[lvc-project] [PATCH] arch-x86-boot-printf: fix unsafe negative value in vsprintf()

[Alexander Sapozhnikov]

Variable 'precision', which may receive negative value at printf.c:171,
is used at printf.c:207 by calling function 'strnlen'.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Alexander Sapozhnikov <alsp705 at gmail.com>
---
 arch/x86/boot/printf.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/boot/printf.c b/arch/x86/boot/printf.c
index 1237beeb9540..86ac64be949f 100644
--- a/arch/x86/boot/printf.c
+++ b/arch/x86/boot/printf.c
@@ -178,9 +178,9 @@ int vsprintf(char *buf, const char *fmt, va_list args)
 				/* it's the next argument */
 				precision = va_arg(args, int);
 			}
-			if (precision < 0)
-				precision = 0;
 		}
+		if (precision < 0)
+			precision = 0;
 
 		/* get the conversion qualifier */
 		qualifier = -1;
-- 
2.34.1