🛡️ UBUNTU-CVE-2025-21643
⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

In the Linux kernel, the following vulnerability has been resolved: netfs: Fix kernel async DIO Netfslib needs to be able to handle kernel-initiated asynchronous DIO that is supplied with a bio_vec[] array. Currently, because of the async flag, this gets passed to netfs_extract_user_iter() which throws a warning and fails because it only handles IOVEC and UBUF iterators. This can be triggered through a combination of cifs and a loopback blockdev with something like: mount //my/cifs/share /foo dd if=/dev/zero of=/foo/m0 bs=4K count=1K losetup --sector-size 4096 --direct-io=on /dev/loop2046 /foo/m0 echo hello >/dev/loop2046 This causes the following to appear in syslog: WARNING: CPU: 2 PID: 109 at fs/netfs/iterator.c:50 netfs_extract_user_iter+0x170/0x250 [netfs] and the write to fail. Fix this by removing the check in netfs_unbuffered_write_iter_locked() that causes async kernel DIO writes to be handled as userspace writes. Note that this change relies on the kernel caller maintaining the existence of the bio_vec array (or kvec[] or folio_queue) until the op is complete.

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2025-01-19
Updated 2026-06-15
Modified 2026-04-22
Fix URL N/A

Affected Packages

Software From version Fixed in
linux 6.8.0-60.63
linux-allwinner-5.19
linux-aws 6.8.0-1029.31
linux-aws-5.0
linux-aws-5.11
linux-aws-5.13
linux-aws-5.19
linux-aws-5.3
linux-aws-5.8
linux-aws-6.2
linux-aws-6.5
linux-aws-6.8 6.8.0-1029.31~22.04.1
linux-azure 6.8.0-1029.34
linux-azure-5.11
linux-azure-5.13
linux-azure-5.19
linux-azure-5.3
linux-azure-5.8
linux-azure-6.11 6.11.0-1012.12~24.04.1
linux-azure-6.2
linux-azure-6.5
linux-azure-6.8 6.8.0-1029.34~22.04.1
linux-azure-edge
linux-azure-fde
linux-azure-fde-5.19
linux-azure-fde-6.2
linux-azure-nvidia 6.8.0-1016.17
linux-fips 6.8.0-78.78+fips1
linux-gcp 6.8.0-1030.32
linux-gcp-5.11
linux-gcp-5.13
linux-gcp-5.19
linux-gcp-5.3
linux-gcp-5.8
linux-gcp-6.11 6.11.0-1011.11~24.04.1
linux-gcp-6.2
linux-gcp-6.5
linux-gcp-6.8 6.8.0-1030.32~22.04.1
linux-gke 6.8.0-1025.29
linux-gke-4.15
linux-gke-5.15
linux-gke-5.4
linux-gkeop 6.8.0-1012.14
linux-gkeop-5.15
linux-gkeop-5.4
linux-hwe
linux-hwe-5.11
linux-hwe-5.13
linux-hwe-5.19
linux-hwe-5.8
linux-hwe-6.11 6.11.0-21.21~24.04.1
linux-hwe-6.2
linux-hwe-6.5
linux-hwe-6.8 6.8.0-60.63~22.04.1
linux-hwe-edge
linux-ibm 6.8.0-1026.26
linux-ibm-6.8 6.8.0-1026.26~22.04.1
linux-intel-5.13
linux-intel-iot-realtime
linux-lowlatency 6.8.0-60.63.1
linux-lowlatency-hwe-5.19
linux-lowlatency-hwe-6.2
linux-lowlatency-hwe-6.5
linux-lowlatency-hwe-6.8 6.8.0-60.63.1~22.04.1
linux-nvidia 6.8.0-1028.31
linux-nvidia-6.11 6.11.0-1007.7
linux-nvidia-6.2
linux-nvidia-6.5
linux-nvidia-6.8 6.8.0-1028.31~22.04.1
linux-nvidia-lowlatency 6.8.0-1028.31.1
linux-nvidia-tegra 6.8.0-1008.8
linux-oem
linux-oem-5.10
linux-oem-5.13
linux-oem-5.14
linux-oem-5.17
linux-oem-5.6
linux-oem-6.0
linux-oem-6.1
linux-oem-6.11 6.11.0-1017.17
linux-oem-6.5
linux-oem-6.8 6.8.0-1028.28
linux-oracle 6.8.0-1026.27
linux-oracle-5.0
linux-oracle-5.11
linux-oracle-5.13
linux-oracle-5.3
linux-oracle-5.8
linux-oracle-6.5
linux-oracle-6.8 6.8.0-1026.27~22.04.1
linux-raspi 6.8.0-1028.32
linux-raspi-realtime 6.8.0-2023.24
linux-raspi2
linux-realtime 6.8.1-1022.23
linux-realtime-6.8 6.8.1-1022.23~22.04.1
linux-riscv 6.8.0-60.63.1
linux-riscv-5.11
linux-riscv-5.19
linux-riscv-5.8
linux-riscv-6.5
linux-riscv-6.8 6.8.0-62.65~22.04.1
linux-starfive-5.19
linux-starfive-6.2
linux-starfive-6.5
linux-xilinx 6.8.0-1017.18

References

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