From ba7ac22f2ed783fd4b304c4e3ca0d1203475a81f Mon Sep 17 00:00:00 2001 From: Yogita Urade Date: Thu, 5 Oct 2023 11:12:52 +0000 Subject: qemu: fix CVE-2023-42467 QEMU through 8.0.0 could trigger a division by zero in scsi_disk_reset in hw/scsi/scsi-disk.c because scsi_disk_emulate_mode_select does not prevent s->qdev.blocksize from being 256. This stops QEMU and the guest immediately. References: https://nvd.nist.gov/vuln/detail/CVE-2023-42467 https://gitlab.com/qemu-project/qemu/-/issues/1813 (From OE-Core rev: 7c42b976d7a72acf917bae9d055768a1350e507d) Signed-off-by: Yogita Urade Signed-off-by: Alexandre Belloni Signed-off-by: Richard Purdie --- .../qemu/qemu/CVE-2023-42467.patch | 49 ++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 meta/recipes-devtools/qemu/qemu/CVE-2023-42467.patch (limited to 'meta/recipes-devtools/qemu/qemu') diff --git a/meta/recipes-devtools/qemu/qemu/CVE-2023-42467.patch b/meta/recipes-devtools/qemu/qemu/CVE-2023-42467.patch new file mode 100644 index 0000000000..86ab7cf81a --- /dev/null +++ b/meta/recipes-devtools/qemu/qemu/CVE-2023-42467.patch @@ -0,0 +1,49 @@ +From 7cfcc79b0ab800959716738aff9419f53fc68c9c Mon Sep 17 00:00:00 2001 +From: Thomas Huth +Date: Thu, 5 Oct 2023 06:01:10 +0000 +Subject: [PATCH] hw/scsi/scsi-disk: Disallow block sizes smaller than 512 + [CVE-2023-42467] + +We are doing things like + + nb_sectors /= (s->qdev.blocksize / BDRV_SECTOR_SIZE); + +in the code here (e.g. in scsi_disk_emulate_mode_sense()), so if +the blocksize is smaller than BDRV_SECTOR_SIZE (=512), this crashes +with a division by 0 exception. Thus disallow block sizes of 256 +bytes to avoid this situation. + +Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1813 +CVE: 2023-42467 +Signed-off-by: Thomas Huth +Message-ID: <20230925091854.49198-1-thuth@redhat.com> +Signed-off-by: Paolo Bonzini + +CVE: CVE-2023-42467 + +Upstream-Status: Backport [https://gitlab.com/qemu-project/qemu/-/commit/7cfcc79b0ab800959716738aff9419f53fc68c9c] + +Signed-off-by: Yogita Urade +--- + hw/scsi/scsi-disk.c | 5 +++-- + 1 file changed, 3 insertions(+), 2 deletions(-) + +diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c +index e0d79c796..477ee2bcd 100644 +--- a/hw/scsi/scsi-disk.c ++++ b/hw/scsi/scsi-disk.c +@@ -1628,9 +1628,10 @@ static void scsi_disk_emulate_mode_select(SCSIDiskReq *r, uint8_t *inbuf) + * Since the existing code only checks/updates bits 8-15 of the block + * size, restrict ourselves to the same requirement for now to ensure + * that a block size set by a block descriptor and then read back by +- * a subsequent SCSI command will be the same ++ * a subsequent SCSI command will be the same. Also disallow a block ++ * size of 256 since we cannot handle anything below BDRV_SECTOR_SIZE. + */ +- if (bs && !(bs & ~0xff00) && bs != s->qdev.blocksize) { ++ if (bs && !(bs & ~0xfe00) && bs != s->qdev.blocksize) { + s->qdev.blocksize = bs; + trace_scsi_disk_mode_select_set_blocksize(s->qdev.blocksize); + } +-- +2.40.0 -- cgit v1.2.3-54-g00ecf