Description
In the Linux kernel, the following vulnerability has been resolved:
xprtrdma: Fix cwnd update ordering
After a reconnect, the reply handler is opening the cwnd (and thus
enabling more RPC Calls to be sent) /before/ rpcrdma_post_recvs()
can post enough Receive WRs to receive their replies. This causes an
RNR and the new connection is lost immediately.
The race is most clearly exposed when KASAN and disconnect injection
are enabled. This slows down rpcrdma_rep_create() enough to allow
the send side to post a bunch of RPC Calls before the Receive
completion handler can invoke ib_post_recv().
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 5.4.13 – < 5.5, 5.5 | 5.5 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 5.10.38-1 | — |
| Debian 13 | linux | 5.10.38-1 | — |
| Debian 12 | linux | 5.10.38-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux-raspi-realtime | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv +22 | No fix yet | — |
| Ubuntu 20.04 LTS | linux | 5.4.0-204.224 | USN-7173-1 |
| Ubuntu 20.04 LTS | linux-aws | 5.4.0-1137.147 | USN-7173-2 |
| Ubuntu 20.04 LTS | linux-azure | 5.4.0-1142.149 | USN-7195-1 |
| Ubuntu 20.04 LTS | linux-bluefield | 5.4.0-1097.104 | USN-7173-2 |
| Ubuntu 20.04 LTS | linux-gcp | 5.4.0-1141.150 | USN-7173-1 |
| Ubuntu 20.04 LTS | linux-gke +27 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-ibm | 5.4.0-1084.89 | USN-7173-2 |
| Ubuntu 20.04 LTS | linux-iot | 5.4.0-1048.51 | USN-7413-1 |
| Ubuntu 20.04 LTS | linux-kvm | 5.4.0-1125.133 | USN-7173-1 |
| Ubuntu 20.04 LTS | linux-oracle | 5.4.0-1136.145 | USN-7173-2 |
| Ubuntu 20.04 LTS | linux-raspi | 5.4.0-1121.133 | USN-7173-1 |
| Ubuntu 20.04 LTS | linux-xilinx-zynqmp | 5.4.0-1056.60 | USN-7173-2 |
| Ubuntu 18.04 LTS | linux-gcp +13 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro FIPS 20.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-aws-fips | 5.4.0-1137.147+fips1 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-azure-fips | 5.4.0-1142.149+fips1 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-fips | 5.4.0-1111.121 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-gcp-fips | 5.4.0-1141.150+fips1 | — |
| Ubuntu Pro 18.04 LTS | linux-aws-5.4 | 5.4.0-1137.147~18.04.1 | USN-7173-2 |
| Ubuntu Pro 18.04 LTS | linux-azure-5.4 | 5.4.0-1142.149~18.04.1 | USN-7195-2 |
| Ubuntu Pro 18.04 LTS | linux-gcp-5.4 | 5.4.0-1141.150~18.04.1 | USN-7173-1 |
| Ubuntu Pro 18.04 LTS | linux-hwe-5.4 | 5.4.0-204.224~18.04.1 | USN-7173-1 |
| Ubuntu Pro 18.04 LTS | linux-ibm-5.4 | 5.4.0-1084.89~18.04.1 | USN-7173-2 |
| Ubuntu Pro 18.04 LTS | linux-oracle-5.4 | 5.4.0-1136.145~18.04.1 | USN-7173-2 |
| Ubuntu Pro 18.04 LTS | linux-raspi-5.4 | 5.4.0-1121.133~18.04.1 | USN-7173-3 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP3 | kernel-64kb +7 | 5.3.18-150300.59.158.1 | SUSE-SU-2024:1489-1 |
| SLES 15 SP3 | kernel-default-base | 5.3.18-150300.59.158.1.150300.18.92.5 | SUSE-SU-2024:1489-1 |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP3 | kernel-default-base | 5.3.18-150300.59.158.1.150300.18.92.5 | SUSE-SU-2024:1489-1 |
| SLES for SAP 15 SP3 | kernel-docs +5 | 5.3.18-150300.59.158.1 | SUSE-SU-2024:1489-1 |
| SLE Micro 5.2 | kernel-default | 5.3.18-150300.59.158.1 | SUSE-SU-2024:1489-1 |
| SLE Micro 5.2 | kernel-default-base | 5.3.18-150300.59.158.1.150300.18.92.5 | SUSE-SU-2024:1489-1 |
| SLE Micro 5.2 | kernel-rt +1 | 5.3.18-150300.166.1 | SUSE-SU-2024:1465-1 |
| SLE Micro 5.1 | kernel-default | 5.3.18-150300.59.158.1 | SUSE-SU-2024:1489-1 |
| SLE Micro 5.1 | kernel-default-base | 5.3.18-150300.59.158.1.150300.18.92.5 | SUSE-SU-2024:1489-1 |
| SLE Micro 5.1 | kernel-rt +1 | 5.3.18-150300.166.1 | SUSE-SU-2024:1465-1 |
| SLE Live Patching 15 SP3 | kernel-default | 5.3.18-150300.59.158.1 | SUSE-SU-2024:1489-1 |
| SLE Live Patching 15 SP3 | kernel-livepatch-SLE15-SP3_Update_43 | 1-150300.7.3.5 | SUSE-SU-2024:1489-1 |
| SLE HPC 15 SP3 | kernel-64kb +6 | 5.3.18-150300.59.158.1 | SUSE-SU-2024:1489-1 |
| SLE HPC 15 SP3 | kernel-default-base | 5.3.18-150300.59.158.1.150300.18.92.5 | SUSE-SU-2024:1489-1 |
| SUSE Enterprise Storage 7.1 | kernel-64kb +6 | 5.3.18-150300.59.158.1 | SUSE-SU-2024:1489-1 |
| SUSE Enterprise Storage 7.1 | kernel-default-base | 5.3.18-150300.59.158.1.150300.18.92.5 | SUSE-SU-2024:1489-1 |
Advisories 8
- USN-7173-1 linux, linux-gcp, linux-gcp-5.4, linux-hwe-5.4, linux-kvm, linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Oct 29, 2026
- USN-7195-2 linux-azure-5.4 vulnerabilities Ubuntu Security Notices (USN) · Oct 29, 2026
- USN-7413-1 linux-iot vulnerabilities Ubuntu Security Notices (USN) · Oct 29, 2026
- USN-7173-2 linux-aws, linux-aws-5.4, linux-bluefield, linux-ibm, linux-ibm-5.4, linux-oracle, linux-oracle-5.4, linux-xilinx-zynqmp vulnerabilities Ubuntu Security Notices (USN) · Oct 29, 2026
- USN-7173-3 linux-raspi-5.4 vulnerabilities Ubuntu Security Notices (USN) · Oct 29, 2026
- USN-7195-1 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Oct 29, 2026
- SUSE-SU-2024:1489-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:1465-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026