core,w32: Avoid recursive use of npth_unprotect.
* src/w32-estream.c (reader): Use standard free.
(writer): Ditto.
--
There are two errors: The minor one is that we allocated with calloc
but released with _gpgrt_free. The major one is the recursive use of
npth_unprotect due to the syscall_clamp mechanism:
1. Around the call to _gpgrt_w32_poll
2. By gpgrt_lock_lock on behalf of a the custom allocation handler in
the worker threads at their _gpgrt_free.
This problem was exhibited by GnuPG's dirmngr component.
GnuPG-bug-id: 3937
Signed-off-by: Werner Koch <wk@gnupg.org>
Werner Koch
6 years ago
| 299 | 299 |
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| 300 | 300 |
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| 301 | 301 |
/* Internal tracing functions. Except for TRACE_FP we use flockfile
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| 302 | |
* and funlockfile to protect their use. */
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|
302 |
* and funlockfile to protect their use.
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|
303 |
*
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|
304 |
* Warning: Take care with the trace functions - they may not use any
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|
305 |
* of our services, in particular not the syscall clamp mechanism for
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|
306 |
* reasons explained in w32-stream.c:create_reader. */
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| 303 | 307 |
static FILE *trace_fp;
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| 304 | 308 |
static int trace_save_errno;
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| 305 | 309 |
static int trace_with_errno;
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| 238 | 238 |
CloseHandle (ctx->have_space_ev);
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| 239 | 239 |
CloseHandle (ctx->thread_hd);
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| 240 | 240 |
DeleteCriticalSection (&ctx->mutex);
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| 241 | |
_gpgrt_free (ctx);
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|
241 |
free (ctx); /* Standard free! See comment in create_reader. */
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| 242 | 242 |
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| 243 | 243 |
return 0;
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| 244 | 244 |
}
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| 255 | 255 |
sec_attr.nLength = sizeof sec_attr;
|
| 256 | 256 |
sec_attr.bInheritHandle = FALSE;
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| 257 | 257 |
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|
258 |
/* The CTX must be allocated in standard system memory so that we
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|
259 |
* won't use any custom allocation handler which may use our lock
|
|
260 |
* primitives for its implementation. The problem here is that the
|
|
261 |
* syscall clamp mechanism (e.g. nPth) would be called recursively:
|
|
262 |
* 1. For example by the caller of _gpgrt_w32_poll and 2. by
|
|
263 |
* gpgrt_lock_lock on behalf of the the custom allocation and free
|
|
264 |
* functions. */
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| 258 | 265 |
ctx = calloc (1, sizeof *ctx);
|
| 259 | 266 |
if (!ctx)
|
| 260 | 267 |
{
|
|
| 541 | 548 |
CloseHandle (ctx->thread_hd);
|
| 542 | 549 |
DeleteCriticalSection (&ctx->mutex);
|
| 543 | 550 |
trace (("%p: writer is destroyed", ctx));
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| 544 | |
_gpgrt_free (ctx);
|
|
551 |
free (ctx); /* Standard free! See comment in create_writer. */
|
| 545 | 552 |
|
| 546 | 553 |
return 0;
|
| 547 | 554 |
}
|
|
| 558 | 565 |
sec_attr.nLength = sizeof sec_attr;
|
| 559 | 566 |
sec_attr.bInheritHandle = FALSE;
|
| 560 | 567 |
|
|
568 |
/* See comment at create_reader. */
|
| 561 | 569 |
ctx = calloc (1, sizeof *ctx);
|
| 562 | 570 |
if (!ctx)
|
| 563 | 571 |
{
|