bootconfig: Fix integer overflow in initrd size check
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 5.7, 6.6.160, 6.12.112, 6.18.53, 7.2.7
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
In the Linux kernel, the following vulnerability has been resolved: bootconfig: Fix integer overflow in initrd size check Sashiko reported that in get_boot_config_from_initrd(), a crafted initrd with a huge bootconfig size (such as 0xFFFFFFFF) can cause the pointer arithmetic: data = ((void *)hdr) - size; to wrap around on 32-bit systems (or when pointer subtraction overflows). Because data wraps around, the subsequent bounds check: if ((unsigned long)data < initrd_start) evaluates to false, bypassing the check. The kernel then calls xbc_calc_checksum(data, size), which attempts to read 4GB of memory, hitting unmapped pages and triggering a fatal kernel page fault during early boot. Furthermore, on 64-bit systems with an initrd > 4.29 GB, an unbounded 32-bit size can similarly bypass the initrd_start check. Fix this by: 1. Ensuring the initrd is at least large enough to contain the bootconfig footer and verifying hdr is within the initrd bounds. 2. Checking that size does not exceed XBC_DATA_MAX and does not exceed the available space between initrd_start and hdr before performing pointer subtraction.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From de462e5f10718517bacf2f84c8aa2804567ef7df · fixed in 97be05f33f79342ea65d9b99c9ad07a93b8eef5a; From de462e5f10718517bacf2f84c8aa2804567ef7df · fixed in 4d45bc0f8cdf606d5409b5f64a8a6609f6520c03; From de462e5f10718517bacf2f84c8aa2804567ef7df · fixed in 8d4343a411eaa182d323ab5b149496416015f27d; From de462e5f10718517bacf2f84c8aa2804567ef7df · fixed in bff9a1579e2c9b2a59fdf3793becc9d7bf5ff1a6; From de462e5f10718517bacf2f84c8aa2804567ef7df · fixed in 7812d6dab0698001e50e8c2f901e17da3eb6f429; From 5.6.14 · fixed in 5.7
- Linux Linux
5.7
- KernelLinux
From 5.7.0 · fixed in 6.6.160; From 6.7.0 · fixed in 6.12.112; From 6.13.0 · fixed in 6.18.53; From 6.19.0 · fixed in 7.2.7