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2018-01-12crypto: hash - prevent using keyed hashes without setting keyEric Biggers
Currently, almost none of the keyed hash algorithms check whether a key has been set before proceeding. Some algorithms are okay with this and will effectively just use a key of all 0's or some other bogus default. However, others will severely break, as demonstrated using "hmac(sha3-512-generic)", the unkeyed use of which causes a kernel crash via a (potentially exploitable) stack buffer overflow. A while ago, this problem was solved for AF_ALG by pairing each hash transform with a 'has_key' bool. However, there are still other places in the kernel where userspace can specify an arbitrary hash algorithm by name, and the kernel uses it as unkeyed hash without checking whether it is really unkeyed. Examples of this include: - KEYCTL_DH_COMPUTE, via the KDF extension - dm-verity - dm-crypt, via the ESSIV support - dm-integrity, via the "internal hash" mode with no key given - drbd (Distributed Replicated Block Device) This bug is especially bad for KEYCTL_DH_COMPUTE as that requires no privileges to call. Fix the bug for all users by adding a flag CRYPTO_TFM_NEED_KEY to the ->crt_flags of each hash transform that indicates whether the transform still needs to be keyed or not. Then, make the hash init, import, and digest functions return -ENOKEY if the key is still needed. The new flag also replaces the 'has_key' bool which algif_hash was previously using, thereby simplifying the algif_hash implementation. 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>
2017-11-29crypto: hmac - require that the underlying hash algorithm is unkeyedEric Biggers
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>
2017-10-11crypto: shash - Fix zero-length shash ahash digest crashHerbert Xu
The shash ahash digest adaptor function may crash if given a zero-length input together with a null SG list. This is because it tries to read the SG list before looking at the length. This patch fixes it by checking the length first. Cc: <stable@vger.kernel.org> Reported-by: Stephan Müller<smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Tested-by: Stephan Müller <smueller@chronox.de>
2017-10-07crypto: shash - Fix a sleep-in-atomic bug in shash_setkey_unalignedJia-Ju Bai
The SCTP program may sleep under a spinlock, and the function call path is: sctp_generate_t3_rtx_event (acquire the spinlock) sctp_do_sm sctp_side_effects sctp_cmd_interpreter sctp_make_init_ack sctp_pack_cookie crypto_shash_setkey shash_setkey_unaligned kmalloc(GFP_KERNEL) For the same reason, the orinoco driver may sleep in interrupt handler, and the function call path is: orinoco_rx_isr_tasklet orinoco_rx orinoco_mic crypto_shash_setkey shash_setkey_unaligned kmalloc(GFP_KERNEL) To fix it, GFP_KERNEL is replaced with GFP_ATOMIC. This bug is found by my static analysis tool and my code review. Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-01-13crypto: Replaced gcc specific attributes with macros from compiler.hGideon Israel Dsouza
Continuing from this commit: 52f5684c8e1e ("kernel: use macros from compiler.h instead of __attribute__((...))") I submitted 4 total patches. They are part of task I've taken up to increase compiler portability in the kernel. I've cleaned up the subsystems under /kernel /mm /block and /security, this patch targets /crypto. There is <linux/compiler.h> which provides macros for various gcc specific constructs. Eg: __weak for __attribute__((weak)). I've cleaned all instances of gcc specific attributes with the right macros for the crypto subsystem. I had to make one additional change into compiler-gcc.h for the case when one wants to use this: __attribute__((aligned) and not specify an alignment factor. From the gcc docs, this will result in the largest alignment for that data type on the target machine so I've named the macro __aligned_largest. Please advise if another name is more appropriate. Signed-off-by: Gideon Israel Dsouza <gidisrael@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-03-17Merge branch 'linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 Pull crypto update from Herbert Xu: "Here is the crypto update for 4.6: API: - Convert remaining crypto_hash users to shash or ahash, also convert blkcipher/ablkcipher users to skcipher. - Remove crypto_hash interface. - Remove crypto_pcomp interface. - Add crypto engine for async cipher drivers. - Add akcipher documentation. - Add skcipher documentation. Algorithms: - Rename crypto/crc32 to avoid name clash with lib/crc32. - Fix bug in keywrap where we zero the wrong pointer. Drivers: - Support T5/M5, T7/M7 SPARC CPUs in n2 hwrng driver. - Add PIC32 hwrng driver. - Support BCM6368 in bcm63xx hwrng driver. - Pack structs for 32-bit compat users in qat. - Use crypto engine in omap-aes. - Add support for sama5d2x SoCs in atmel-sha. - Make atmel-sha available again. - Make sahara hashing available again. - Make ccp hashing available again. - Make sha1-mb available again. - Add support for multiple devices in ccp. - Improve DMA performance in caam. - Add hashing support to rockchip" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (116 commits) crypto: qat - remove redundant arbiter configuration crypto: ux500 - fix checks of error code returned by devm_ioremap_resource() crypto: atmel - fix checks of error code returned by devm_ioremap_resource() crypto: qat - Change the definition of icp_qat_uof_regtype hwrng: exynos - use __maybe_unused to hide pm functions crypto: ccp - Add abstraction for device-specific calls crypto: ccp - CCP versioning support crypto: ccp - Support for multiple CCPs crypto: ccp - Remove check for x86 family and model crypto: ccp - memset request context to zero during import lib/mpi: use "static inline" instead of "extern inline" lib/mpi: avoid assembler warning hwrng: bcm63xx - fix non device tree compatibility crypto: testmgr - allow rfc3686 aes-ctr variants in fips mode. crypto: qat - The AE id should be less than the maximal AE number lib/mpi: Endianness fix crypto: rockchip - add hash support for crypto engine in rk3288 crypto: xts - fix compile errors crypto: doc - add skcipher API documentation crypto: doc - update AEAD AD handling ...
2016-02-06crypto: hash - Remove crypto_hash interfaceHerbert Xu
This patch removes all traces of the crypto_hash interface, now that everyone has switched over to shash or ahash. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-01-27crypto: shash - Fix has_key settingHerbert Xu
The has_key logic is wrong for shash algorithms as they always have a setkey function. So we should instead be testing against shash_no_setkey. Fixes: a5596d633278 ("crypto: hash - Add crypto_ahash_has_setkey") Cc: stable@vger.kernel.org Reported-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Tested-by: Stephan Mueller <smueller@chronox.de>
2016-01-18crypto: hash - Add crypto_ahash_has_setkeyHerbert Xu
This patch adds a way for ahash users to determine whether a key is required by a crypto_ahash transform. Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-21crypto: shash - Use crypto_alg_extsize helperHerbert Xu
This patch replaces crypto_shash_extsize function with crypto_alg_extsize. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2014-06-07crypto: LLVMLinux: aligned-attribute.patchMark Charlebois
__attribute__((aligned)) applies the default alignment for the largest scalar type for the target ABI. gcc allows it to be applied inline to a defined type. Clang only allows it to be applied to a type definition (PR11071). Making it into 2 lines makes it more readable and works with both compilers. Author: Mark Charlebois <charlebm@gmail.com> Signed-off-by: Mark Charlebois <charlebm@gmail.com> Signed-off-by: Behan Webster <behanw@converseincode.com>
2013-02-19crypto: user - fix info leaks in report APIMathias Krause
Three errors resulting in kernel memory disclosure: 1/ The structures used for the netlink based crypto algorithm report API are located on the stack. As snprintf() does not fill the remainder of the buffer with null bytes, those stack bytes will be disclosed to users of the API. Switch to strncpy() to fix this. 2/ crypto_report_one() does not initialize all field of struct crypto_user_alg. Fix this to fix the heap info leak. 3/ For the module name we should copy only as many bytes as module_name() returns -- not as much as the destination buffer could hold. But the current code does not and therefore copies random data from behind the end of the module name, as the module name is always shorter than CRYPTO_MAX_ALG_NAME. Also switch to use strncpy() to copy the algorithm's name and driver_name. They are strings, after all. Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2012-08-01crypto: add crypto_[un]register_shashes for [un]registering multiple shash ↵Jussi Kivilinna
entries at once Add crypto_[un]register_shashes() to allow simplifying init/exit code of shash crypto modules that register multiple algorithms. Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2012-04-02crypto: Stop using NLA_PUT*().David S. Miller
These macros contain a hidden goto, and are thus extremely error prone and make code hard to audit. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-20crypto: remove the second argument of k[un]map_atomic()Cong Wang
Signed-off-by: Cong Wang <amwang@redhat.com>
2011-11-11crypto: algapi - Fix build problem with NET disabledHerbert Xu
The report functions use NLA_PUT so we need to ensure that NET is enabled. Reported-by: Luis Henriques <henrix@camandro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2011-10-21crypto: Add userspace report for shash type algorithmsSteffen Klassert
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2010-11-04crypto: hash - Fix async import on shash algorithmHerbert Xu
The function shash_async_import did not initialise the descriptor correctly prior to calling the underlying shash import function. This patch adds the required initialisation. Reported-by: Miloslav Trmac <mitr@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2010-05-19crypto: shash - Remove usage of CRYPTO_MINALIGNHerbert Xu
The macro CRYPTO_MINALIGN is not meant to be used directly. This patch replaces it with crypto_tfm_ctx_alignment. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-24crypto: shash - Test for the algorithms import function before exporting itSteffen Klassert
crypto_init_shash_ops_async() tests for setkey and not for import before exporting the algorithms import function to ahash. This patch fixes this. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-22crypto: shash - Require all algorithms to support export/importHerbert Xu
This patch provides a default export/import function for all shash algorithms. It simply copies the descriptor context as is done by sha1_generic. This in essence means that all existing shash algorithms now support export/import. This is something that will be depended upon in implementations such as hmac. Therefore all new shash and ahash implementations must support export/import. For those that cannot obtain a partial result, padlock-sha's fallback model should be used so that a partial result is always available. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-15crypto: shash - Fix async finup handling of null digestHerbert Xu
When shash_ahash_finup encounters a null request, we end up not calling the underlying final function. This patch fixes that. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-15crypto: ahash - Add unaligned handling and default operationsHerbert Xu
This patch exports the finup operation where available and adds a default finup operation for ahash. The operations final, finup and digest also will now deal with unaligned result pointers by copying it. Finally export/import operations are will now be exported too. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-14crypto: shash - Fix alignment in unaligned operationsHerbert Xu
When we encounter an unaligned pointer we are supposed to copy it to a temporary aligned location. However the temporary buffer isn't aligned properly. This patch fixes that. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-14crypto: hash - Zap unaligned buffersHerbert Xu
Some unaligned buffers on the stack weren't zapped properly which may cause secret data to be leaked. This patch fixes them by doing a zero memset. It is also possible for us to place random kernel stack contents in the digest buffer if a digest operation fails. This is fixed by only copying if the operation succeeded. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-14crypto: ahash - Remove old_ahash_algHerbert Xu
Now that all ahash implementations have been converted to the new ahash type, we can remove old_ahash_alg and its associated support. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-14crypto: ahash - Convert to new style algorithmsHerbert Xu
This patch converts crypto_ahash to the new style. The old ahash algorithm type is retained until the existing ahash implementations are also converted. All ahash users will automatically get the new crypto_ahash type. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-14crypto: api - Remove frontend argument from extsize/init_tfmHerbert Xu
As the extsize and init_tfm functions belong to the frontend the frontend argument is superfluous. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-14crypto: shash - Export async functionsHerbert Xu
This patch exports the async functions so that they can be reused by cryptd when it switches over to using shash. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-14crypto: shash - Make descsize a run-time attributeHerbert Xu
This patch changes descsize to a run-time attribute so that implementations can change it in their init functions. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-12crypto: shash - Move null setkey check to registration timeHerbert Xu
This patch moves the run-time null setkey check to shash_prepare_alg just like we did for finup/digest. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-11crypto: shash - Move finup/digest null checks to registration timeHerbert Xu
This patch moves the run-time null finup/digest checks to the shash_prepare_alg function which is run at registration time. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-11crypto: shash - Export/import hash state onlyHerbert Xu
This patch replaces the full descriptor export with an export of the partial hash state. This allows the use of a consistent export format across all implementations of a given algorithm. This is useful because a number of cases require the use of the partial hash state, e.g., PadLock can use the SHA1 hash state to get around the fact that it can only hash contiguous data chunks. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-08crypto: shash - Propagate reinit return valueHerbert Xu
This patch fixes crypto_shash_import to propagate the value returned by reinit. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-08crypto: shash - Use finup in default digestHerbert Xu
This patch simplifies the default digest function by using finup. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-08crypto: shash - Add shash_register_instanceHerbert Xu
This patch adds shash_register_instance so that shash instances can be registered without bypassing the shash checks applied to normal algorithms. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-08crypto: shash - Add shash_attr_alg2 helperHerbert Xu
This patch adds the helper shash_attr_alg2 which locates a shash algorithm based on the information in the given attribute. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-08crypto: shash - Add spawn supportHerbert Xu
This patch adds the functions needed to create and use shash spawns, i.e., to use shash algorithms in a template. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-08crypto: shash - Add shash_instanceHerbert Xu
This patch adds shash_instance and the associated alloc/free functions. This is meant to be an instance that with a shash algorithm under it. Note that the instance itself doesn't have to be shash. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-03-27crypto: shash - Fix unaligned calculation with short lengthYehuda Sadeh
When the total length is shorter than the calculated number of unaligned bytes, the call to shash->update breaks. For example, calling crc32c on unaligned buffer with length of 1 can result in a system crash. Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-02-18crypto: api - Fix crypto_alloc_tfm/create_create_tfm return conventionHerbert Xu
This is based on a report and patch by Geert Uytterhoeven. The functions crypto_alloc_tfm and create_create_tfm return a pointer that needs to be adjusted by the caller when successful and otherwise an error value. This means that the caller has to check for the error and only perform the adjustment if the pointer returned is valid. Since all callers want to make the adjustment and we know how to adjust it ourselves, it's much easier to just return adjusted pointer directly. The only caveat is that we have to return a void * instead of struct crypto_tfm *. However, this isn't that bad because both of these functions are for internal use only (by types code like shash.c, not even algorithms code). This patch also moves crypto_alloc_tfm into crypto/internal.h (crypto_create_tfm is already there) to reflect this. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-02-18crypto: shash - Remove superfluous check in init_tfmHerbert Xu
We're currently checking the frontend type in init_tfm. This is completely pointless because the fact that we're called at all means that the frontend is ours so the type must match as well. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-02-05crypto: shash - Fix module refcountAdrian-Ken Rueegsegger
Module reference counting for shash is incorrect: when a new shash transformation is created the refcount is not increased as it should. Signed-off-by: Adrian-Ken Rueegsegger <rueegsegger@swiss-it.ch> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-12-25crypto: hash - Make setkey optionalHerbert Xu
Since most cryptographic hash algorithms have no keys, this patch makes the setkey function optional for ahash and shash. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-12-25crypto: hash - Export shash through hashHerbert Xu
This patch allows shash algorithms to be used through the old hash interface. This is a transitional measure so we can convert the underlying algorithms to shash before converting the users across. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-12-25crypto: hash - Add import/export interfaceHerbert Xu
It is often useful to save the partial state of a hash function so that it can be used as a base for two or more computations. The most prominent example is HMAC where all hashes start from a base determined by the key. Having an import/export interface means that we only have to compute that base once rather than for each message. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-12-25crypto: hash - Export shash through ahashHerbert Xu
This patch allows shash algorithms to be used through the ahash interface. This is required before we can convert digest algorithms over to shash. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-12-25crypto: hash - Add shash interfaceHerbert Xu
The shash interface replaces the current synchronous hash interface. It improves over hash in two ways. Firstly shash is reentrant, meaning that the same tfm may be used by two threads simultaneously as all hashing state is stored in a local descriptor. The other enhancement is that shash no longer takes scatter list entries. This is because shash is specifically designed for synchronous algorithms and as such scatter lists are unnecessary. All existing hash users will be converted to shash once the algorithms have been completely converted. There is also a new finup function that combines update with final. This will be extended to ahash once the algorithm conversion is done. This is also the first time that an algorithm type has their own registration function. Existing algorithm types will be converted to this way in due course. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>