powerpc/kexec_file: Prevent kexec range truncation
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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 6.6.160, 6.12.110, 6.18.51, 7.2.5
- 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: powerpc/kexec_file: Prevent kexec range truncation Sashiko AI review pointed out the following issue. The __merge_memory_ranges() function incorrectly handles overlapping memory ranges when merging them. Although sort_memory_ranges() sorts all ranges by their start address in ascending order beforehand, the merge logic remains defective in two ways: 1. It compares the current range's start against the previous element (i-1) instead of the running target index (idx) 2. It unconditionally overwrites 'ranges[idx].end' with 'ranges[i].end'. This logic flaw leads to critical memory truncation when a larger memory range completely subsumes subsequent smaller ranges. For example, consider a sorted input array with three ranges: Range A (idx=0): [0x1000 - 0x9000] Range B (i=1): [0x2000 - 0x5000] (completely inside Range A) Range C (i=2): [0x6000 - 0x8000] (completely inside Range A) 1. When i=1 (Range B): ranges[1].start (0x2000) <= ranges[0].end + 1 (0x9001) is TRUE. The code executes: ranges[0].end = ranges[1].end, which erroneously shrinks Range A's end from 0x9000 down to 0x5000. 2. When i=2 (Range C): ranges[2].start (0x6000) <= ranges[1].end + 1 (0x5001) is FALSE. The code falls into the else block, creating a broken new range. As a result, valid memory fragments [0x5001 - 0x5fff] and [0x8001 - 0x9000] are completely lost from the kexec exclude lists, potentially allowing the crash kernel to overwrite active memory, causing data corruption or crashes. Fix this by ensuring the start of the current range is compared against the end of the active merged range (idx), and use max() to safely prevent the outer boundary from being truncated.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From 180adfc532a83c1d74146449f7385f767d4b8059 · fixed in ffbdc2a3834a3e47bac7236a71bbc82b45c83832; From 180adfc532a83c1d74146449f7385f767d4b8059 · fixed in 9ef63622e6cee588ea4b763a6afc87065254b36a; From 180adfc532a83c1d74146449f7385f767d4b8059 · fixed in da88a2a2119e4fd0e8919a7a2448682f574e1545; From 180adfc532a83c1d74146449f7385f767d4b8059 · fixed in c4cb547f26d9b73b489c5278d0c8db837c5a174f; From 180adfc532a83c1d74146449f7385f767d4b8059 · fixed in fa40f9dbdd4af53e7445d9135b5b207eb8adf372
- Linux Linux
5.9
- KernelLinux
From 5.9.0 · fixed in 6.6.160; From 6.7.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.51; From 6.19.0 · fixed in 7.2.5