[OE-core] [PATCH 2/3] qemu: fix CVE-2015-6855
wenzong.fan at windriver.com
wenzong.fan at windriver.com
Mon Nov 16 07:32:12 UTC 2015
From: Wenzong Fan <wenzong.fan at windriver.com>
hw/ide/core.c in QEMU does not properly restrict the commands accepted
by an ATAPI device, which allows guest users to cause a denial of
service or possibly have unspecified other impact via certain IDE
commands, as demonstrated by a WIN_READ_NATIVE_MAX command to an empty
drive, which triggers a divide-by-zero error and instance crash.
Backport upstream commit:
http://git.qemu.org/?p=qemu.git;a=commit;h=d9033e1d3aa666c5071580617a57bd853c5d794a
Signed-off-by: Wenzong Fan <wenzong.fan at windriver.com>
---
.../qemu/qemu/qemu-CVE-2015-6855.patch | 151 +++++++++++++++++++++
meta/recipes-devtools/qemu/qemu_2.4.0.bb | 1 +
2 files changed, 152 insertions(+)
create mode 100644 meta/recipes-devtools/qemu/qemu/qemu-CVE-2015-6855.patch
diff --git a/meta/recipes-devtools/qemu/qemu/qemu-CVE-2015-6855.patch b/meta/recipes-devtools/qemu/qemu/qemu-CVE-2015-6855.patch
new file mode 100644
index 0000000..f7f6452
--- /dev/null
+++ b/meta/recipes-devtools/qemu/qemu/qemu-CVE-2015-6855.patch
@@ -0,0 +1,151 @@
+From d9033e1d3aa666c5071580617a57bd853c5d794a Mon Sep 17 00:00:00 2001
+From: John Snow <jsnow at redhat.com>
+Date: Thu, 17 Sep 2015 14:17:05 -0400
+Subject: [PATCH] ide: fix ATAPI command permissions
+
+We're a little too lenient with what we'll let an ATAPI drive handle.
+Clamp down on the IDE command execution table to remove CD_OK permissions
+from commands that are not and have never been ATAPI commands.
+
+For ATAPI command validity, please see:
+- ATA4 Section 6.5 ("PACKET Command feature set")
+- ATA8/ACS Section 4.3 ("The PACKET feature set")
+- ACS3 Section 4.3 ("The PACKET feature set")
+
+ACS3 has a historical command validity table in Table B.4
+("Historical Command Assignments") that can be referenced to find when
+a command was introduced, deprecated, obsoleted, etc.
+
+The only reference for ATAPI command validity is by checking that
+version's PACKET feature set section.
+
+ATAPI was introduced by T13 into ATA4, all commands retired prior to ATA4
+therefore are assumed to have never been ATAPI commands.
+
+Mandatory commands, as listed in ATA8-ACS3, are:
+
+- DEVICE RESET
+- EXECUTE DEVICE DIAGNOSTIC
+- IDENTIFY DEVICE
+- IDENTIFY PACKET DEVICE
+- NOP
+- PACKET
+- READ SECTOR(S)
+- SET FEATURES
+
+Optional commands as listed in ATA8-ACS3, are:
+
+- FLUSH CACHE
+- READ LOG DMA EXT
+- READ LOG EXT
+- WRITE LOG DMA EXT
+- WRITE LOG EXT
+
+All other commands are illegal to send to an ATAPI device and should
+be rejected by the device.
+
+CD_OK removal justifications:
+
+0x06 WIN_DSM Defined in ACS2. Not valid for ATAPI.
+0x21 WIN_READ_ONCE Retired in ATA5. Not ATAPI in ATA4.
+0x94 WIN_STANDBYNOW2 Retired in ATA4. Did not coexist with ATAPI.
+0x95 WIN_IDLEIMMEDIATE2 Retired in ATA4. Did not coexist with ATAPI.
+0x96 WIN_STANDBY2 Retired in ATA4. Did not coexist with ATAPI.
+0x97 WIN_SETIDLE2 Retired in ATA4. Did not coexist with ATAPI.
+0x98 WIN_CHECKPOWERMODE2 Retired in ATA4. Did not coexist with ATAPI.
+0x99 WIN_SLEEPNOW2 Retired in ATA4. Did not coexist with ATAPI.
+0xE0 WIN_STANDBYNOW1 Not part of ATAPI in ATA4, ACS or ACS3.
+0xE1 WIN_IDLEIMMDIATE Not part of ATAPI in ATA4, ACS or ACS3.
+0xE2 WIN_STANDBY Not part of ATAPI in ATA4, ACS or ACS3.
+0xE3 WIN_SETIDLE1 Not part of ATAPI in ATA4, ACS or ACS3.
+0xE4 WIN_CHECKPOWERMODE1 Not part of ATAPI in ATA4, ACS or ACS3.
+0xE5 WIN_SLEEPNOW1 Not part of ATAPI in ATA4, ACS or ACS3.
+0xF8 WIN_READ_NATIVE_MAX Obsoleted in ACS3. Not ATAPI in ATA4 or ACS.
+
+This patch fixes a divide by zero fault that can be caused by sending
+the WIN_READ_NATIVE_MAX command to an ATAPI drive, which causes it to
+attempt to use zeroed CHS values to perform sector arithmetic.
+
+Reported-by: Qinghao Tang <luodalongde at gmail.com>
+Signed-off-by: John Snow <jsnow at redhat.com>
+Reviewed-by: Markus Armbruster <armbru at redhat.com>
+Message-id: 1441816082-21031-1-git-send-email-jsnow at redhat.com
+CC: qemu-stable at nongnu.org
+
+Upstream-Status: Backport
+
+Backport upstream commit:
+http://git.qemu.org/?p=qemu.git;a=commit;h=d9033e1d3aa666c5071580617a57bd853c5d794a
+
+Signed-off-by: Wenzong Fan <wenzong.fan at windriver.com>
+---
+ hw/ide/core.c | 30 +++++++++++++++---------------
+ 1 file changed, 15 insertions(+), 15 deletions(-)
+
+diff --git a/hw/ide/core.c b/hw/ide/core.c
+index 8ba04df..1cc6945 100644
+--- a/hw/ide/core.c
++++ b/hw/ide/core.c
+@@ -1746,11 +1746,11 @@ static const struct {
+ } ide_cmd_table[0x100] = {
+ /* NOP not implemented, mandatory for CD */
+ [CFA_REQ_EXT_ERROR_CODE] = { cmd_cfa_req_ext_error_code, CFA_OK },
+- [WIN_DSM] = { cmd_data_set_management, ALL_OK },
++ [WIN_DSM] = { cmd_data_set_management, HD_CFA_OK },
+ [WIN_DEVICE_RESET] = { cmd_device_reset, CD_OK },
+ [WIN_RECAL] = { cmd_nop, HD_CFA_OK | SET_DSC},
+ [WIN_READ] = { cmd_read_pio, ALL_OK },
+- [WIN_READ_ONCE] = { cmd_read_pio, ALL_OK },
++ [WIN_READ_ONCE] = { cmd_read_pio, HD_CFA_OK },
+ [WIN_READ_EXT] = { cmd_read_pio, HD_CFA_OK },
+ [WIN_READDMA_EXT] = { cmd_read_dma, HD_CFA_OK },
+ [WIN_READ_NATIVE_MAX_EXT] = { cmd_read_native_max, HD_CFA_OK | SET_DSC },
+@@ -1769,12 +1769,12 @@ static const struct {
+ [CFA_TRANSLATE_SECTOR] = { cmd_cfa_translate_sector, CFA_OK },
+ [WIN_DIAGNOSE] = { cmd_exec_dev_diagnostic, ALL_OK },
+ [WIN_SPECIFY] = { cmd_nop, HD_CFA_OK | SET_DSC },
+- [WIN_STANDBYNOW2] = { cmd_nop, ALL_OK },
+- [WIN_IDLEIMMEDIATE2] = { cmd_nop, ALL_OK },
+- [WIN_STANDBY2] = { cmd_nop, ALL_OK },
+- [WIN_SETIDLE2] = { cmd_nop, ALL_OK },
+- [WIN_CHECKPOWERMODE2] = { cmd_check_power_mode, ALL_OK | SET_DSC },
+- [WIN_SLEEPNOW2] = { cmd_nop, ALL_OK },
++ [WIN_STANDBYNOW2] = { cmd_nop, HD_CFA_OK },
++ [WIN_IDLEIMMEDIATE2] = { cmd_nop, HD_CFA_OK },
++ [WIN_STANDBY2] = { cmd_nop, HD_CFA_OK },
++ [WIN_SETIDLE2] = { cmd_nop, HD_CFA_OK },
++ [WIN_CHECKPOWERMODE2] = { cmd_check_power_mode, HD_CFA_OK | SET_DSC },
++ [WIN_SLEEPNOW2] = { cmd_nop, HD_CFA_OK },
+ [WIN_PACKETCMD] = { cmd_packet, CD_OK },
+ [WIN_PIDENTIFY] = { cmd_identify_packet, CD_OK },
+ [WIN_SMART] = { cmd_smart, HD_CFA_OK | SET_DSC },
+@@ -1788,19 +1788,19 @@ static const struct {
+ [WIN_WRITEDMA] = { cmd_write_dma, HD_CFA_OK },
+ [WIN_WRITEDMA_ONCE] = { cmd_write_dma, HD_CFA_OK },
+ [CFA_WRITE_MULTI_WO_ERASE] = { cmd_write_multiple, CFA_OK },
+- [WIN_STANDBYNOW1] = { cmd_nop, ALL_OK },
+- [WIN_IDLEIMMEDIATE] = { cmd_nop, ALL_OK },
+- [WIN_STANDBY] = { cmd_nop, ALL_OK },
+- [WIN_SETIDLE1] = { cmd_nop, ALL_OK },
+- [WIN_CHECKPOWERMODE1] = { cmd_check_power_mode, ALL_OK | SET_DSC },
+- [WIN_SLEEPNOW1] = { cmd_nop, ALL_OK },
++ [WIN_STANDBYNOW1] = { cmd_nop, HD_CFA_OK },
++ [WIN_IDLEIMMEDIATE] = { cmd_nop, HD_CFA_OK },
++ [WIN_STANDBY] = { cmd_nop, HD_CFA_OK },
++ [WIN_SETIDLE1] = { cmd_nop, HD_CFA_OK },
++ [WIN_CHECKPOWERMODE1] = { cmd_check_power_mode, HD_CFA_OK | SET_DSC },
++ [WIN_SLEEPNOW1] = { cmd_nop, HD_CFA_OK },
+ [WIN_FLUSH_CACHE] = { cmd_flush_cache, ALL_OK },
+ [WIN_FLUSH_CACHE_EXT] = { cmd_flush_cache, HD_CFA_OK },
+ [WIN_IDENTIFY] = { cmd_identify, ALL_OK },
+ [WIN_SETFEATURES] = { cmd_set_features, ALL_OK | SET_DSC },
+ [IBM_SENSE_CONDITION] = { cmd_ibm_sense_condition, CFA_OK | SET_DSC },
+ [CFA_WEAR_LEVEL] = { cmd_cfa_erase_sectors, HD_CFA_OK | SET_DSC },
+- [WIN_READ_NATIVE_MAX] = { cmd_read_native_max, ALL_OK | SET_DSC },
++ [WIN_READ_NATIVE_MAX] = { cmd_read_native_max, HD_CFA_OK | SET_DSC },
+ };
+
+ static bool ide_cmd_permitted(IDEState *s, uint32_t cmd)
+--
+2.3.5
+
diff --git a/meta/recipes-devtools/qemu/qemu_2.4.0.bb b/meta/recipes-devtools/qemu/qemu_2.4.0.bb
index 24e8ef5..4244ecf 100644
--- a/meta/recipes-devtools/qemu/qemu_2.4.0.bb
+++ b/meta/recipes-devtools/qemu/qemu_2.4.0.bb
@@ -11,6 +11,7 @@ SRC_URI += "file://configure-fix-Darwin-target-detection.patch \
file://smc91c111_fix3.patch \
file://no-valgrind.patch \
file://qemu-CVE-2015-5225.patch \
+ file://qemu-CVE-2015-6855.patch \
"
SRC_URI_prepend = "http://wiki.qemu-project.org/download/${BP}.tar.bz2"
SRC_URI[md5sum] = "186ee8194140a484a455f8e3c74589f4"
--
1.9.1
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