ghsa-hh96-p296-x7m4
Vulnerability from github
Published
2024-05-17 12:31
Modified
2024-07-03 18:42
Severity ?
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Details

In the Linux kernel, the following vulnerability has been resolved:

usb: gadget: ncm: Avoid dropping datagrams of properly parsed NTBs

It is observed sometimes when tethering is used over NCM with Windows 11 as host, at some instances, the gadget_giveback has one byte appended at the end of a proper NTB. When the NTB is parsed, unwrap call looks for any leftover bytes in SKB provided by u_ether and if there are any pending bytes, it treats them as a separate NTB and parses it. But in case the second NTB (as per unwrap call) is faulty/corrupt, all the datagrams that were parsed properly in the first NTB and saved in rx_list are dropped.

Adding a few custom traces showed the following: [002] d..1 7828.532866: dwc3_gadget_giveback: ep1out: req 000000003868811a length 1025/16384 zsI ==> 0 [002] d..1 7828.532867: ncm_unwrap_ntb: K: ncm_unwrap_ntb toprocess: 1025 [002] d..1 7828.532867: ncm_unwrap_ntb: K: ncm_unwrap_ntb nth: 1751999342 [002] d..1 7828.532868: ncm_unwrap_ntb: K: ncm_unwrap_ntb seq: 0xce67 [002] d..1 7828.532868: ncm_unwrap_ntb: K: ncm_unwrap_ntb blk_len: 0x400 [002] d..1 7828.532868: ncm_unwrap_ntb: K: ncm_unwrap_ntb ndp_len: 0x10 [002] d..1 7828.532869: ncm_unwrap_ntb: K: Parsed NTB with 1 frames

In this case, the giveback is of 1025 bytes and block length is 1024. The rest 1 byte (which is 0x00) won't be parsed resulting in drop of all datagrams in rx_list.

Same is case with packets of size 2048: [002] d..1 7828.557948: dwc3_gadget_giveback: ep1out: req 0000000011dfd96e length 2049/16384 zsI ==> 0 [002] d..1 7828.557949: ncm_unwrap_ntb: K: ncm_unwrap_ntb nth: 1751999342 [002] d..1 7828.557950: ncm_unwrap_ntb: K: ncm_unwrap_ntb blk_len: 0x800

Lecroy shows one byte coming in extra confirming that the byte is coming in from PC:

Transfer 2959 - Bytes Transferred(1025) Timestamp((18.524 843 590) - Transaction 8391 - Data(1025 bytes) Timestamp(18.524 843 590) --- Packet 4063861 Data(1024 bytes) Duration(2.117us) Idle(14.700ns) Timestamp(18.524 843 590) --- Packet 4063863 Data(1 byte) Duration(66.160ns) Time(282.000ns) Timestamp(18.524 845 722)

According to Windows driver, no ZLP is needed if wBlockLength is non-zero, because the non-zero wBlockLength has already told the function side the size of transfer to be expected. However, there are in-market NCM devices that rely on ZLP as long as the wBlockLength is multiple of wMaxPacketSize. To deal with such devices, it pads an extra 0 at end so the transfer is no longer multiple of wMaxPacketSize.

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{
   affected: [],
   aliases: [
      "CVE-2024-27405",
   ],
   database_specific: {
      cwe_ids: [
         "CWE-476",
      ],
      github_reviewed: false,
      github_reviewed_at: null,
      nvd_published_at: "2024-05-17T12:15:10Z",
      severity: "HIGH",
   },
   details: "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: ncm: Avoid dropping datagrams of properly parsed NTBs\n\nIt is observed sometimes when tethering is used over NCM with Windows 11\nas host, at some instances, the gadget_giveback has one byte appended at\nthe end of a proper NTB. When the NTB is parsed, unwrap call looks for\nany leftover bytes in SKB provided by u_ether and if there are any pending\nbytes, it treats them as a separate NTB and parses it. But in case the\nsecond NTB (as per unwrap call) is faulty/corrupt, all the datagrams that\nwere parsed properly in the first NTB and saved in rx_list are dropped.\n\nAdding a few custom traces showed the following:\n[002] d..1  7828.532866: dwc3_gadget_giveback: ep1out:\nreq 000000003868811a length 1025/16384 zsI ==> 0\n[002] d..1  7828.532867: ncm_unwrap_ntb: K: ncm_unwrap_ntb toprocess: 1025\n[002] d..1  7828.532867: ncm_unwrap_ntb: K: ncm_unwrap_ntb nth: 1751999342\n[002] d..1  7828.532868: ncm_unwrap_ntb: K: ncm_unwrap_ntb seq: 0xce67\n[002] d..1  7828.532868: ncm_unwrap_ntb: K: ncm_unwrap_ntb blk_len: 0x400\n[002] d..1  7828.532868: ncm_unwrap_ntb: K: ncm_unwrap_ntb ndp_len: 0x10\n[002] d..1  7828.532869: ncm_unwrap_ntb: K: Parsed NTB with 1 frames\n\nIn this case, the giveback is of 1025 bytes and block length is 1024.\nThe rest 1 byte (which is 0x00) won't be parsed resulting in drop of\nall datagrams in rx_list.\n\nSame is case with packets of size 2048:\n[002] d..1  7828.557948: dwc3_gadget_giveback: ep1out:\nreq 0000000011dfd96e length 2049/16384 zsI ==> 0\n[002] d..1  7828.557949: ncm_unwrap_ntb: K: ncm_unwrap_ntb nth: 1751999342\n[002] d..1  7828.557950: ncm_unwrap_ntb: K: ncm_unwrap_ntb blk_len: 0x800\n\nLecroy shows one byte coming in extra confirming that the byte is coming\nin from PC:\n\n Transfer 2959 - Bytes Transferred(1025)  Timestamp((18.524 843 590)\n - Transaction 8391 - Data(1025 bytes) Timestamp(18.524 843 590)\n --- Packet 4063861\n       Data(1024 bytes)\n       Duration(2.117us) Idle(14.700ns) Timestamp(18.524 843 590)\n --- Packet 4063863\n       Data(1 byte)\n       Duration(66.160ns) Time(282.000ns) Timestamp(18.524 845 722)\n\nAccording to Windows driver, no ZLP is needed if wBlockLength is non-zero,\nbecause the non-zero wBlockLength has already told the function side the\nsize of transfer to be expected. However, there are in-market NCM devices\nthat rely on ZLP as long as the wBlockLength is multiple of wMaxPacketSize.\nTo deal with such devices, it pads an extra 0 at end so the transfer is no\nlonger multiple of wMaxPacketSize.",
   id: "GHSA-hh96-p296-x7m4",
   modified: "2024-07-03T18:42:21Z",
   published: "2024-05-17T12:31:00Z",
   references: [
      {
         type: "ADVISORY",
         url: "https://nvd.nist.gov/vuln/detail/CVE-2024-27405",
      },
      {
         type: "WEB",
         url: "https://git.kernel.org/stable/c/059285e04ebb273d32323fbad5431c5b94f77e48",
      },
      {
         type: "WEB",
         url: "https://git.kernel.org/stable/c/2b7ec68869d50ea998908af43b643bca7e54577e",
      },
      {
         type: "WEB",
         url: "https://git.kernel.org/stable/c/2cb66b62a5d64ccf09b0591ab86fb085fa491fc5",
      },
      {
         type: "WEB",
         url: "https://git.kernel.org/stable/c/35b604a37ec70d68b19dafd10bbacf1db505c9ca",
      },
      {
         type: "WEB",
         url: "https://git.kernel.org/stable/c/57ca0e16f393bb21d69734e536e383a3a4c665fd",
      },
      {
         type: "WEB",
         url: "https://git.kernel.org/stable/c/76c51146820c5dac629f21deafab0a7039bc3ccd",
      },
      {
         type: "WEB",
         url: "https://git.kernel.org/stable/c/a31cf46d108dabce3df80b3e5c07661e24912151",
      },
      {
         type: "WEB",
         url: "https://git.kernel.org/stable/c/c7f43900bc723203d7554d299a2ce844054fab8e",
      },
      {
         type: "WEB",
         url: "https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html",
      },
      {
         type: "WEB",
         url: "https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html",
      },
   ],
   schema_version: "1.4.0",
   severity: [
      {
         score: "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
         type: "CVSS_V3",
      },
   ],
}


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