🛡️ CVE-2023-53503 on Ubuntu — linux
Description
In the Linux kernel, the following vulnerability has been resolved: ext4: allow ext4_get_group_info() to fail Previously, ext4_get_group_info() would treat an invalid group number as BUG(), since in theory it should never happen. However, if a malicious attaker (or fuzzer) modifies the superblock via the block device while it is the file system is mounted, it is possible for s_first_data_block to get set to a very large number. In that case, when calculating the block group of some block number (such as the starting block of a preallocation region), could result in an underflow and very large block group number. Then the BUG_ON check in ext4_get_group_info() would fire, resutling in a denial of service attack that can be triggered by root or someone with write access to the block device. For a quality of implementation perspective, it's best that even if the system administrator does something that they shouldn't, that it will not trigger a BUG. So instead of BUG'ing, ext4_get_group_info() will call ext4_error and return NULL. We also add fallback code in all of the callers of ext4_get_group_info() that it might NULL. Also, since ext4_get_group_info() was already borderline to be an inline function, un-inline it. The results in a next reduction of the compiled text size of ext4 by roughly 2k.
Distribution advisory
This page covers CVE-2023-53503 as tracked by Ubuntu, for the package linux. The fix is available in version 5.15.0-83.92; 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-2023-53503 is recorded against 124 packages.
- linux (fixed in 5.15.0-83.92)
- linux-allwinner-5.19
- linux-aws (fixed in 5.15.0-1044.49)
- linux-aws-5.0
- linux-aws-5.11
- linux-aws-5.13
- linux-aws-5.15 (fixed in 5.15.0-1044.49~20.04.1)
- 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 5.15.0-1046.53)
- linux-azure-4.15
- linux-azure-5.11
- linux-azure-5.13
- linux-azure-5.15 (fixed in 5.15.0-1046.53~20.04.1)
- linux-azure-5.19
- linux-azure-5.3
- linux-azure-5.4
- linux-azure-5.8
Show the remaining 100 packages
- linux-azure-6.11
- linux-azure-6.2
- linux-azure-6.5
- linux-azure-edge
- linux-azure-fde
- linux-azure-fde-5.15 (fixed in 5.15.0-1114.123~20.04.1)
- linux-azure-fde-5.19
- linux-azure-fde-6.2
- linux-azure-fips
- linux-bluefield
- linux-fips
- linux-gcp (fixed in 5.15.0-1041.49)
- linux-gcp-4.15
- linux-gcp-5.11
- linux-gcp-5.13
- linux-gcp-5.15 (fixed in 5.15.0-1041.49~20.04.1)
- 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 5.15.0-1041.46)
- linux-gke-4.15
- linux-gke-5.15
- linux-gke-5.4
- linux-gkeop (fixed in 5.15.0-1027.32)
- linux-gkeop-5.15
- linux-gkeop-5.4
- linux-hwe
- linux-hwe-5.11
- linux-hwe-5.13
- linux-hwe-5.15 (fixed in 5.15.0-83.92~20.04.1)
- 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 5.15.0-1037.40)
- linux-ibm-5.15 (fixed in 5.15.0-1037.40~20.04.1)
- linux-ibm-5.4
- linux-intel
- linux-intel-5.13
- linux-intel-iot-realtime (fixed in 5.15.0-1038.40)
- linux-intel-iotg (fixed in 5.15.0-1039.45)
- linux-intel-iotg-5.15 (fixed in 5.15.0-1040.46~20.04.1)
- linux-iot
- linux-kvm (fixed in 5.15.0-1041.46)
- linux-lowlatency (fixed in 5.15.0-83.92)
- linux-lowlatency-hwe-5.15 (fixed in 5.15.0-83.92~20.04.1)
- linux-lowlatency-hwe-5.19
- linux-lowlatency-hwe-6.11
- linux-lowlatency-hwe-6.2
- linux-lowlatency-hwe-6.5
- linux-lts-xenial
- linux-nvidia (fixed in 5.15.0-1032.32)
- linux-nvidia-6.2
- linux-nvidia-6.5
- linux-nvidia-tegra (fixed in 5.15.0-1017.17)
- linux-nvidia-tegra-5.15 (fixed in 5.15.0-1017.17~20.04.1)
- linux-nvidia-tegra-igx (fixed in 5.15.0-1004.4)
- 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 5.15.0-1042.48)
- linux-oracle-5.0
- linux-oracle-5.11
- linux-oracle-5.13
- linux-oracle-5.15 (fixed in 5.15.0-1042.48~20.04.1)
- linux-oracle-5.3
- linux-oracle-5.4
- linux-oracle-5.8
- linux-oracle-6.5
- linux-raspi (fixed in 5.15.0-1037.40)
- linux-raspi-5.4
- linux-raspi-realtime
- linux-raspi2
- linux-realtime
- linux-riscv
- linux-riscv-5.11
- linux-riscv-5.15 (fixed in 5.15.0-1040.44~20.04.3)
- 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 1 October 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-mcwh-q4vm-9f29 (published 29 Jan 2026)
- CGA-w6xv-3fg4-grm5 (published 29 Jan 2026)
- CGA-8vhr-fq3f-qx7q (published 7 Jan 2026)
- CGA-p49v-mx3v-9ff2 (published 7 Jan 2026)
CVE-2023-53503 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 | — | 5.15.0-83.92 |
| linux-allwinner-5.19 | — | — |
| linux-aws | — | 5.15.0-1044.49 |
| linux-aws-5.0 | — | — |
| linux-aws-5.11 | — | — |
| linux-aws-5.13 | — | — |
| linux-aws-5.15 | — | 5.15.0-1044.49~20.04.1 |
| 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 | — | 5.15.0-1046.53 |
| linux-azure-4.15 | — | — |
| linux-azure-5.11 | — | — |
| linux-azure-5.13 | — | — |
| linux-azure-5.15 | — | 5.15.0-1046.53~20.04.1 |
| 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-5.15 | — | 5.15.0-1114.123~20.04.1 |
| linux-azure-fde-5.19 | — | — |
| linux-azure-fde-6.2 | — | — |
| linux-azure-fips | — | — |
| linux-bluefield | — | — |
| linux-fips | — | — |
| linux-gcp | — | 5.15.0-1041.49 |
| linux-gcp-4.15 | — | — |
| linux-gcp-5.11 | — | — |
| linux-gcp-5.13 | — | — |
| linux-gcp-5.15 | — | 5.15.0-1041.49~20.04.1 |
| 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 | — | 5.15.0-1041.46 |
| linux-gke-4.15 | — | — |
| linux-gke-5.15 | — | — |
| linux-gke-5.4 | — | — |
| linux-gkeop | — | 5.15.0-1027.32 |
| linux-gkeop-5.15 | — | — |
| linux-gkeop-5.4 | — | — |
| linux-hwe | — | — |
| linux-hwe-5.11 | — | — |
| linux-hwe-5.13 | — | — |
| linux-hwe-5.15 | — | 5.15.0-83.92~20.04.1 |
| 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 | — | 5.15.0-1037.40 |
| linux-ibm-5.15 | — | 5.15.0-1037.40~20.04.1 |
| linux-ibm-5.4 | — | — |
| linux-intel | — | — |
| linux-intel-5.13 | — | — |
| linux-intel-iot-realtime | — | 5.15.0-1038.40 |
| linux-intel-iotg | — | 5.15.0-1039.45 |
| linux-intel-iotg-5.15 | — | 5.15.0-1040.46~20.04.1 |
| linux-iot | — | — |
| linux-kvm | — | 5.15.0-1041.46 |
| linux-lowlatency | — | 5.15.0-83.92 |
| linux-lowlatency-hwe-5.15 | — | 5.15.0-83.92~20.04.1 |
| linux-lowlatency-hwe-5.19 | — | — |
| linux-lowlatency-hwe-6.11 | — | — |
| linux-lowlatency-hwe-6.2 | — | — |
| linux-lowlatency-hwe-6.5 | — | — |
| linux-lts-xenial | — | — |
| linux-nvidia | — | 5.15.0-1032.32 |
| linux-nvidia-6.2 | — | — |
| linux-nvidia-6.5 | — | — |
| linux-nvidia-tegra | — | 5.15.0-1017.17 |
| linux-nvidia-tegra-5.15 | — | 5.15.0-1017.17~20.04.1 |
| linux-nvidia-tegra-igx | — | 5.15.0-1004.4 |
| 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 | — | 5.15.0-1042.48 |
| linux-oracle-5.0 | — | — |
| linux-oracle-5.11 | — | — |
| linux-oracle-5.13 | — | — |
| linux-oracle-5.15 | — | 5.15.0-1042.48~20.04.1 |
| linux-oracle-5.3 | — | — |
| linux-oracle-5.4 | — | — |
| linux-oracle-5.8 | — | — |
| linux-oracle-6.5 | — | — |
| linux-raspi | — | 5.15.0-1037.40 |
| linux-raspi-5.4 | — | — |
| linux-raspi-realtime | — | — |
| linux-raspi2 | — | — |
| linux-realtime | — | — |
| linux-riscv | — | — |
| linux-riscv-5.11 | — | — |
| linux-riscv-5.15 | — | 5.15.0-1040.44~20.04.3 |
| 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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