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authorRonald S. Bultje <rsbultje@gmail.com>2016-01-16 14:44:28 -0500
committerRonald S. Bultje <rsbultje@gmail.com>2016-01-18 11:12:47 -0500
commit0f88b3f82fafd536979993aeaafcb11a22266dbd (patch)
tree22eb634e98b3fe99dd3c5de65f0d8960901aa24e /libavcodec
parent5da1477fa01b8f5eb9804435f26e76ba423624e9 (diff)
downloadffmpeg-0f88b3f82fafd536979993aeaafcb11a22266dbd.tar.gz
videodsp: fix 1-byte overread in top/bottom READ_NUM_BYTES iterations.
This can overread (either before start or beyond end) of the buffer in Nx1 (i.e. height=1) images. Fixes mozilla bug 1240080.
Diffstat (limited to 'libavcodec')
-rw-r--r--libavcodec/x86/videodsp.asm21
1 files changed, 6 insertions, 15 deletions
diff --git a/libavcodec/x86/videodsp.asm b/libavcodec/x86/videodsp.asm
index 48f5ac0ce6..a807d3b888 100644
--- a/libavcodec/x86/videodsp.asm
+++ b/libavcodec/x86/videodsp.asm
@@ -193,14 +193,10 @@ hvar_fn
mov valb, [srcq+%2-1]
%elif (%2-%%off) == 2
mov valw, [srcq+%2-2]
-%elifidn %1, body
+%else
mov valb, [srcq+%2-1]
- sal vald, 16
+ ror vald, 16
mov valw, [srcq+%2-3]
-%elifidn %1, bottom
- movd mm %+ %%mmx_idx, [srcq+%2-4]
-%else ; top
- movd mm %+ %%mmx_idx, [srcq+%2-3]
%endif
%endif ; (%2-%%off) >= 1
%endmacro ; READ_NUM_BYTES
@@ -253,18 +249,13 @@ hvar_fn
mov [dstq+%2-1], valb
%elif (%2-%%off) == 2
mov [dstq+%2-2], valw
-%elifidn %1, body
- mov [dstq+%2-3], valw
- sar vald, 16
- mov [dstq+%2-1], valb
%else
- movd vald, mm %+ %%mmx_idx
-%ifidn %1, bottom
- sar vald, 8
-%endif
mov [dstq+%2-3], valw
- sar vald, 16
+ ror vald, 16
mov [dstq+%2-1], valb
+%ifnidn %1, body
+ ror vald, 16
+%endif
%endif
%endif ; (%2-%%off) >= 1
%endmacro ; WRITE_NUM_BYTES