From eba1ff31304e407db3cefd7532108408f364367b Mon Sep 17 00:00:00 2001 From: Xi Wang Date: Fri, 15 Mar 2013 06:31:21 -0400 Subject: [PATCH] atrac3: avoid oversized shifting in decode_bytes() When `off' is 0, `0x537F6103 << 32' in the following expression invokes undefined behavior, the result of which is not necessarily 0. (0x537F6103 >> (off * 8)) | (0x537F6103 << (32 - (off * 8))) Avoid oversized shifting. CC: libav-stable@libav.org Signed-off-by: Xi Wang Signed-off-by: Luca Barbato --- libavcodec/atrac3.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/libavcodec/atrac3.c b/libavcodec/atrac3.c index da0bff0bf3..a52c5c618a 100644 --- a/libavcodec/atrac3.c +++ b/libavcodec/atrac3.c @@ -163,7 +163,10 @@ static int decode_bytes(const uint8_t *input, uint8_t *out, int bytes) off = (intptr_t)input & 3; buf = (const uint32_t *)(input - off); - c = av_be2ne32((0x537F6103 >> (off * 8)) | (0x537F6103 << (32 - (off * 8)))); + if (off) + c = av_be2ne32((0x537F6103U >> (off * 8)) | (0x537F6103U << (32 - (off * 8)))); + else + c = av_be2ne32(0x537F6103U); bytes += 3 + off; for (i = 0; i < bytes / 4; i++) output[i] = c ^ buf[i];