| From 1328fe0c32d5474604105b8105310e944976b058 Mon Sep 17 00:00:00 2001 |
| From: Prasad J Pandit <pjp@fedoraproject.org> |
| Date: Tue, 15 Sep 2020 23:52:58 +0530 |
| Subject: [PATCH] hw: usb: hcd-ohci: check len and frame_number variables |
| |
| While servicing the OHCI transfer descriptors(TD), OHCI host |
| controller derives variables 'start_addr', 'end_addr', 'len' |
| etc. from values supplied by the host controller driver. |
| Host controller driver may supply values such that using |
| above variables leads to out-of-bounds access issues. |
| Add checks to avoid them. |
| |
| AddressSanitizer: stack-buffer-overflow on address 0x7ffd53af76a0 |
| READ of size 2 at 0x7ffd53af76a0 thread T0 |
| #0 ohci_service_iso_td ../hw/usb/hcd-ohci.c:734 |
| #1 ohci_service_ed_list ../hw/usb/hcd-ohci.c:1180 |
| #2 ohci_process_lists ../hw/usb/hcd-ohci.c:1214 |
| #3 ohci_frame_boundary ../hw/usb/hcd-ohci.c:1257 |
| #4 timerlist_run_timers ../util/qemu-timer.c:572 |
| #5 qemu_clock_run_timers ../util/qemu-timer.c:586 |
| #6 qemu_clock_run_all_timers ../util/qemu-timer.c:672 |
| #7 main_loop_wait ../util/main-loop.c:527 |
| #8 qemu_main_loop ../softmmu/vl.c:1676 |
| #9 main ../softmmu/main.c:50 |
| |
| Reported-by: Gaoning Pan <pgn@zju.edu.cn> |
| Reported-by: Yongkang Jia <j_kangel@163.com> |
| Reported-by: Yi Ren <yunye.ry@alibaba-inc.com> |
| Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org> |
| Message-id: 20200915182259.68522-2-ppandit@redhat.com |
| Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> |
| |
| Upstream-Status: Backport |
| CVE: CVE-2020-25624 |
| [https://git.qemu.org/?p=qemu.git;a=commit;h=1328fe0c32d5474604105b8105310e944976b058] |
| Signed-off-by: Li Wang <li.wang@windriver.com> |
| --- |
| hw/usb/hcd-ohci.c | 24 ++++++++++++++++++++++-- |
| 1 file changed, 22 insertions(+), 2 deletions(-) |
| |
| diff --git a/hw/usb/hcd-ohci.c b/hw/usb/hcd-ohci.c |
| index 1e6e85e..9dc5910 100644 |
| --- a/hw/usb/hcd-ohci.c |
| +++ b/hw/usb/hcd-ohci.c |
| @@ -731,7 +731,11 @@ static int ohci_service_iso_td(OHCIState *ohci, struct ohci_ed *ed, |
| } |
| |
| start_offset = iso_td.offset[relative_frame_number]; |
| - next_offset = iso_td.offset[relative_frame_number + 1]; |
| + if (relative_frame_number < frame_count) { |
| + next_offset = iso_td.offset[relative_frame_number + 1]; |
| + } else { |
| + next_offset = iso_td.be; |
| + } |
| |
| if (!(OHCI_BM(start_offset, TD_PSW_CC) & 0xe) || |
| ((relative_frame_number < frame_count) && |
| @@ -764,7 +768,12 @@ static int ohci_service_iso_td(OHCIState *ohci, struct ohci_ed *ed, |
| } |
| } else { |
| /* Last packet in the ISO TD */ |
| - end_addr = iso_td.be; |
| + end_addr = next_offset; |
| + } |
| + |
| + if (start_addr > end_addr) { |
| + trace_usb_ohci_iso_td_bad_cc_overrun(start_addr, end_addr); |
| + return 1; |
| } |
| |
| if ((start_addr & OHCI_PAGE_MASK) != (end_addr & OHCI_PAGE_MASK)) { |
| @@ -773,6 +782,9 @@ static int ohci_service_iso_td(OHCIState *ohci, struct ohci_ed *ed, |
| } else { |
| len = end_addr - start_addr + 1; |
| } |
| + if (len > sizeof(ohci->usb_buf)) { |
| + len = sizeof(ohci->usb_buf); |
| + } |
| |
| if (len && dir != OHCI_TD_DIR_IN) { |
| if (ohci_copy_iso_td(ohci, start_addr, end_addr, ohci->usb_buf, len, |
| @@ -975,8 +987,16 @@ static int ohci_service_td(OHCIState *ohci, struct ohci_ed *ed) |
| if ((td.cbp & 0xfffff000) != (td.be & 0xfffff000)) { |
| len = (td.be & 0xfff) + 0x1001 - (td.cbp & 0xfff); |
| } else { |
| + if (td.cbp > td.be) { |
| + trace_usb_ohci_iso_td_bad_cc_overrun(td.cbp, td.be); |
| + ohci_die(ohci); |
| + return 1; |
| + } |
| len = (td.be - td.cbp) + 1; |
| } |
| + if (len > sizeof(ohci->usb_buf)) { |
| + len = sizeof(ohci->usb_buf); |
| + } |
| |
| pktlen = len; |
| if (len && dir != OHCI_TD_DIR_IN) { |
| -- |
| 2.17.1 |
| |