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authorAndreas Rheinhardt <andreas.rheinhardt@gmail.com>2019-09-15 22:01:20 +0200
committerAndreas Rheinhardt <andreas.rheinhardt@gmail.com>2020-07-03 14:13:50 +0200
commiteb892918778164ff0b7a398954109e5fc5bf8872 (patch)
treebc720ad8d5449b2189cecabb37943185ec45b635
parent25a0887c5a1d4e2cc4d84ddeabdfd7dc26a69786 (diff)
downloadffmpeg-eb892918778164ff0b7a398954109e5fc5bf8872.tar.gz
avcodec/ttaenc: Fix undefined shift
ttaenc contained (1 << unary) - 1 as an argument for a function expecting an unsigned int. unary can be as big as 31 in this case. The type of the shift and the whole expression is int, because 1 fits into an integer, so that the behaviour is undefined if unary == 31 as the result of the shift can't be represented in an int §. Subtraction by 1 (which makes the result of the whole expression representable in an int) doesn't change that this is undefined (it usually leads to signed integer overflow which is undefined, too). The solution is simple: Make 1 unsigned to change the type of the whole expression to unsigned int (as the function expects anyway). Fixes ticket #8153. §: This of course presupposes the common int range of -2^31..2^31-1 Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com> Reviewed-by: Paul B Mahol <onemda@gmail.com> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc> (cherry picked from commit 3ab488a5407f833ecc66e8fa4c537dc4852db720) Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
-rw-r--r--libavcodec/ttaenc.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/libavcodec/ttaenc.c b/libavcodec/ttaenc.c
index 3cc54d78c5..08a0d0483a 100644
--- a/libavcodec/ttaenc.c
+++ b/libavcodec/ttaenc.c
@@ -164,7 +164,7 @@ pkt_alloc:
put_bits(&pb, 31, 0x7FFFFFFF);
unary -= 31;
} else {
- put_bits(&pb, unary, (1 << unary) - 1);
+ put_bits(&pb, unary, (1U << unary) - 1);
unary = 0;
}
} while (unary);