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6.3
CVE-2021-4442: Linux kernel can corrupt network data when TCP queue altered
CVE-2021-4442 · published 2 years ago
Summary
The core Linux operating system could mishandle incoming internet traffic if a special command changes the TCP data queue while it still contains data, potentially corrupting the data stream. This issue impacts any system running the standard Linux kernel, including various Canonical and NVIDIA Linux builds. Apply the latest kernel updates from your vendor to fix the problem.
What to do
- Update canonical linux-azure to version 4.15.0-1115.128~14.04.1.
- Update canonical linux-aws-hwe to version 4.15.0-1103.110~16.04.1.
- Update canonical linux-azure to version 4.15.0-1115.128~16.04.1.
- Update canonical linux-gcp to version 4.15.0-1100.113~16.04.1.
- Update canonical linux-hwe to version 4.15.0-144.148~16.04.1.
- Update canonical linux-oracle to version 4.15.0-1072.80~16.04.1.
- Update canonical linux to version 4.15.0-144.148.
- Update canonical linux-aws to version 4.15.0-1103.110.
- Update canonical linux-aws-5.4 to version 5.4.0-1048.50~18.04.1.
- Update canonical linux-azure-4.15 to version 4.15.0-1115.128.
- Update canonical linux-azure-5.4 to version 5.4.0-1047.49~18.04.1.
- Update canonical linux-gcp-4.15 to version 4.15.0-1100.113.
- Update canonical linux-gcp-5.4 to version 5.4.0-1043.46~18.04.1.
- Update canonical linux-hwe-5.4 to version 5.4.0-73.82~18.04.1.
- Update canonical linux-kvm to version 4.15.0-1092.94.
- Update canonical linux-oracle to version 4.15.0-1072.80.
- Update canonical linux-oracle-5.4 to version 5.4.0-1044.47~18.04.1.
- Update canonical linux-raspi-5.4 to version 5.4.0-1035.38~18.04.1.
- Update canonical linux-aws-fips to version 4.15.0-2045.47.
- Update canonical linux-azure-fips to version 4.15.0-2027.30.
- Update canonical linux-fips to version 4.15.0-1060.68.
- Update canonical linux to version 5.4.0-73.82.
- Update canonical linux-aws to version 5.4.0-1048.50.
- Update canonical linux-azure to version 5.4.0-1047.49.
- Update canonical linux-gcp to version 5.4.0-1043.46.
- Update canonical linux-gkeop to version 5.4.0-1015.16.
- Update canonical linux-kvm to version 5.4.0-1039.40.
- Update canonical linux-oracle to version 5.4.0-1045.49.
- Update canonical linux-raspi to version 5.4.0-1035.38.
- Update canonical linux-aws-fips to version 5.4.0-1069.73+fips2.
- Update canonical linux-azure-fips to version 5.4.0-1073.76+fips1.
- Update canonical linux-gcp-fips to version 5.4.0-1067.71~20.04.1.
- Update debian linux to version 5.10.24-1.
Affected software
| Ecosystem | Vendor | Product | Affected versions |
|---|---|---|---|
| – | linux | linux_kernel |
>= 3.5, < 4.19.181 >= 4.20, < 5.4.106 >= 5.5, < 5.10.24 >= 5.11, < 5.11.7 5.12 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Ubuntu:26.04 | canonical | linux-nvidia | All versions |
| Ubuntu:20.04:LTS | canonical | linux-gke-5.15 | All versions |
| Ubuntu:Pro:14.04:LTS | canonical | linux-azure |
< 4.15.0-1115.128~14.04.1 Fix: upgrade to 4.15.0-1115.128~14.04.1
|
| Ubuntu:Pro:14.04:LTS | canonical | linux | All versions |
| Ubuntu:Pro:14.04:LTS | canonical | linux-aws | All versions |
| Ubuntu:Pro:14.04:LTS | canonical | linux-lts-xenial | All versions |
| Ubuntu:Pro:16.04:LTS | canonical | linux | All versions |
| Ubuntu:Pro:16.04:LTS | canonical | linux-aws | All versions |
| Ubuntu:Pro:16.04:LTS | canonical | linux-aws-hwe |
< 4.15.0-1103.110~16.04.1 Fix: upgrade to 4.15.0-1103.110~16.04.1
|
| Ubuntu:Pro:16.04:LTS | canonical | linux-azure |
< 4.15.0-1115.128~16.04.1 Fix: upgrade to 4.15.0-1115.128~16.04.1
|
| Ubuntu:Pro:16.04:LTS | canonical | linux-gcp |
< 4.15.0-1100.113~16.04.1 Fix: upgrade to 4.15.0-1100.113~16.04.1
|
| Ubuntu:Pro:16.04:LTS | canonical | linux-hwe |
< 4.15.0-144.148~16.04.1 Fix: upgrade to 4.15.0-144.148~16.04.1
|
| Ubuntu:16.04:LTS | canonical | linux-hwe-edge | All versions |
| Ubuntu:Pro:16.04:LTS | canonical | linux-kvm | All versions |
| Ubuntu:Pro:16.04:LTS | canonical | linux-oracle |
< 4.15.0-1072.80~16.04.1 Fix: upgrade to 4.15.0-1072.80~16.04.1
|
| Ubuntu:Pro:FIPS:16.04:LTS | canonical | linux-fips | All versions |
| Ubuntu:18.04:LTS | canonical | linux |
< 4.15.0-144.148 Fix: upgrade to 4.15.0-144.148
|
| Ubuntu:18.04:LTS | canonical | linux-aws |
< 4.15.0-1103.110 Fix: upgrade to 4.15.0-1103.110
|
| Ubuntu:20.04:LTS | canonical | linux-hwe-5.11 | All versions |
| Ubuntu:18.04:LTS | canonical | linux-aws-5.4 |
< 5.4.0-1048.50~18.04.1 Fix: upgrade to 5.4.0-1048.50~18.04.1
|
| Ubuntu:18.04:LTS | canonical | linux-azure-4.15 |
< 4.15.0-1115.128 Fix: upgrade to 4.15.0-1115.128
|
| Ubuntu:18.04:LTS | canonical | linux-azure-5.4 |
< 5.4.0-1047.49~18.04.1 Fix: upgrade to 5.4.0-1047.49~18.04.1
|
| Ubuntu:18.04:LTS | canonical | linux-gcp-4.15 |
< 4.15.0-1100.113 Fix: upgrade to 4.15.0-1100.113
|
| Ubuntu:18.04:LTS | canonical | linux-gcp-5.4 |
< 5.4.0-1043.46~18.04.1 Fix: upgrade to 5.4.0-1043.46~18.04.1
|
| Ubuntu:18.04:LTS | canonical | linux-hwe-5.4 |
< 5.4.0-73.82~18.04.1 Fix: upgrade to 5.4.0-73.82~18.04.1
|
| Ubuntu:18.04:LTS | canonical | linux-kvm |
< 4.15.0-1092.94 Fix: upgrade to 4.15.0-1092.94
|
| Ubuntu:18.04:LTS | canonical | linux-oracle |
< 4.15.0-1072.80 Fix: upgrade to 4.15.0-1072.80
|
| Ubuntu:18.04:LTS | canonical | linux-oracle-5.4 |
< 5.4.0-1044.47~18.04.1 Fix: upgrade to 5.4.0-1044.47~18.04.1
|
| Ubuntu:18.04:LTS | canonical | linux-raspi-5.4 |
< 5.4.0-1035.38~18.04.1 Fix: upgrade to 5.4.0-1035.38~18.04.1
|
| Ubuntu:18.04:LTS | canonical | linux-aws-5.0 | All versions |
| Ubuntu:18.04:LTS | canonical | linux-aws-5.3 | All versions |
| Ubuntu:18.04:LTS | canonical | linux-azure | All versions |
| Ubuntu:18.04:LTS | canonical | linux-azure-5.3 | All versions |
| Ubuntu:18.04:LTS | canonical | linux-azure-edge | All versions |
| Ubuntu:18.04:LTS | canonical | linux-gcp | All versions |
| Ubuntu:18.04:LTS | canonical | linux-gcp-5.3 | All versions |
| Ubuntu:18.04:LTS | canonical | linux-gke-4.15 | All versions |
| Ubuntu:18.04:LTS | canonical | linux-gke-5.4 | All versions |
| Ubuntu:18.04:LTS | canonical | linux-gkeop-5.4 | All versions |
| Ubuntu:18.04:LTS | canonical | linux-hwe | All versions |
| Ubuntu:18.04:LTS | canonical | linux-hwe-edge | All versions |
| Ubuntu:18.04:LTS | canonical | linux-oem | All versions |
| Ubuntu:18.04:LTS | canonical | linux-oracle-5.0 | All versions |
| Ubuntu:18.04:LTS | canonical | linux-oracle-5.3 | All versions |
| Ubuntu:Pro:FIPS-updates:18.04:LTS | canonical | linux-aws-fips |
< 4.15.0-2045.47 Fix: upgrade to 4.15.0-2045.47
|
| Ubuntu:Pro:FIPS-updates:18.04:LTS | canonical | linux-azure-fips |
< 4.15.0-2027.30 Fix: upgrade to 4.15.0-2027.30
|
| Ubuntu:Pro:FIPS-updates:18.04:LTS | canonical | linux-fips |
< 4.15.0-1060.68 Fix: upgrade to 4.15.0-1060.68
|
| Ubuntu:Pro:FIPS:18.04:LTS | canonical | linux-aws-fips | All versions |
| Ubuntu:Pro:FIPS:18.04:LTS | canonical | linux-azure-fips | All versions |
Showing 50 of 126. Show the rest
| Ecosystem | Vendor | Product | Affected versions |
|---|---|---|---|
| Ubuntu:Pro:FIPS:18.04:LTS | canonical | linux-fips | All versions |
| Ubuntu:Pro:FIPS:18.04:LTS | canonical | linux-gcp-fips | All versions |
| Ubuntu:20.04:LTS | canonical | linux |
< 5.4.0-73.82 Fix: upgrade to 5.4.0-73.82
|
| Ubuntu:20.04:LTS | canonical | linux-aws |
< 5.4.0-1048.50 Fix: upgrade to 5.4.0-1048.50
|
| Ubuntu:20.04:LTS | canonical | linux-azure |
< 5.4.0-1047.49 Fix: upgrade to 5.4.0-1047.49
|
| Ubuntu:20.04:LTS | canonical | linux-gcp |
< 5.4.0-1043.46 Fix: upgrade to 5.4.0-1043.46
|
| Ubuntu:20.04:LTS | canonical | linux-gkeop |
< 5.4.0-1015.16 Fix: upgrade to 5.4.0-1015.16
|
| Ubuntu:20.04:LTS | canonical | linux-kvm |
< 5.4.0-1039.40 Fix: upgrade to 5.4.0-1039.40
|
| Ubuntu:20.04:LTS | canonical | linux-oracle |
< 5.4.0-1045.49 Fix: upgrade to 5.4.0-1045.49
|
| Ubuntu:20.04:LTS | canonical | linux-raspi |
< 5.4.0-1035.38 Fix: upgrade to 5.4.0-1035.38
|
| Ubuntu:20.04:LTS | canonical | linux-aws-5.11 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-aws-5.13 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-aws-5.8 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-azure-5.11 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-azure-5.13 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-azure-5.8 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-azure-fde | All versions |
| Ubuntu:20.04:LTS | canonical | linux-gcp-5.11 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-gcp-5.13 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-gcp-5.8 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-gke | All versions |
| Ubuntu:20.04:LTS | canonical | linux-hwe-5.13 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-hwe-5.8 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-intel-5.13 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-oem-5.10 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-oem-5.13 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-oem-5.14 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-oem-5.6 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-oracle-5.11 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-oracle-5.13 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-oracle-5.8 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-raspi2 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-riscv | All versions |
| Ubuntu:20.04:LTS | canonical | linux-riscv-5.11 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-riscv-5.8 | All versions |
| Ubuntu:Pro:FIPS-updates:20.04:LTS | canonical | linux-aws-fips |
< 5.4.0-1069.73+fips2 Fix: upgrade to 5.4.0-1069.73+fips2
|
| Ubuntu:Pro:FIPS-updates:20.04:LTS | canonical | linux-azure-fips |
< 5.4.0-1073.76+fips1 Fix: upgrade to 5.4.0-1073.76+fips1
|
| Ubuntu:Pro:FIPS-updates:20.04:LTS | canonical | linux-gcp-fips |
< 5.4.0-1067.71~20.04.1 Fix: upgrade to 5.4.0-1067.71~20.04.1
|
| Ubuntu:Pro:FIPS:20.04:LTS | canonical | linux-aws-fips | All versions |
| Ubuntu:Pro:FIPS:20.04:LTS | canonical | linux-azure-fips | All versions |
| Ubuntu:Pro:FIPS:20.04:LTS | canonical | linux-fips | All versions |
| Ubuntu:Pro:FIPS:20.04:LTS | canonical | linux-gcp-fips | All versions |
| Ubuntu:22.04:LTS | canonical | linux-allwinner-5.19 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-aws-5.19 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-aws-6.2 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-aws-6.5 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-azure-5.19 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-azure-6.2 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-azure-6.5 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-azure-fde-5.19 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-azure-fde-6.2 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-gcp-5.19 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-gcp-6.2 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-gcp-6.5 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-hwe-5.19 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-hwe-6.2 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-hwe-6.5 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-intel-iot-realtime | All versions |
| Ubuntu:22.04:LTS | canonical | linux-lowlatency-hwe-5.19 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-lowlatency-hwe-6.2 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-lowlatency-hwe-6.5 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-nvidia-6.2 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-oem-5.17 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-oem-6.0 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-oem-6.1 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-oem-6.5 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-oracle-6.5 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-realtime | All versions |
| Ubuntu:22.04:LTS | canonical | linux-riscv | All versions |
| Ubuntu:22.04:LTS | canonical | linux-riscv-5.19 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-riscv-6.5 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-starfive-5.19 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-starfive-6.2 | All versions |
| Ubuntu:22.04:LTS | canonical | linux-starfive-6.5 | All versions |
| Ubuntu:24.04:LTS | canonical | linux-raspi-realtime | All versions |
| Debian:12 | debian | linux |
< 5.10.24-1 Fix: upgrade to 5.10.24-1
|
Original advisory text
In the Linux kernel, the following vulnerability has been resolved: tcp: add sanity tests to TCP_QUEUE_SEQ Qingyu Li reported a syzkaller bug where the repro changes RCV SEQ _after_ restoring data ...
In the Linux kernel, the following vulnerability has been resolved: tcp: add sanity tests to TCP_QUEUE_SEQ Qingyu Li reported a syzkaller bug where the repro changes RCV SEQ _after_ restoring data in the receive queue. mprotect(0x4aa000, 12288, PROT_READ) = 0 mmap(0x1ffff000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x1ffff000 mmap(0x20000000, 16777216, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000 mmap(0x21000000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x21000000 socket(AF_INET6, SOCK_STREAM, IPPROTO_IP) = 3 setsockopt(3, SOL_TCP, TCP_REPAIR, [1], 4) = 0 connect(3, {sa_family=AF_INET6, sin6_port=htons(0), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "::1", &sin6_addr), sin6_scope_id=0}, 28) = 0 setsockopt(3, SOL_TCP, TCP_REPAIR_QUEUE, [1], 4) = 0 sendmsg(3, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="0x0000000000000003\0\0", iov_len=20}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 20 setsockopt(3, SOL_TCP, TCP_REPAIR, [0], 4) = 0 setsockopt(3, SOL_TCP, TCP_QUEUE_SEQ, [128], 4) = 0 recvfrom(3, NULL, 20, 0, NULL, NULL) = -1 ECONNRESET (Connection reset by peer) syslog shows: [ 111.205099] TCP recvmsg seq # bug 2: copied 80, seq 0, rcvnxt 80, fl 0 [ 111.207894] WARNING: CPU: 1 PID: 356 at net/ipv4/tcp.c:2343 tcp_recvmsg_locked+0x90e/0x29a0 This should not be allowed. TCP_QUEUE_SEQ should only be used when queues are empty. This patch fixes this case, and the tx path as well.
References
- https://ubuntu.com/security/CVE-2021-4442 Third Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2021-4442 Third Party Advisory
- https://git.kernel.org/linus/8811f4a9836e31c14ecdf79d9f3cb7c5d463265d Third Party Advisory
- https://git.kernel.org/stable/c/046f3c1c2ff450fb7ae53650e9a95e0074a61f3e Third Party Advisory
- https://git.kernel.org/stable/c/3b72d5a703842f582502d97906f17d6ee122dac2 Third Party Advisory
- https://git.kernel.org/stable/c/8811f4a9836e31c14ecdf79d9f3cb7c5d463265d Third Party Advisory
- https://security-tracker.debian.org/tracker/CVE-2021-4442 Vendor Advisory
- https://git.kernel.org/stable/c/319f460237fc2965a80aa9a055044e1da7b3692a Third Party Advisory
- https://git.kernel.org/stable/c/3bf899438c123c444f6b644a57784dfbb6b15ad6 Third Party Advisory
Internet-facing
60 days
Internal
At next upgrade
- Not known to be exploited
- Needs hands-on effort to exploit
- Gives an attacker partial control
Severity
6.3
Medium
Timeline
Published29 Aug 2024
Updated4 Nov 2026
First seen7 Mar 2026
Track software like this
Free during beta