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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2025-01-13 21:28:01 +02:00

avcodec/x86/lossless_videoencdsp: Fix handling of small widths

Fixes out of array access
Fixes: crash-huf.avi

Regression since: 6b41b44149

This could also be fixed by adding checks in the C code that calls the dsp

Found-by: Zhibin Hu and 连一汉 <lianyihan@360.cn>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit df62b70de8)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2017-09-30 00:20:09 +02:00
parent ab43bc50c0
commit 0a231e7dd3

View File

@ -42,10 +42,11 @@ cglobal diff_bytes, 4,5,2, dst, src1, src2, w
%define i t0q %define i t0q
%endmacro %endmacro
; label to jump to if w < regsize ; labels to jump to if w < regsize and w < 0
%macro DIFF_BYTES_LOOP_PREP 1 %macro DIFF_BYTES_LOOP_PREP 2
mov i, wq mov i, wq
and i, -2 * regsize and i, -2 * regsize
js %2
jz %1 jz %1
add dstq, i add dstq, i
add src1q, i add src1q, i
@ -87,7 +88,7 @@ cglobal diff_bytes, 4,5,2, dst, src1, src2, w
%if mmsize > 16 %if mmsize > 16
; fall back to narrower xmm ; fall back to narrower xmm
%define regsize mmsize / 2 %define regsize mmsize / 2
DIFF_BYTES_LOOP_PREP .setup_loop_gpr_aa DIFF_BYTES_LOOP_PREP .setup_loop_gpr_aa, .end_aa
.loop2_%1%2: .loop2_%1%2:
DIFF_BYTES_LOOP_CORE %1, %2, xm0, xm1 DIFF_BYTES_LOOP_CORE %1, %2, xm0, xm1
add i, 2 * regsize add i, 2 * regsize
@ -114,7 +115,7 @@ cglobal diff_bytes, 4,5,2, dst, src1, src2, w
INIT_MMX mmx INIT_MMX mmx
DIFF_BYTES_PROLOGUE DIFF_BYTES_PROLOGUE
%define regsize mmsize %define regsize mmsize
DIFF_BYTES_LOOP_PREP .skip_main_aa DIFF_BYTES_LOOP_PREP .skip_main_aa, .end_aa
DIFF_BYTES_BODY a, a DIFF_BYTES_BODY a, a
%undef i %undef i
%endif %endif
@ -122,7 +123,7 @@ DIFF_BYTES_PROLOGUE
INIT_XMM sse2 INIT_XMM sse2
DIFF_BYTES_PROLOGUE DIFF_BYTES_PROLOGUE
%define regsize mmsize %define regsize mmsize
DIFF_BYTES_LOOP_PREP .skip_main_aa DIFF_BYTES_LOOP_PREP .skip_main_aa, .end_aa
test dstq, regsize - 1 test dstq, regsize - 1
jnz .loop_uu jnz .loop_uu
test src1q, regsize - 1 test src1q, regsize - 1
@ -138,7 +139,7 @@ DIFF_BYTES_PROLOGUE
%define regsize mmsize %define regsize mmsize
; Directly using unaligned SSE2 version is marginally faster than ; Directly using unaligned SSE2 version is marginally faster than
; branching based on arguments. ; branching based on arguments.
DIFF_BYTES_LOOP_PREP .skip_main_uu DIFF_BYTES_LOOP_PREP .skip_main_uu, .end_uu
test dstq, regsize - 1 test dstq, regsize - 1
jnz .loop_uu jnz .loop_uu
test src1q, regsize - 1 test src1q, regsize - 1