Date: Fri, 20 Nov 2015 22:36:41 +0000 (UTC) From: Ravi Pokala <rpokala@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r291114 - head/lib/libc/gen Message-ID: <201511202236.tAKMaf06048447@repo.freebsd.org>
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Author: rpokala Date: Fri Nov 20 22:36:41 2015 New Revision: 291114 URL: https://svnweb.freebsd.org/changeset/base/291114 Log: popen() requires check for fdopen() failure Move fdopen() up near other resource allocation like malloc(); do proper deallocation on failure later on in the function. Submitted by: Ramachandra Topannavar <rtopannavar@panasas.com> Reviewed by: jilles Approved by: jhb (mentor) MFC after: 2 weeks Sponsored by: Panasas, Inc. Differential Revision: https://reviews.freebsd.org/D4126 M lib/libc/gen/popen.c Modified: head/lib/libc/gen/popen.c Modified: head/lib/libc/gen/popen.c ============================================================================== --- head/lib/libc/gen/popen.c Fri Nov 20 21:56:20 2015 (r291113) +++ head/lib/libc/gen/popen.c Fri Nov 20 22:36:41 2015 (r291114) @@ -72,6 +72,7 @@ popen(const char *command, const char *t struct pid *cur; FILE *iop; int pdes[2], pid, twoway, cloexec; + int pdes_unused_in_parent; char *argv[4]; struct pid *p; @@ -98,6 +99,20 @@ popen(const char *command, const char *t return (NULL); } + if (*type == 'r') { + iop = fdopen(pdes[0], type); + pdes_unused_in_parent = pdes[1]; + } else { + iop = fdopen(pdes[1], type); + pdes_unused_in_parent = pdes[0]; + } + if (iop == NULL) { + (void)_close(pdes[0]); + (void)_close(pdes[1]); + free(cur); + return (NULL); + } + argv[0] = "sh"; argv[1] = "-c"; argv[2] = (char *)command; @@ -107,9 +122,14 @@ popen(const char *command, const char *t switch (pid = vfork()) { case -1: /* Error. */ THREAD_UNLOCK(); - (void)_close(pdes[0]); - (void)_close(pdes[1]); + /* + * The _close() closes the unused end of pdes[], while + * the fclose() closes the used end of pdes[], *and* cleans + * up iop. + */ + (void)_close(pdes_unused_in_parent); free(cur); + (void)fclose(iop); return (NULL); /* NOTREACHED */ case 0: /* Child. */ @@ -145,14 +165,8 @@ popen(const char *command, const char *t } THREAD_UNLOCK(); - /* Parent; assume fdopen can't fail. */ - if (*type == 'r') { - iop = fdopen(pdes[0], type); - (void)_close(pdes[1]); - } else { - iop = fdopen(pdes[1], type); - (void)_close(pdes[0]); - } + /* Parent. */ + (void)_close(pdes_unused_in_parent); /* Link into list of file descriptors. */ cur->fp = iop;
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