UBUNTU-CVE-2025-40054: Null Pointer Dereference

Published Oct 28, 2025

Updated

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix UAF issue in f2fsmergepagebio() As JY reported in bugzilla [1], Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 pc : [0xffffffe51d249484] f2fsiscpguaranteed+0x70/0x98 lr : [0xffffffe51d24adbc] f2fsmergepagebio+0x520/0x6d4 CPU: 3 UID: 0 PID: 6790 Comm: kworker/u16:3 Tainted: P B W OE 6.12.30-android16-5-maybe-dirty-4k #1 5f7701c9cbf727d1eebe77c89bbbeb3371e895e5 Tainted: [P]=PROPRIETARYMODULE, [B]=BADPAGE, [W]=WARN, [O]=OOTMODULE, [E]=UNSIGNEDMODULE Workqueue: writeback wbworkfn (flush-254:49) Call trace: f2fsiscpguaranteed+0x70/0x98 f2fsinplacewritedata+0x174/0x2f4 f2fsdowritedatapage+0x214/0x81c f2fswritesingledatapage+0x28c/0x764 f2fswritedatapages+0x78c/0xce4 dowritepages+0xe8/0x2fc writebacksingleinode+0x4c/0x4b4 writebacksbinodes+0x314/0x540 writebackinodeswb+0xa4/0xf4 wbwriteback+0x160/0x448 wbworkfn+0x2f0/0x5dc processscheduledworks+0x1c8/0x458 workerthread+0x334/0x3f0 kthread+0x118/0x1ac retfromfork+0x10/0x20 [1] https://bugzilla.kernel.org/showbug.cgi?id=220575 The panic was caused by UAF issue w/ below race condition: kworker - writepages - f2fswritecachepages - f2fswritesingledatapage - f2fsdowritedatapage - f2fsinplacewritedata - f2fsmergepagebio - addinupage : cache page #1 into bio & cache bio in io->biolist - f2fswritesingledatapage - f2fsdowritedatapage - f2fsinplacewritedata - f2fsmergepagebio - addinupage : cache page #2 into bio which is linked in io->biolist write - f2fswritebegin : write page #1 - f2fsfoliowaitwriteback - f2fssubmitmergedipuwrite - f2fssubmitwritebio : submit bio which inclues page #1 and #2 software IRQ - f2fswriteendio - fscryptfreebouncepage : freed bounced page which belongs to page #2 - incpagecount( , WBDATATYPE(datafolio), false) : datafolio points to fio->encryptedpage the bounced page can be freed before accessing it in f2fsiscpguarantee() It can reproduce w/ below testcase: Run below script in shell #1: for ((i=1;i>0;i++)) do xfsio -f /mnt/f2fs/enc/file \ -c "pwrite 0 32k" -c "fdatasync" Run below script in shell #2: for ((i=1;i>0;i++)) do xfsio -f /mnt/f2fs/enc/file \ -c "pwrite 0 32k" -c "fdatasync" So, in f2fsmergepagebio(), let's avoid using fio->encryptedpage after commit page into internal ipu cache.

Affected Software

185 affected componentsFixes available

ubuntu/linux-hwe-edge*

ubuntu/linux-aws-5.0*

ubuntu/linux-aws-5.3*

ubuntu/linux-azure*

ubuntu/linux-azure-5.3*

ubuntu/linux-azure-edge*

ubuntu/linux-gcp*

ubuntu/linux-gcp-5.3*

ubuntu/linux-gke-4.15*

ubuntu/linux-gke-5.4*

ubuntu/linux-gkeop-5.4*

ubuntu/linux-hwe*

ubuntu/linux-hwe-edge*

ubuntu/linux-oem*

ubuntu/linux-oracle-5.0*

ubuntu/linux-oracle-5.3*

ubuntu/linux-aws-5.11*

ubuntu/linux-aws-5.13*

ubuntu/linux-aws-5.15<5.15.0-1119.126~20.04.1

5.15.0-1119.126~20.04.1

ubuntu/linux-aws-5.8*

ubuntu/linux-azure-5.11*

ubuntu/linux-azure-5.13*

ubuntu/linux-azure-5.15<5.15.0-1125.134~20.04.1

5.15.0-1125.134~20.04.1

ubuntu/linux-azure-5.8*

ubuntu/linux-azure-fde*

ubuntu/linux-azure-fde-5.15<5.15.0-1124.133~20.04.1

5.15.0-1124.133~20.04.1

ubuntu/linux-gcp-5.11*

ubuntu/linux-gcp-5.13*

ubuntu/linux-gcp-5.15<5.15.0-1120.130~20.04.1

5.15.0-1120.130~20.04.1

ubuntu/linux-gcp-5.8*

ubuntu/linux-gke*

ubuntu/linux-gke-5.15*

ubuntu/linux-gkeop*

ubuntu/linux-gkeop-5.15*

ubuntu/linux-hwe-5.11*

ubuntu/linux-hwe-5.13*

ubuntu/linux-hwe-5.15<5.15.0-202.212~20.04.1

5.15.0-202.212~20.04.1

ubuntu/linux-hwe-5.8*

ubuntu/linux-ibm-5.15<5.15.0-1113.117~20.04.1

5.15.0-1113.117~20.04.1

ubuntu/linux-intel-5.13*

ubuntu/linux-intel-iotg-5.15<5.15.0-1114.120~20.04.1

5.15.0-1114.120~20.04.1

ubuntu/linux-lowlatency-hwe-5.15<5.15.0-197.207~20.04.1

5.15.0-197.207~20.04.1

ubuntu/linux-nvidia-tegra-5.15<5.15.0-1070.72~20.04.1

5.15.0-1070.72~20.04.1

ubuntu/linux-oem-5.10*

ubuntu/linux-oem-5.13*

ubuntu/linux-oem-5.6*

ubuntu/linux-oracle-5.11*

ubuntu/linux-oracle-5.13*

ubuntu/linux-oracle-5.15<5.15.0-1116.122~20.04.1

5.15.0-1116.122~20.04.1

ubuntu/linux-oracle-5.8*

ubuntu/linux-raspi2*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.11*

ubuntu/linux-riscv-5.15<5.15.0-1113.117~20.04.2

5.15.0-1113.117~20.04.2

ubuntu/linux-riscv-5.8*

ubuntu/linux<5.15.0-202.212

5.15.0-202.212

ubuntu/linux-allwinner-5.19*

ubuntu/linux-aws<5.15.0-1119.126

5.15.0-1119.126

ubuntu/linux-aws-5.19*

ubuntu/linux-aws-6.2*

ubuntu/linux-aws-6.5*

ubuntu/linux-aws-6.8*

ubuntu/linux-azure<5.15.0-1125.134

5.15.0-1125.134

ubuntu/linux-azure-5.19*

ubuntu/linux-azure-6.2*

ubuntu/linux-azure-6.5*

ubuntu/linux-azure-6.8*

ubuntu/linux-azure-fde*

ubuntu/linux-azure-fde-5.19*

ubuntu/linux-azure-fde-6.2*

ubuntu/linux-azure-fde-6.8*

ubuntu/linux-gcp<5.15.0-1120.130

5.15.0-1120.130

ubuntu/linux-gcp-5.19*

ubuntu/linux-gcp-6.2*

ubuntu/linux-gcp-6.5*

ubuntu/linux-gcp-6.8*

ubuntu/linux-gke<5.15.0-1115.121

5.15.0-1115.121

ubuntu/linux-gkeop<5.15.0-1102.110

5.15.0-1102.110

ubuntu/linux-hwe-5.19*

ubuntu/linux-hwe-6.2*

ubuntu/linux-hwe-6.5*

ubuntu/linux-ibm<5.15.0-1113.117

5.15.0-1113.117

ubuntu/linux-ibm-6.8*

ubuntu/linux-intel-iot-realtime*

ubuntu/linux-intel-iotg<5.15.0-1114.120

5.15.0-1114.120

ubuntu/linux-kvm<5.15.0-1111.116

5.15.0-1111.116

ubuntu/linux-lowlatency<5.15.0-197.207

5.15.0-197.207

ubuntu/linux-lowlatency-hwe-5.19*

ubuntu/linux-lowlatency-hwe-6.2*

ubuntu/linux-lowlatency-hwe-6.5*

ubuntu/linux-lowlatency-hwe-6.8*

ubuntu/linux-nvidia<5.15.0-1114.115

5.15.0-1114.115

ubuntu/linux-nvidia-6.2*

ubuntu/linux-nvidia-6.5*

ubuntu/linux-nvidia-6.8*

ubuntu/linux-nvidia-tegra<5.15.0-1070.72

5.15.0-1070.72

ubuntu/linux-nvidia-tegra-igx<5.15.0-1059.59

5.15.0-1059.59

ubuntu/linux-oem-5.17*

ubuntu/linux-oem-6.0*

ubuntu/linux-oem-6.1*

ubuntu/linux-oem-6.5*

ubuntu/linux-oracle<5.15.0-1116.122

5.15.0-1116.122

ubuntu/linux-oracle-6.5*

ubuntu/linux-oracle-6.8*

ubuntu/linux-raspi*

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.19*

ubuntu/linux-riscv-6.5*

ubuntu/linux-riscv-6.8*

ubuntu/linux-starfive-5.19*

ubuntu/linux-starfive-6.2*

ubuntu/linux-starfive-6.5*

ubuntu/linux-xilinx-zynqmp*

ubuntu/linux-bluefield<5.15.0-1103.105

5.15.0-1103.105

ubuntu/linux-intel-iot-realtime<5.15.0-1111.115

5.15.0-1111.115

ubuntu/linux-realtime<5.15.0-1118.127

5.15.0-1118.127

ubuntu/linux-realtime-6.8*

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-fips<5.15.0-1119.126+fips1

5.15.0-1119.126+fips1

ubuntu/linux-azure-fips<5.15.0-1125.134+fips1

5.15.0-1125.134+fips1

ubuntu/linux-fips<5.15.0-202.212+fips1

5.15.0-202.212+fips1

ubuntu/linux-gcp-fips<5.15.0-1120.130+fips1

5.15.0-1120.130+fips1

ubuntu/linux*

ubuntu/linux-aws*

ubuntu/linux-aws-6.14*

ubuntu/linux-aws-6.17<6.17.0-1007.7~24.04.1

6.17.0-1007.7~24.04.1

ubuntu/linux-azure*

ubuntu/linux-azure-6.11*

ubuntu/linux-azure-6.14*

ubuntu/linux-azure-fde*

ubuntu/linux-azure-fde-6.14*

ubuntu/linux-azure-fde-6.17*

ubuntu/linux-azure-nvidia*

ubuntu/linux-azure-nvidia-6.14*

ubuntu/linux-gcp*

ubuntu/linux-gcp-6.11*

ubuntu/linux-gcp-6.14*

ubuntu/linux-gcp-6.17<6.17.0-1008.8~24.04.1

6.17.0-1008.8~24.04.1

ubuntu/linux-gke*

ubuntu/linux-gkeop*

ubuntu/linux-hwe-6.11*

ubuntu/linux-hwe-6.14*

ubuntu/linux-ibm*

ubuntu/linux-lowlatency*

ubuntu/linux-lowlatency-hwe-6.11*

ubuntu/linux-nvidia*

ubuntu/linux-nvidia-6.11*

ubuntu/linux-nvidia-6.17<6.17.0-1008.8

6.17.0-1008.8

ubuntu/linux-nvidia-lowlatency*

ubuntu/linux-nvidia-tegra<6.8.0-1035.38

6.8.0-1035.38

ubuntu/linux-oem-6.11*

ubuntu/linux-oem-6.14*

ubuntu/linux-oem-6.17<6.17.0-1011.11

6.17.0-1011.11

ubuntu/linux-oem-6.8*

ubuntu/linux-oracle*

ubuntu/linux-oracle-6.14*

ubuntu/linux-oracle-6.17<6.17.0-1007.7~24.04.1

6.17.0-1007.7~24.04.1

ubuntu/linux-raspi*

ubuntu/linux-raspi-realtime*

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-6.14*

ubuntu/linux-xilinx*

ubuntu/linux-bluefield*

ubuntu/linux-raspi-realtime*

ubuntu/linux-realtime*

ubuntu/linux-realtime-6.14*

ubuntu/linux-realtime-6.17<6.17.0-1006.7~24.04.1

6.17.0-1006.7~24.04.1

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux<6.17.0-14.14

6.17.0-14.14

ubuntu/linux-aws<6.17.0-1007.7

6.17.0-1007.7

ubuntu/linux-azure<6.17.0-1008.8

6.17.0-1008.8

ubuntu/linux-azure-fde*

ubuntu/linux-gcp<6.17.0-1007.7

6.17.0-1007.7

ubuntu/linux-oracle<6.17.0-1007.7

6.17.0-1007.7

ubuntu/linux-raspi<6.17.0-1008.8

6.17.0-1008.8

ubuntu/linux-realtime<6.17.0-1006.7

6.17.0-1006.7

ubuntu/linux-riscv<6.17.0-14.14.1

6.17.0-14.14.1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade ubuntu/linux-aws-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1119.126~20.04.1
Upgrade
Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1125.134~20.04.1
Upgrade
Upgrade ubuntu/linux-azure-fde-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1124.133~20.04.1
Upgrade
Upgrade ubuntu/linux-gcp-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1120.130~20.04.1
Upgrade
Upgrade ubuntu/linux-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-202.212~20.04.1
Upgrade
Upgrade ubuntu/linux-ibm-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1113.117~20.04.1
Upgrade
Upgrade ubuntu/linux-intel-iotg-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1114.120~20.04.1
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-197.207~20.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1070.72~20.04.1
Upgrade
Upgrade ubuntu/linux-oracle-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1116.122~20.04.1
Upgrade
Upgrade ubuntu/linux-riscv-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1113.117~20.04.2
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 5.15.0-202.212
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 5.15.0-1119.126
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 5.15.0-1125.134
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 5.15.0-1120.130
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 5.15.0-1115.121
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 5.15.0-1102.110
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 5.15.0-1113.117
Upgrade
Upgrade ubuntu/linux-intel-iotg to a version that resolves this vulnerability.
Fixed in 5.15.0-1114.120
Upgrade
Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.
Fixed in 5.15.0-1111.116
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 5.15.0-197.207
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 5.15.0-1114.115
Upgrade
Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.
Fixed in 5.15.0-1070.72
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-igx to a version that resolves this vulnerability.
Fixed in 5.15.0-1059.59
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 5.15.0-1116.122
Upgrade
Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.
Fixed in 5.15.0-1103.105
Upgrade
Upgrade ubuntu/linux-intel-iot-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1111.115
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1118.127
Upgrade
Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1119.126+fips1
Upgrade
Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1125.134+fips1
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-202.212+fips1
Upgrade
Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1120.130+fips1
Upgrade
Upgrade ubuntu/linux-aws-6.17 to a version that resolves this vulnerability.
Fixed in 6.17.0-1007.7~24.04.1
Upgrade
Upgrade ubuntu/linux-gcp-6.17 to a version that resolves this vulnerability.
Fixed in 6.17.0-1008.8~24.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-6.17 to a version that resolves this vulnerability.
Fixed in 6.17.0-1008.8
Upgrade
Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.
Fixed in 6.8.0-1035.38
Upgrade
Upgrade ubuntu/linux-oem-6.17 to a version that resolves this vulnerability.
Fixed in 6.17.0-1011.11
Upgrade
Upgrade ubuntu/linux-oracle-6.17 to a version that resolves this vulnerability.
Fixed in 6.17.0-1007.7~24.04.1
Upgrade
Upgrade ubuntu/linux-realtime-6.17 to a version that resolves this vulnerability.
Fixed in 6.17.0-1006.7~24.04.1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 6.17.0-14.14
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 6.17.0-1007.7
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 6.17.0-1008.8
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 6.17.0-1007.7
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 6.17.0-1007.7
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 6.17.0-1008.8
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 6.17.0-1006.7
Upgrade
Upgrade ubuntu/linux-riscv to a version that resolves this vulnerability.
Fixed in 6.17.0-14.14.1
Compensating control
In f2fs_merge_page_bio(), avoid using fio->encrypted_page after the page has been committed to the internal IPU cache, preventing access to a potentially freed bounced page.

Event History

Oct 28, 2025

CVE Published

via OSV·12:15 PM

Data Sourced

via OSV·12:15 PM

DescriptionSeverityAffected Software

Frequently Asked Questions

Which systems are exposed to this issue?

Systems running one of the listed Ubuntu Linux kernel packages may be exposed if they use the F2FS filesystem. The provided data does not identify affected package versions or whether F2FS must be mounted in a particular configuration.

What level of access does an attacker need?

The severity vector indicates local access, low privileges, and no user interaction are required. The reported impact is availability only, consistent with a kernel panic or denial of service.

How might this appear on an affected system?

The report describes a kernel NULL-pointer dereference during writeback, with f2fs_merge_page_bio(), f2fs_is_cp_guaranteed(), and F2FS data-page write functions in the call trace. Affected systems may panic while writeback work is running.

UBUNTU-CVE-2025-40054: Null Pointer Dereference

Affected Software

Remediation

Event History

Frequently Asked Questions

Which systems are exposed to this issue?

What level of access does an attacker need?

How might this appear on an affected system?

Company

Resources

Contact

Frequently Asked Questions

Which systems are exposed to this issue?

What level of access does an attacker need?

How might this appear on an affected system?