forked from brl/citadel
100 lines
2.9 KiB
Diff
100 lines
2.9 KiB
Diff
From 3328e98bcbf2930cd7eea3e6c92ad5dcbdf4794f Mon Sep 17 00:00:00 2001
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From: Yuanjie Huang <yuanjie.huang@windriver.com>
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Date: Wed, 24 Aug 2016 03:15:43 +0000
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Subject: [PATCH] Fix potential signed overflow in pointer arithmatic
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Pointer arithmatic results in implementation defined signed integer
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type, so that 's - src' in strlcpy and others may trigger signed overflow.
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In case of compilation by gcc or clang with -ftrapv option, the overflow
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would lead to program abort.
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Upstream-Status: Submitted [http://bugzilla.mindrot.org/show_bug.cgi?id=2608]
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Signed-off-by: Yuanjie Huang <yuanjie.huang@windriver.com>
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---
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openbsd-compat/strlcat.c | 8 ++++++--
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openbsd-compat/strlcpy.c | 8 ++++++--
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openbsd-compat/strnlen.c | 8 ++++++--
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3 files changed, 18 insertions(+), 6 deletions(-)
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diff --git a/openbsd-compat/strlcat.c b/openbsd-compat/strlcat.c
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index bcc1b61..e758ebf 100644
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--- a/openbsd-compat/strlcat.c
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+++ b/openbsd-compat/strlcat.c
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@@ -23,6 +23,7 @@
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#include <sys/types.h>
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#include <string.h>
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+#include <stdint.h>
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/*
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* Appends src to string dst of size siz (unlike strncat, siz is the
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@@ -55,8 +56,11 @@ strlcat(char *dst, const char *src, size_t siz)
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s++;
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}
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*d = '\0';
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-
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- return(dlen + (s - src)); /* count does not include NUL */
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+ /*
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+ * Cast pointers to unsigned type before calculation, to avoid signed
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+ * overflow when the string ends where the MSB has changed.
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+ */
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+ return (dlen + ((uintptr_t)s - (uintptr_t)src)); /* count does not include NUL */
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}
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#endif /* !HAVE_STRLCAT */
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diff --git a/openbsd-compat/strlcpy.c b/openbsd-compat/strlcpy.c
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index b4b1b60..b06f374 100644
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--- a/openbsd-compat/strlcpy.c
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+++ b/openbsd-compat/strlcpy.c
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@@ -23,6 +23,7 @@
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#include <sys/types.h>
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#include <string.h>
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+#include <stdint.h>
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/*
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* Copy src to string dst of size siz. At most siz-1 characters
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@@ -51,8 +52,11 @@ strlcpy(char *dst, const char *src, size_t siz)
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while (*s++)
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;
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}
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-
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- return(s - src - 1); /* count does not include NUL */
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+ /*
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+ * Cast pointers to unsigned type before calculation, to avoid signed
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+ * overflow when the string ends where the MSB has changed.
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+ */
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+ return ((uintptr_t)s - (uintptr_t)src - 1); /* count does not include NUL */
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}
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#endif /* !HAVE_STRLCPY */
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diff --git a/openbsd-compat/strnlen.c b/openbsd-compat/strnlen.c
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index 93d5155..9b8de5d 100644
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--- a/openbsd-compat/strnlen.c
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+++ b/openbsd-compat/strnlen.c
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@@ -23,6 +23,7 @@
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#include <sys/types.h>
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#include <string.h>
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+#include <stdint.h>
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size_t
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strnlen(const char *str, size_t maxlen)
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@@ -31,7 +32,10 @@ strnlen(const char *str, size_t maxlen)
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for (cp = str; maxlen != 0 && *cp != '\0'; cp++, maxlen--)
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;
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-
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- return (size_t)(cp - str);
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+ /*
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+ * Cast pointers to unsigned type before calculation, to avoid signed
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+ * overflow when the string ends where the MSB has changed.
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+ */
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+ return (size_t)((uintptr_t)cp - (uintptr_t)str);
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}
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#endif
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--
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1.9.1
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