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FIX proposal for a crash that happens because of some misuse of const_cast<> #1920

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FIX proposal for a crash that happens because of some misuse of const_cast<> #1920

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f196006
FIX proposal for a crash that happens when feeding ACE::sendv_n_i and
Nibelheims Sep 8, 2022
738003b
Merge branch 'master' into const_cast_issue
jwillemsen Sep 14, 2022
ae097a4
Merge branch 'master' into const_cast_issue
jwillemsen Feb 1, 2025
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120 changes: 111 additions & 9 deletions ACE/ace/ACE.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1765,7 +1765,13 @@ ACE::sendv_n_i (ACE_HANDLE handle,
size_t &bytes_transferred = bt == 0 ? temp : *bt;
bytes_transferred = 0;

iovec *iov = const_cast<iovec *> (i);
const iovec *iov = i;
// as per its prototype, this function shall not modify i, even in case of
// partial send, when it is required to update iov->base
// in that case, this local copy will be used instead
// NOTE: the performance penalty of memory allocation only occurs if
// required
iovec *shadow_iovec = nullptr;

for (int s = 0;
s < iovcnt;
Expand Down Expand Up @@ -1807,13 +1813,41 @@ ACE::sendv_n_i (ACE_HANDLE handle,

if (n != 0)
{
if (shadow_iovec == nullptr)
{
# ifdef ACE_HAS_ALLOC_HOOKS
ACE_ALLOCATOR_RETURN (shadow_iovec, (iovec *)
ACE_Allocator::instance ()->malloc (iovcnt *
sizeof (iovec)),
-1);
# else
ACE_NEW_RETURN (shadow_iovec,
iovec[iovcnt],
-1);
# endif /* ACE_HAS_ALLOC_HOOKS */
ACE_OS::memcpy(shadow_iovec, iov, iovcnt * sizeof(iovec));
// from now on, shadow_iovec is the backend data used by iov
iov = shadow_iovec;
}

char *base = reinterpret_cast<char *> (iov[s].iov_base);
iov[s].iov_base = base + n;
// updating the value requires a pointer to non-const, so directly
// rely on shadow_iovec
shadow_iovec[s].iov_base = base + n;
// This blind cast is safe because n < iov_len, after above loop.
iov[s].iov_len = iov[s].iov_len - static_cast<u_long> (n);
shadow_iovec[s].iov_len = shadow_iovec[s].iov_len - static_cast<u_long> (n);
}
}

if (shadow_iovec != nullptr)
{
# ifdef ACE_HAS_ALLOC_HOOKS
ACE_Allocator::instance ()->free (shadow_iovec);
# else
delete [] shadow_iovec;
# endif /* ACE_HAS_ALLOC_HOOKS */
}

return ACE_Utils::truncate_cast<ssize_t> (bytes_transferred);
}

Expand All @@ -1833,7 +1867,13 @@ ACE::sendv_n_i (ACE_HANDLE handle,
int val = 0;
ACE::record_and_set_non_blocking_mode (handle, val);

iovec *iov = const_cast<iovec *> (i);
const iovec *iov = i;
// as per its prototype, this function shall not modify i, even in case of
// partial send, when it is required to update iov->base
// in that case, this local copy will be used instead
// NOTE: the performance penalty of memory allocation only occurs if
// required
iovec *shadow_iovec = nullptr;

for (int s = 0;
s < iovcnt;
Expand Down Expand Up @@ -1879,13 +1919,41 @@ ACE::sendv_n_i (ACE_HANDLE handle,

if (n != 0)
{
if (shadow_iovec == nullptr)
{
# ifdef ACE_HAS_ALLOC_HOOKS
ACE_ALLOCATOR_RETURN (shadow_iovec, (iovec *)
ACE_Allocator::instance ()->malloc (iovcnt *
sizeof (iovec)),
-1);
# else
ACE_NEW_RETURN (shadow_iovec,
iovec[iovcnt],
-1);
# endif /* ACE_HAS_ALLOC_HOOKS */
ACE_OS::memcpy(shadow_iovec, iov, iovcnt * sizeof(iovec));
// from now on, shadow_iovec is the backend data used by iov
iov = shadow_iovec;
}

char *base = reinterpret_cast<char *> (iov[s].iov_base);
iov[s].iov_base = base + n;
// updating the value requires a pointer to non-const, so directly
// rely on shadow_iovec
shadow_iovec[s].iov_base = base + n;
// This blind cast is safe because n < iov_len, after above loop.
iov[s].iov_len = iov[s].iov_len - static_cast<u_long> (n);
shadow_iovec[s].iov_len = shadow_iovec[s].iov_len - static_cast<u_long> (n);
}
}

if (shadow_iovec != nullptr)
{
# ifdef ACE_HAS_ALLOC_HOOKS
ACE_Allocator::instance ()->free (shadow_iovec);
# else
delete [] shadow_iovec;
# endif /* ACE_HAS_ALLOC_HOOKS */
}

ACE::restore_non_blocking_mode (handle, val);

if (error)
Expand Down Expand Up @@ -2142,7 +2210,13 @@ ACE::writev_n (ACE_HANDLE handle,
size_t &bytes_transferred = bt == 0 ? temp : *bt;
bytes_transferred = 0;

iovec *iov = const_cast<iovec *> (i);
const iovec *iov = i;
// as per its prototype, this function shall not modify i, even in case of
// partial send, when it is required to update iov->base
// in that case, this local copy will be used instead
// NOTE: the performance penalty of memory allocation only occurs if
// required
iovec *shadow_iovec = nullptr;

for (int s = 0;
s < iovcnt;
Expand All @@ -2165,13 +2239,41 @@ ACE::writev_n (ACE_HANDLE handle,

if (n != 0)
{
if (shadow_iovec == nullptr)
{
# ifdef ACE_HAS_ALLOC_HOOKS
ACE_ALLOCATOR_RETURN (shadow_iovec, (iovec *)
ACE_Allocator::instance ()->malloc (iovcnt *
sizeof (iovec)),
-1);
# else
ACE_NEW_RETURN (shadow_iovec,
iovec[iovcnt],
-1);
# endif /* ACE_HAS_ALLOC_HOOKS */
ACE_OS::memcpy(shadow_iovec, iov, iovcnt * sizeof(iovec));
// from now on, shadow_iovec is the backend data used by iov
iov = shadow_iovec;
}

char *base = reinterpret_cast<char *> (iov[s].iov_base);
iov[s].iov_base = base + n;
// updating the value requires a pointer to non-const, so directly
// rely on shadow_iovec
shadow_iovec[s].iov_base = base + n;
// This blind cast is safe because n < iov_len, after above loop.
iov[s].iov_len = iov[s].iov_len - static_cast<u_long> (n);
shadow_iovec[s].iov_len = shadow_iovec[s].iov_len - static_cast<u_long> (n);
}
}

if (shadow_iovec != nullptr)
{
# ifdef ACE_HAS_ALLOC_HOOKS
ACE_Allocator::instance ()->free (shadow_iovec);
# else
delete [] shadow_iovec;
# endif /* ACE_HAS_ALLOC_HOOKS */
}

return ACE_Utils::truncate_cast<ssize_t> (bytes_transferred);
}

Expand Down