CVE-2026-72197

HIGHCVSS 8.4/10EPSS 0.21%

Last modified

CVE-2026-72197 is a high-severity vulnerability rated 8.4/10 on the CVSS scale. 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(). EPSS estimates a 0.21% chance of exploitation in the next 30 days.

Description

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. [almaz.alexandrovich@paragon-software.com: clang-formatted the changes]

Metrics

CVSS 3.1
8.4/10

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
0.21%

10.9th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= b46acd6a6a627d876898e1c84d3f84902264b445, < c38ed2ab62fab75fd6d0fdc2bee540fbebc7b959; >= b46acd6a6a627d876898e1c84d3f84902264b445, < b509b9613f20dc5b653d54bf78fab00d79cc43c8; >= b46acd6a6a627d876898e1c84d3f84902264b445, < 4c8aac931c1cd70347961ba5157aa916448c6a25; >= b46acd6a6a627d876898e1c84d3f84902264b445, < f383aae59ec3994c14804f4191c59038b206be81; >= b46acd6a6a627d876898e1c84d3f84902264b445, < 09fddd52c1b0cef2c086d61be8f3d5dc92e36565; >= b46acd6a6a627d876898e1c84d3f84902264b445, < 554700c65d398276cb00a8ef95f1d5e00b9eff93; >= b46acd6a6a627d876898e1c84d3f84902264b445, < fc4626bb3656362de8b0ecd56605d47a19ec3518
LinuxLinux5.15

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is CVE-2026-72197?
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. [almaz.alexandrovich@paragon-software.com: clang-formatted the changes]
How severe is CVE-2026-72197?
CVE-2026-72197 has a CVSS score of 8.4/10 (HIGH severity). The EPSS model estimates a 0.21% probability of exploitation in the next 30 days.
How do I fix CVE-2026-72197?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST