CVE-2026-72197
HighCVSS 8.4Exploitation Probability (EPSS)
Low risk8th percentile - higher than 8% of all known CVEs
Summary
In the Linux kernel's NTFS3 filesystem, the DeleteIndexEntryAllocation function did not bound the memmove length, potentially leading to out-of-bounds access. The fix adds proper checks, including rejecting zero length.
Risk Assessment
The vulnerability can be exploited by mounting a malicious NTFS image, leading to kernel oops and potentially privilege escalation.
Recommendation
Apply the Linux kernel update containing this fix. Avoid mounting untrusted NTFS images.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: bound DeleteIndexEntryAllocation memmove length In do_action()'s DeleteIndexEntryAllocation case, e->size comes from an on-disk INDEX_BUFFER entry. When e->size makes e + e->size point past hdr + hdr->used, PtrOffset(e1, Add2Ptr(hdr, used)) returns a negative ptrdiff_t that is silently cast to a quasi-infinite size_t when passed to memmove(). The memmove then walks past the destination buffer. The sibling DeleteIndexEntryRoot case at fslog.c:3540-3543 already carries the corresponding guard: if (PtrOffset(e1, Add2Ptr(hdr, used)) < esize || Add2Ptr(e, esize) > Add2Ptr(lrh, rec_len) || used + esize > le32_to_cpu(hdr->total)) { goto dirty_vol; } Apply the same shape to the allocation-path case. Also reject esize == 0: memmove(e, e, ...) is a no-op and leaves hdr->used unchanged, hiding a malformed entry from the existing check_index_header() walk. Reproduced under UML+KASAN on mainline 8d90b09e6741 by mounting a crafted NTFS image: the unguarded memmove takes a length of 0xffffffffffffff00 and the kernel oopses in memmove+0x81/0x1a0 on the do_action+0x36a2 frame. [[email protected]: clang-formatted the changes]