddr_alg addr = {
.salg_type = "skcipher",
.salg_name = "salsa20",
};
char key[16] = { 0 };
algfd = socket(AF_ALG, SOCK_SEQPACKET, 0);
bind(algfd, (void *)&addr, sizeof(addr));
reqfd = accept(algfd, 0, 0);
setsockopt(algfd, SOL_ALG, ALG_SET_KEY, key, sizeof(key));
read(reqfd, key, sizeof(key));
}
Reported-by: syzbot <syzkaller@googlegroups.com>
Fixes: eb6f13eb9f ("[CRYPTO] salsa20_generic: Fix multi-page processing")
Cc: <stable@vger.kernel.org> # v2.6.25+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Because the HMAC template didn't check that its underlying hash
algorithm is unkeyed, trying to use "hmac(hmac(sha3-512-generic))"
through AF_ALG or through KEYCTL_DH_COMPUTE resulted in the inner HMAC
being used without having been keyed, resulting in sha3_update() being
called without sha3_init(), causing a stack buffer overflow.
This is a very old bug, but it seems to have only started causing real
problems when SHA-3 support was added (requires CONFIG_CRYPTO_SHA3)
because the innermost hash's state is ->import()ed from a zeroed buffer,
and it just so happens that other hash algorithms are fine with that,
but SHA-3 is not. However, there could be arch or hardware-dependent
hash algorithms also affected; I couldn't test everything.
Fix the bug by introducing a function crypto_shash_alg_has_setkey()
which tests whether a shash algorithm is keyed. Then update the HMAC
template to require that its underlying hash algorithm is unkeyed.
Here is a reproducer:
#include <linux/if_alg.h>
#include <sys/socket.h>
int main()
{
int algfd;
struct sockaddr_alg addr = {
.salg_type = "hash",
.salg_name = "hmac(hmac(sha3-512-generic))",
};
char key[4096] = { 0 };
algfd = socket(AF_ALG, SOCK_SEQPACKET, 0);
bind(algfd, (const struct sockaddr *)&addr, sizeof(addr));
setsockopt(algfd, SOL_ALG, ALG_SET_KEY, key, sizeof(key));
}
Here was the KASAN report from syzbot:
BUG: KASAN: stack-out-of-bounds in memcpy include/linux/string.h:341 [inline]
BUG: KASAN: stack-out-of-bounds in sha3_update+0xdf/0x2e0 crypto/sha3_generic.c:161
Write of size 4096 at addr ffff8801cca07c40 by task syzkaller076574/3044
CPU: 1 PID: 3044 Comm: syzkaller076574 Not tainted 4.14.0-mm1+ #25
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x257 lib/dump_stack.c:53
print_address_description+0x73/0x250 mm/kasan/report.c:252
kasan_report_error mm/kasan/report.c:351 [inline]
kasan_report+0x25b/0x340 mm/kasan/report.c:409
check_memory_region_inline mm/kasan/kasan.c:260 [inline]
check_memory_region+0x137/0x190 mm/kasan/kasan.c:267
memcpy+0x37/0x50 mm/kasan/kasan.c:303
memcpy include/linux/string.h:341 [inline]
sha3_update+0xdf/0x2e0 crypto/sha3_generic.c:161
crypto_shash_update+0xcb/0x220 crypto/shash.c:109
shash_finup_unaligned+0x2a/0x60 crypto/shash.c:151
crypto_shash_finup+0xc4/0x120 crypto/shash.c:165
hmac_finup+0x182/0x330 crypto/hmac.c:152
crypto_shash_finup+0xc4/0x120 crypto/shash.c:165
shash_digest_unaligned+0x9e/0xd0 crypto/shash.c:172
crypto_shash_digest+0xc4/0x120 crypto/shash.c:186
hmac_setkey+0x36a/0x690 crypto/hmac.c:66
crypto_shash_setkey+0xad/0x190 crypto/shash.c:64
shash_async_setkey+0x47/0x60 crypto/shash.c:207
crypto_ahash_setkey+0xaf/0x180 crypto/ahash.c:200
hash_setkey+0x40/0x90 crypto/algif_hash.c:446
alg_setkey crypto/af_alg.c:221 [inline]
alg_setsockopt+0x2a1/0x350 crypto/af_alg.c:254
SYSC_setsockopt net/socket.c:1851 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1830
entry_SYSCALL_64_fastpath+0x1f/0x96
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
af_alg_free_areq_sgls()
If allocating the ->tsgl member of 'struct af_alg_async_req' failed,
during cleanup we dereferenced the NULL ->tsgl pointer in
af_alg_free_areq_sgls(), because ->tsgl_entries was nonzero.
Fix it by only freeing the ->tsgl list if it is non-NULL.
This affected both algif_skcipher and algif_aead.
Fixes: e870456d8e ("crypto: algif_skcipher - overhaul memory management")
Fixes: d887c52d6a ("crypto: algif_aead - overhaul memory management")
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: <stable@vger.kernel.org> # v4.14+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
In the AEAD interface for AF_ALG, the reference to the "null skcipher"
held by each tfm was being dropped in the wrong place -- when each
af_alg_ctx was freed instead of when the aead_tfm was freed. As
discovered by syzkaller, a specially crafted program could use this to
cause the null skcipher to be freed while it is still in use.
Fix it by dropping the reference in the right place.
Fixes: 72548b093e ("crypto: algif_aead - copy AAD from src to dst")
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: <stable@vger.kernel.org> # v4.14+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
In rsa_get_n(), if the buffer contained all 0's and "FIPS mode" is
enabled, we would read one byte past the end of the buffer while
scanning the leading zeroes. Fix it by checking 'n_sz' before '!*ptr'.
This bug was reachable by adding a specially crafted key of type
"asymmetric" (requires CONFIG_RSA and CONFIG_X509_CERTIFICATE_PARSER).
KASAN report:
BUG: KASAN: slab-out-of-bounds in rsa_get_n+0x19e/0x1d0 crypto/rsa_helper.c:33
Read of size 1 at addr ffff88003501a708 by task keyctl/196
CPU: 1 PID: 196 Comm: keyctl Not tainted 4.14.0-09238-g1d3b78bbc6e9 #26
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-20171110_100015-anatol 04/01/2014
Call Trace:
rsa_get_n+0x19e/0x1d0 crypto/rsa_helper.c:33
asn1_ber_decoder+0x82a/0x1fd0 lib/asn1_decoder.c:328
rsa_set_pub_key+0xd3/0x320 crypto/rsa.c:278
crypto_akcipher_set_pub_key ./include/crypto/akcipher.h:364 [inline]
pkcs1pad_set_pub_key+0xae/0x200 crypto/rsa-pkcs1pad.c:117
crypto_akcipher_set_pub_key ./include/crypto/akcipher.h:364 [inline]
public_key_verify_signature+0x270/0x9d0 crypto/asymmetric_keys/public_key.c:106
x509_check_for_self_signed+0x2ea/0x480 crypto/asymmetric_keys/x509_public_key.c:141
x509_cert_parse+0x46a/0x620 crypto/asymmetric_keys/x509_cert_parser.c:129
x509_key_preparse+0x61/0x750 crypto/asymmetric_keys/x509_public_key.c:174
asymmetric_key_preparse+0xa4/0x150 crypto/asymmetric_keys/asymmetric_type.c:388
key_create_or_update+0x4d4/0x10a0 security/keys/key.c:850
SYSC_add_key security/keys/keyctl.c:122 [inline]
SyS_add_key+0xe8/0x290 security/keys/keyctl.c:62
entry_SYSCALL_64_fastpath+0x1f/0x96
Allocated by task 196:
__do_kmalloc mm/slab.c:3711 [inline]
__kmalloc_track_caller+0x118/0x2e0 mm/slab.c:3726
kmemdup+0x17/0x40 mm/util.c:118
kmemdup ./include/linux/string.h:414 [inline]
x509_cert_parse+0x2cb/0x620 crypto/asymmetric_keys/x509_cert_parser.c:106
x509_key_preparse+0x61/0x750 crypto/asymmetric_keys/x509_public_key.c:174
asymmetric_key_preparse+0xa4/0x150 crypto/asymmetric_keys/asymmetric_type.c:388
key_create_or_update+0x4d4/0x10a0 security/keys/key.c:850
SYSC_add_key security/keys/keyctl.c:122 [inline]
SyS_add_key+0xe8/0x290 security/keys/keyctl.c:62
entry_SYSCALL_64_fastpath+0x1f/0x96
Fixes: 5a7de97309 ("crypto: rsa - return raw integers for the ASN.1 parser")
Cc: <stable@vger.kernel.org> # v4.8+
Cc: Tudor Ambarus <tudor-dan.ambarus@nxp.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The skcipher_walk_aead_common function calls scatterwalk_copychunks on
the input and output walks to skip the associated data. If the AD end
at an SG list entry boundary, then after these calls the walks will
still be pointing to the end of the skipped region.
These offsets are later checked for alignment in skcipher_walk_next,
so the skcipher_walk may detect the alignment incorrectly.
This patch fixes it by calling scatterwalk_done after the copychunks
calls to ensure that the offsets refer to the right SG list entry.
Fixes: b286d8b1a6 ("crypto: skcipher - Add skcipher walk interface")
Cc: <stable@vger.kernel.org>
Signed-off-by: Ondrej Mosnacek <omosnacek@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The code paths protected by the socket-lock do not use or modify the
socket in a non-atomic fashion. The actions pertaining the socket do not
even need to be handled as an atomic operation. Thus, the socket-lock
can be safely ignored.
This fixes a bug regarding scheduling in atomic as the callback function
may be invoked in interrupt context.
In addition, the sock_hold is moved before the AIO encrypt/decrypt
operation to ensure that the socket is always present. This avoids a
tiny race window where the socket is unprotected and yet used by the AIO
operation.
Finally, the release of resources for a crypto operation is moved into a
common function of af_alg_free_resources.
Cc: <stable@vger.kernel.org>
Fixes: e870456d8e ("crypto: algif_skcipher - overhaul memory management")
Fixes: d887c52d6a ("crypto: algif_aead - overhaul memory management")
Reported-by: Romain Izard <romain.izard.pro@gmail.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Tested-by: Romain Izard <romain.izard.pro@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The TX SGL may contain SGL entries that are assigned a NULL page. This
may happen if a multi-stage AIO operation is performed where the data
for each stage is pointed to by one SGL entry. Upon completion of that
stage, af_alg_pull_tsgl will assign NULL to the SGL entry.
The NULL cipher used to copy the AAD from TX SGL to the destination
buffer, however, cannot handle the case where the SGL starts with an SGL
entry having a NULL page. Thus, the code needs to advance the start
pointer into the SGL to the first non-NULL entry.
This fixes a crash visible on Intel x86 32 bit using the libkcapi test
suite.
Cc: <stable@vger.kernel.org>
Fixes: 72548b093e ("crypto: algif_aead - copy AAD from src to dst")
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Set the module licence to prevent the kernel from being tainted if loaded
as a module.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Pull crypto updates from Herbert Xu:
"Here is the crypto update for 4.15:
API:
- Disambiguate EBUSY when queueing crypto request by adding ENOSPC.
This change touches code outside the crypto API.
- Reset settings when empty string is written to rng_current.
Algorithms:
- Add OSCCA SM3 secure hash.
Drivers:
- Remove old mv_cesa driver (replaced by marvell/cesa).
- Enable rfc3686/ecb/cfb/ofb AES in crypto4xx.
- Add ccm/gcm AES in crypto4xx.
- Add support for BCM7278 in iproc-rng200.
- Add hash support on Exynos in s5p-sss.
- Fix fallback-induced error in vmx.
- Fix output IV in atmel-aes.
- Fix empty GCM hash in mediatek.
Others:
- Fix DoS potential in lib/mpi.
- Fix potential out-of-order issues with padata"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (162 commits)
lib/mpi: call cond_resched() from mpi_powm() loop
crypto: stm32/hash - Fix return issue on update
crypto: dh - Remove pointless checks for NULL 'p' and 'g'
crypto: qat - Clean up error handling in qat_dh_set_secret()
crypto: dh - Don't permit 'key' or 'g' size longer than 'p'
crypto: dh - Don't permit 'p' to be 0
crypto: dh - Fix double free of ctx->p
hwrng: iproc-rng200 - Add support for BCM7278
dt-bindings: rng: Document BCM7278 RNG200 compatible
crypto: chcr - Replace _manual_ swap with swap macro
crypto: marvell - Add a NULL entry at the end of mv_cesa_plat_id_table[]
hwrng: virtio - Virtio RNG devices need to be re-registered after suspend/resume
crypto: atmel - remove empty functions
crypto: ecdh - remove empty exit()
MAINTAINERS: update maintainer for qat
crypto: caam - remove unused param of ctx_map_to_sec4_sg()
crypto: caam - remove unneeded edesc zeroization
crypto: atmel-aes - Reset the controller before each use
crypto: atmel-aes - properly set IV after {en,de}crypt
hwrng: core - Reset user selected rng by writing "" to rng_current
...
Neither 'p' nor 'g' can be NULL, as they were unpacked using
crypto_dh_decode_key(). And it makes no sense for them to be optional.
So remove the NULL checks that were copy-and-pasted into both modules.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The "qat-dh" DH implementation assumes that 'key' and 'g' can be copied
into a buffer with size 'p_size'. However it was never checked that
that was actually the case, which most likely allowed users to cause a
buffer underflow via KEYCTL_DH_COMPUTE.
Fix this by updating crypto_dh_decode_key() to verify this precondition
for all DH implementations.
Fixes: c9839143eb ("crypto: qat - Add DH support")
Cc: <stable@vger.kernel.org> # v4.8+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Bart Van Assche
Linus Torvalds
Eric Biggers
Ondrej Mosnáček
Stephan Mueller
James Morris
Levin, Alexander (Sasha Levin)
David Howells