Mercurial > hg
diff mercurial/bitmanipulation.h @ 38303:1fb2510cf8c8
bitmanipulation: fix undefined behavior in bit shift in getbe32
OSS-Fuzz caught this in its ubsan mode[0]. I'm not worried about a
security issue here because in practice this should work out the way
we naively expected, we're just making things explicit to the
compiler with the casts.
0: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=8876
Differential Revision: https://phab.mercurial-scm.org/D3729
| author | Augie Fackler <augie@google.com> |
|---|---|
| date | Wed, 13 Jun 2018 10:24:44 -0400 |
| parents | ce77b0563228 |
| children | eed42f1c22d6 |
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--- a/mercurial/bitmanipulation.h Wed Jun 13 21:58:42 2018 +0900 +++ b/mercurial/bitmanipulation.h Wed Jun 13 10:24:44 2018 -0400 @@ -9,7 +9,8 @@ { const unsigned char *d = (const unsigned char *)c; - return ((d[0] << 24) | (d[1] << 16) | (d[2] << 8) | (d[3])); + return ((((uint32_t)d[0]) << 24) | (((uint32_t)d[1]) << 16) | + (((uint32_t)d[2]) << 8) | (d[3])); } static inline int16_t getbeint16(const char *c)