UBUNTU-CVE-2021-47587
In the Linux kernel, the following vulnerability has been resolved: net: systemport: Add global locking for descriptor lifecycle The descriptor list is a shared resource across all of the transmit queues, and the locking mechanism used today only protects concurrency across a given transmit queue between the transmit and reclaiming. This creates an opportunity for the SYSTEMPORT hardware to work on corrupted descriptors if we have multiple producers at once which is the case when using multiple transmit queues. This was particularly noticeable when using multiple flows/transmit queues and it showed up in interesting ways in that UDP packets would get a correct UDP header checksum being calculated over an incorrect packet length. Similarly TCP packets would get an equally correct checksum computed by the hardware over an incorrect packet length. The SYSTEMPORT hardware maintains an internal descriptor list that it re-arranges when the driver produces a new descriptor anytime it writes to the WRITE_PORT_{HI,LO} registers, there is however some delay in the hardware to re-organize its descriptors and it is possible that concurrent TX queues eventually break this internal allocation scheme to the point where the length/status part of the descriptor gets used for an incorrect data buffer. The fix is to impose a global serialization for all TX queues in the short section where we are writing to the WRITE_PORT_{HI,LO} registers which solves the corruption even with multiple concurrent TX queues being used.
02 / AFFECTED SOFTWARE
Affected packages
50 explicit affected versions
6 explicit affected versions
12 explicit affected versions
6 explicit affected versions
15 explicit affected versions
7 explicit affected versions
76 explicit affected versions
41 explicit affected versions
56 explicit affected versions
29 explicit affected versions
35 explicit affected versions
18 explicit affected versions
88 explicit affected versions
13 explicit affected versions
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23 explicit affected versions
107 explicit affected versions
1 explicit affected versions
1 explicit affected versions
21 explicit affected versions
16 explicit affected versions
10 explicit affected versions
1 explicit affected versions
7 explicit affected versions
12 explicit affected versions
12 explicit affected versions
1 explicit affected versions
7 explicit affected versions
12 explicit affected versions
45 explicit affected versions
5 explicit affected versions
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12 explicit affected versions
44 explicit affected versions
106 explicit affected versions
31 explicit affected versions
10 explicit affected versions
174 explicit affected versions
37 explicit affected versions
10 explicit affected versions
1 explicit affected versions
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13 explicit affected versions
1 explicit affected versions
29 explicit affected versions
13 explicit affected versions
70 explicit affected versions
1 explicit affected versions
46 explicit affected versions
33 explicit affected versions
23 explicit affected versions
10 explicit affected versions
55 explicit affected versions
11 explicit affected versions
12 explicit affected versions
78 explicit affected versions
7 explicit affected versions
12 explicit affected versions
44 explicit affected versions
2 explicit affected versions
151 explicit affected versions
41 explicit affected versions
10 explicit affected versions
26 explicit affected versions
13 explicit affected versions
16 explicit affected versions
3 explicit affected versions
1 explicit affected versions
12 explicit affected versions
51 explicit affected versions
32 explicit affected versions
12 explicit affected versions
27 explicit affected versions
1 explicit affected versions
1 explicit affected versions
36 explicit affected versions
8 explicit affected versions
5 explicit affected versions
35 explicit affected versions
8 explicit affected versions
1 explicit affected versions
34 explicit affected versions
10 explicit affected versions
13 explicit affected versions
1 explicit affected versions
7 explicit affected versions
32 explicit affected versions
10 explicit affected versions
12 explicit affected versions
31 explicit affected versions
44 explicit affected versions
16 explicit affected versions
3 explicit affected versions
13 explicit affected versions
26 explicit affected versions
37 explicit affected versions
38 explicit affected versions
9 explicit affected versions
11 explicit affected versions
34 explicit affected versions
7 explicit affected versions
84 explicit affected versions
14 explicit affected versions
86 explicit affected versions
63 explicit affected versions
4 explicit affected versions
54 explicit affected versions
34 explicit affected versions
43 explicit affected versions
1 explicit affected versions
130 explicit affected versions
103 explicit affected versions
10 explicit affected versions
8 explicit affected versions
14 explicit affected versions
35 explicit affected versions
4 explicit affected versions
23 explicit affected versions
1 explicit affected versions
10 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: net: systemport: Add global locking for descriptor lifecycle The descriptor list is a shared resource across all of the transmit queues, and the locking mechanism used today only protects concurrency across a given transmit queue between the transmit and reclaiming. This creates an opportunity for the SYSTEMPORT hardware to work on corrupted descriptors if we have multiple producers at once which is the case when using multiple transmit queues. This was particularly noticeable when using multiple flows/transmit queues and it showed up in interesting ways in that UDP packets would get a correct UDP header checksum being calculated over an incorrect packet length. Similarly TCP packets would get an equally correct checksum computed by the hardware over an incorrect packet length. The SYSTEMPORT hardware maintains an internal descriptor list that it re-arranges when the driver produces a new descriptor anytime it writes to the WRITE_PORT_{HI,LO} registers, there is however some delay in the hardware to re-organize its descriptors and it is possible that concurrent TX queues eventually break this internal allocation scheme to the point where the length/status part of the descriptor gets used for an incorrect data buffer. The fix is to impose a global serialization for all TX queues in the short section where we are writing to the WRITE_PORT_{HI,LO} registers which solves the corruption even with multiple concurrent TX queues being used.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/8b8e6e782456f1ce02a7ae914bbd5b1053f0b034
- https://git.kernel.org/stable/c/595a684fa6f23b21958379a18cfa83862c73c2e1
- https://git.kernel.org/stable/c/6e1011cd183faae8daff275c72444edcdfe0d473
- https://git.kernel.org/stable/c/8b8e6e782456f1ce02a7ae914bbd5b1053f0b034
- https://git.kernel.org/stable/c/8ed2f5d08d6e59f8c78b2869bfb95d0be32c094c
- https://git.kernel.org/stable/c/c675256a7f131f5ba3f331efb715e8f31ea0e392
- https://git.kernel.org/stable/c/de57f62f76450b934de8203711bdc4f7953c3421
- https://git.kernel.org/stable/c/eb4687c7442942e115420a30185f8d83faf37696
- https://git.kernel.org/stable/c/f3fde37d3f0d429f0fcce214cb52588a9e21260e
- https://ubuntu.com/security/CVE-2021-47587
- https://ubuntu.com/security/notices/USN-7506-1
- https://ubuntu.com/security/notices/USN-7506-2
- https://ubuntu.com/security/notices/USN-7506-3
- https://ubuntu.com/security/notices/USN-7506-4
- https://www.cve.org/CVERecord?id=CVE-2021-47587