Signed-off-by: Sakib Sajal <sakib.sa...@windriver.com> --- meta/recipes-devtools/qemu/qemu.inc | 2 + .../qemu/qemu/CVE-2021-20196_1.patch | 54 +++++++++++++++ .../qemu/qemu/CVE-2021-20196_2.patch | 67 +++++++++++++++++++ 3 files changed, 123 insertions(+) create mode 100644 meta/recipes-devtools/qemu/qemu/CVE-2021-20196_1.patch create mode 100644 meta/recipes-devtools/qemu/qemu/CVE-2021-20196_2.patch
diff --git a/meta/recipes-devtools/qemu/qemu.inc b/meta/recipes-devtools/qemu/qemu.inc index 4a5379893c..3401fd7194 100644 --- a/meta/recipes-devtools/qemu/qemu.inc +++ b/meta/recipes-devtools/qemu/qemu.inc @@ -80,6 +80,8 @@ SRC_URI = "https://download.qemu.org/${BPN}-${PV}.tar.xz \ file://CVE-2021-3713.patch \ file://CVE-2021-3748.patch \ file://CVE-2021-3930.patch \ + file://CVE-2021-20196_1.patch \ + file://CVE-2021-20196_2.patch \ " UPSTREAM_CHECK_REGEX = "qemu-(?P<pver>\d+(\.\d+)+)\.tar" diff --git a/meta/recipes-devtools/qemu/qemu/CVE-2021-20196_1.patch b/meta/recipes-devtools/qemu/qemu/CVE-2021-20196_1.patch new file mode 100644 index 0000000000..8b1ad0423b --- /dev/null +++ b/meta/recipes-devtools/qemu/qemu/CVE-2021-20196_1.patch @@ -0,0 +1,54 @@ +From e907ff3d4cb7fd20d402f45355059e67d0dc93e7 Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= <phi...@redhat.com> +Date: Wed, 24 Nov 2021 17:15:34 +0100 +Subject: [PATCH 11/12] hw/block/fdc: Extract blk_create_empty_drive() +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +We are going to re-use this code in the next commit, +so extract it as a new blk_create_empty_drive() function. + +Inspired-by: Hanna Reitz <hre...@redhat.com> +Signed-off-by: Philippe Mathieu-Daudé <phi...@redhat.com> +Message-id: 20211124161536.631563-2-phi...@redhat.com +Signed-off-by: John Snow <js...@redhat.com> + +Upstream-Status: Backport [b154791e7b6d4ca5cdcd54443484d97360bd7ad2] +CVE: CVE-2021-20196 + +Signed-off-by: Sakib Sajal <sakib.sa...@windriver.com> +--- + hw/block/fdc.c | 9 +++++++-- + 1 file changed, 7 insertions(+), 2 deletions(-) + +diff --git a/hw/block/fdc.c b/hw/block/fdc.c +index 4c2c35e22..854b4f172 100644 +--- a/hw/block/fdc.c ++++ b/hw/block/fdc.c +@@ -61,6 +61,12 @@ + } while (0) + + ++/* Anonymous BlockBackend for empty drive */ ++static BlockBackend *blk_create_empty_drive(void) ++{ ++ return blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL); ++} ++ + /********************************************************/ + /* qdev floppy bus */ + +@@ -543,8 +549,7 @@ static void floppy_drive_realize(DeviceState *qdev, Error **errp) + } + + if (!dev->conf.blk) { +- /* Anonymous BlockBackend for an empty drive */ +- dev->conf.blk = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL); ++ dev->conf.blk = blk_create_empty_drive(); + ret = blk_attach_dev(dev->conf.blk, qdev); + assert(ret == 0); + +-- +2.31.1 + diff --git a/meta/recipes-devtools/qemu/qemu/CVE-2021-20196_2.patch b/meta/recipes-devtools/qemu/qemu/CVE-2021-20196_2.patch new file mode 100644 index 0000000000..dd442ccb8f --- /dev/null +++ b/meta/recipes-devtools/qemu/qemu/CVE-2021-20196_2.patch @@ -0,0 +1,67 @@ +From 1d48445a951fd5504190a38abeda70ea9372cf77 Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= <phi...@redhat.com> +Date: Wed, 24 Nov 2021 17:15:35 +0100 +Subject: [PATCH 12/12] hw/block/fdc: Kludge missing floppy drive to fix + CVE-2021-20196 +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +Guest might select another drive on the bus by setting the +DRIVE_SEL bit of the DIGITAL OUTPUT REGISTER (DOR). +The current controller model doesn't expect a BlockBackend +to be NULL. A simple way to fix CVE-2021-20196 is to create +an empty BlockBackend when it is missing. All further +accesses will be safely handled, and the controller state +machines keep behaving correctly. + +Cc: qemu-sta...@nongnu.org +Fixes: CVE-2021-20196 +Reported-by: Gaoning Pan (Ant Security Light-Year Lab) <p...@zju.edu.cn> +Reviewed-by: Darren Kenny <darren.ke...@oracle.com> +Reviewed-by: Hanna Reitz <hre...@redhat.com> +Signed-off-by: Philippe Mathieu-Daudé <phi...@redhat.com> +Message-id: 20211124161536.631563-3-phi...@redhat.com +BugLink: https://bugs.launchpad.net/qemu/+bug/1912780 +Resolves: https://gitlab.com/qemu-project/qemu/-/issues/338 +Reviewed-by: Darren Kenny <darren.ke...@oracle.com> +Reviewed-by: Hanna Reitz <hre...@redhat.com> +Signed-off-by: Philippe Mathieu-Daudé <phi...@redhat.com> +Signed-off-by: John Snow <js...@redhat.com> + +Upstream-Status: Backport [1ab95af033a419e7a64e2d58e67dd96b20af5233] +CVE: CVE-2021-20196 + +Signed-off-by: Sakib Sajal <sakib.sa...@windriver.com> +--- + hw/block/fdc.c | 14 +++++++++++++- + 1 file changed, 13 insertions(+), 1 deletion(-) + +diff --git a/hw/block/fdc.c b/hw/block/fdc.c +index 854b4f172..a736c4d14 100644 +--- a/hw/block/fdc.c ++++ b/hw/block/fdc.c +@@ -1365,7 +1365,19 @@ static FDrive *get_drv(FDCtrl *fdctrl, int unit) + + static FDrive *get_cur_drv(FDCtrl *fdctrl) + { +- return get_drv(fdctrl, fdctrl->cur_drv); ++ FDrive *cur_drv = get_drv(fdctrl, fdctrl->cur_drv); ++ ++ if (!cur_drv->blk) { ++ /* ++ * Kludge: empty drive line selected. Create an anonymous ++ * BlockBackend to avoid NULL deref with various BlockBackend ++ * API calls within this model (CVE-2021-20196). ++ * Due to the controller QOM model limitations, we don't ++ * attach the created to the controller device. ++ */ ++ cur_drv->blk = blk_create_empty_drive(); ++ } ++ return cur_drv; + } + + /* Status A register : 0x00 (read-only) */ +-- +2.31.1 + -- 2.33.0
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