diff options
Diffstat (limited to 'lib/libc/gen/popen.c')
| -rw-r--r-- | lib/libc/gen/popen.c | 25 |
1 files changed, 12 insertions, 13 deletions
diff --git a/lib/libc/gen/popen.c b/lib/libc/gen/popen.c index b0597c8..e54bb5c 100644 --- a/lib/libc/gen/popen.c +++ b/lib/libc/gen/popen.c @@ -90,7 +90,7 @@ popen(command, type) (type[1] && (type[1] != 'e' || type[2]))) return (NULL); } - if ((cloexec ? pipe2(pdes, O_CLOEXEC) : pipe(pdes)) < 0) + if (pipe2(pdes, O_CLOEXEC) < 0) return (NULL); if ((cur = malloc(sizeof(struct pid))) == NULL) { @@ -123,29 +123,20 @@ popen(command, type) * the compiler is free to corrupt all the local * variables. */ - if (!cloexec) - (void)_close(pdes[0]); if (pdes[1] != STDOUT_FILENO) { (void)_dup2(pdes[1], STDOUT_FILENO); - if (!cloexec) - (void)_close(pdes[1]); if (twoway) (void)_dup2(STDOUT_FILENO, STDIN_FILENO); } else if (twoway && (pdes[1] != STDIN_FILENO)) { (void)_dup2(pdes[1], STDIN_FILENO); - if (cloexec) - (void)_fcntl(pdes[1], F_SETFD, 0); - } else if (cloexec) + (void)_fcntl(pdes[1], F_SETFD, 0); + } else (void)_fcntl(pdes[1], F_SETFD, 0); } else { if (pdes[0] != STDIN_FILENO) { (void)_dup2(pdes[0], STDIN_FILENO); - if (!cloexec) - (void)_close(pdes[0]); - } else if (cloexec) + } else (void)_fcntl(pdes[0], F_SETFD, 0); - if (!cloexec) - (void)_close(pdes[1]); } SLIST_FOREACH(p, &pidlist, next) (void)_close(fileno(p->fp)); @@ -171,6 +162,14 @@ popen(command, type) SLIST_INSERT_HEAD(&pidlist, cur, next); THREAD_UNLOCK(); + /* + * To guard against undesired fd passing with concurrent calls, + * only clear the close-on-exec flag after linking the file into + * the list which will cause an explicit close. + */ + if (!cloexec) + (void)_fcntl(*type == 'r' ? pdes[0] : pdes[1], F_SETFD, 0); + return (iop); } |
