# CVE-2023-53101: linux: In the Linux kernel, the following vulnerability has been resolved: ext4: zero i_disksize when initializing the boot... CVE-2023-53101 is fixed in 20 products on 1 platform, first by ALAS2023-2023-148, released March 30, 2023. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2023-53101 - Priority: Routine - CVSS: 5.5 (medium) - EPSS: 0.0020 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Mar 30, 2023 ## Description In the Linux kernel, the following vulnerability has been resolved: ext4: zero i_disksize when initializing the bootloader inode If the boot loader inode has never been used before, the EXT4_IOC_SWAP_BOOT inode will initialize it, including setting the i_size to 0. However, if the "never before used" boot loader has a non-zero i_size, then i_disksize will be non-zero, and the inconsistency between i_size and i_disksize can trigger a kernel warning: WARNING: CPU: 0 PID: 2580 at fs/ext4/file.c:319 CPU: 0 PID: 2580 Comm: bb Not tainted 6.3.0-rc1-00004-g703695902cfa RIP: 0010:ext4_file_write_iter+0xbc7/0xd10 Call Trace: vfs_write+0x3b1/0x5c0 ksys_write+0x77/0x160 __x64_sys_write+0x22/0x30 do_syscall_64+0x39/0x80 Reproducer: 1. create corrupted image and mount it: mke2fs -t ext4 /tmp/foo.img 200 debugfs -wR "sif <5> size 25700" /tmp/foo.img mount -t ext4 /tmp/foo.img /mnt cd /mnt echo 123 > file 2. Run the reproducer program: posix_memalign(&buf, 1024, 1024) fd = open("file", O_RDWR | O_DIRECT); ioctl(fd, EXT4_IOC_SWAP_BOOT); write(fd, buf, 1024); Fix this by setting i_disksize as well as i_size to zero when initiaizing the boot loader inode. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | bpftool-debuginfo amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-debuginfo amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-debuginfo-common-aarch64 amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-debuginfo-common-x86_64 amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-devel amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-headers amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-libbpf amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-libbpf-devel amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-libbpf-static amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-livepatch-6.1.21-1.45 amzn 2023 | 1.0-0.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-tools amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-tools-debuginfo amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | kernel-tools-devel amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | linux Debian 12.15 (bookworm) | 6.1.20-1 | [DEBIAN-CVE-2023-53101](https://patchblox.com/security/data/fix/linux/debian-cve-2023-53101.md) | May 2, 2025 | | Linux | linux Debian 13.5 (trixie) | 6.1.20-1 | [DEBIAN-CVE-2023-53101](https://patchblox.com/security/data/fix/linux/debian-cve-2023-53101.md) | May 2, 2025 | | Linux | linux Debian 14 | 6.1.20-1 | [DEBIAN-CVE-2023-53101](https://patchblox.com/security/data/fix/linux/debian-cve-2023-53101.md) | May 2, 2025 | | Linux | perf amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | perf-debuginfo amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | python3-perf amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | | Linux | python3-perf-debuginfo amzn 2023 | 6.1.21-1.45.amzn2023 | [ALAS2023-2023-148](https://patchblox.com/security/data/fix/linux/alas2023-2023-148.md) | Mar 30, 2023 | --- Data as of 2026-11-09T13:31:49Z UTC. 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