UBUNTU-CVE-2024-35825
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.
02 / AFFECTED SOFTWARE
Affected packages
93 explicit affected versions
29 explicit affected versions
10 explicit affected versions
46 explicit affected versions
11 explicit affected versions
40 explicit affected versions
1 explicit affected versions
31 explicit affected versions
45 explicit affected versions
37 explicit affected versions
40 explicit affected versions
7 explicit affected versions
51 explicit affected versions
26 explicit affected versions
45 explicit affected versions
46 explicit affected versions
37 explicit affected versions
81 explicit affected versions
10 explicit affected versions
10 explicit affected versions
13 explicit affected versions
13 explicit affected versions
31 explicit affected versions
38 explicit affected versions
61 explicit affected versions
37 explicit affected versions
51 explicit affected versions
8 explicit affected versions
4 explicit affected versions
8 explicit affected versions
19 explicit affected versions
47 explicit affected versions
27 explicit affected versions
2 explicit affected versions
23 explicit affected versions
7 explicit affected versions
10 explicit affected versions
93 explicit affected versions
54 explicit affected versions
33 explicit affected versions
16 explicit affected versions
70 explicit affected versions
101 explicit affected versions
27 explicit affected versions
13 explicit affected versions
12 explicit affected versions
52 explicit affected versions
38 explicit affected versions
51 explicit affected versions
13 explicit affected versions
34 explicit affected versions
32 explicit affected versions
10 explicit affected versions
40 explicit affected versions
10 explicit affected versions
13 explicit affected versions
9 explicit affected versions
10 explicit affected versions
58 explicit affected versions
89 explicit affected versions
8 explicit affected versions
13 explicit affected versions
21 explicit affected versions
88 explicit affected versions
81 explicit affected versions
6 explicit affected versions
13 explicit affected versions
12 explicit affected versions
7 explicit affected versions
7 explicit affected versions
14 explicit affected versions
12 explicit affected versions
11 explicit affected versions
26 explicit affected versions
77 explicit affected versions
40 explicit affected versions
23 explicit affected versions
37 explicit affected versions
14 explicit affected versions
5 explicit affected versions
39 explicit affected versions
81 explicit affected versions
90 explicit affected versions
3 explicit affected versions
48 explicit affected versions
26 explicit affected versions
12 explicit affected versions
46 explicit affected versions
12 explicit affected versions
44 explicit affected versions
40 explicit affected versions
51 explicit affected versions
4 explicit affected versions
4 explicit affected versions
16 explicit affected versions
6 explicit affected versions
9 explicit affected versions
12 explicit affected versions
92 explicit affected versions
13 explicit affected versions
7 explicit affected versions
21 explicit affected versions
13 explicit affected versions
7 explicit affected versions
10 explicit affected versions
14 explicit affected versions
18 explicit affected versions
3 explicit affected versions
16 explicit affected versions
78 explicit affected versions
45 explicit affected versions
43 explicit affected versions
51 explicit affected versions
49 explicit affected versions
43 explicit affected versions
11 explicit affected versions
23 explicit affected versions
35 explicit affected versions
12 explicit affected versions
13 explicit affected versions
80 explicit affected versions
6 explicit affected versions
12 explicit affected versions
50 explicit affected versions
11 explicit affected versions
12 explicit affected versions
48 explicit affected versions
27 explicit affected versions
35 explicit affected versions
12 explicit affected versions
7 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
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.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/f90ce1e04cbcc76639d6cba0fdbd820cd80b3c70
- https://git.kernel.org/stable/c/6b2c73111a252263807b7598682663dc33aa4b4c
- https://git.kernel.org/stable/c/7664ee8bd80309b90d53488b619764f0a057f2b7
- https://git.kernel.org/stable/c/92b051b87658df7649ffcdef522593f21a2b296b
- https://git.kernel.org/stable/c/a0f77b5d6067285b8eca0ee3bd1e448a6258026f
- https://git.kernel.org/stable/c/a766761d206e7c36d7526e0ae749949d17ca582c
- https://git.kernel.org/stable/c/e2dbfea520e60d58e0c498ba41bde10452257779
- https://git.kernel.org/stable/c/ef846cdbd100f7f9dc045e8bcd7fe4b3a3713c03
- https://git.kernel.org/stable/c/f90ce1e04cbcc76639d6cba0fdbd820cd80b3c70
- https://ubuntu.com/security/CVE-2024-35825
- https://ubuntu.com/security/notices/USN-6896-1
- https://ubuntu.com/security/notices/USN-6896-2
- https://ubuntu.com/security/notices/USN-6896-3
- https://ubuntu.com/security/notices/USN-6896-4
- https://ubuntu.com/security/notices/USN-6896-5
- https://ubuntu.com/security/notices/USN-6898-1
- https://ubuntu.com/security/notices/USN-6898-2
- https://ubuntu.com/security/notices/USN-6898-3
- https://ubuntu.com/security/notices/USN-6898-4
- https://ubuntu.com/security/notices/USN-6917-1
- https://ubuntu.com/security/notices/USN-6919-1
- https://ubuntu.com/security/notices/USN-6927-1
- https://ubuntu.com/security/notices/USN-7019-1
- https://www.cve.org/CVERecord?id=CVE-2024-35825