🛡️ CVE-2023-53326 on Ubuntu — linux
Description
In the Linux kernel, the following vulnerability has been resolved: powerpc: Don't try to copy PPR for task with NULL pt_regs powerpc sets up PF_KTHREAD and PF_IO_WORKER with a NULL pt_regs, which from my (arguably very short) checking is not commonly done for other archs. This is fine, except when PF_IO_WORKER's have been created and the task does something that causes a coredump to be generated. Then we get this crash: Kernel attempted to read user page (160) - exploit attempt? (uid: 1000) BUG: Kernel NULL pointer dereference on read at 0x00000160 Faulting instruction address: 0xc0000000000c3a60 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=32 NUMA pSeries Modules linked in: bochs drm_vram_helper drm_kms_helper xts binfmt_misc ecb ctr syscopyarea sysfillrect cbc sysimgblt drm_ttm_helper aes_generic ttm sg libaes evdev joydev virtio_balloon vmx_crypto gf128mul drm dm_mod fuse loop configfs drm_panel_orientation_quirks ip_tables x_tables autofs4 hid_generic usbhid hid xhci_pci xhci_hcd usbcore usb_common sd_mod CPU: 1 PID: 1982 Comm: ppc-crash Not tainted 6.3.0-rc2+ #88 Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries NIP: c0000000000c3a60 LR: c000000000039944 CTR: c0000000000398e0 REGS: c0000000041833b0 TRAP: 0300 Not tainted (6.3.0-rc2+) MSR: 800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 88082828 XER: 200400f8 ... NIP memcpy_power7+0x200/0x7d0 LR ppr_get+0x64/0xb0 Call Trace: ppr_get+0x40/0xb0 (unreliable) __regset_get+0x180/0x1f0 regset_get_alloc+0x64/0x90 elf_core_dump+0xb98/0x1b60 do_coredump+0x1c34/0x24a0 get_signal+0x71c/0x1410 do_notify_resume+0x140/0x6f0 interrupt_exit_user_prepare_main+0x29c/0x320 interrupt_exit_user_prepare+0x6c/0xa0 interrupt_return_srr_user+0x8/0x138 Because ppr_get() is trying to copy from a PF_IO_WORKER with a NULL pt_regs. Check for a valid pt_regs in both ppc_get/ppr_set, and return an error if not set. The actual error value doesn't seem to be important here, so just pick -EINVAL. [mpe: Trim oops in change log, add Fixes & Cc stable]
Distribution advisory
This page covers CVE-2023-53326 as tracked by Ubuntu, for the package linux. The fix is available in version 5.15.0-79.86; earlier versions remain affected.
How this vulnerability can be exploited
This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.
CVSS metrics in full
The score comes from this vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Attack vector: Local — a local account, shell or session on the host is needed.
- Attack complexity: Low — the attack works reliably, with no preparation.
- Privileges required: Low — an ordinary user account is enough.
- User interaction: None — nobody has to be tricked into anything.
- Scope: Unchanged — the damage stays inside the vulnerable component.
- Confidentiality impact: None.
- Integrity impact: None.
- Availability impact: High — total loss, or loss the attacker controls.
Affected software
UBUNTU-CVE-2023-53326 is recorded against 122 packages.
- linux (fixed in 5.15.0-79.86)
- linux-allwinner-5.19
- linux-aws (fixed in 5.15.0-1042.47)
- linux-aws-5.0
- linux-aws-5.11
- linux-aws-5.13
- linux-aws-5.15 (fixed in 5.15.0-1041.46~20.04.1)
- linux-aws-5.19
- linux-aws-5.3
- linux-aws-5.4
- linux-aws-5.8
- linux-aws-6.2
- linux-aws-6.5
- linux-aws-fips
- linux-aws-hwe
- linux-azure (fixed in 5.15.0-1045.52)
- linux-azure-4.15
- linux-azure-5.11
- linux-azure-5.13
- linux-azure-5.15 (fixed in 5.15.0-1045.52~20.04.1)
- linux-azure-5.19
- linux-azure-5.3
- linux-azure-5.4
- linux-azure-5.8
Show the remaining 98 packages
- linux-azure-6.11
- linux-azure-6.2
- linux-azure-6.5
- linux-azure-edge
- linux-azure-fde
- linux-azure-fde-5.19
- linux-azure-fde-6.2
- linux-azure-fips
- linux-bluefield
- linux-fips
- linux-gcp (fixed in 5.15.0-1039.47)
- linux-gcp-4.15
- linux-gcp-5.11
- linux-gcp-5.13
- linux-gcp-5.15 (fixed in 5.15.0-1039.47~20.04.1)
- linux-gcp-5.19
- linux-gcp-5.3
- linux-gcp-5.4
- linux-gcp-5.8
- linux-gcp-6.11
- linux-gcp-6.2
- linux-gcp-6.5
- linux-gcp-fips
- linux-gke (fixed in 5.15.0-1039.44)
- linux-gke-4.15
- linux-gke-5.15
- linux-gke-5.4
- linux-gkeop (fixed in 5.15.0-1025.30)
- linux-gkeop-5.15
- linux-gkeop-5.4
- linux-hwe
- linux-hwe-5.11
- linux-hwe-5.13
- linux-hwe-5.15 (fixed in 5.15.0-79.86~20.04.2)
- linux-hwe-5.19
- linux-hwe-5.4
- linux-hwe-5.8
- linux-hwe-6.11
- linux-hwe-6.2
- linux-hwe-6.5
- linux-hwe-edge
- linux-ibm (fixed in 5.15.0-1035.38)
- linux-ibm-5.15 (fixed in 5.15.0-1036.39~20.04.1)
- linux-ibm-5.4
- linux-intel
- linux-intel-5.13
- linux-intel-iot-realtime (fixed in 5.15.0-1036.38)
- linux-intel-iotg (fixed in 5.15.0-1037.42)
- linux-intel-iotg-5.15 (fixed in 5.15.0-1037.42~20.04.1)
- linux-iot
- linux-kvm (fixed in 5.15.0-1039.44)
- linux-lowlatency (fixed in 5.15.0-79.88)
- linux-lowlatency-hwe-5.15 (fixed in 5.15.0-79.88~20.04.1)
- linux-lowlatency-hwe-5.19
- linux-lowlatency-hwe-6.11
- linux-lowlatency-hwe-6.2
- linux-lowlatency-hwe-6.5
- linux-nvidia (fixed in 5.15.0-1030.30)
- linux-nvidia-6.2
- linux-nvidia-6.5
- linux-nvidia-tegra (fixed in 5.15.0-1016.16)
- linux-nvidia-tegra-5.15 (fixed in 5.15.0-1016.16~20.04.1)
- linux-nvidia-tegra-igx (fixed in 5.15.0-1002.2)
- 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
- linux-oem-6.5
- linux-oem-6.8
- linux-oracle (fixed in 5.15.0-1040.46)
- linux-oracle-5.0
- linux-oracle-5.11
- linux-oracle-5.13
- linux-oracle-5.15 (fixed in 5.15.0-1040.46~20.04.1)
- linux-oracle-5.3
- linux-oracle-5.4
- linux-oracle-5.8
- linux-oracle-6.5
- linux-raspi (fixed in 5.15.0-1035.38)
- linux-raspi-5.4
- linux-raspi-realtime
- linux-raspi2
- linux-realtime
- linux-riscv
- linux-riscv-5.11
- linux-riscv-5.15 (fixed in 5.15.0-1038.42~20.04.2)
- linux-riscv-5.19
- linux-riscv-5.8
- linux-riscv-6.5
- linux-starfive-5.19
- linux-starfive-6.2
- linux-starfive-6.5
- linux-xilinx-zynqmp (fixed in 5.15.0-1025.29)
Timeline and source
Published on 16 September 2025 and last revised on 19 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.
References
ubuntu.com (Report)
www.cve.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
git.kernel.org (Report)
Other advisories for this package
linux has other advisories on record. If you are patching this one, these are worth checking on the same host:
- DEBIAN-CVE-2022-4994 (published 30 Jul 2026)
- CVE-2026-35233 (4.4 Medium, published 1 May 2026)
- CVE-2026-21996 (3.3 Low, published 1 May 2026)
- CVE-2026-21991 (5.5 Medium, published 16 Mar 2026)
- CGA-w6xv-3fg4-grm5 (published 29 Jan 2026)
- CGA-mcwh-q4vm-9f29 (published 29 Jan 2026)
- CGA-6xjj-65cr-mc7v (published 7 Jan 2026)
- CGA-m3jq-vcq5-mqrx (published 7 Jan 2026)
CVE-2023-53326 on other distributions
Each distribution ships its own build and its own fixed version. Pick the one you run:
Details
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| linux | — | 5.15.0-79.86 |
| linux-allwinner-5.19 | — | — |
| linux-aws | — | 5.15.0-1042.47 |
| linux-aws-5.0 | — | — |
| linux-aws-5.11 | — | — |
| linux-aws-5.13 | — | — |
| linux-aws-5.15 | — | 5.15.0-1041.46~20.04.1 |
| linux-aws-5.19 | — | — |
| linux-aws-5.3 | — | — |
| linux-aws-5.4 | — | — |
| linux-aws-5.8 | — | — |
| linux-aws-6.2 | — | — |
| linux-aws-6.5 | — | — |
| linux-aws-fips | — | — |
| linux-aws-hwe | — | — |
| linux-azure | — | 5.15.0-1045.52 |
| linux-azure-4.15 | — | — |
| linux-azure-5.11 | — | — |
| linux-azure-5.13 | — | — |
| linux-azure-5.15 | — | 5.15.0-1045.52~20.04.1 |
| linux-azure-5.19 | — | — |
| linux-azure-5.3 | — | — |
| linux-azure-5.4 | — | — |
| linux-azure-5.8 | — | — |
| linux-azure-6.11 | — | — |
| linux-azure-6.2 | — | — |
| linux-azure-6.5 | — | — |
| linux-azure-edge | — | — |
| linux-azure-fde | — | — |
| linux-azure-fde-5.19 | — | — |
| linux-azure-fde-6.2 | — | — |
| linux-azure-fips | — | — |
| linux-bluefield | — | — |
| linux-fips | — | — |
| linux-gcp | — | 5.15.0-1039.47 |
| linux-gcp-4.15 | — | — |
| linux-gcp-5.11 | — | — |
| linux-gcp-5.13 | — | — |
| linux-gcp-5.15 | — | 5.15.0-1039.47~20.04.1 |
| linux-gcp-5.19 | — | — |
| linux-gcp-5.3 | — | — |
| linux-gcp-5.4 | — | — |
| linux-gcp-5.8 | — | — |
| linux-gcp-6.11 | — | — |
| linux-gcp-6.2 | — | — |
| linux-gcp-6.5 | — | — |
| linux-gcp-fips | — | — |
| linux-gke | — | 5.15.0-1039.44 |
| linux-gke-4.15 | — | — |
| linux-gke-5.15 | — | — |
| linux-gke-5.4 | — | — |
| linux-gkeop | — | 5.15.0-1025.30 |
| linux-gkeop-5.15 | — | — |
| linux-gkeop-5.4 | — | — |
| linux-hwe | — | — |
| linux-hwe-5.11 | — | — |
| linux-hwe-5.13 | — | — |
| linux-hwe-5.15 | — | 5.15.0-79.86~20.04.2 |
| linux-hwe-5.19 | — | — |
| linux-hwe-5.4 | — | — |
| linux-hwe-5.8 | — | — |
| linux-hwe-6.11 | — | — |
| linux-hwe-6.2 | — | — |
| linux-hwe-6.5 | — | — |
| linux-hwe-edge | — | — |
| linux-ibm | — | 5.15.0-1035.38 |
| linux-ibm-5.15 | — | 5.15.0-1036.39~20.04.1 |
| linux-ibm-5.4 | — | — |
| linux-intel | — | — |
| linux-intel-5.13 | — | — |
| linux-intel-iot-realtime | — | 5.15.0-1036.38 |
| linux-intel-iotg | — | 5.15.0-1037.42 |
| linux-intel-iotg-5.15 | — | 5.15.0-1037.42~20.04.1 |
| linux-iot | — | — |
| linux-kvm | — | 5.15.0-1039.44 |
| linux-lowlatency | — | 5.15.0-79.88 |
| linux-lowlatency-hwe-5.15 | — | 5.15.0-79.88~20.04.1 |
| linux-lowlatency-hwe-5.19 | — | — |
| linux-lowlatency-hwe-6.11 | — | — |
| linux-lowlatency-hwe-6.2 | — | — |
| linux-lowlatency-hwe-6.5 | — | — |
| linux-nvidia | — | 5.15.0-1030.30 |
| linux-nvidia-6.2 | — | — |
| linux-nvidia-6.5 | — | — |
| linux-nvidia-tegra | — | 5.15.0-1016.16 |
| linux-nvidia-tegra-5.15 | — | 5.15.0-1016.16~20.04.1 |
| linux-nvidia-tegra-igx | — | 5.15.0-1002.2 |
| 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 | — | — |
| linux-oem-6.5 | — | — |
| linux-oem-6.8 | — | — |
| linux-oracle | — | 5.15.0-1040.46 |
| linux-oracle-5.0 | — | — |
| linux-oracle-5.11 | — | — |
| linux-oracle-5.13 | — | — |
| linux-oracle-5.15 | — | 5.15.0-1040.46~20.04.1 |
| linux-oracle-5.3 | — | — |
| linux-oracle-5.4 | — | — |
| linux-oracle-5.8 | — | — |
| linux-oracle-6.5 | — | — |
| linux-raspi | — | 5.15.0-1035.38 |
| linux-raspi-5.4 | — | — |
| linux-raspi-realtime | — | — |
| linux-raspi2 | — | — |
| linux-realtime | — | — |
| linux-riscv | — | — |
| linux-riscv-5.11 | — | — |
| linux-riscv-5.15 | — | 5.15.0-1038.42~20.04.2 |
| linux-riscv-5.19 | — | — |
| linux-riscv-5.8 | — | — |
| linux-riscv-6.5 | — | — |
| linux-starfive-5.19 | — | — |
| linux-starfive-6.2 | — | — |
| linux-starfive-6.5 | — | — |
| linux-xilinx-zynqmp | — | 5.15.0-1025.29 |
References
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