path: root/src
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authorRich Felker <>2014-04-07 01:36:40 -0400
committerRich Felker <>2014-04-07 01:36:40 -0400
commit109048e031f39fbb370211fde44ababf6c04c8fb (patch)
tree7974ab603f1c7e6aa3bc081202ac530b7fa5ad82 /src
parent7e8b0761e57266f40b8d51105b84c50e504e89c5 (diff)
fix carry into uninitialized slots during printf floating point rounding
in cases where rounding caused a carry, the slot into which the carry was taking place was unconditionally treated as valid, despite the possibility that it could be a new slot prior to the beginning of the existing non-rounded number. in theory this could lead to unbounded runaway carry, but in order for that to happen, the whole uninitialized buffer would need to have been pre-filled with 32-bit integer values greater than or equal to 999999999. patch based on proposed fix by Morten Welinder, who also discovered and reported the bug.
Diffstat (limited to 'src')
1 files changed, 1 insertions, 1 deletions
diff --git a/src/stdio/vfprintf.c b/src/stdio/vfprintf.c
index 31c3d5dd..bec63ecf 100644
--- a/src/stdio/vfprintf.c
+++ b/src/stdio/vfprintf.c
@@ -356,9 +356,9 @@ static int fmt_fp(FILE *f, long double y, int w, int p, int fl, int t)
*d = *d + i;
while (*d > 999999999) {
+ if (d<a) *--a=0;
- if (d<a) a=d;
for (i=10, e=9*(r-a); *a>=i; i*=10, e++);