From 05973dc3bbc1aca9b3c8347de6879ed72147ab3b Mon Sep 17 00:00:00 2001 From: Natanael Copa Date: Thu, 8 Sep 2016 19:07:31 +0200 Subject: [PATCH 18/18] use dynamic buffer for getmntent overlayfs may have fairly long lines so we use getline to allocate a buffer dynamically. The buffer will be allocated on first use, expand as needed, but will never be free'ed. Downstream bug: http://bugs.alpinelinux.org/issues/5703 Signed-off-by: Natanael Copa --- src/misc/mntent.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/src/misc/mntent.c b/src/misc/mntent.c index a16d652..eabb820 100644 --- a/src/misc/mntent.c +++ b/src/misc/mntent.c @@ -3,6 +3,11 @@ #include #include +static char *internal_buf; +static size_t internal_bufsize; + +#define SENTINEL (char *)&internal_buf + FILE *setmntent(const char *name, const char *mode) { return fopen(name, mode); @@ -16,13 +21,18 @@ int endmntent(FILE *f) struct mntent *getmntent_r(FILE *f, struct mntent *mnt, char *linebuf, int buflen) { - int cnt, n[8]; + int cnt, n[8], use_internal = (linebuf == SENTINEL); mnt->mnt_freq = 0; mnt->mnt_passno = 0; do { - fgets(linebuf, buflen, f); + if (use_internal) { + getline(&internal_buf, &internal_bufsize, f); + linebuf = internal_buf; + } else { + fgets(linebuf, buflen, f); + } if (feof(f) || ferror(f)) return 0; if (!strchr(linebuf, '\n')) { fscanf(f, "%*[^\n]%*[\n]"); @@ -49,9 +59,8 @@ struct mntent *getmntent_r(FILE *f, struct mntent *mnt, char *linebuf, int bufle struct mntent *getmntent(FILE *f) { - static char linebuf[256]; static struct mntent mnt; - return getmntent_r(f, &mnt, linebuf, sizeof linebuf); + return getmntent_r(f, &mnt, SENTINEL, 0); } int addmntent(FILE *f, const struct mntent *mnt) -- 2.10.1