From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 7868) id 6EA183858281; Wed, 2 Aug 2023 13:00:08 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 6EA183858281 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1690981208; bh=aOzalrKcqqc9fey6W4BquFaJcVMzSLGnUI0Fl3bzIDE=; h=From:To:Subject:Date:From; b=LgVVMg4t4vkHDYzsNkPOLchJpwfCvOeTb8P3nTfEPSp7ktuqsAY7j0/OZWk8qQN0I LyXlrDoEDdOddpg9JQzSxez5TPExw/yQlB9tJ7HiiqZm25+A+EEM8wo6zOWoVCBqDK pox37yzzKePxILwuvkcmVfAf25flK7g1ofDz1w+Y= Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable From: Takashi Yano To: cygwin-cvs@sourceware.org, newlib-cvs@sourceware.org Subject: [newlib-cygwin/cygwin-3_4-branch] newlib: Fix memory leak regarding gdtoa-based _ldtoa_r(). X-Act-Checkin: newlib-cygwin X-Git-Author: Takashi Yano X-Git-Refname: refs/heads/cygwin-3_4-branch X-Git-Oldrev: 60ae342e8f22ad2d91eec7278629b9b53a2edded X-Git-Newrev: 841b7307d60b4b21418df93190d8134262324eb7 Message-Id: <20230802130008.6EA183858281@sourceware.org> Date: Wed, 2 Aug 2023 13:00:08 +0000 (GMT) List-Id: https://sourceware.org/git/gitweb.cgi?p=3Dnewlib-cygwin.git;h=3D841b7307d60= b4b21418df93190d8134262324eb7 commit 841b7307d60b4b21418df93190d8134262324eb7 Author: Takashi Yano Date: Wed Aug 2 14:31:53 2023 +0900 newlib: Fix memory leak regarding gdtoa-based _ldtoa_r(). =20 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 =20 This patch makes rv_alloc()/freedtoa() allocate/free the buffer in a compatible way with legacy _ldtoa_r(). =20 Fixes: a4705d387f78 ("ldtoa: Import gdtoa from OpenBSD.") Reported-by: natan_b Reviewed-by: Corinna Vinschen Signed-off-by: Takashi Yano Diff: --- newlib/libc/stdlib/gdtoa-dmisc.c | 23 +++++++++++++---------- newlib/libc/stdlib/gdtoa-ldtoa.c | 4 +--- winsup/cygwin/release/3.4.8 | 3 +++ 3 files changed, 17 insertions(+), 13 deletions(-) diff --git a/newlib/libc/stdlib/gdtoa-dmisc.c b/newlib/libc/stdlib/gdtoa-dm= isc.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; =20 + /* Allocate buffer in a compatible way with legacy _ldtoa_r(). */ j =3D sizeof(ULong); - for(k =3D 0; - sizeof(Bigint) - sizeof(ULong) - sizeof(int) + j <=3D i; - j <<=3D 1) - k++; - r =3D (int*)Balloc(ptr, k); + for (_REENT_MP_RESULT_K (ptr) =3D 0; + sizeof (Bigint) - sizeof (ULong) + j <=3D i; j <<=3D 1) + _REENT_MP_RESULT_K (ptr)++; + _REENT_MP_RESULT (ptr) =3D eBalloc (ptr, _REENT_MP_RESULT_K (ptr)); + r =3D (char *) _REENT_MP_RESULT (ptr); + if (r =3D=3D NULL) return ( #ifndef MULTIPLE_THREADS dtoa_result =3D #endif NULL); - *r =3D k; return #ifndef MULTIPLE_THREADS dtoa_result =3D #endif - (char *)(r+1); + r; } =20 char * @@ -100,8 +102,9 @@ freedtoa(ptr, s) struct _reent *ptr, char *s; freedtoa(struct _reent *ptr, char *s) #endif { - Bigint *b =3D (Bigint *)((int *)s - 1); - b->_maxwds =3D 1 << (b->_k =3D *(int*)b); + /* Free buffer allocated in a compatible way with legacy _ldtoa_r(). */ + Bigint *b =3D (Bigint *)s; + b->_maxwds =3D 1 << (b->_k =3D _REENT_MP_RESULT_K (ptr)); Bfree(ptr, b); #ifndef MULTIPLE_THREADS if (s =3D=3D dtoa_result) diff --git a/newlib/libc/stdlib/gdtoa-ldtoa.c b/newlib/libc/stdlib/gdtoa-ld= toa.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, =20 /* reentrancy addition to use mprec storage pool */ if (_REENT_MP_RESULT (ptr)) { - _REENT_MP_RESULT (ptr)->_k =3D _REENT_MP_RESULT_K (ptr); - _REENT_MP_RESULT (ptr)->_maxwds =3D 1 << _REENT_MP_RESULT_K (ptr); - Bfree (ptr, _REENT_MP_RESULT (ptr)); + freedtoa (ptr, _REENT_MP_RESULT (ptr)); _REENT_MP_RESULT (ptr) =3D 0; } =20 diff --git a/winsup/cygwin/release/3.4.8 b/winsup/cygwin/release/3.4.8 index d37272eef..448831c65 100644 --- a/winsup/cygwin/release/3.4.8 +++ b/winsup/cygwin/release/3.4.8 @@ -14,3 +14,6 @@ Bug Fixes - Rename internal macros _NL_CTYPE_OUTDIGITSx_MB/WC to GLibc compatible _NL_CTYPE_OUTDIGITx_MB/WC. Addresses: https://cygwin.com/pipermail/cygwin-developers/2023-July/0126= 37.html + +- Fix memory leak in printf() regarding gdtoa-based _ldtoa_r(). + Addresses: https://cygwin.com/pipermail/cygwin/2023-July/254054.html