From 94a0171d807dc94302d6505041fc58879c27f3bd Mon Sep 17 00:00:00 2001
From: Rich Felker <dalias@aerifal.cx>
Date: Sat, 16 Jul 2011 21:24:02 -0400
Subject: fix logic error in fread
fread was calling f->read without checking that the file was in
reading mode. this could:
1. crash, if f->read was a null pointer
2. cause unwanted blocking on a terminal already at eof
3. allow reading on a write-only file
---
src/stdio/fread.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
(limited to 'src')
diff --git a/src/stdio/fread.c b/src/stdio/fread.c
index 8105fe99..5c235777 100644
--- a/src/stdio/fread.c
+++ b/src/stdio/fread.c
@@ -21,14 +21,9 @@ size_t fread(void *destv, size_t size, size_t nmemb, FILE *f)
l -= k;
}
- if (!l) {
- FUNLOCK(f);
- return nmemb;
- }
-
/* Read the remainder directly */
for (; l; l-=k, dest+=k) {
- k = f->read(f, dest, l);
+ k = __toread(f) ? 0 : f->read(f, dest, l);
if (k+1<=1) {
FUNLOCK(f);
return (len-l)/size;
--
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