CVE-2024-42256

Publication date 8 August 2024

Last updated 26 August 2025


Ubuntu priority

Cvss 3 Severity Score

9.8 · Critical

Score breakdown

Description

In the Linux kernel, the following vulnerability has been resolved: cifs: Fix server re-repick on subrequest retry When a subrequest is marked for needing retry, netfs will call cifs_prepare_write() which will make cifs repick the server for the op before renegotiating credits; it then calls cifs_issue_write() which invokes smb2_async_writev() - which re-repicks the server. If a different server is then selected, this causes the increment of server->in_flight to happen against one record and the decrement to happen against another, leading to misaccounting. Fix this by just removing the repick code in smb2_async_writev(). As this is only called from netfslib-driven code, cifs_prepare_write() should always have been called first, and so server should never be NULL and the preparatory step is repeated in the event that we do a retry. The problem manifests as a warning looking something like: WARNING: CPU: 4 PID: 72896 at fs/smb/client/smb2ops.c:97 smb2_add_credits+0x3f0/0x9e0 [cifs] ... RIP: 0010:smb2_add_credits+0x3f0/0x9e0 [cifs] ... smb2_writev_callback+0x334/0x560 [cifs] cifs_demultiplex_thread+0x77a/0x11b0 [cifs] kthread+0x187/0x1d0 ret_from_fork+0x34/0x60 ret_from_fork_asm+0x1a/0x30 Which may be triggered by a number of different xfstests running against an Azure server in multichannel mode. generic/249 seems the most repeatable, but generic/215, generic/249 and generic/308 may also show it.

Status

Package Ubuntu Release Status
linux 24.04 LTS noble
Not affected
22.04 LTS jammy
Not affected
20.04 LTS focal
Not affected
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty
Not affected
linux-hwe 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic Ignored replaced by linux-hwe-5.4
16.04 LTS xenial
Not affected
linux-hwe-5.4 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic
Not affected
linux-hwe-5.8 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored superseded by linux-hwe-5.11
linux-hwe-5.11 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored superseded by linux-hwe-5.13
linux-hwe-5.13 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored superseded by linux-hwe-5.15
linux-hwe-5.15 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal
Not affected
linux-hwe-5.19 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-hwe-6.2
20.04 LTS focal Not in release
linux-hwe-6.2 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-hwe-6.5
20.04 LTS focal Not in release
linux-hwe-6.5 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-hwe-6.8
20.04 LTS focal Not in release
linux-hwe-edge 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic Ignored superseded by linux-hwe-5.4
16.04 LTS xenial Ignored superseded by linux-hwe
linux-lts-xenial 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
14.04 LTS trusty
Not affected
linux-kvm 24.04 LTS noble Not in release
22.04 LTS jammy
Not affected
20.04 LTS focal
Not affected
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected
linux-allwinner-5.19 24.04 LTS noble Not in release
22.04 LTS jammy Ignored end of kernel support
20.04 LTS focal Not in release
linux-aws 24.04 LTS noble
Not affected
22.04 LTS jammy
Not affected
20.04 LTS focal
Not affected
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty
Not affected
linux-aws-5.0 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic Ignored superseded by linux-aws-5.3
linux-aws-5.3 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic Ignored superseded by linux-aws-5.4
linux-aws-5.4 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic
Not affected
linux-aws-5.8 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored superseded by linux-aws-5.11
linux-aws-5.11 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored superseded by linux-aws-5.13
linux-aws-5.13 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored superseded by linux-aws-5.15
linux-aws-5.15 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal
Not affected
linux-aws-5.19 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-aws-6.2
20.04 LTS focal Not in release
linux-aws-6.2 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-aws-6.5
20.04 LTS focal Not in release
linux-aws-6.5 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-aws-6.8
20.04 LTS focal Not in release
linux-aws-hwe 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
16.04 LTS xenial
Not affected
linux-azure 24.04 LTS noble
Not affected
22.04 LTS jammy
Not affected
20.04 LTS focal
Not affected
18.04 LTS bionic Ignored superseded by linux-azure-5.3
16.04 LTS xenial
Not affected
14.04 LTS trusty
Not affected
linux-azure-4.15 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic
Not affected
linux-azure-5.3 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic Ignored superseded by linux-azure-5.4
linux-azure-5.4 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic
Not affected
linux-azure-5.8 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored superseded by linux-azure-5.11
linux-azure-5.11 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored superseded by linux-azure-5.13
linux-azure-5.13 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored superseded by linux-azure-5.15
linux-azure-5.15 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal
Not affected
linux-azure-5.19 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-azure-6.2
20.04 LTS focal Not in release
linux-azure-6.2 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-azure-6.5
20.04 LTS focal Not in release
linux-azure-6.5 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-azure-6.8
20.04 LTS focal Not in release
linux-azure-fde 24.04 LTS noble
Not affected
22.04 LTS jammy
Not affected
20.04 LTS focal Ignored superseded by linux-azure-fde-5.15
linux-azure-fde-5.15 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal
Not affected
linux-azure-fde-5.19 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-azure-fde-6.2
20.04 LTS focal Not in release
linux-azure-fde-6.2 24.04 LTS noble Not in release
22.04 LTS jammy Ignored replaced by linux-azure-6.5
20.04 LTS focal Not in release
linux-bluefield 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal
Not affected
linux-azure-edge 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic Ignored superseded by linux-azure-5.3
linux-fips 24.04 LTS noble Not in release
22.04 LTS jammy  
Not affected
20.04 LTS focal  
Not affected
18.04 LTS bionic  
Not affected
16.04 LTS xenial  
Not affected
linux-aws-fips 24.04 LTS noble Not in release
22.04 LTS jammy  
Not affected
20.04 LTS focal  
Not affected
18.04 LTS bionic  
Not affected
linux-azure-fips 24.04 LTS noble Not in release
22.04 LTS jammy  
Not affected
20.04 LTS focal  
Not affected
18.04 LTS bionic  
Not affected
linux-gcp-fips 24.04 LTS noble Not in release
22.04 LTS jammy  
Not affected
20.04 LTS focal  
Not affected
18.04 LTS bionic  
Not affected
linux-gcp 24.04 LTS noble
Not affected
22.04 LTS jammy
Not affected
20.04 LTS focal
Not affected
18.04 LTS bionic Ignored superseded by linux-gcp-5.3
16.04 LTS xenial
Not affected
linux-gcp-4.15 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic
Not affected
linux-gcp-5.3 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic Ignored superseded by linux-gcp-5.4
linux-gcp-5.4 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic
Not affected
linux-gcp-5.8 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored superseded by linux-gcp-5.11
linux-gcp-5.11 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored superseded by linux-gcp-5.13
linux-gcp-5.13 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored superseded by linux-gcp-5.15
linux-gcp-5.15 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal
Not affected
linux-gcp-5.19 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-gcp-6.2
20.04 LTS focal Not in release
linux-gcp-6.2 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-gcp-6.5
20.04 LTS focal Not in release
linux-gcp-6.5 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-gcp-6.8
20.04 LTS focal Not in release
linux-gke 24.04 LTS noble
Not affected
22.04 LTS jammy
Not affected
20.04 LTS focal Ignored end of kernel support
linux-gke-4.15 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic Ignored superseded by linux-gke-5.0
linux-gke-5.4 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic Ignored end of kernel support
linux-gke-5.15 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored end of kernel support
linux-gkeop 24.04 LTS noble
Not affected
22.04 LTS jammy
Not affected
20.04 LTS focal
Not affected
linux-gkeop-5.4 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic Ignored end of kernel support
linux-gkeop-5.15 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal
Not affected
linux-ibm 24.04 LTS noble
Not affected
22.04 LTS jammy
Not affected
20.04 LTS focal
Not affected
linux-ibm-5.4 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic
Not affected
linux-ibm-5.15 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal
Not affected
linux-intel-5.13 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored end of kernel support
linux-intel-iotg 24.04 LTS noble Not in release
22.04 LTS jammy
Not affected
20.04 LTS focal Not in release
linux-intel-iotg-5.15 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal
Not affected
linux-iot 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal
Not affected
linux-lowlatency 24.04 LTS noble
Not affected
22.04 LTS jammy
Not affected
20.04 LTS focal Not in release
linux-lowlatency-hwe-5.15 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal
Not affected
linux-lowlatency-hwe-5.19 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-lowlatency-hwe-6.2
20.04 LTS focal Not in release
linux-lowlatency-hwe-6.2 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-lowlatency-hwe-6.5
20.04 LTS focal Not in release
linux-lowlatency-hwe-6.5 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-lowlatency-hwe-6.8
20.04 LTS focal Not in release
linux-nvidia 24.04 LTS noble
Not affected
22.04 LTS jammy
Not affected
20.04 LTS focal Not in release
linux-nvidia-6.2 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-nvidia-6.5
20.04 LTS focal Not in release
linux-nvidia-6.5 24.04 LTS noble Not in release
22.04 LTS jammy
Not affected
20.04 LTS focal Not in release
linux-nvidia-6.8 24.04 LTS noble Not in release
22.04 LTS jammy
Not affected
20.04 LTS focal Not in release
linux-nvidia-lowlatency 24.04 LTS noble
Not affected
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
linux-oracle 24.04 LTS noble
Not affected
22.04 LTS jammy
Not affected
20.04 LTS focal
Not affected
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected
linux-oracle-5.0 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic Ignored superseded by linux-oracle-5.3
linux-oracle-5.3 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic Ignored superseded by linux-oracle-5.4
linux-oracle-5.4 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic
Not affected
linux-oracle-5.8 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored superseded by linux-oracle-5.11
linux-oracle-5.11 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored superseded by linux-oracle-5.13
linux-oracle-5.13 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored superseded by linux-oracle-5.15
linux-oracle-5.15 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal
Not affected
linux-oracle-6.5 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-oracle-6.8
20.04 LTS focal Not in release
linux-oem 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic Ignored replaced by linux-hwe-5.4
linux-oem-5.6 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored superseded by linux-oem-5.10
linux-oem-5.10 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored superseded by linux-oem-5.13
linux-oem-5.13 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored superseded by linux-oem-5.14
linux-oem-5.14 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored replaced by linux-hwe-5.15
linux-oem-5.17 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-oem-6.1
20.04 LTS focal Not in release
linux-oem-6.0 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-oem-6.1
20.04 LTS focal Not in release
linux-oem-6.1 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-oem-6.5
20.04 LTS focal Not in release
linux-oem-6.5 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-oem-6.8
20.04 LTS focal Not in release
linux-oem-6.8 24.04 LTS noble
Not affected
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
linux-raspi 24.04 LTS noble
Not affected
22.04 LTS jammy
Not affected
20.04 LTS focal
Not affected
linux-raspi2 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored replaced by linux-raspi
linux-raspi-5.4 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic
Not affected
linux-riscv 24.04 LTS noble
Not affected
22.04 LTS jammy Ignored end of kernel support
20.04 LTS focal Ignored superseded by linux-riscv-5.8
linux-riscv-5.8 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored superseded by linux-riscv-5.11
linux-riscv-5.11 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal Ignored superseded by linux-riscv-5.13
linux-riscv-5.15 24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal
Not affected
linux-riscv-5.19 24.04 LTS noble Not in release
22.04 LTS jammy Ignored end of kernel support
20.04 LTS focal Not in release
linux-riscv-6.5 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-riscv-6.8
20.04 LTS focal Not in release
linux-starfive-5.19 24.04 LTS noble Not in release
22.04 LTS jammy Ignored end of kernel support
20.04 LTS focal Not in release
linux-starfive-6.2 24.04 LTS noble Not in release
22.04 LTS jammy Ignored superseded by linux-starfive-6.5
20.04 LTS focal Not in release
linux-starfive-6.5 24.04 LTS noble Not in release
22.04 LTS jammy Ignored end of kernel support
20.04 LTS focal Not in release
linux-xilinx-zynqmp 24.04 LTS noble Not in release
22.04 LTS jammy
Not affected
20.04 LTS focal
Not affected
linux-hwe-6.8 24.04 LTS noble Not in release
22.04 LTS jammy
Not affected
20.04 LTS focal Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-lowlatency-hwe-6.8 24.04 LTS noble Not in release
22.04 LTS jammy
Not affected
20.04 LTS focal Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-riscv-6.8 24.04 LTS noble Not in release
22.04 LTS jammy
Not affected
20.04 LTS focal Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-intel 24.04 LTS noble
Not affected
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-intel-iot-realtime 24.04 LTS noble Not in release
22.04 LTS jammy  
Not affected
20.04 LTS focal Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-raspi-realtime 24.04 LTS noble  
Not affected
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-realtime 24.04 LTS noble  
Not affected
22.04 LTS jammy  
Not affected
20.04 LTS focal Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
linux

Severity score breakdown

Parameter Value
Base score 9.8 · Critical
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact High
Availability impact High
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H