From c277b24173eb78a9ba6b36cf28e985e247b48d12 Mon Sep 17 00:00:00 2001 From: "Ronald S. Bultje" Date: Sat, 16 Jan 2016 14:44:28 -0500 Subject: [PATCH] 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. (cherry picked from commit 0f88b3f82fafd536979993aeaafcb11a22266dbd) Signed-off-by: Michael Niedermayer --- libavcodec/x86/videodsp.asm | 21 ++++++--------------- 1 file changed, 6 insertions(+), 15 deletions(-) diff --git a/libavcodec/x86/videodsp.asm b/libavcodec/x86/videodsp.asm index 77189fa6ef..0685b03c2b 100644 --- a/libavcodec/x86/videodsp.asm +++ b/libavcodec/x86/videodsp.asm @@ -184,14 +184,10 @@ 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 @@ -244,18 +240,13 @@ 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