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| author | Rolf Eike Beer <eike@sf-mail.de> | 2018-05-13 10:57:31 (GMT) |
|---|---|---|
| committer | Serhiy Storchaka <storchaka@gmail.com> | 2018-05-13 10:57:31 (GMT) |
| commit | 1e2ec8a996daec65d8d5a3d43b66a9909c6d0653 (patch) | |
| tree | df22f6c057afff4a95edf1d2b795fe47e33ec531 /Python | |
| parent | 7ec8f28656ea9d84048e9b5655375c6a74a59f53 (diff) | |
| download | cpython-1e2ec8a996daec65d8d5a3d43b66a9909c6d0653.zip cpython-1e2ec8a996daec65d8d5a3d43b66a9909c6d0653.tar.gz cpython-1e2ec8a996daec65d8d5a3d43b66a9909c6d0653.tar.bz2 | |
bpo-28055: Fix unaligned accesses in siphash24(). (GH-6123)
The hash implementation casts the input pointer to uint64_t* and directly reads
from this, which may cause unaligned accesses. Use memcpy() instead so this code
will not crash with SIGBUS on sparc.
https://bugs.gentoo.org/show_bug.cgi?id=636400
Diffstat (limited to 'Python')
| -rw-r--r-- | Python/pyhash.c | 26 |
1 files changed, 13 insertions, 13 deletions
diff --git a/Python/pyhash.c b/Python/pyhash.c index 9e6e594..6fc12fd 100644 --- a/Python/pyhash.c +++ b/Python/pyhash.c @@ -366,7 +366,7 @@ static PyHash_FuncDef PyHash_Func = {fnv, "fnv", 8 * SIZEOF_PY_HASH_T, static uint64_t siphash24(uint64_t k0, uint64_t k1, const void *src, Py_ssize_t src_sz) { uint64_t b = (uint64_t)src_sz << 56; - const uint64_t *in = (uint64_t*)src; + const uint8_t *in = (uint8_t*)src; uint64_t v0 = k0 ^ 0x736f6d6570736575ULL; uint64_t v1 = k1 ^ 0x646f72616e646f6dULL; @@ -375,12 +375,13 @@ siphash24(uint64_t k0, uint64_t k1, const void *src, Py_ssize_t src_sz) { uint64_t t; uint8_t *pt; - uint8_t *m; while (src_sz >= 8) { - uint64_t mi = _le64toh(*in); - in += 1; - src_sz -= 8; + uint64_t mi; + memcpy(&mi, in, sizeof(mi)); + mi = _le64toh(mi); + in += sizeof(mi); + src_sz -= sizeof(mi); v3 ^= mi; DOUBLE_ROUND(v0,v1,v2,v3); v0 ^= mi; @@ -388,15 +389,14 @@ siphash24(uint64_t k0, uint64_t k1, const void *src, Py_ssize_t src_sz) { t = 0; pt = (uint8_t *)&t; - m = (uint8_t *)in; switch (src_sz) { - case 7: pt[6] = m[6]; /* fall through */ - case 6: pt[5] = m[5]; /* fall through */ - case 5: pt[4] = m[4]; /* fall through */ - case 4: memcpy(pt, m, sizeof(uint32_t)); break; - case 3: pt[2] = m[2]; /* fall through */ - case 2: pt[1] = m[1]; /* fall through */ - case 1: pt[0] = m[0]; /* fall through */ + case 7: pt[6] = in[6]; /* fall through */ + case 6: pt[5] = in[5]; /* fall through */ + case 5: pt[4] = in[4]; /* fall through */ + case 4: memcpy(pt, in, sizeof(uint32_t)); break; + case 3: pt[2] = in[2]; /* fall through */ + case 2: pt[1] = in[1]; /* fall through */ + case 1: pt[0] = in[0]; /* fall through */ } b |= _le64toh(t); |