Integer underflow in Linux kernel - CVE-2026-93048
Published: September 18, 2026
Vulnerability details
The vulnerability allows a local user to trigger a kernel warning.
The vulnerability exists due to integer underflow in mtd_add_partition() when processing BLKPG ioctl requests on NAND devices. A local user can pass MTDPART_OFS_RETAIN (-3) as a partition offset to trigger a kernel warning.
Depending on the size calculation, an empty disabled partition can be created.
Affected software
Debian Linux
SUSE Linux Micro Extras
SUSE Linux Micro
Ubuntu
linux (Ubuntu package)
linux-kvm (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-azure (Ubuntu package)
linux-oracle (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-gke (Ubuntu package)
linux-aws-5.15 (Ubuntu package)
linux-lowlatency-hwe-5.15 (Ubuntu package)
linux-hwe-5.15 (Ubuntu package)
linux-fips (Ubuntu package)
linux-azure-5.15 (Ubuntu package)
linux-realtime (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-ibm-5.15 (Ubuntu package)
linux-intel-iotg (Ubuntu package)
linux-nvidia-tegra-igx (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-gkeop (Ubuntu package)
linux-azure-fde-5.15 (Ubuntu package)
linux-ibm (Ubuntu package)
linux-intel-iotg-5.15 (Ubuntu package)
linux-oracle-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-intel-iot-realtime (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux-aws-fips (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
kernel-default-devel-debuginfo
kernel-default-debugsource
kernel-obs-build-debugsource
kernel-obs-build
kernel-syms
kernel-default-devel
kernel-64kb-devel
kernel-64kb-debugsource
kernel-default
kernel-64kb
linux (Debian package)
How to mitigate CVE-2026-93048
linux-kvm (Ubuntu package) - update to 5.15.0-1111.116
linux-aws (Ubuntu package) - addressed in versions 5.15.0-1119.126, 7.0.0-1016.17
linux-gcp (Ubuntu package) - addressed in versions 5.15.0-1120.130, 7.0.0-1016.18
linux-azure (Ubuntu package) - update to 5.15.0-1125.134
linux-oracle (Ubuntu package) - addressed in versions 5.15.0-1116.122, 7.0.0-1015.16
linux-lowlatency (Ubuntu package) - update to 5.15.0-197.207
linux-gke (Ubuntu package) - update to 5.15.0-1115.121
linux-aws-5.15 (Ubuntu package) - update to 5.15.0-1119.126~20.04.1
linux-lowlatency-hwe-5.15 (Ubuntu package) - update to 5.15.0-197.207~20.04.1
linux-hwe-5.15 (Ubuntu package) - update to 5.15.0-202.212~20.04.1
linux-fips (Ubuntu package) - update to 5.15.0-202.212+fips1
linux-azure-5.15 (Ubuntu package) - update to 5.15.0-1125.134~20.04.1
linux-realtime (Ubuntu package) - update to 5.15.0-1118.127
linux-nvidia (Ubuntu package) - update to 5.15.0-1114.115
linux-ibm-5.15 (Ubuntu package) - update to 5.15.0-1113.117~20.04.1
linux-intel-iotg (Ubuntu package) - update to 5.15.0-1114.120
linux-nvidia-tegra-igx (Ubuntu package) - update to 5.15.0-1059.59
linux-nvidia-tegra (Ubuntu package) - update to 5.15.0-1070.72
linux-gkeop (Ubuntu package) - update to 5.15.0-1102.110
linux-azure-fde-5.15 (Ubuntu package) - update to 5.15.0-1124.133~20.04.1
linux-ibm (Ubuntu package) - addressed in versions 5.15.0-1113.117, 7.0.0-1017.17
linux-intel-iotg-5.15 (Ubuntu package) - update to 5.15.0-1114.120~20.04.1
linux-oracle-5.15 (Ubuntu package) - update to 5.15.0-1116.122~20.04.1
linux-gcp-5.15 (Ubuntu package) - update to 5.15.0-1120.130~20.04.1
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1070.72~20.04.1
linux-azure-fde (Ubuntu package) - update to 5.15.0-1124.133
linux-intel-iot-realtime (Ubuntu package) - update to 5.15.0-1111.115
linux-gcp-fips (Ubuntu package) - update to 5.15.0-1120.130+fips1
linux-aws-fips (Ubuntu package) - update to 5.15.0-1119.126+fips1
linux-azure-fips (Ubuntu package) - update to 5.15.0-1125.134+fips1
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17
kernel-default-devel-debuginfo - update to 6.4.0-159998.55.1
kernel-default-debugsource - update to 6.4.0-159998.55.1
kernel-obs-build-debugsource - update to 6.4.0-159998.55.1
kernel-obs-build - update to 6.4.0-159998.55.1
kernel-syms - update to 6.4.0-159998.55.1
kernel-default-devel - update to 6.4.0-159998.55.1
kernel-64kb-devel - update to 6.4.0-159998.55.1
kernel-64kb-debugsource - update to 6.4.0-159998.55.1
kernel-default - update to 6.4.0-159998.55.1
kernel-64kb - update to 6.4.0-159998.55.1
linux (Debian package) - update to 6.12.111-1
External References
- https://git.kernel.org/stable/c/181c1bff940e7d3e34ca485d37e3cdbfe409203c
- https://git.kernel.org/stable/c/398aca2f90122d5abbabff1079deaeb885fe9e40
- https://git.kernel.org/stable/c/6aaab2ace3f7b55733d904e5549acf8405f03642
- https://git.kernel.org/stable/c/701c3ae7273e1adc20db5d97c42e0139b479f16b
- https://git.kernel.org/stable/c/a536eb57be58442b19398b2783071007ecfb1735
- https://git.kernel.org/stable/c/b759d5bb6265419344ee9729fd0dc07ad85719d8
- https://git.kernel.org/stable/c/c645f6dd1af2ecc70fd3578e141f2f71fa9e4eff
- https://git.kernel.org/stable/c/e204e5c49a012f99638633fdbd773e3c86260053
Related Security Bulletins
- Integer underflow in Linux kernel mtd driver
- Debian update for linux
- Ubuntu update for linux-azure-fde
- Ubuntu update for linux-oem-7.0
- Ubuntu update for linux, linux-aws, linux-gcp and more
- Ubuntu update for linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx
- Ubuntu update for linux, linux-aws, linux-aws-5.15 and more
- SUSE update for the Linux Kernel