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| author |   Rolf Eike Beer <eike@sf-mail.de> | 2018-05-13 04:40:03 -0700 |
|---|---|---|
| committer |   Michał Górny <mgorny@gentoo.org> | 2019-12-29 11:31:44 +0100 |
| commit | bb9f847eed94085a30fbf99729d227c1a604ae34 (patch) | |
| tree | 1127a9a1f9a0020087ca5e19637e8587d47bbfa8 | |
| parent | Disable nis (diff) | |
| download | cpython-gentoo-3.5.9.tar.gz cpython-gentoo-3.5.9.tar.bz2 cpython-gentoo-3.5.9.zip | |
bpo-28055: Fix unaligned accesses in siphash24(). (GH-6123)gentoo-3.5.9
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.
| -rw-r--r-- | Python/pyhash.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/Python/pyhash.c b/Python/pyhash.c index 97cb54759b6..e105c15b32c 100644 --- a/Python/pyhash.c +++ b/Python/pyhash.c @@ -372,7 +372,7 @@ siphash24(const void *src, Py_ssize_t src_sz) { PY_UINT64_T k0 = _le64toh(_Py_HashSecret.siphash.k0); PY_UINT64_T k1 = _le64toh(_Py_HashSecret.siphash.k1); PY_UINT64_T b = (PY_UINT64_T)src_sz << 56; - const PY_UINT64_T *in = (PY_UINT64_T*)src; + const PY_UINT8_T *in = (PY_UINT8_T*)src; PY_UINT64_T v0 = k0 ^ 0x736f6d6570736575ULL; PY_UINT64_T v1 = k1 ^ 0x646f72616e646f6dULL; @@ -381,12 +381,14 @@ siphash24(const void *src, Py_ssize_t src_sz) { PY_UINT64_T t; PY_UINT8_T *pt; - PY_UINT8_T *m; + const PY_UINT8_T *m; while (src_sz >= 8) { - PY_UINT64_T mi = _le64toh(*in); - in += 1; - src_sz -= 8; + PY_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; @@ -394,7 +396,7 @@ siphash24(const void *src, Py_ssize_t src_sz) { t = 0; pt = (PY_UINT8_T *)&t; - m = (PY_UINT8_T *)in; + m = in; switch (src_sz) { case 7: pt[6] = m[6]; case 6: pt[5] = m[5]; |