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| author | Robin Watts <Robin.Watts@artifex.com> | 2017-02-09 07:12:16 -0800 |
|---|---|---|
| committer | Robin Watts <Robin.Watts@artifex.com> | 2017-02-09 07:15:01 -0800 |
| commit | 2c4e5867ee699b1081527bc6c6ea0e99a35a5c27 (patch) | |
| tree | 9e5e02785be274d781cc34c7c389fd4ec8d07a2d | |
| parent | 90fa6203ad032fe161d85a3e580941ce3d1216f0 (diff) | |
| download | mupdf-2c4e5867ee699b1081527bc6c6ea0e99a35a5c27.tar.xz | |
bug 697515: Fix out of bounds read in fz_subsample_pixmap
Pointer arithmetic for final special case was going wrong.
| -rw-r--r-- | source/fitz/pixmap.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/source/fitz/pixmap.c b/source/fitz/pixmap.c index a8317127..f1291dc2 100644 --- a/source/fitz/pixmap.c +++ b/source/fitz/pixmap.c @@ -1104,6 +1104,7 @@ fz_subsample_pixmap_ARM(unsigned char *ptr, int w, int h, int f, int factor, "@STACK:r1,<9>,factor,n,fwd,back,back2,fwd2,divX,back4,fwd4,fwd3,divY,back5,divXY\n" "ldr r4, [r13,#4*22] @ r4 = divXY \n" "ldr r5, [r13,#4*11] @ for (nn = n; nn > 0; n--) { \n" + "ldr r8, [r13,#4*17] @ r8 = back4 \n" "18: @ \n" "mov r14,#0 @ r14= v = 0 \n" "sub r5, r5, r1, LSL #8 @ for (xx = x; xx > 0; x--) { \n" @@ -1120,7 +1121,7 @@ fz_subsample_pixmap_ARM(unsigned char *ptr, int w, int h, int f, int factor, "mul r14,r4, r14 @ r14= v *= divX \n" "mov r14,r14,LSR #16 @ r14= v >>= 16 \n" "strb r14,[r9], #1 @ *d++ = r14 \n" - "sub r0, r0, r8 @ s -= back2 \n" + "sub r0, r0, r8 @ s -= back4 \n" "subs r5, r5, #1 @ n-- \n" "bgt 18b @ } \n" "21: @ \n" @@ -1249,6 +1250,7 @@ fz_subsample_pixmap(fz_context *ctx, fz_pixmap *tile, int factor) x += f; if (x > 0) { + int back4 = x * n - 1; div = x * y; for (nn = n; nn > 0; nn--) { @@ -1263,7 +1265,7 @@ fz_subsample_pixmap(fz_context *ctx, fz_pixmap *tile, int factor) s -= back5; } *d++ = v / div; - s -= back2; + s -= back4; } } } |