CVE-2024-35825usb: gadget: ncm: Fix handling of zero block length packets

Description

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: ncm: Fix handling of zero block length packets While connecting to a Linux host with CDC_NCM_NTB_DEF_SIZE_TX set to 65536, it has been observed that we receive short packets, which come at interval of 5-10 seconds sometimes and have block length zero but still contain 1-2 valid datagrams present. According to the NCM spec: "If wBlockLength = 0x0000, the block is terminated by a short packet. In this case, the USB transfer must still be shorter than dwNtbInMaxSize or dwNtbOutMaxSize. If exactly dwNtbInMaxSize or dwNtbOutMaxSize bytes are sent, and the size is a multiple of wMaxPacketSize for the given pipe, then no ZLP shall be sent. wBlockLength= 0x0000 must be used with extreme care, because of the possibility that the host and device may get out of sync, and because of test issues. wBlockLength = 0x0000 allows the sender to reduce latency by starting to send a very large NTB, and then shortening it when the sender discovers that there’s not sufficient data to justify sending a large NTB" However, there is a potential issue with the current implementation, as it checks for the occurrence of multiple NTBs in a single giveback by verifying if the leftover bytes to be processed is zero or not. If the block length reads zero, we would process the same NTB infintely because the leftover bytes is never zero and it leads to a crash. Fix this by bailing out if block length reads zero.

Timeline

Scores

EPSS (exploitation in 30 days)

0.23% · top 86% of all CVEs (13 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.

Affected products

• Linux · Linux

  • affected ff3ba016263ee93a1c6209bf5ab1599de7ab1512 – < e2dbfea520e60d58e0c498ba41bde10452257779
  • affected e7ca00f35d8a17af1ae19d529193ebc21bfda164 – < a766761d206e7c36d7526e0ae749949d17ca582c
  • affected 17c653d4913bbc50d284aa96cf12bfc63e41ee5c – < ef846cdbd100f7f9dc045e8bcd7fe4b3a3713c03
  • affected 7014807fb7efa169a47a7a0a0a41d2c513925de0 – < 92b051b87658df7649ffcdef522593f21a2b296b
  • affected 49fbc18378ae72a47feabee97fdb86f3cea09765 – < 7664ee8bd80309b90d53488b619764f0a057f2b7
  • affected 427694cfaafa565a3db5c5ea71df6bc095dca92f – < a0f77b5d6067285b8eca0ee3bd1e448a6258026f
  • affected 427694cfaafa565a3db5c5ea71df6bc095dca92f – < 6b2c73111a252263807b7598682663dc33aa4b4c
  • affected 427694cfaafa565a3db5c5ea71df6bc095dca92f – < f90ce1e04cbcc76639d6cba0fdbd820cd80b3c70
  • affected 5bdf93a2f5459f944b416b188178ca4a92fd206f
  • affected 4bf1a9d20c65b9e80ca4b171267103f8d4f2c61f
  • affected 4.19.297 – < 4.19.312
  • affected 5.4.259 – < 5.4.274
  • affected 5.10.199 – < 5.10.215
  • affected 5.15.136 – < 5.15.154
  • affected 6.1.59 – < 6.1.84
  • affected 4.14.328 – < 4.15
  • affected 6.5.8 – < 6.6

• Linux · Linux

  • affected 6.6
  • unaffected < 6.6
  • unaffected 4.19.312 – ≤ 4.19.*
  • unaffected 5.4.274 – ≤ 5.4.*
  • unaffected 5.10.215 – ≤ 5.10.*
  • unaffected 5.15.154 – ≤ 5.15.*
  • unaffected 6.1.84 – ≤ 6.1.*
  • unaffected 6.6.24 – ≤ 6.6.*
  • unaffected 6.7.12 – ≤ 6.7.*
  • unaffected 6.8 – ≤ *

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2024-35809 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2024-35825](https://cveledger.app/badge/CVE-2024-35825.svg)](https://cveledger.app/cve/CVE-2024-35825)

Record last updated 23 May 2026, 15:43 UTC.