fix unsynchronized access to FILE structure in fflush(0)

[musl] / src / stdio / getdelim.c

diff --git a/src/stdio/getdelim.c b/src/stdio/getdelim.c
index b7e04ac..1ccd802 100644 (file)
--- a/src/stdio/getdelim.c
+++ b/src/stdio/getdelim.c
@@ -1,8 +1,11 @@
 #include "stdio_impl.h"
+#include <string.h>
+#include <inttypes.h>
+#include <errno.h>
 
 #define MIN(a,b) ((a)<(b) ? (a) : (b))
 
-ssize_t getdelim(char **s, size_t *n, int delim, FILE *f)
+ssize_t getdelim(char **restrict s, size_t *restrict n, int delim, FILE *restrict f)
 {
        char *tmp;
        unsigned char *z;
@@ -10,29 +13,32 @@ ssize_t getdelim(char **s, size_t *n, int delim, FILE *f)
        size_t i=0;
        int c;
 
+       FLOCK(f);
+
        if (!n || !s) {
+               f->flags |= F_ERR;
+               FUNLOCK(f);
                errno = EINVAL;
                return -1;
        }
 
        if (!*s) *n=0;
 
-       FLOCK(f);
-
        for (;;) {
                z = memchr(f->rpos, delim, f->rend - f->rpos);
                k = z ? z - f->rpos + 1 : f->rend - f->rpos;
-               if (i+k >= *n) {
+               if (i+k+1 >= *n) {
                        if (k >= SIZE_MAX/2-i) goto oom;
-                       *n = i+k+2;
-                       if (*n < SIZE_MAX/4) *n *= 2;
-                       tmp = realloc(*s, *n);
+                       size_t m = i+k+2;
+                       if (!z && m < SIZE_MAX/4) m += m/2;
+                       tmp = realloc(*s, m);
                        if (!tmp) {
-                               *n = i+k+2;
-                               tmp = realloc(*s, *n);
+                               m = i+k+2;
+                               tmp = realloc(*s, m);
                                if (!tmp) goto oom;
                        }
                        *s = tmp;
+                       *n = m;
                }
                memcpy(*s+i, f->rpos, k);
                f->rpos += k;
@@ -53,6 +59,7 @@ ssize_t getdelim(char **s, size_t *n, int delim, FILE *f)
 
        return i;
 oom:
+       f->flags |= F_ERR;
        FUNLOCK(f);
        errno = ENOMEM;
        return -1;