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| author |   deraadt <deraadt@openbsd.org> | 2014-04-19 11:21:15 +0000 |
|---|---|---|
| committer | deraadt <deraadt@openbsd.org> | 2014-04-19 11:21:15 +0000 |
| commit | dbb0cc08449abad3f342fcf9c32963a15d46b26b (patch) | |
| tree | 617553f62c62752cbea3703c9a2aa70eea2d2e53 /lib/libc/stdio/printf.3 | |
| parent | Split inet(3) into three pages by decade: 1980s -> inet_lnaof(3), (diff) | |
| download | wireguard-openbsd-dbb0cc08449abad3f342fcf9c32963a15d46b26b.tar.xz wireguard-openbsd-dbb0cc08449abad3f342fcf9c32963a15d46b26b.zip | |
Demonstrate correct usage of snprintf (regarding overflow detection)
ok guenther
Diffstat (limited to 'lib/libc/stdio/printf.3')
| -rw-r--r-- | lib/libc/stdio/printf.3 | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/lib/libc/stdio/printf.3 b/lib/libc/stdio/printf.3 index 072a7949c05..7a394c4f9df 100644 --- a/lib/libc/stdio/printf.3 +++ b/lib/libc/stdio/printf.3 @@ -1,4 +1,4 @@ -.\" $OpenBSD: printf.3,v 1.64 2013/07/17 05:42:11 schwarze Exp $ +.\" $OpenBSD: printf.3,v 1.65 2014/04/19 11:21:15 deraadt Exp $ .\" .\" Copyright (c) 1990, 1991, 1993 .\" The Regents of the University of California. All rights reserved. @@ -33,7 +33,7 @@ .\" .\" @(#)printf.3 8.1 (Berkeley) 6/4/93 .\" -.Dd $Mdocdate: July 17 2013 $ +.Dd $Mdocdate: April 19 2014 $ .Dt PRINTF 3 .Os .Sh NAME @@ -871,7 +871,9 @@ for later interpolation by .Pp Be sure to use the proper secure idiom: .Bd -literal -offset indent -snprintf(buffer, sizeof(buffer), "%s", string); +ret = snprintf(buffer, sizeof(buffer), "%s", string); +if (ret == -1 || ret >= sizeof(buffer) + goto toolong; .Ed .Pp There is no way for |