linux-kernel - [PATCH 2/4] lib/vsprintf.c: also improve sanity check in bstr

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Date:	Fri, 25 Sep 2015 19:41:03 +0200
From:	Rasmus Villemoes <linux@...musvillemoes.dk>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Tejun Heo <tj@...nel.org>,
	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
	linux-kernel@...r.kernel.org, Kees Cook <keescook@...omium.org>,
	Rasmus Villemoes <linux@...musvillemoes.dk>
Subject: [PATCH 2/4] lib/vsprintf.c: also improve sanity check in bstr_printf()

Quoting from 2aa2f9e21e4e ("lib/vsprintf.c: improve sanity check in
vsnprintf()"):

    On 64 bit, size may very well be huge even if bit 31 happens to be 0.
    Somehow it doesn't feel right that one can pass a 5 GiB buffer but not a
    3 GiB one.  So cap at INT_MAX as was probably the intention all along.
    This is also the made-up value passed by sprintf and vsprintf.

I should have seen this copy-pasted instance back then, but let's just
do it now.

Signed-off-by: Rasmus Villemoes <linux@...musvillemoes.dk>
---
 lib/vsprintf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index f2590a80937f..03fa10b4be96 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -2294,7 +2294,7 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
 	char *str, *end;
 	const char *args = (const char *)bin_buf;
 
-	if (WARN_ON_ONCE((int) size < 0))
+	if (WARN_ON_ONCE(size > INT_MAX))
 		return 0;
 
 	str = buf;
-- 
2.1.3

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