user/sven/linux.git/crypto, branch v3.16.67

crypto: authenc - fix parsing key with misaligned rta_len

2019-05-02T20:41:18Z

commit 8f9c469348487844328e162db57112f7d347c49f upstream. Keys for "authenc" AEADs are formatted as an rtattr containing a 4-byte 'enckeylen', followed by an authentication key and an encryption key. crypto_authenc_extractkeys() parses the key to find the inner keys. However, it fails to consider the case where the rtattr's payload is longer than 4 bytes but not 4-byte aligned, and where the key ends before the next 4-byte aligned boundary. In this case, 'keylen -= RTA_ALIGN(rta->rta_len);' underflows to a value near UINT_MAX. This causes a buffer overread and crash during crypto_ahash_setkey(). Fix it by restricting the rtattr payload to the expected size. Reproducer using AF_ALG: #include #include #include int main() { int fd; struct sockaddr_alg addr = { .salg_type = "aead", .salg_name = "authenc(hmac(sha256),cbc(aes))", }; struct { struct rtattr attr; __be32 enckeylen; char keys[1]; } __attribute__((packed)) key = { .attr.rta_len = sizeof(key), .attr.rta_type = 1 /* CRYPTO_AUTHENC_KEYA_PARAM */, }; fd = socket(AF_ALG, SOCK_SEQPACKET, 0); bind(fd, (void *)&addr, sizeof(addr)); setsockopt(fd, SOL_ALG, ALG_SET_KEY, &key, sizeof(key)); } It caused: BUG: unable to handle kernel paging request at ffff88007ffdc000 PGD 2e01067 P4D 2e01067 PUD 2e04067 PMD 2e05067 PTE 0 Oops: 0000 [#1] SMP CPU: 0 PID: 883 Comm: authenc Not tainted 4.20.0-rc1-00108-g00c9fe37a7f27 #13 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-20181126_142135-anatol 04/01/2014 RIP: 0010:sha256_ni_transform+0xb3/0x330 arch/x86/crypto/sha256_ni_asm.S:155 [...] Call Trace: sha256_ni_finup+0x10/0x20 arch/x86/crypto/sha256_ssse3_glue.c:321 crypto_shash_finup+0x1a/0x30 crypto/shash.c:178 shash_digest_unaligned+0x45/0x60 crypto/shash.c:186 crypto_shash_digest+0x24/0x40 crypto/shash.c:202 hmac_setkey+0x135/0x1e0 crypto/hmac.c:66 crypto_shash_setkey+0x2b/0xb0 crypto/shash.c:66 shash_async_setkey+0x10/0x20 crypto/shash.c:223 crypto_ahash_setkey+0x2d/0xa0 crypto/ahash.c:202 crypto_authenc_setkey+0x68/0x100 crypto/authenc.c:96 crypto_aead_setkey+0x2a/0xc0 crypto/aead.c:62 aead_setkey+0xc/0x10 crypto/algif_aead.c:526 alg_setkey crypto/af_alg.c:223 [inline] alg_setsockopt+0xfe/0x130 crypto/af_alg.c:256 __sys_setsockopt+0x6d/0xd0 net/socket.c:1902 __do_sys_setsockopt net/socket.c:1913 [inline] __se_sys_setsockopt net/socket.c:1910 [inline] __x64_sys_setsockopt+0x1f/0x30 net/socket.c:1910 do_syscall_64+0x4a/0x180 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Fixes: e236d4a89a2f ("[CRYPTO] authenc: Move enckeylen into key itself") Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Ben Hutchings

crypto: user - support incremental algorithm dumps

2019-04-04T15:13:49Z

commit 0ac6b8fb23c724b015d9ca70a89126e8d1563166 upstream. CRYPTO_MSG_GETALG in NLM_F_DUMP mode sometimes doesn't return all registered crypto algorithms, because it doesn't support incremental dumps. crypto_dump_report() only permits itself to be called once, yet the netlink subsystem allocates at most ~64 KiB for the skb being dumped to. Thus only the first recvmsg() returns data, and it may only include a subset of the crypto algorithms even if the user buffer passed to recvmsg() is large enough to hold all of them. Fix this by using one of the arguments in the netlink_callback structure to keep track of the current position in the algorithm list. Then userspace can do multiple recvmsg() on the socket after sending the dump request. This is the way netlink dumps work elsewhere in the kernel; it's unclear why this was different (probably just an oversight). Also fix an integer overflow when calculating the dump buffer size hint. Fixes: a38f7907b926 ("crypto: Add userspace configuration API") Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings

pcrypt: use format specifier in kobject_add

2019-04-04T15:13:40Z

commit b1e3874c75ab15288f573b3532e507c37e8e7656 upstream. Passing string 'name' as the format specifier is potentially hazardous because name could (although very unlikely to) have a format specifier embedded in it causing issues when parsing the non-existent arguments to these. Follow best practice by using the "%s" format string for the string 'name'. Cleans up clang warning: crypto/pcrypt.c:397:40: warning: format string is not a string literal (potentially insecure) [-Wformat-security] Fixes: a3fb1e330dd2 ("pcrypt: Added sysfs interface to pcrypt") Signed-off-by: Colin Ian King Signed-off-by: Herbert Xu Signed-off-by: Ben Hutchings

crypto: lrw - Fix out-of bounds access on counter overflow

2019-02-11T17:53:22Z

commit fbe1a850b3b1522e9fc22319ccbbcd2ab05328d2 upstream. When the LRW block counter overflows, the current implementation returns 128 as the index to the precomputed multiplication table, which has 128 entries. This patch fixes it to return the correct value (127). Fixes: 64470f1b8510 ("[CRYPTO] lrw: Liskov Rivest Wagner, a tweakable narrow block cipher mode") Reported-by: Eric Biggers Signed-off-by: Ondrej Mosnacek Signed-off-by: Herbert Xu Signed-off-by: Ben Hutchings

crypto: ablkcipher - fix crash flushing dcache in error path

2018-12-16T22:08:34Z

commit 318abdfbe708aaaa652c79fb500e9bd60521f9dc upstream. Like the skcipher_walk and blkcipher_walk cases: scatterwalk_done() is only meant to be called after a nonzero number of bytes have been processed, since scatterwalk_pagedone() will flush the dcache of the *previous* page. But in the error case of ablkcipher_walk_done(), e.g. if the input wasn't an integer number of blocks, scatterwalk_done() was actually called after advancing 0 bytes. This caused a crash ("BUG: unable to handle kernel paging request") during '!PageSlab(page)' on architectures like arm and arm64 that define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE, provided that the input was page-aligned as in that case walk->offset == 0. Fix it by reorganizing ablkcipher_walk_done() to skip the scatterwalk_advance() and scatterwalk_done() if an error has occurred. Reported-by: Liu Chao Fixes: bf06099db18a ("crypto: skcipher - Add ablkcipher_walk interfaces") Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Ben Hutchings

crypto: blkcipher - fix crash flushing dcache in error path

2018-12-16T22:08:34Z

commit 0868def3e4100591e7a1fdbf3eed1439cc8f7ca3 upstream. Like the skcipher_walk case: scatterwalk_done() is only meant to be called after a nonzero number of bytes have been processed, since scatterwalk_pagedone() will flush the dcache of the *previous* page. But in the error case of blkcipher_walk_done(), e.g. if the input wasn't an integer number of blocks, scatterwalk_done() was actually called after advancing 0 bytes. This caused a crash ("BUG: unable to handle kernel paging request") during '!PageSlab(page)' on architectures like arm and arm64 that define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE, provided that the input was page-aligned as in that case walk->offset == 0. Fix it by reorganizing blkcipher_walk_done() to skip the scatterwalk_advance() and scatterwalk_done() if an error has occurred. This bug was found by syzkaller fuzzing. Reproducer, assuming ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE: #include #include #include int main() { struct sockaddr_alg addr = { .salg_type = "skcipher", .salg_name = "ecb(aes-generic)", }; char buffer[4096] __attribute__((aligned(4096))) = { 0 }; int fd; fd = socket(AF_ALG, SOCK_SEQPACKET, 0); bind(fd, (void *)&addr, sizeof(addr)); setsockopt(fd, SOL_ALG, ALG_SET_KEY, buffer, 16); fd = accept(fd, NULL, NULL); write(fd, buffer, 15); read(fd, buffer, 15); } Reported-by: Liu Chao Fixes: 5cde0af2a982 ("[CRYPTO] cipher: Added block cipher type") Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Ben Hutchings

crypto: vmac - separate tfm and request context

2018-12-16T22:08:08Z

commit bb29648102335586e9a66289a1d98a0cb392b6e5 upstream. syzbot reported a crash in vmac_final() when multiple threads concurrently use the same "vmac(aes)" transform through AF_ALG. The bug is pretty fundamental: the VMAC template doesn't separate per-request state from per-tfm (per-key) state like the other hash algorithms do, but rather stores it all in the tfm context. That's wrong. Also, vmac_final() incorrectly zeroes most of the state including the derived keys and cached pseudorandom pad. Therefore, only the first VMAC invocation with a given key calculates the correct digest. Fix these bugs by splitting the per-tfm state from the per-request state and using the proper init/update/final sequencing for requests. Reproducer for the crash: #include #include #include int main() { int fd; struct sockaddr_alg addr = { .salg_type = "hash", .salg_name = "vmac(aes)", }; char buf[256] = { 0 }; fd = socket(AF_ALG, SOCK_SEQPACKET, 0); bind(fd, (void *)&addr, sizeof(addr)); setsockopt(fd, SOL_ALG, ALG_SET_KEY, buf, 16); fork(); fd = accept(fd, NULL, NULL); for (;;) write(fd, buf, 256); } The immediate cause of the crash is that vmac_ctx_t.partial_size exceeds VMAC_NHBYTES, causing vmac_final() to memset() a negative length. Reported-by: syzbot+264bca3a6e8d645550d3@syzkaller.appspotmail.com Fixes: f1939f7c5645 ("crypto: vmac - New hash algorithm for intel_txt support") Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Ben Hutchings

crypto: memzero_explicit - make sure to clear out sensitive data

2018-12-16T22:08:08Z

commit 7185ad2672a7d50bc384de0e38d90b75d99f3d82 upstream. Recently, in commit 13aa93c70e71 ("random: add and use memzero_explicit() for clearing data"), we have found that GCC may optimize some memset() cases away when it detects a stack variable is not being used anymore and going out of scope. This can happen, for example, in cases when we are clearing out sensitive information such as keying material or any e.g. intermediate results from crypto computations, etc. With the help of Coccinelle, we can figure out and fix such occurences in the crypto subsytem as well. Julia Lawall provided the following Coccinelle program: @@ type T; identifier x; @@ T x; ... when exists when any -memset +memzero_explicit (&x, -0, ...) ... when != x when strict @@ type T; identifier x; @@ T x[...]; ... when exists when any -memset +memzero_explicit (x, -0, ...) ... when != x when strict Therefore, make use of the drop-in replacement memzero_explicit() for exactly such cases instead of using memset(). Signed-off-by: Daniel Borkmann Cc: Julia Lawall Cc: Herbert Xu Cc: Theodore Ts'o Cc: Hannes Frederic Sowa Acked-by: Hannes Frederic Sowa Acked-by: Herbert Xu Signed-off-by: Theodore Ts'o Signed-off-by: Ben Hutchings

crypto: vmac - require a block cipher with 128-bit block size

2018-12-16T22:08:07Z

commit 73bf20ef3df262026c3470241ae4ac8196943ffa upstream. The VMAC template assumes the block cipher has a 128-bit block size, but it failed to check for that. Thus it was possible to instantiate it using a 64-bit block size cipher, e.g. "vmac(cast5)", causing uninitialized memory to be used. Add the needed check when instantiating the template. Fixes: f1939f7c5645 ("crypto: vmac - New hash algorithm for intel_txt support") Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Ben Hutchings

X.509: unpack RSA signatureValue field from BIT STRING

2018-11-20T18:05:27Z

commit b65c32ec5a942ab3ada93a048089a938918aba7f upstream. The signatureValue field of a X.509 certificate is encoded as a BIT STRING. For RSA signatures this BIT STRING is of so-called primitive subtype, which contains a u8 prefix indicating a count of unused bits in the encoding. We have to strip this prefix from signature data, just as we already do for key data in x509_extract_key_data() function. This wasn't noticed earlier because this prefix byte is zero for RSA key sizes divisible by 8. Since BIT STRING is a big-endian encoding adding zero prefixes has no bearing on its value. The signature length, however was incorrect, which is a problem for RSA implementations that need it to be exactly correct (like AMD CCP). Signed-off-by: Maciej S. Szmigiero Fixes: c26fd69fa009 ("X.509: Add a crypto key parser for binary (DER) X.509 certificates") Signed-off-by: James Morris [bwh: Backported to 3.16: - x509_certificate::sig is a structure, not a pointer - public_key_signature::pkey_algo is an enumeration type, not a string] Signed-off-by: Ben Hutchings