kernel/linux.git/fs/ntfs3, branch v6.12.97

ntfs3: fix out-of-bounds read in decompress_lznt

2026-07-24T14:11:33+00:00

commit 7160a57192fb16d7a6fa9b7f5c7ac341d2444a89 upstream. decompress_lznt() does not validate array index bounds before accessing the decompression table. A corrupted NTFS3 image with invalid compressed data can trigger an out-of-bounds read. Add index bounds checking to prevent the OOB access. Reported-by: syzbot+39b2fb0f2638669008ec@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Tristan Madani Signed-off-by: Konstantin Komarov Signed-off-by: Greg Kroah-Hartman

ntfs3: validate split-point offset in indx_insert_into_buffer

2026-07-24T14:11:33+00:00

commit f1df9d771df47aa40de6d70949c28720ae1e430d upstream. indx_insert_into_buffer() computes used = used1 - to_copy - sp_size; memmove(de_t, Add2Ptr(sp, sp_size), used - le32_to_cpu(hdr1->de_off)); where sp and sp_size come from hdr_find_split(). hdr_find_split() walks entries by le16_to_cpu(e->size) without validating that each step stays within hdr->used or that the size field is at least sizeof(struct NTFS_DE). index_hdr_check(), the on-load gatekeeper, only validates header-level fields (used, total, de_off) and does not walk per-entry sizes. A crafted NTFS image whose leaf INDEX_HDR reports used == total but contains one interior NTFS_DE with size = 0xFFF0 therefore passes validation, descends to indx_insert_into_buffer() through the ntfs_create() -> indx_insert_entry() path, and makes hdr_find_split() return an sp whose sp_size (0xFFF0) greatly exceeds the remaining bytes in the buffer. The u32 subtraction underflows and the memmove count becomes a near-4-GiB value, producing an out-of-bounds kernel write that corrupts adjacent allocations and panics the kernel. Reproduced on 7.0.0-rc7 with UML + KASAN via a crafted image and a single 'touch' inside the mounted directory; crash site resolves to fs/ntfs3/index.c at the memmove. Trigger requires only local mount of an attacker-supplied filesystem image (USB, loopback, or removable media auto-mount). Reject the split whenever the chosen sp plus its declared size already extends past hdr1->used. This is the minimal fix; it preserves the existing hdr_find_split() contract and relies on the same out: cleanup path as the pre-existing error returns. A prior OOB read in the very same indx_insert_into_buffer() memmove was fixed in commit b8c44949044e ("fs/ntfs3: Fix OOB read in indx_insert_into_buffer") by tightening hdr_find_e(), but that fix does not cover the split-point size field path addressed here: sp is returned by hdr_find_split(), not hdr_find_e(), and the underflow is driven by sp->size rather than hdr->used exceeding hdr->total. Fixes: 82cae269cfa9 ("fs/ntfs3: Add initialization of super block") Cc: stable@vger.kernel.org Reported-by: Michael Bommarito Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito Signed-off-by: Konstantin Komarov Signed-off-by: Greg Kroah-Hartman

ntfs3: bound to_move in indx_insert_into_root before hdr_insert_head

2026-07-24T14:11:33+00:00

commit 9b6926ac9c970ae0b2c2fe6289b16e9aa10b6a67 upstream. indx_insert_into_root() promotes a full resident $INDEX_ROOT into $INDEX_ALLOCATION and copies all non-last resident root entries into a newly allocated INDEX_BUFFER via hdr_insert_head(). The source byte count 'to_move' is summed from the on-disk resident entry sizes and is independent of the destination buffer size, which comes from root->index_block_size (via indx->index_bits). A crafted NTFS image that keeps a valid, full resident root but shrinks root->index_block_size down to 512 after the root has been populated makes hdr_insert_head() memcpy attacker-controlled resident entry bytes past the end of the kmalloc(1u << indx->index_bits) allocation returned by indx_new(). For a 512-byte destination and a resident root whose non-last entries total 560 bytes, the memcpy overruns by 120 bytes and a following memmove extends the highest written offset to 136 bytes past the allocation. The overflow bytes are a direct copy of on-disk entries (via kmemdup), so they are fully attacker-controlled. The write is reachable from unprivileged open(O_CREAT) on a mounted crafted NTFS image: a single sufficiently long create in a directory whose resident root is already full forces root promotion and triggers the copy. This is a controlled out-of-bounds write of 120-136 bytes past a kmalloc(index_block_size) allocation, with attacker-controlled content. It is a bounded adjacent-heap corruption primitive; it is not an arbitrary-address write. Successful exploitation into a named victim object depends on the surrounding slab layout. Reject the copy at the sink. The destination's INDEX_HDR already reports hdr_total (the payload capacity of the new buffer) and hdr_used (the bytes already consumed by the terminal END entry installed by indx_new()); require that to_move fits in the remaining payload before calling hdr_insert_head(). On mismatch, fail with -EINVAL and mark the filesystem as having a detected on-disk inconsistency, which is the same behaviour as the surrounding validation in this function. Fixes: 82cae269cfa9 ("fs/ntfs3: Add initialization of super block") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito Signed-off-by: Konstantin Komarov Signed-off-by: Greg Kroah-Hartman

ntfs3: cap RESTART_TABLE free-chain walker at rt->used

2026-07-24T14:11:33+00:00

commit 9611f644302c07d21bc8af97e3e06a3d30064253 upstream. A crafted NTFS3 disk image triggers an in-kernel infinite loop at mount time, hanging the mounting thread and firing the soft-lockup watchdog within ~22s on multi-CPU hosts (panic with kernel.softlockup_panic=1). The bug is reachable from desktop USB auto-mount on distributions where udisks2 routes the NTFS signature to the in-tree ntfs3 driver (Arch family and an increasing fraction of Fedora / openSUSE / RHEL deployments); CAP_SYS_ADMIN-class manual mount elsewhere. check_rstbl()'s second walker iterates the free-entry singly-linked list headed by rt->first_free with no upper bound on iteration count: for (off = ff; off;) { if (off == RESTART_ENTRY_ALLOCATED) return false; off = le32_to_cpu(*(__le32 *)Add2Ptr(rt, off)); if (off > ts - sizeof(__le32)) return false; } The existing guards cover three exits: end-of-list (off == 0), the in-use marker (off == RESTART_ENTRY_ALLOCATED), and out-of-bounds (off > ts - sizeof(__le32)). None of the three prevents an in-bounds cycle. A crafted on-disk RESTART_TABLE whose free chain contains a self-loop or A->B->A cycle whose offsets satisfy: - in range [sizeof(struct RESTART_TABLE), ts - sizeof(__le32)] - (off - sizeof(struct RESTART_TABLE)) % rsize == 0 passes all existing guards and spins the mount-time thread forever. Reproduced in UML by hand-forging a 2 MB NTFS3 image whose journal RESTART_TABLE first_free = 0x18 and whose entry at offset 0x18 stores 0x18 as its next pointer; mount of the forged image with the in-tree ntfs3 driver never returns. Bound the walker by rt->used. Each entry on a legitimate free chain is unique, and the total slot count is ne = le16_to_cpu (rt->used). A traversal that visits more than ne slots is by construction malformed; reject it as a corrupt RESTART_TABLE. After this patch, mount of the forged image returns with -EINVAL and a log_replay failure message, and mkntfs-produced legitimate images mount cleanly (verified in the same UML harness). Fixes: b46acd6a6a62 ("fs/ntfs3: Add NTFS journal") Cc: stable@vger.kernel.org Signed-off-by: Michael Bommarito Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Konstantin Komarov Signed-off-by: Greg Kroah-Hartman

fs/ntfs3: bound NTFS_DE view.data_off in UpdateRecordData{Root,Allocation}

2026-07-24T14:11:33+00:00

commit 3e127829e57f5190f612412ece4541cb96d5ec7a upstream. In do_action()'s UpdateRecordDataRoot (fslog.c:3489) and UpdateRecordDataAllocation (fslog.c:3697) cases, the memmove destination is `Add2Ptr(e, le16_to_cpu(e->view.data_off))`, where e->view.data_off comes from an on-disk NTFS_DE inside an INDEX_ROOT or INDEX_BUFFER. Neither case validates view.data_off + dlen against e->size; the existing check_if_index_root / check_if_alloc_index helpers walk the entry chain and validate the entry's offset, but not its internal view fields. The neighbouring read sites (e.g., fs/ntfs3/index.c when iterating view entries) check view.data_off + view.data_size <= e->size. Apply the same bound at the two memmove sites. Reproduced under UML+KASAN on mainline 8d90b09e6741 via pr_warn-only probe instrumentation: with view.data_off forced to 0xFFFC, the memmove writes 32 bytes past the end of the NTFS_DE. This is similar in shape to Pavitra Jha's 2026-05-02 patch "fs/ntfs3: prevent oob in case UpdateRecordDataRoot" (<20260502105008.21827-1-jhapavitra98@gmail.com>) which proposes calling ntfs3_bad_de_range(); that helper does not exist in mainline. This patch uses inline checks. Fixes: b46acd6a6a62 ("fs/ntfs3: Add NTFS journal") Cc: stable@vger.kernel.org Reported-by: Pavitra Jha Closes: https://lore.kernel.org/ntfs3/20260502105008.21827-1-jhapavitra98@gmail.com/ Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito Signed-off-by: Konstantin Komarov Signed-off-by: Greg Kroah-Hartman

fs/ntfs3: add depth limit to indx_find_buffer to prevent stack overflow

2026-07-24T14:11:33+00:00

commit 1ebd684b8f627f75bc3e03f8b2ad8400fd1f02cd upstream. indx_find_buffer() recursively descends the B+ tree index with no depth limit. A crafted NTFS image with circular index node references causes unbounded recursion, overflowing the kernel stack and panicking the system. This is reachable by mounting a malicious NTFS filesystem (e.g. from a USB drive via desktop automount) and deleting a file whose index entry triggers the rebalancing fallback path in indx_delete_entry(). Add a depth parameter and bail out with -EINVAL when it reaches the fnd->nodes array bound, matching the constraint already enforced by fnd_push() in indx_find(). The related function indx_find() was previously patched for a similar infinite-loop issue (commit 1732053c8a6b), but indx_find_buffer() was missed. Fixes: 82cae269cfa9 ("fs/ntfs3: Add initialization of super block") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-6 Assisted-by: Codex:gpt-5-4 Signed-off-by: Michael Bommarito Signed-off-by: Konstantin Komarov Signed-off-by: Greg Kroah-Hartman

fs/ntfs3: validate lcns_follow in log_replay conversion

2026-07-24T14:11:33+00:00

commit 6a4c53a2e26a865565bd6a460961e8d6fcb32329 upstream. log_replay() converts DIR_PAGE_ENTRY_32 records into DIR_PAGE_ENTRY records when replaying version 0 restart tables. During this conversion, the memmove() length is derived directly from the on-disk lcns_follow field: memmove(&dp->vcn, &dp0->vcn_low, 2 * sizeof(u64) + le32_to_cpu(dp->lcns_follow) * sizeof(u64)); check_rstbl() validates restart table structure, but does not constrain per-entry lcns_follow values relative to the entry size. A malformed filesystem image can provide an oversized lcns_follow value, causing the conversion memmove() to access memory beyond the bounds of the allocated restart table buffer. The same field is later used to bound iteration over page_lcns[], so validating lcns_follow during conversion also prevents downstream out-of-bounds access from the same malformed metadata. Compute the maximum valid lcns_follow from the already-validated restart table entry size and reject entries that exceed this bound. Reuse the existing t16/t32 scratch variables already declared in log_replay() to avoid introducing new declarations. Fixes: b46acd6a6a62 ("fs/ntfs3: Add NTFS journal") Cc: stable@vger.kernel.org Signed-off-by: Pavitra Jha [almaz.alexandrovich@paragon-software.com: fixed the conflicts] Signed-off-by: Konstantin Komarov Signed-off-by: Greg Kroah-Hartman

fs/ntfs3: bound attr_off in UpdateResidentValue against data_off

2026-07-24T14:11:32+00:00

commit d1570c48f49a693974d000251030370ee2e83539 upstream. In do_action()'s UpdateResidentValue case (fslog.c:3307), lrh->attr_off and lrh->redo_len come from the on-disk LRH. When they satisfy aoff + dlen < attr->res.data_off, the assignment attr->res.data_size = cpu_to_le32(aoff + dlen - data_off); underflows to ~4 GiB (e.g. 0xFFFFFFF9 when aoff=0x10, dlen=1, data_off=0x18). Subsequent code that reads attr->res.data_size to walk the resident attribute payload would then read up to 4 GiB past the 1024-byte MFT record allocation. The existing mi_enum_attr() defense in fs/ntfs3/record.c:287 catches the corrupted data_size on the next attribute walk and fails the mount, but only on the path that walks all attributes. A read site that picks an attribute by name and reads its data_size without re-validating is not covered. Validate aoff against data_off and asize at the source. Reproduced under UML+KASAN on mainline 8d90b09e6741 via pr_warn-only probe: with aoff=0x10 and data_off=0x18, the post-assignment data_size is 0xfffffff9 (mount then fails at -22 from mi_enum_attr). Fixes: b46acd6a6a62 ("fs/ntfs3: Add NTFS journal") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito [almaz.alexandrovich@paragon-software.com: clang-formatted the changes] Signed-off-by: Konstantin Komarov Signed-off-by: Greg Kroah-Hartman

fs/ntfs3: bound copy_lcns dp->page_lcns[] index in analysis pass

2026-07-24T14:11:32+00:00

commit 5e7b598660cfa8e5af172cf4c65cffc126333307 upstream. In log_replay()'s analysis pass, after find_dp() returns a valid DIR_PAGE_ENTRY for the (target_attr, target_vcn) tuple, the copy_lcns block walks lrh->lcns_follow further entries: t16 = le16_to_cpu(lrh->lcns_follow); for (i = 0; i < t16; i++) { size_t j = (size_t)(le64_to_cpu(lrh->target_vcn) - le64_to_cpu(dp->vcn)); dp->page_lcns[j + i] = lrh->page_lcns[i]; } find_dp() only validates that target_vcn falls within [dp->vcn, dp->vcn + dp->lcns_follow), i.e., that the FIRST cluster is covered. The walk through the further entries is not bounded against dp->lcns_follow. For a malformed LRH where target_vcn = dp->vcn + dp->lcns_follow - 1 and lrh->lcns_follow > 1, the i > 0 writes overflow the dp's allocated page_lcns[] array. Add the missing j + lrh->lcns_follow <= dp->lcns_follow guard. Reproduced under UML+KASAN on mainline 8d90b09e6741 as a slab-out-of-bounds write of size 8 from log_replay+0x68d4 on the mount path. This is distinct from Pavitra Jha's 2026-05-02 patch ("fs/ntfs3: validate lcns_follow in log_replay conversion", <20260502154252.164586-1-jhapavitra98@gmail.com>) which addresses the separate version-0 dirty-page-table conversion path's memmove(&dp->vcn, ...) call. The two fixes are complementary; both should land. Fixes: b46acd6a6a62 ("fs/ntfs3: Add NTFS journal") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito [almaz.alexandrovich@paragon-software.com: clang-formatted the changes, fixed conflicts] Signed-off-by: Konstantin Komarov Signed-off-by: Greg Kroah-Hartman

fs/ntfs3: bound DeleteIndexEntryAllocation memmove length

2026-07-24T14:11:32+00:00

commit fc4626bb3656362de8b0ecd56605d47a19ec3518 upstream. 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. Fixes: b46acd6a6a62 ("fs/ntfs3: Add NTFS journal") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito [almaz.alexandrovich@paragon-software.com: clang-formatted the changes] Signed-off-by: Konstantin Komarov Signed-off-by: Greg Kroah-Hartman