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.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
ff3ba016263ee93a1c6209bf5ab1599de7ab1512 to < e2dbfea520e60d58e0c498ba41bde10452257779affectede7ca00f35d8a17af1ae19d529193ebc21bfda164 to < a766761d206e7c36d7526e0ae749949d17ca582caffected17c653d4913bbc50d284aa96cf12bfc63e41ee5c to < ef846cdbd100f7f9dc045e8bcd7fe4b3a3713c03affected7014807fb7efa169a47a7a0a0a41d2c513925de0 to < 92b051b87658df7649ffcdef522593f21a2b296baffected49fbc18378ae72a47feabee97fdb86f3cea09765 to < 7664ee8bd80309b90d53488b619764f0a057f2b7affected427694cfaafa565a3db5c5ea71df6bc095dca92f to < a0f77b5d6067285b8eca0ee3bd1e448a6258026faffected427694cfaafa565a3db5c5ea71df6bc095dca92f to < 6b2c73111a252263807b7598682663dc33aa4b4caffected427694cfaafa565a3db5c5ea71df6bc095dca92f to < f90ce1e04cbcc76639d6cba0fdbd820cd80b3c70affected5bdf93a2f5459f944b416b188178ca4a92fd206faffected4bf1a9d20c65b9e80ca4b171267103f8d4f2c61faffected4.19.297 to < 4.19.312affected5.4.259 to < 5.4.274affected5.10.199 to < 5.10.215affected5.15.136 to < 5.15.154affected6.1.59 to < 6.1.84affected4.14.328 to < 4.15affected6.5.8 to < 6.6affected
Linux Linux
Default version status: affected
6.6affected0 to < 6.6unaffected4.19.312 to ≤ 4.19.*unaffected5.4.274 to ≤ 5.4.*unaffected5.10.215 to ≤ 5.10.*unaffected5.15.154 to ≤ 5.15.*unaffected6.1.84 to ≤ 6.1.*unaffected6.6.24 to ≤ 6.6.*unaffected6.7.12 to ≤ 6.7.*unaffected6.8 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/e2dbfea520e60d58e0c498ba41bde10452257779 ↗
- https://git.kernel.org/stable/c/a766761d206e7c36d7526e0ae749949d17ca582c ↗
- https://git.kernel.org/stable/c/ef846cdbd100f7f9dc045e8bcd7fe4b3a3713c03 ↗
- https://git.kernel.org/stable/c/92b051b87658df7649ffcdef522593f21a2b296b ↗
- https://git.kernel.org/stable/c/7664ee8bd80309b90d53488b619764f0a057f2b7 ↗
- https://git.kernel.org/stable/c/a0f77b5d6067285b8eca0ee3bd1e448a6258026f ↗
- https://git.kernel.org/stable/c/6b2c73111a252263807b7598682663dc33aa4b4c ↗
- https://git.kernel.org/stable/c/f90ce1e04cbcc76639d6cba0fdbd820cd80b3c70 ↗
- https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html ↗
- https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html ↗