From ea62893915678119070eaec78322ed2e34edd21f Mon Sep 17 00:00:00 2001 From: Armin Kuster Date: Mon, 19 Sep 2016 18:12:42 -0700 Subject: qemu: Security Fix CVE-2016-3712 affects qemu < 2.6.0 (From OE-Core rev: ed78691a46a3c928297ae166e92fabdffa9e53c9) Signed-off-by: Armin Kuster Signed-off-by: Richard Purdie --- .../qemu/qemu/CVE-2016-3712_p1.patch | 73 ++++++++++++ .../qemu/qemu/CVE-2016-3712_p2.patch | 132 +++++++++++++++++++++ .../qemu/qemu/CVE-2016-3712_p3.patch | 34 ++++++ .../qemu/qemu/CVE-2016-3712_p4.patch | 80 +++++++++++++ meta/recipes-devtools/qemu/qemu_2.5.0.bb | 4 + 5 files changed, 323 insertions(+) create mode 100644 meta/recipes-devtools/qemu/qemu/CVE-2016-3712_p1.patch create mode 100644 meta/recipes-devtools/qemu/qemu/CVE-2016-3712_p2.patch create mode 100644 meta/recipes-devtools/qemu/qemu/CVE-2016-3712_p3.patch create mode 100644 meta/recipes-devtools/qemu/qemu/CVE-2016-3712_p4.patch diff --git a/meta/recipes-devtools/qemu/qemu/CVE-2016-3712_p1.patch b/meta/recipes-devtools/qemu/qemu/CVE-2016-3712_p1.patch new file mode 100644 index 0000000000..07582ef929 --- /dev/null +++ b/meta/recipes-devtools/qemu/qemu/CVE-2016-3712_p1.patch @@ -0,0 +1,73 @@ +From 46aff2c7e91ef9f372ad38ba5e90c42b9b27ac75 Mon Sep 17 00:00:00 2001 +From: Gerd Hoffmann +Date: Tue, 26 Apr 2016 14:11:34 +0200 +Subject: [PATCH 1/4] vga: add vbe_enabled() helper + +Makes code a bit easier to read. + +Signed-off-by: Gerd Hoffmann +Signed-off-by: Michael Roth + +Upstream-Status: Backport +CVE: CVE-2016-3712 patch1 +Signed-off-by: Armin Kuster + +--- + hw/display/vga.c | 13 +++++++++---- + 1 file changed, 9 insertions(+), 4 deletions(-) + +diff --git a/hw/display/vga.c b/hw/display/vga.c +index 442fee9..cc1a682 100644 +--- a/hw/display/vga.c ++++ b/hw/display/vga.c +@@ -140,6 +140,11 @@ static uint32_t expand4[256]; + static uint16_t expand2[256]; + static uint8_t expand4to8[16]; + ++static inline bool vbe_enabled(VGACommonState *s) ++{ ++ return s->vbe_regs[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED; ++} ++ + static void vga_update_memory_access(VGACommonState *s) + { + hwaddr base, offset, size; +@@ -562,7 +567,7 @@ static void vbe_fixup_regs(VGACommonState *s) + uint16_t *r = s->vbe_regs; + uint32_t bits, linelength, maxy, offset; + +- if (!(r[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED)) { ++ if (!vbe_enabled(s)) { + /* vbe is turned off -- nothing to do */ + return; + } +@@ -1056,7 +1061,7 @@ static void vga_get_offsets(VGACommonState *s, + { + uint32_t start_addr, line_offset, line_compare; + +- if (s->vbe_regs[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED) { ++ if (vbe_enabled(s)) { + line_offset = s->vbe_line_offset; + start_addr = s->vbe_start_addr; + line_compare = 65535; +@@ -1381,7 +1386,7 @@ static int vga_get_bpp(VGACommonState *s) + { + int ret; + +- if (s->vbe_regs[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED) { ++ if (vbe_enabled(s)) { + ret = s->vbe_regs[VBE_DISPI_INDEX_BPP]; + } else { + ret = 0; +@@ -1393,7 +1398,7 @@ static void vga_get_resolution(VGACommonState *s, int *pwidth, int *pheight) + { + int width, height; + +- if (s->vbe_regs[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED) { ++ if (vbe_enabled(s)) { + width = s->vbe_regs[VBE_DISPI_INDEX_XRES]; + height = s->vbe_regs[VBE_DISPI_INDEX_YRES]; + } else { +-- +2.7.4 + diff --git a/meta/recipes-devtools/qemu/qemu/CVE-2016-3712_p2.patch b/meta/recipes-devtools/qemu/qemu/CVE-2016-3712_p2.patch new file mode 100644 index 0000000000..11330d766d --- /dev/null +++ b/meta/recipes-devtools/qemu/qemu/CVE-2016-3712_p2.patch @@ -0,0 +1,132 @@ +From 2f2f74e87c15e830f5a4dda7a166effcab5047ec Mon Sep 17 00:00:00 2001 +From: Gerd Hoffmann +Date: Tue, 26 Apr 2016 15:24:18 +0200 +Subject: [PATCH 2/4] vga: factor out vga register setup + +When enabling vbe mode qemu will setup a bunch of vga registers to make +sure the vga emulation operates in correct mode for a linear +framebuffer. Move that code to a separate function so we can call it +from other places too. + +Signed-off-by: Gerd Hoffmann +Signed-off-by: Michael Roth + +Upstream-Status: Backport +CVE: CVE-2016-3712 patch2 +Signed-off-by: Armin Kuster + +--- + hw/display/vga.c | 78 ++++++++++++++++++++++++++++++++------------------------ + 1 file changed, 44 insertions(+), 34 deletions(-) + +diff --git a/hw/display/vga.c b/hw/display/vga.c +index cc1a682..f1987e3 100644 +--- a/hw/display/vga.c ++++ b/hw/display/vga.c +@@ -642,6 +642,49 @@ static void vbe_fixup_regs(VGACommonState *s) + s->vbe_start_addr = offset / 4; + } + ++/* we initialize the VGA graphic mode */ ++static void vbe_update_vgaregs(VGACommonState *s) ++{ ++ int h, shift_control; ++ ++ if (!vbe_enabled(s)) { ++ /* vbe is turned off -- nothing to do */ ++ return; ++ } ++ ++ /* graphic mode + memory map 1 */ ++ s->gr[VGA_GFX_MISC] = (s->gr[VGA_GFX_MISC] & ~0x0c) | 0x04 | ++ VGA_GR06_GRAPHICS_MODE; ++ s->cr[VGA_CRTC_MODE] |= 3; /* no CGA modes */ ++ s->cr[VGA_CRTC_OFFSET] = s->vbe_line_offset >> 3; ++ /* width */ ++ s->cr[VGA_CRTC_H_DISP] = ++ (s->vbe_regs[VBE_DISPI_INDEX_XRES] >> 3) - 1; ++ /* height (only meaningful if < 1024) */ ++ h = s->vbe_regs[VBE_DISPI_INDEX_YRES] - 1; ++ s->cr[VGA_CRTC_V_DISP_END] = h; ++ s->cr[VGA_CRTC_OVERFLOW] = (s->cr[VGA_CRTC_OVERFLOW] & ~0x42) | ++ ((h >> 7) & 0x02) | ((h >> 3) & 0x40); ++ /* line compare to 1023 */ ++ s->cr[VGA_CRTC_LINE_COMPARE] = 0xff; ++ s->cr[VGA_CRTC_OVERFLOW] |= 0x10; ++ s->cr[VGA_CRTC_MAX_SCAN] |= 0x40; ++ ++ if (s->vbe_regs[VBE_DISPI_INDEX_BPP] == 4) { ++ shift_control = 0; ++ s->sr[VGA_SEQ_CLOCK_MODE] &= ~8; /* no double line */ ++ } else { ++ shift_control = 2; ++ /* set chain 4 mode */ ++ s->sr[VGA_SEQ_MEMORY_MODE] |= VGA_SR04_CHN_4M; ++ /* activate all planes */ ++ s->sr[VGA_SEQ_PLANE_WRITE] |= VGA_SR02_ALL_PLANES; ++ } ++ s->gr[VGA_GFX_MODE] = (s->gr[VGA_GFX_MODE] & ~0x60) | ++ (shift_control << 5); ++ s->cr[VGA_CRTC_MAX_SCAN] &= ~0x9f; /* no double scan */ ++} ++ + static uint32_t vbe_ioport_read_index(void *opaque, uint32_t addr) + { + VGACommonState *s = opaque; +@@ -728,52 +771,19 @@ void vbe_ioport_write_data(void *opaque, uint32_t addr, uint32_t val) + case VBE_DISPI_INDEX_ENABLE: + if ((val & VBE_DISPI_ENABLED) && + !(s->vbe_regs[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED)) { +- int h, shift_control; + + s->vbe_regs[VBE_DISPI_INDEX_VIRT_WIDTH] = 0; + s->vbe_regs[VBE_DISPI_INDEX_X_OFFSET] = 0; + s->vbe_regs[VBE_DISPI_INDEX_Y_OFFSET] = 0; + s->vbe_regs[VBE_DISPI_INDEX_ENABLE] |= VBE_DISPI_ENABLED; + vbe_fixup_regs(s); ++ vbe_update_vgaregs(s); + + /* clear the screen */ + if (!(val & VBE_DISPI_NOCLEARMEM)) { + memset(s->vram_ptr, 0, + s->vbe_regs[VBE_DISPI_INDEX_YRES] * s->vbe_line_offset); + } +- +- /* we initialize the VGA graphic mode */ +- /* graphic mode + memory map 1 */ +- s->gr[VGA_GFX_MISC] = (s->gr[VGA_GFX_MISC] & ~0x0c) | 0x04 | +- VGA_GR06_GRAPHICS_MODE; +- s->cr[VGA_CRTC_MODE] |= 3; /* no CGA modes */ +- s->cr[VGA_CRTC_OFFSET] = s->vbe_line_offset >> 3; +- /* width */ +- s->cr[VGA_CRTC_H_DISP] = +- (s->vbe_regs[VBE_DISPI_INDEX_XRES] >> 3) - 1; +- /* height (only meaningful if < 1024) */ +- h = s->vbe_regs[VBE_DISPI_INDEX_YRES] - 1; +- s->cr[VGA_CRTC_V_DISP_END] = h; +- s->cr[VGA_CRTC_OVERFLOW] = (s->cr[VGA_CRTC_OVERFLOW] & ~0x42) | +- ((h >> 7) & 0x02) | ((h >> 3) & 0x40); +- /* line compare to 1023 */ +- s->cr[VGA_CRTC_LINE_COMPARE] = 0xff; +- s->cr[VGA_CRTC_OVERFLOW] |= 0x10; +- s->cr[VGA_CRTC_MAX_SCAN] |= 0x40; +- +- if (s->vbe_regs[VBE_DISPI_INDEX_BPP] == 4) { +- shift_control = 0; +- s->sr[VGA_SEQ_CLOCK_MODE] &= ~8; /* no double line */ +- } else { +- shift_control = 2; +- /* set chain 4 mode */ +- s->sr[VGA_SEQ_MEMORY_MODE] |= VGA_SR04_CHN_4M; +- /* activate all planes */ +- s->sr[VGA_SEQ_PLANE_WRITE] |= VGA_SR02_ALL_PLANES; +- } +- s->gr[VGA_GFX_MODE] = (s->gr[VGA_GFX_MODE] & ~0x60) | +- (shift_control << 5); +- s->cr[VGA_CRTC_MAX_SCAN] &= ~0x9f; /* no double scan */ + } else { + s->bank_offset = 0; + } +-- +2.7.4 + diff --git a/meta/recipes-devtools/qemu/qemu/CVE-2016-3712_p3.patch b/meta/recipes-devtools/qemu/qemu/CVE-2016-3712_p3.patch new file mode 100644 index 0000000000..3e6644d942 --- /dev/null +++ b/meta/recipes-devtools/qemu/qemu/CVE-2016-3712_p3.patch @@ -0,0 +1,34 @@ +From a6e5e5dd4bbc022acbd10ebcf415a6a57418d09e Mon Sep 17 00:00:00 2001 +From: Gerd Hoffmann +Date: Tue, 26 Apr 2016 15:39:22 +0200 +Subject: [PATCH 3/4] vga: update vga register setup on vbe changes + +Call the new vbe_update_vgaregs() function on vbe configuration +changes, to make sure vga registers are up-to-date. + +Signed-off-by: Gerd Hoffmann +Signed-off-by: Michael Roth + +Upstream-Status: Backport +CVE: CVE-2016-3712 patch3 +Signed-off-by: Armin Kuster + +--- + hw/display/vga.c | 1 + + 1 file changed, 1 insertion(+) + +diff --git a/hw/display/vga.c b/hw/display/vga.c +index f1987e3..10ac7df 100644 +--- a/hw/display/vga.c ++++ b/hw/display/vga.c +@@ -761,6 +761,7 @@ void vbe_ioport_write_data(void *opaque, uint32_t addr, uint32_t val) + case VBE_DISPI_INDEX_Y_OFFSET: + s->vbe_regs[s->vbe_index] = val; + vbe_fixup_regs(s); ++ vbe_update_vgaregs(s); + break; + case VBE_DISPI_INDEX_BANK: + val &= s->vbe_bank_mask; +-- +2.7.4 + diff --git a/meta/recipes-devtools/qemu/qemu/CVE-2016-3712_p4.patch b/meta/recipes-devtools/qemu/qemu/CVE-2016-3712_p4.patch new file mode 100644 index 0000000000..96e980a58d --- /dev/null +++ b/meta/recipes-devtools/qemu/qemu/CVE-2016-3712_p4.patch @@ -0,0 +1,80 @@ +From 44b86aa32e4147c727fadd9a0f0bc503a5dedb72 Mon Sep 17 00:00:00 2001 +From: Gerd Hoffmann +Date: Tue, 26 Apr 2016 14:48:06 +0200 +Subject: [PATCH 4/4] vga: make sure vga register setup for vbe stays intact + (CVE-2016-3712). + +Call vbe_update_vgaregs() when the guest touches GFX, SEQ or CRT +registers, to make sure the vga registers will always have the +values needed by vbe mode. This makes sure the sanity checks +applied by vbe_fixup_regs() are effective. + +Without this guests can muck with shift_control, can turn on planar +vga modes or text mode emulation while VBE is active, making qemu +take code paths meant for CGA compatibility, but with the very +large display widths and heigts settable using VBE registers. + +Which is good for one or another buffer overflow. Not that +critical as they typically read overflows happening somewhere +in the display code. So guests can DoS by crashing qemu with a +segfault, but it is probably not possible to break out of the VM. + +Fixes: CVE-2016-3712 +Reported-by: Zuozhi Fzz +Reported-by: P J P +Signed-off-by: Gerd Hoffmann +Signed-off-by: Michael Roth + +Upstream-Status: Backport +CVE: CVE-2016-3712 patch4 ( the fix) +Signed-off-by: Armin Kuster + +--- + hw/display/vga.c | 6 ++++++ + 1 file changed, 6 insertions(+) + +diff --git a/hw/display/vga.c b/hw/display/vga.c +index 10ac7df..679070e 100644 +--- a/hw/display/vga.c ++++ b/hw/display/vga.c +@@ -140,6 +140,8 @@ static uint32_t expand4[256]; + static uint16_t expand2[256]; + static uint8_t expand4to8[16]; + ++static void vbe_update_vgaregs(VGACommonState *s); ++ + static inline bool vbe_enabled(VGACommonState *s) + { + return s->vbe_regs[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED; +@@ -482,6 +484,7 @@ void vga_ioport_write(void *opaque, uint32_t addr, uint32_t val) + printf("vga: write SR%x = 0x%02x\n", s->sr_index, val); + #endif + s->sr[s->sr_index] = val & sr_mask[s->sr_index]; ++ vbe_update_vgaregs(s); + if (s->sr_index == VGA_SEQ_CLOCK_MODE) { + s->update_retrace_info(s); + } +@@ -513,6 +516,7 @@ void vga_ioport_write(void *opaque, uint32_t addr, uint32_t val) + printf("vga: write GR%x = 0x%02x\n", s->gr_index, val); + #endif + s->gr[s->gr_index] = val & gr_mask[s->gr_index]; ++ vbe_update_vgaregs(s); + vga_update_memory_access(s); + break; + case VGA_CRT_IM: +@@ -531,10 +535,12 @@ void vga_ioport_write(void *opaque, uint32_t addr, uint32_t val) + if (s->cr_index == VGA_CRTC_OVERFLOW) { + s->cr[VGA_CRTC_OVERFLOW] = (s->cr[VGA_CRTC_OVERFLOW] & ~0x10) | + (val & 0x10); ++ vbe_update_vgaregs(s); + } + return; + } + s->cr[s->cr_index] = val; ++ vbe_update_vgaregs(s); + + switch(s->cr_index) { + case VGA_CRTC_H_TOTAL: +-- +2.7.4 + diff --git a/meta/recipes-devtools/qemu/qemu_2.5.0.bb b/meta/recipes-devtools/qemu/qemu_2.5.0.bb index 7651e9a5ae..a38edd59a4 100644 --- a/meta/recipes-devtools/qemu/qemu_2.5.0.bb +++ b/meta/recipes-devtools/qemu/qemu_2.5.0.bb @@ -17,6 +17,10 @@ SRC_URI += "file://configure-fix-Darwin-target-detection.patch \ file://rng_move_request_queue_cleanup_from_RngEgd_to_RngBackend.patch \ file://CVE-2016-2858.patch \ file://CVE-2016-3710.patch \ + file://CVE-2016-3712_p1.patch \ + file://CVE-2016-3712_p2.patch \ + file://CVE-2016-3712_p3.patch \ + file://CVE-2016-3712_p4.patch \ " SRC_URI_prepend = "http://wiki.qemu-project.org/download/${BP}.tar.bz2" SRC_URI[md5sum] = "f469f2330bbe76e3e39db10e9ac4f8db" -- cgit v1.2.3-54-g00ecf