In the Linux kernel, the following vulnerability has been resolved:
usb: xhci: Apply the link chain quirk on NEC isoc endpoints
Two clearly different specimens of NEC uPD720200 (one with start/stop
bug, one without) were seen to cause IOMMU faults after some Missed
Service Errors. Faulting address is immediately after a transfer ring
segment and patched dynamic debug messages revealed that the MSE was
received when waiting for a TD near the end of that segment:
[ 1.041954] xhci_hcd: Miss service interval error for slot 1 ep 2 expected TD DMA ffa08fe0
[ 1.042120] xhci_hcd: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x0005 address=0xffa09000 flags=0x0000]
[ 1.042146] xhci_hcd: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x0005 address=0xffa09040 flags=0x0000]
It gets even funnier if the next page is a ring segment accessible to
the HC. Below, it reports MSE in segment at ff1e8000, plows through a
zero-filled page at ff1e9000 and starts reporting events for TRBs in
page at ff1ea000 every microframe, instead of jumping to seg ff1e6000.
[ 7.041671] xhci_hcd: Miss service interval error for slot 1 ep 2 expected TD DMA ff1e8fe0
[ 7.041999] xhci_hcd: Miss service interval error for slot 1 ep 2 expected TD DMA ff1e8fe0
[ 7.042011] xhci_hcd: WARN: buffer overrun event for slot 1 ep 2 on endpoint
[ 7.042028] xhci_hcd: All TDs skipped for slot 1 ep 2. Clear skip flag.
[ 7.042134] xhci_hcd: WARN: buffer overrun event for slot 1 ep 2 on endpoint
[ 7.042138] xhci_hcd: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 2 comp_code 31
[ 7.042144] xhci_hcd: Looking for event-dma 00000000ff1ea040 trb-start 00000000ff1e6820 trb-end 00000000ff1e6820
[ 7.042259] xhci_hcd: WARN: buffer overrun event for slot 1 ep 2 on endpoint
[ 7.042262] xhci_hcd: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 2 comp_code 31
[ 7.042266] xhci_hcd: Looking for event-dma 00000000ff1ea050 trb-start 00000000ff1e6820 trb-end 00000000ff1e6820
At some point completion events change from Isoch Buffer Overrun to
Short Packet and the HC finally finds cycle bit mismatch in ff1ec000.
[ 7.098130] xhci_hcd: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 2 comp_code 13
[ 7.098132] xhci_hcd: Looking for event-dma 00000000ff1ecc50 trb-start 00000000ff1e6820 trb-end 00000000ff1e6820
[ 7.098254] xhci_hcd: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 2 comp_code 13
[ 7.098256] xhci_hcd: Looking for event-dma 00000000ff1ecc60 trb-start 00000000ff1e6820 trb-end 00000000ff1e6820
[ 7.098379] xhci_hcd: Overrun event on slot 1 ep 2
It's possible that data from the isochronous device were written to
random buffers of pending TDs on other endpoints (either IN or OUT),
other devices or even other HCs in the same IOMMU domain.
Lastly, an error from a different USB device on another HC. Was it
caused by the above? I don't know, but it may have been. The disk
was working without any other issues and generated PCIe traffic to
starve the NEC of upstream BW and trigger those MSEs. The two HCs
shared one x1 slot by means of a commercial "PCIe splitter" board.
[ 7.162604] usb 10-2: reset SuperSpeed USB device number 3 using xhci_hcd
[ 7.178990] sd 9:0:0:0: [sdb] tag#0 UNKNOWN(0x2003) Result: hostbyte=0x07 driverbyte=DRIVER_OK cmd_age=0s
[ 7.179001] sd 9:0:0:0: [sdb] tag#0 CDB: opcode=0x28 28 00 04 02 ae 00 00 02 00 00
[ 7.179004] I/O error, dev sdb, sector 67284480 op 0x0:(READ) flags 0x80700 phys_seg 5 prio class 0
Fortunately, it appears that this ridiculous bug is avoided by setting
the chain bit of Link TRBs on isochronous rings. Other ancient HCs are
known which also expect the bit to be set and they ignore Link TRBs if
it's not. Reportedly, 0.95 spec guaranteed that the bit is set.
The bandwidth-starved NEC HC running a 32KB/uframe UVC endpoint reports
tens of MSEs per second and runs into the bug within seconds. Chaining
Link TRBs allows the same workload to run for many minutes, many times.
No ne
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In the Linux kernel, the following vulnerability has been resolved:
regulator: check that dummy regulator has been probed before using it
Due to asynchronous driver probing there is a chance that the dummy
regulator hasn't already been probed when first accessing it.
In the Linux kernel, the following vulnerability has been resolved:
net: atm: fix use after free in lec_send()
The ->send() operation frees skb so save the length before calling
->send() to avoid a use after free.
In the Linux kernel, the following vulnerability has been resolved:
HID: ignore non-functional sensor in HP 5MP Camera
The HP 5MP Camera (USB ID 0408:5473) reports a HID sensor interface that
is not actually implemented. Attempting to access this non-functional
sensor via iio_info causes system hangs as runtime PM tries to wake up
an unresponsive sensor.
[453] hid-sensor-hub 0003:0408:5473.0003: Report latency attributes: ffffffff:ffffffff
[453] hid-sensor-hub 0003:0408:5473.0003: common attributes: 5:1, 2:1, 3:1 ffffffff:ffffffff
Add this device to the HID ignore list since the sensor interface is
non-functional by design and should not be exposed to userspace.
In the Linux kernel, the following vulnerability has been resolved:
iscsi_ibft: Fix UBSAN shift-out-of-bounds warning in ibft_attr_show_nic()
When performing an iSCSI boot using IPv6, iscsistart still reads the
/sys/firmware/ibft/ethernetX/subnet-mask entry. Since the IPv6 prefix
length is 64, this causes the shift exponent to become negative,
triggering a UBSAN warning. As the concept of a subnet mask does not
apply to IPv6, the value is set to ~0 to suppress the warning message.
In the Linux kernel, the following vulnerability has been resolved:
scsi: qla1280: Fix kernel oops when debug level > 2
A null dereference or oops exception will eventually occur when qla1280.c
driver is compiled with DEBUG_QLA1280 enabled and ql_debug_level > 2. I
think its clear from the code that the intention here is sg_dma_len(s) not
length of sg_next(s) when printing the debug info.
In the Linux kernel, the following vulnerability has been resolved:
ppp: Fix KMSAN uninit-value warning with bpf
Syzbot caught an "KMSAN: uninit-value" warning [1], which is caused by the
ppp driver not initializing a 2-byte header when using socket filter.
The following code can generate a PPP filter BPF program:
'''
struct bpf_program fp;
pcap_t *handle;
handle = pcap_open_dead(DLT_PPP_PPPD, 65535);
pcap_compile(handle, &fp, "ip and outbound", 0, 0);
bpf_dump(&fp, 1);
'''
Its output is:
'''
(000) ldh [2]
(001) jeq #0x21 jt 2 jf 5
(002) ldb [0]
(003) jeq #0x1 jt 4 jf 5
(004) ret #65535
(005) ret #0
'''
Wen can find similar code at the following link:
https://github.com/ppp-project/ppp/blob/master/pppd/options.c#L1680
The maintainer of this code repository is also the original maintainer
of the ppp driver.
As you can see the BPF program skips 2 bytes of data and then reads the
'Protocol' field to determine if it's an IP packet. Then it read the first
byte of the first 2 bytes to determine the direction.
The issue is that only the first byte indicating direction is initialized
in current ppp driver code while the second byte is not initialized.
For normal BPF programs generated by libpcap, uninitialized data won't be
used, so it's not a problem. However, for carefully crafted BPF programs,
such as those generated by syzkaller [2], which start reading from offset
0, the uninitialized data will be used and caught by KMSAN.
[1] https://syzkaller.appspot.com/bug?extid=853242d9c9917165d791
[2] https://syzkaller.appspot.com/text?tag=ReproC&x=11994913980000