diff options
| author | Takashi Yano <takashi.yano@nifty.ne.jp> | 2023-08-02 08:31:53 +0300 |
|---|---|---|
| committer | Takashi Yano <takashi.yano@nifty.ne.jp> | 2023-08-02 09:00:56 +0300 |
| commit | 5ac83ea47a7acd704c2fb0dff1edb7f51f081e52 (patch) | |
| tree | 38cf506b29b68137622361e112d62fcdd7661d47 /newlib | |
| parent | dedbbd74d0a8f3b7dfae6188321703a47bb8a2b3 (diff) | |
newlib: Fix memory leak regarding gdtoa-based _ldtoa_r().
After the commit a4705d387f78, printf() for floating-point values
causes a memory leak. The legacy _ldtoa_r() assumed the char pointer
returned will be free'ed by Bfree(). However, gdtoa-based _ldtoa_r()
returns the pointer returned by gdtoa() which should be free'ed by
freedtoa(). Due to this issue, the caller of _ldtoa_r() fails to free
the allocated char buffer. This is the cause of the said memory leak.
https://cygwin.com/pipermail/cygwin/2023-July/254054.html
This patch makes rv_alloc()/freedtoa() allocate/free the buffer in
a compatible way with legacy _ldtoa_r().
Fixes: a4705d387f78 ("ldtoa: Import gdtoa from OpenBSD.")
Reported-by: natan_b <natan_b@libero.it>
Reviewed-by: Corinna Vinschen <corinna@vinschen.de>
Signed-off-by: Takashi Yano <takashi.yano@nifty.ne.jp>
Diffstat (limited to 'newlib')
| -rw-r--r-- | newlib/libc/stdlib/gdtoa-dmisc.c | 23 | ||||
| -rw-r--r-- | newlib/libc/stdlib/gdtoa-ldtoa.c | 4 |
2 files changed, 14 insertions, 13 deletions
diff --git a/newlib/libc/stdlib/gdtoa-dmisc.c b/newlib/libc/stdlib/gdtoa-dmisc.c index 332023dae..f330f8ae7 100644 --- a/newlib/libc/stdlib/gdtoa-dmisc.c +++ b/newlib/libc/stdlib/gdtoa-dmisc.c @@ -46,26 +46,28 @@ rv_alloc(ptr, i) struct _reent *ptr, int i; rv_alloc(struct _reent *ptr, int i) #endif { - int j, k, *r; + int j; + char *r; + /* Allocate buffer in a compatible way with legacy _ldtoa_r(). */ j = sizeof(ULong); - for(k = 0; - sizeof(Bigint) - sizeof(ULong) - sizeof(int) + j <= i; - j <<= 1) - k++; - r = (int*)Balloc(ptr, k); + for (_REENT_MP_RESULT_K (ptr) = 0; + sizeof (Bigint) - sizeof (ULong) + j <= i; j <<= 1) + _REENT_MP_RESULT_K (ptr)++; + _REENT_MP_RESULT (ptr) = eBalloc (ptr, _REENT_MP_RESULT_K (ptr)); + r = (char *) _REENT_MP_RESULT (ptr); + if (r == NULL) return ( #ifndef MULTIPLE_THREADS dtoa_result = #endif NULL); - *r = k; return #ifndef MULTIPLE_THREADS dtoa_result = #endif - (char *)(r+1); + r; } char * @@ -100,8 +102,9 @@ freedtoa(ptr, s) struct _reent *ptr, char *s; freedtoa(struct _reent *ptr, char *s) #endif { - Bigint *b = (Bigint *)((int *)s - 1); - b->_maxwds = 1 << (b->_k = *(int*)b); + /* Free buffer allocated in a compatible way with legacy _ldtoa_r(). */ + Bigint *b = (Bigint *)s; + b->_maxwds = 1 << (b->_k = _REENT_MP_RESULT_K (ptr)); Bfree(ptr, b); #ifndef MULTIPLE_THREADS if (s == dtoa_result) diff --git a/newlib/libc/stdlib/gdtoa-ldtoa.c b/newlib/libc/stdlib/gdtoa-ldtoa.c index 14b99042c..09ba6b34b 100644 --- a/newlib/libc/stdlib/gdtoa-ldtoa.c +++ b/newlib/libc/stdlib/gdtoa-ldtoa.c @@ -72,9 +72,7 @@ _ldtoa_r(struct _reent *ptr, /* reentrancy addition to use mprec storage pool */ if (_REENT_MP_RESULT (ptr)) { - _REENT_MP_RESULT (ptr)->_k = _REENT_MP_RESULT_K (ptr); - _REENT_MP_RESULT (ptr)->_maxwds = 1 << _REENT_MP_RESULT_K (ptr); - Bfree (ptr, _REENT_MP_RESULT (ptr)); + freedtoa (ptr, _REENT_MP_RESULT (ptr)); _REENT_MP_RESULT (ptr) = 0; } |