From 66fd848cadaa6be974a8c780fbeb328f0af4d3bd Mon Sep 17 00:00:00 2001 From: Ralf Baechle Date: Thu, 26 Jan 2017 02:16:47 +0100 Subject: [PATCH] MIPS: Fix special case in 64 bit IP checksumming. For certain arguments such as saddr = 0xc0a8fd60, daddr = 0xc0a8fda1, len = 80, proto = 17, sum = 0x7eae049d there will be a carry when folding the intermediate 64 bit checksum to 32 bit but the code doesn't add the carry back to the one's complement sum, thus an incorrect result will be generated. Reported-by: Mark Zhang Signed-off-by: Ralf Baechle Reviewed-by: James Hogan Cc: stable@vger.kernel.org Signed-off-by: James Hogan --- arch/mips/include/asm/checksum.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/mips/include/asm/checksum.h b/arch/mips/include/asm/checksum.h index 7749daf2a465..c8b574f7e0cc 100644 --- a/arch/mips/include/asm/checksum.h +++ b/arch/mips/include/asm/checksum.h @@ -186,7 +186,9 @@ static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, " daddu %0, %4 \n" " dsll32 $1, %0, 0 \n" " daddu %0, $1 \n" + " sltu $1, %0, $1 \n" " dsra32 %0, %0, 0 \n" + " addu %0, $1 \n" #endif " .set pop" : "=r" (sum) -- 2.20.1