To fix CVE-2025-22022, commit bb0ba4cb1065 is required; however, it depends on commit 7476a2215c07. Therefore, both patches have been backported to v5.10-v6.1.
Michal Pecio (1): usb: xhci: Apply the link chain quirk on NEC isoc endpoints
Niklas Neronin (1): usb: xhci: move link chain bit quirk checks into one helper function.
drivers/usb/host/xhci-mem.c | 10 ++-------- drivers/usb/host/xhci-ring.c | 8 ++------ drivers/usb/host/xhci.h | 16 ++++++++++++++-- 3 files changed, 18 insertions(+), 16 deletions(-)
From: Niklas Neronin niklas.neronin@linux.intel.com
commit 7476a2215c07703db5e95efaa3fc5b9f957b9417 upstream.
Older 0.95 xHCI hosts and some other specific newer hosts require the chain bit to be set for Link TRBs even if the link TRB is not in the middle of a transfer descriptor (TD).
move the checks for all those cases into one xhci_link_chain_quirk() function to clean up and avoid code duplication.
No functional changes.
[skip renaming chain_links flag, reword commit message -Mathias]
Signed-off-by: Niklas Neronin niklas.neronin@linux.intel.com Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com Link: https://lore.kernel.org/r/20240626124835.1023046-10-mathias.nyman@linux.inte... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org [Shivani: Modified to apply on v5.10.y-v6.1.y] Signed-off-by: Shivani Agarwal shivani.agarwal@broadcom.com --- drivers/usb/host/xhci-mem.c | 10 ++-------- drivers/usb/host/xhci-ring.c | 8 ++------ drivers/usb/host/xhci.h | 7 +++++-- 3 files changed, 9 insertions(+), 16 deletions(-)
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c index 57f739f93321..42c12b382e9f 100644 --- a/drivers/usb/host/xhci-mem.c +++ b/drivers/usb/host/xhci-mem.c @@ -133,10 +133,7 @@ static void xhci_link_rings(struct xhci_hcd *xhci, struct xhci_ring *ring, if (!ring || !first || !last) return;
- /* Set chain bit for 0.95 hosts, and for isoc rings on AMD 0.96 host */ - chain_links = !!(xhci_link_trb_quirk(xhci) || - (ring->type == TYPE_ISOC && - (xhci->quirks & XHCI_AMD_0x96_HOST))); + chain_links = xhci_link_chain_quirk(xhci, ring->type);
next = ring->enq_seg->next; xhci_link_segments(ring->enq_seg, first, ring->type, chain_links); @@ -326,10 +323,7 @@ static int xhci_alloc_segments_for_ring(struct xhci_hcd *xhci, struct xhci_segment *prev; bool chain_links;
- /* Set chain bit for 0.95 hosts, and for isoc rings on AMD 0.96 host */ - chain_links = !!(xhci_link_trb_quirk(xhci) || - (type == TYPE_ISOC && - (xhci->quirks & XHCI_AMD_0x96_HOST))); + chain_links = xhci_link_chain_quirk(xhci, type);
prev = xhci_segment_alloc(xhci, cycle_state, max_packet, flags); if (!prev) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index cb0bf8b6e017..1f047f38ef46 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -250,9 +250,7 @@ static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring, * AMD 0.96 host, carry over the chain bit of the previous TRB * (which may mean the chain bit is cleared). */ - if (!(ring->type == TYPE_ISOC && - (xhci->quirks & XHCI_AMD_0x96_HOST)) && - !xhci_link_trb_quirk(xhci)) { + if (!xhci_link_chain_quirk(xhci, ring->type)) { next->link.control &= cpu_to_le32(~TRB_CHAIN); next->link.control |= cpu_to_le32(chain); } @@ -3355,9 +3353,7 @@ static int prepare_ring(struct xhci_hcd *xhci, struct xhci_ring *ep_ring, /* If we're not dealing with 0.95 hardware or isoc rings * on AMD 0.96 host, clear the chain bit. */ - if (!xhci_link_trb_quirk(xhci) && - !(ep_ring->type == TYPE_ISOC && - (xhci->quirks & XHCI_AMD_0x96_HOST))) + if (!xhci_link_chain_quirk(xhci, ep_ring->type)) ep_ring->enqueue->link.control &= cpu_to_le32(~TRB_CHAIN); else diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index fd095ff9fc8b..07591a498b5e 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1788,9 +1788,12 @@ static inline void xhci_write_64(struct xhci_hcd *xhci, lo_hi_writeq(val, regs); }
-static inline int xhci_link_trb_quirk(struct xhci_hcd *xhci) + +/* Link TRB chain should always be set on 0.95 hosts, and AMD 0.96 ISOC rings */ +static inline bool xhci_link_chain_quirk(struct xhci_hcd *xhci, enum xhci_ring_type type) { - return xhci->quirks & XHCI_LINK_TRB_QUIRK; + return (xhci->quirks & XHCI_LINK_TRB_QUIRK) || + (type == TYPE_ISOC && (xhci->quirks & XHCI_AMD_0x96_HOST)); }
/* xHCI debugging */
From: Michal Pecio michal.pecio@gmail.com
commit bb0ba4cb1065e87f9cc75db1fa454e56d0894d01 upstream.
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 negative side effects seen in UVC recording and UAC playback with a few devices at full speed, high speed and SuperSpeed.
The problem doesn't reproduce on the newer Renesas uPD720201/uPD720202 and on old Etron EJ168 and VIA VL805 (but the VL805 has other bug).
[shorten line length of log snippets in commit messge -Mathias]
Signed-off-by: Michal Pecio michal.pecio@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com Link: https://lore.kernel.org/r/20250306144954.3507700-14-mathias.nyman@linux.inte... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org [Shivani: Modified to apply on v5.10.y-v6.1.y] Signed-off-by: Shivani Agarwal shivani.agarwal@broadcom.com --- drivers/usb/host/xhci.h | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 07591a498b5e..b43e88102200 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1789,11 +1789,20 @@ static inline void xhci_write_64(struct xhci_hcd *xhci, }
-/* Link TRB chain should always be set on 0.95 hosts, and AMD 0.96 ISOC rings */ +/* + * Reportedly, some chapters of v0.95 spec said that Link TRB always has its chain bit set. + * Other chapters and later specs say that it should only be set if the link is inside a TD + * which continues from the end of one segment to the next segment. + * + * Some 0.95 hardware was found to misbehave if any link TRB doesn't have the chain bit set. + * + * 0.96 hardware from AMD and NEC was found to ignore unchained isochronous link TRBs when + * "resynchronizing the pipe" after a Missed Service Error. + */ static inline bool xhci_link_chain_quirk(struct xhci_hcd *xhci, enum xhci_ring_type type) { return (xhci->quirks & XHCI_LINK_TRB_QUIRK) || - (type == TYPE_ISOC && (xhci->quirks & XHCI_AMD_0x96_HOST)); + (type == TYPE_ISOC && (xhci->quirks & (XHCI_AMD_0x96_HOST | XHCI_NEC_HOST))); }
/* xHCI debugging */
linux-stable-mirror@lists.linaro.org
-
Shivani Agarwal