diff options
Diffstat (limited to 'meta/recipes-devtools/qemu/qemu/CVE-2020-14394.patch')
| -rw-r--r-- | meta/recipes-devtools/qemu/qemu/CVE-2020-14394.patch | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/meta/recipes-devtools/qemu/qemu/CVE-2020-14394.patch b/meta/recipes-devtools/qemu/qemu/CVE-2020-14394.patch new file mode 100644 index 0000000000..aff91a7355 --- /dev/null +++ b/meta/recipes-devtools/qemu/qemu/CVE-2020-14394.patch @@ -0,0 +1,79 @@ +From effaf5a240e03020f4ae953e10b764622c3e87cc Mon Sep 17 00:00:00 2001 +From: Thomas Huth <thuth@redhat.com> +Date: Tue, 8 Aug 2023 10:44:51 +0000 +Subject: [PATCH] hw/usb/hcd-xhci: Fix unbounded loop in + xhci_ring_chain_length() (CVE-2020-14394) + +The loop condition in xhci_ring_chain_length() is under control of +the guest, and additionally the code does not check for failed DMA +transfers (e.g. if reaching the end of the RAM), so the loop there +could run for a very long time or even forever. Fix it by checking +the return value of dma_memory_read() and by introducing a maximum +loop length. + +Resolves: https://gitlab.com/qemu-project/qemu/-/issues/646 +Message-Id: <20220804131300.96368-1-thuth@redhat.com> +Reviewed-by: Mauro Matteo Cascella <mcascell@redhat.com> +Acked-by: Gerd Hoffmann <kraxel@redhat.com> +Signed-off-by: Thomas Huth <thuth@redhat.com> + +CVE: CVE-2020-14394 + +Upstream-Status: Backport [https://gitlab.com/qemu-project/qemu/-/commit/effaf5a240e03020f4ae953e10b764622c3e87cc] + +Signed-off-by: Yogita Urade <yogita.urade@windriver.com> +--- + hw/usb/hcd-xhci.c | 23 +++++++++++++++++++---- + 1 file changed, 19 insertions(+), 4 deletions(-) + +diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c +index 14bdb8967..c63a36dcc 100644 +--- a/hw/usb/hcd-xhci.c ++++ b/hw/usb/hcd-xhci.c +@@ -21,6 +21,7 @@ + + #include "qemu/osdep.h" + #include "qemu/timer.h" ++#include "qemu/log.h" + #include "qemu/module.h" + #include "qemu/queue.h" + #include "migration/vmstate.h" +@@ -725,10 +726,14 @@ static int xhci_ring_chain_length(XHCIState *xhci, const XHCIRing *ring) + bool control_td_set = 0; + uint32_t link_cnt = 0; + +- while (1) { ++ do { + TRBType type; +- dma_memory_read(xhci->as, dequeue, &trb, TRB_SIZE, +- MEMTXATTRS_UNSPECIFIED); ++ if (dma_memory_read(xhci->as, dequeue, &trb, TRB_SIZE, ++ MEMTXATTRS_UNSPECIFIED) != MEMTX_OK) { ++ qemu_log_mask(LOG_GUEST_ERROR, "%s: DMA memory access failed!\n", ++ __func__); ++ return -1; ++ } + le64_to_cpus(&trb.parameter); + le32_to_cpus(&trb.status); + le32_to_cpus(&trb.control); +@@ -762,7 +767,17 @@ static int xhci_ring_chain_length(XHCIState *xhci, const XHCIRing *ring) + if (!control_td_set && !(trb.control & TRB_TR_CH)) { + return length; + } +- } ++ ++ /* ++ * According to the xHCI spec, Transfer Ring segments should have ++ * a maximum size of 64 kB (see chapter "6 Data Structures") ++ */ ++ } while (length < TRB_LINK_LIMIT * 65536 / TRB_SIZE); ++ ++ qemu_log_mask(LOG_GUEST_ERROR, "%s: exceeded maximum tranfer ring size!\n", ++ __func__); ++ ++ return -1; + } + + static void xhci_er_reset(XHCIState *xhci, int v) +-- +2.35.5 |