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Search Results (378778 CVEs found)

CVE Vendors Products Updated CVSS v3.1
CVE-2026-72288 1 Linux 1 Linux Kernel 2026-08-17 9.3 Critical
In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: vgic: Handle race between interrupt affinity change and LPI disabling Hyunwoo Kim reports some really bad races should the following situation occur: - LPI-I is pending in vcpu-B's AP list - vcpu-A writes to vcpu-B's RD to disable its LPIs - vcpu-C moves I from B to C If the last two race nicely enough, vgic_prune_ap_list() can drop the irq and AP list locks, reacquire them, and in the interval the irq has been freed. UAF follows. The fix is two-fold: - Before dropping the irq and ap_list locks, take a reference on the irq - Do not try to handle migration of the pending bit: there is no expectation that this state is retained, as per the architecture With that, we're sure that the interrupt is still around, and we safely remove it from the AP list as it has no target at this stage (unless another interrupt fires, but that's another story).
CVE-2026-72286 1 Linux 1 Linux Kernel 2026-08-17 8.8 High
In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Do not allow intra-host migration/mirroring of SNP VMs The intra-host migration/mirroring feature is not fully implemented for SEV-SNP VMs. The proper migration requires additional SNP-specific state such as guest_req_mutex, guest_req_buf, and guest_resp_buf to be transferred or initialized on the destination. The SNP VM mirroring requires vmsa features to be copied as well otherwise ASID would be bound to SNP range while VM is detected as a SEV VM. Reject SNP source VMs in migration/mirroring until proper SNP state transfer is implemented. [sean: let lines poke past 80 chars, tag for stable]
CVE-2026-72261 1 Linux 1 Linux Kernel 2026-08-17 7.8 High
In the Linux kernel, the following vulnerability has been resolved: ASoC: SOF: ipc3-control: Validate size in snd_sof_update_control In snd_sof_update_control(), firmware-provided cdata->num_elems is checked against local_cdata->data->size but never against the actual allocation size. If local_cdata->data->size was previously set to an inconsistent value, the memcpy could write past the allocated buffer. Add a bounds check to ensure num_elems fits within the available space in the ipc_control_data allocation before copying.
CVE-2026-72251 1 Linux 1 Linux Kernel 2026-08-17 9.8 Critical
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_nat_sip: reload possible stale data pointer quoting sashiko: ------------------------------------------------------------------------ [..] noticed a potential memory bug and header corruption involving the SIP NAT helper. In net/netfilter/nf_nat_sip.c:nf_nat_sip(): if (skb_ensure_writable(skb, skb->len)) { nf_ct_helper_log(skb, ct, "cannot mangle packet"); return NF_DROP; } uh = (void *)skb->data + protoff; uh->dest = ct_sip_info->forced_dport; if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo, protoff, 0, 0, NULL, 0)) { If a cloned or fragmented SKB is reallocated by skb_ensure_writable(), the old data buffer is freed. However, nf_nat_sip() fails to update *dptr to point to the new buffer. It also appears to use nf_nat_mangle_udp_packet() on what could be a TCP packet, which would overwrite the sequence number with a checksum update. ------------------------------------------------------------------------ nf_conntrack_sip linerizes skbs, hence no fragmented skb can be seen. But clones are possible, so rebuild dptr. Disable nf_nat_mangle_udp_packet() branch for TCP streams. It doesn't look like this can ever happen, else we should have received bug reports about this, so just check the conntrack is UDP and drop otherwise. The calling conntrack_sip set ->forced_dport for SIP_HDR_VIA_UDP messages, so I don't think this is ever expected to be true for a TCP stream.
CVE-2026-72244 1 Linux 1 Linux Kernel 2026-08-17 7.8 High
In the Linux kernel, the following vulnerability has been resolved: gpu/buddy: bail out of try_harder when alignment cannot be honoured The try_harder contiguous fallback could return a range whose start offset did not match the caller's min_block_size. When a candidate's start is misaligned, realign it: free the misaligned run and reallocate exactly @size at the next lower min_block_size boundary. This keeps the returned size unchanged with no surplus to trim, and rejects the request only when no aligned candidate fits. v2: align misaligned candidates down to min_block_size instead of bailing out, for both the RHS and LHS paths (Matthew).
CVE-2026-72222 1 Linux 1 Linux Kernel 2026-08-17 9.8 Critical
In the Linux kernel, the following vulnerability has been resolved: sunrpc: pin svc_xprt across the asynchronous TLS handshake callback svc_tcp_handshake() stores the raw svc_xprt pointer in tls_handshake_args.ta_data and submits the request through tls_server_hello_x509(). The handshake core takes only sock_hold(req->hr_sk); nothing references the embedding struct svc_sock that svc_tcp_handshake_done() reaches via container_of(). Two close races leave the in-flight callback writing through a freed svc_sock. svc_sock_free() calls tls_handshake_cancel() and discards its return value: a false return means handshake_complete() has already set HANDSHAKE_F_REQ_COMPLETED but hp_done() may not have finished, yet svc_sock_free() proceeds to kfree(svsk). The cancel-loser fall-through inside svc_tcp_handshake() itself produces the same window: when wait_for_completion_interruptible_timeout() returns <= 0 (timeout or signal) and tls_handshake_cancel() returns false, the function does not drain, returns, and svc_handle_xprt() calls svc_xprt_received(), which clears XPT_BUSY and can drop the last reference. A concurrent close then runs svc_sock_free() while svc_tcp_handshake_done() is still updating xpt_flags and walking svsk->sk_handshake_done. The corruption surfaces as set_bit/clear_bit RMW into the freed xpt_flags slab slot and as complete_all() walking and writing the freed wait_queue_head_t list embedded in sk_handshake_done -- a slab-corruption primitive, not a benign read. The path is reachable on any TLS-enabled NFS server whenever a connection close overlaps the tlshd downcall delivery window; the interruptible wait means signal delivery suffices, not just SVC_HANDSHAKE_TO expiry. Take svc_xprt_get(xprt) immediately before tls_server_hello_x509() so the in-flight callback owns its own reference. Release it on the two edges where the callback is guaranteed not to fire -- submission failure from tls_server_hello_x509() and a successful tls_handshake_cancel() -- and at the tail of svc_tcp_handshake_done() after complete_all(). [cel: rewrote commit message to describe the actual change]
CVE-2026-72221 1 Linux 1 Linux Kernel 2026-08-17 9.8 Critical
In the Linux kernel, the following vulnerability has been resolved: sunrpc: wait for in-flight TLS handshake callback when cancel loses race When wait_for_completion_interruptible_timeout() in svc_tcp_handshake() returns 0 (timeout) or -ERESTARTSYS (signal) and tls_handshake_cancel() then returns false, handshake_complete() has won the cancellation race: it has set HANDSHAKE_F_REQ_COMPLETED and is about to invoke svc_tcp_handshake_done(), but the callback's side effects on xpt_flags and on svsk->sk_handshake_done have not yet committed. The current code reads xpt_flags immediately to decide whether the session succeeded. Two races result. If the callback has executed set_bit(XPT_TLS_SESSION) but not yet clear_bit(XPT_HANDSHAKE), svc_tcp_handshake() sees a session, enqueues the transport, and returns. svc_xprt_received() then clears XPT_BUSY, a worker thread picks the transport up, the dispatcher in svc_handle_xprt() observes XPT_HANDSHAKE still set, and xpo_handshake is invoked a second time. That svc_tcp_handshake() calls init_completion(&svsk->sk_handshake_done) while the original callback concurrently calls complete_all() on it, corrupting the embedded swait_queue. If the callback has set HANDSHAKE_F_REQ_COMPLETED but not yet entered svc_tcp_handshake_done(), svc_tcp_handshake() reads XPT_TLS_SESSION as clear and tears the connection down even though the handshake is about to succeed. Wait for the callback to commit before inspecting xpt_flags. The completion is guaranteed to fire because handshake_complete() invokes svc_tcp_handshake_done() unconditionally once it has set HANDSHAKE_F_REQ_COMPLETED.
CVE-2026-72209 1 Linux 1 Linux Kernel 2026-08-17 9.8 Critical
In the Linux kernel, the following vulnerability has been resolved: ntfs: validate attribute values on lookup ntfs_attr_find() and ntfs_external_attr_find() check that generic resident attribute values fit in their attribute records and that fixed-size resident values are large enough. For variable-length resident formats, however, the fixed part is not enough: embedded length fields can still point callers past the resident value. A crafted image can set a small resident $FILE_NAME value_length while leaving file_name_length large. Callers then trust file_name_length and read past the resident value when converting or comparing the name. This was reproduced with a crafted image under KASAN as a slab-out-of-bounds read from the kmalloc-1k MFT record copy. The stack included ntfs_lookup(), ntfs_iget(), ntfs_read_locked_inode(), ntfs_attr_name_get(), ntfs_ucstonls(), and utf16s_to_utf8s(). Add a shared attribute value validator and use it before a lookup path can return an attribute, including the AT_UNUSED enumeration case where callers inspect returned attributes directly. The helper validates resident value bounds, minimum resident value sizes, variable-length $FILE_NAME fields, and non-resident mapping-pairs metadata that was previously checked separately in both lookup paths. This also preserves the intended resident @val matching semantics in the external attribute lookup path. The old duplicated validation block overwrote the actual resident value length with the type-specific minimum length before comparing @val, so variable-length resident values could fail to match even when the bytes were identical. Keep the comparison on the actual value length, and make ntfs_attrlist_entry_add() compare resident attributes with lowest_vcn zero instead of reading the non-resident union member after a successful resident match. Reject non-resident $FILE_NAME records too: the format requires $FILE_NAME to be resident and callers treat returned records as resident.
CVE-2026-72203 1 Linux 1 Linux Kernel 2026-08-17 7.5 High
In the Linux kernel, the following vulnerability has been resolved: ntfs: skip extent mft records in writeback to prevent deadlock This patch fixes the ABBA deadlock between extent_lock and extent mrec_lock triggered by xfstests generic/113, that occurs since the commit 6994acf33bae ("ntfs: use base mft_no when looking up base inode for extent record"). Path A (inode writeback): VFS writeback -> ntfs_write_inode() -> __ntfs_write_inode() -> mutex_lock(&ni->extent_lock) -> mutex_lock(&tni->mrec_lock) Path B (MFT folio writeback): VFS writeback of $MFT dirty folios -> ntfs_mft_writepages() -> ntfs_write_mft_block() -> ntfs_may_write_mft_record() -> holds one extent mrec_lock from a previous iteration -> tries to acquire another base inode extent_lock By removing all extent_lock and extent mrec_lock acquisition from the MFT folio writeback path, the ABBA lock ordering is eliminated: Path A: __ntfs_write_inode(): extent_lock -> mrec_lock Path B (removed): ntfs_write_mft_block(): mrec_lock -> extent_lock Path B is always redundant for extent records because: 1. mark_mft_record_dirty(ext_ni) does NOT dirty the MFT folio. It only sets NInoDirty(ext_ni) and marks the base VFS inode dirty via __mark_inode_dirty(I_DIRTY_DATASYNC), which triggers Path A. Therefore, normal extent modifications never create a situation where the MFT folio is dirty and Path B is not scheduled. 2. The MFT folio only gets dirtied via ntfs_mft_mark_dirty() inside ntfs_mft_record_alloc(). But all identified callers in attrib.c (ntfs_attr_add, ntfs_attr_record_move_away, ntfs_attr_make_non_resident, ntfs_attr_record_resize) follow through with mark_mft_record_dirty(), which triggers Path A to write the complete record. 3. ntfs_evict_big_inode() calls ntfs_commit_inode() before freeing extent inodes, ensuring all dirty extents are flushed via Path A before the base inode leaves the icache.
CVE-2026-72197 1 Linux 1 Linux Kernel 2026-08-17 8.4 High
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]
CVE-2026-72162 1 Linux 1 Linux Kernel 2026-08-17 7.8 High
In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix UBSAN array-index-out-of-bounds in ocfs2_sum_rightmost_rec [BUG] On-disk corruption setting l_next_free_rec to 0 in an inode's embedded extent list triggers a UBSAN panic on the next write to that file. [CAUSE] ocfs2_sum_rightmost_rec() computes i = le16_to_cpu(el->l_next_free_rec) - 1 and accesses el->l_recs[i] without validating i. When l_next_free_rec is 0, i becomes -1; when l_next_free_rec exceeds l_count, i falls past the end of the array. Either case violates the __counted_by_le(l_count) annotation on l_recs[] and triggers UBSAN. [FIX] Validate the inode's embedded extent list when the inode is read, in ocfs2_validate_inode_block(): l_count must be non-zero and no larger than the inode block can hold, and l_next_free_rec must not exceed l_count. A corrupt list is rejected at read time, before the b-tree code can index l_recs[] out of bounds.
CVE-2026-72160 1 Linux 1 Linux Kernel 2026-08-17 8.8 High
In the Linux kernel, the following vulnerability has been resolved: ocfs2: reject dinodes with non-canonical i_mode type Patch series "ocfs2: harden inode validators against forged metadata", v2. This series adds three structural checks to OCFS2 dinode validation so malformed on-disk fields are rejected before ocfs2_populate_inode() copies them into the in-core inode. The checks cover: - i_mode values whose type bits do not name a canonical POSIX file type; - non-device dinodes whose id1.dev1.i_rdev field is non-zero; and - non-inline dinodes that claim non-zero i_size while i_clusters is zero, covering directories unconditionally and regular files on non-sparse volumes. The normal read path reports these through ocfs2_error(), matching the existing suballoc-slot, inline-data, chain-list, and refcount checks. The online filecheck path uses the same structural predicates but keeps its own reporting contract, returning OCFS2_FILECHECK_ERR_INVALIDINO instead of calling ocfs2_error(). This patch (of 3): ocfs2_validate_inode_block() currently accepts any non-zero i_mode value. ocfs2_populate_inode() then copies that mode verbatim into inode->i_mode and dispatches on i_mode & S_IFMT to the file/dir/symlink/special_file iops; an unrecognised type falls through to ocfs2_special_file_iops and init_special_inode(). Reject dinodes whose type bits do not name one of the seven canonical POSIX file types. Use fs_umode_to_ftype(), the same generic file-type conversion helper OCFS2 already uses for directory entries, so the accepted inode type set matches the kernel file-type vocabulary instead of open-coding a local switch. Apply the same structural check to the online filecheck read path. filecheck keeps its own error namespace, so it reports malformed i_mode through the filecheck logger and OCFS2_FILECHECK_ERR_INVALIDINO instead of calling ocfs2_error(), but it must not allow a malformed dinode to proceed into ocfs2_populate_inode().
CVE-2026-72157 1 Linux 1 Linux Kernel 2026-08-17 8.8 High
In the Linux kernel, the following vulnerability has been resolved: net: thunderbolt: Fix frags[] overflow by bounding frame_count tbnet_poll() assembles a multi-frame ThunderboltIP packet into one skb. The first frame goes into the skb linear area and every further frame is added as a page fragment. skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, hdr_size, frame_size, TBNET_RX_PAGE_SIZE - hdr_size); A packet of frame_count frames therefore ends up with frame_count - 1 fragments. tbnet_check_frame() only bounds the peer supplied frame_count to TBNET_RING_SIZE / 4 (64), which is far above MAX_SKB_FRAGS (17 by default). A peer that sends a packet of 19 or more small frames pushes nr_frags past MAX_SKB_FRAGS, so skb_add_rx_frag() writes past skb_shinfo()->frags[] and corrupts memory after the shared info. Tighten the start of packet bound to MAX_SKB_FRAGS + 1 so a packet can never produce more fragments than frags[] can hold. This matches the recent skb frags overflow fixes in other receive paths, for example f0813bcd2d9d ("net: wwan: t7xx: fix potential skb->frags overflow in RX path") and 600dc40554dc ("net: usb: cdc-phonet: fix skb frags[] overflow in rx_complete()").
CVE-2026-72143 1 Linux 1 Linux Kernel 2026-08-17 7.1 High
In the Linux kernel, the following vulnerability has been resolved: platform/x86: ISST: Restore SST-PP control to all domains The SST-PP control offset is only restored to power domain 0 after resume. During suspend, control values are read and stored for all power domains. Use pd_info->sst_base instead of power_domain_info->sst_base, which only points to power domain 0 base address.
CVE-2026-72141 1 Linux 1 Linux Kernel 2026-08-17 7.5 High
In the Linux kernel, the following vulnerability has been resolved: i2c: imx: fix locked bus on SMBus block-read of 0 (IRQ) SMBus 3.1 6.5.7 allows a Block Read byte count of 0, but the interrupt-driven block-read state machine rejects it as -EPROTO. Worse, it returns without a NACK+STOP: the next receive cycle has already started, so the target keeps holding SDA and the bus stays stuck until a power cycle of this i2c controller. Accept count=0: NACK the in-flight dummy byte (TXAK) and set msg->len to 2 so i2c_imx_isr_read_continue() emits STOP via its normal last-byte path. The dummy byte is discarded; block-read callers only consume buf[0..count-1]. Reading I2DR has likewise already armed the next byte on the count > I2C_SMBUS_BLOCK_MAX error path, so NACK it (TXAK) before aborting with -EPROTO; otherwise the failing transfer's STOP cannot complete and the bus stays held. The atomic path regressed earlier (v3.16) and is fixed separately; this patch covers only the v6.13 state-machine rework.
CVE-2026-72137 1 Linux 1 Linux Kernel 2026-08-17 9.8 Critical
In the Linux kernel, the following vulnerability has been resolved: xfrm: nat_keepalive: avoid double free on send error nat_keepalive_send() frees the keepalive skb whenever the IPv4 or IPv6 send helper reports an error. That cleanup is only correct before the skb is handed to the output path. Once ip_build_and_send_pkt() or ip6_xmit() takes ownership, the networking stack may already have consumed the skb before returning an error, so freeing it again is unsafe. Handle the pre-handoff failure cases inside nat_keepalive_send_ipv4() and nat_keepalive_send_ipv6(), where the caller still owns the skb, and keep nat_keepalive_send() responsible only for family dispatch and the unsupported-family cleanup path.
CVE-2026-72129 1 Linux 1 Linux Kernel 2026-08-17 9.8 Critical
In the Linux kernel, the following vulnerability has been resolved: nvmet-rdma: handle inline data with a nonzero offset nvmet_rdma_use_inline_sg() maps the host-controlled inline data offset into the per-command inline scatterlist. The bounds check admits any offset with off + len <= inline_data_size, but the mapping still assumes the data begins in the first inline page: sg->offset = off; sg->length = min_t(int, len, PAGE_SIZE - off); When a port is configured with inline_data_size > PAGE_SIZE (settable up to max(SZ_16K, PAGE_SIZE)), an offset in (PAGE_SIZE, inline_data_size] makes "PAGE_SIZE - off" underflow, so sg->length is set to ~4 GiB and the block backend reads far past the first inline page. num_pages(len) also ignores the offset, so an in-bounds offset whose [off, off+len) span crosses a page boundary under-counts the scatterlist. Map the offset properly: split it into a page index and an in-page offset, start the scatterlist at that page, and size the page count from page_off + len. Because the request scatterlist may now start at inline_sg[page_idx] rather than inline_sg[0], generalize the inline-SGL identity test in nvmet_rdma_release_rsp() to a range test; otherwise the persistent inline scatterlist is mistaken for an allocated one and nvmet_req_free_sgls() frees an inline page (and warns in free_large_kmalloc()).
CVE-2026-72115 1 Linux 1 Linux Kernel 2026-08-17 8.1 High
In the Linux kernel, the following vulnerability has been resolved: can: bcm: track a single source interface for ANYDEV timeout/throttle ops An ANYDEV rx op (ifindex == 0) with an active RX timeout and/or throttle timer has no defined semantics when matching frames arrive from several interfaces: bcm_rx_handler() can run concurrently for the same op on different CPUs, racing hrtimer_cancel()/ bcm_rx_starttimer() against bcm_rx_timeout_handler() and causing spurious RX_TIMEOUT notifications and last_frames corruption. The same concurrency lets throttled multiplex frames from different interfaces clobber the single rx_ifindex/rx_stamp fields shared by the op. Add op->if_detected to track the first interface that delivers a matching frame while a timeout/throttle timer is configured, and reject frames from any other interface for that op. The claim is decided in bcm_rx_handler() before hrtimer_cancel() touches op->timer, so a rejected frame can never disturb the claimed interface's watchdog. RTR-mode ops are excluded via RX_RTR_FRAME, independent of kt_ival1/kt_ival2, since those may briefly hold a stale value from an earlier non-RTR configuration. The claim is released in bcm_notify() on NETDEV_UNREGISTER and in bcm_rx_setup() when SETTIMER reconfigures the timer values. A (re-)claim is only possible on CAN devices in NETREG_REGISTERED dev->reg_state to cover the release in bcm_notify() where reg_state becomes NETREG_UNREGISTERING until synchronize_net().
CVE-2026-72109 1 Linux 1 Linux Kernel 2026-08-17 7.8 High
In the Linux kernel, the following vulnerability has been resolved: net: sparx5: unregister blocking notifier on init failure sparx5_register_notifier_blocks() registers the switchdev blocking notifier before allocating the ordered workqueue. If the workqueue allocation fails, the error path unregisters the switchdev and netdevice notifiers, but leaves the blocking notifier registered. Add a separate error label for the workqueue allocation failure path and unregister the switchdev blocking notifier there.
CVE-2026-72108 1 Linux 1 Linux Kernel 2026-08-17 7.8 High
In the Linux kernel, the following vulnerability has been resolved: dm thin metadata: fix metadata snapshot consistency on commit failure __reserve_metadata_snap() and __release_metadata_snap() modify the superblock's held_root directly in the block_manager's buffer. If the subsequent metadata commit fails, the held_root gets flushed to disk through the abort_transaction path, resulting in inconsistent metadata. Reproducer 1: __reserve_metadata_snap() 1. Create a 2 MiB metadata device and make the region after the 14th block inaccessible, to trigger metadata commit failure in the subsequent reserve_metadata_snap operation. The 14th block will be the shadow destination for the index block. dmsetup create tmeta --table "0 112 linear /dev/sdc 0 112 3984 error" 2. Create a 16 MiB thin-pool dmsetup create tdata --table "0 32768 zero" dd if=/dev/zero of=/dev/mapper/tmeta bs=4k count=1 dmsetup create tpool --table "0 32768 thin-pool /dev/mapper/tmeta \ /dev/mapper/tdata 128 0 1 skip_block_zeroing" 3. Take a metadata snapshot to trigger metadata commit failure and transaction abort. However, the held_root is written to disk, breaking metadata consistency. dmsetup message tpool 0 "reserve_metadata_snap" thin_check v1.2.2 result: Bad reference count for metadata block 6. Expected 2, but space map contains 1. Bad reference count for metadata block 7. Expected 2, but space map contains 1. Bad reference count for metadata block 13. Expected 1, but space map contains 0. Reproducer 2: __release_metadata_snap() 1. Create a 2 MiB metadata device and make the region after the 16th block inaccessible, to trigger metadata commit failure in the subsequent release_metadata_snap operation. The 16th block will be the shadow destination for the index block. dmsetup create tmeta --table "0 128 linear /dev/sdc 0 128 3968 error" 2. Create a 16 MiB thin-pool dmsetup create tdata --table "0 32768 zero" dd if=/dev/zero of=/dev/mapper/tmeta bs=4k count=1 dmsetup create tpool --table "0 32768 thin-pool /dev/mapper/tmeta \ /dev/mapper/tdata 128 0 1 skip_block_zeroing" 3. Reserve then release the metadata snapshot, to trigger metadata commit failure and transaction abort. The held_root gets removed from the on-disk superblock, causing inconsistent metadata. dmsetup message tpool 0 "reserve_metadata_snap" dmsetup message tpool 0 "release_metadata_snap" thin_check v1.2.2 result: Bad reference count for metadata block 6. Expected 1, but space map contains 2. Bad reference count for metadata block 7. Expected 1, but space map contains 2. 1 metadata blocks have leaked. Fix by deferring the held_root update to commit time. Additionally, move the existing-snapshot check in __reserve_metadata_snap before the shadow operation to avoid unnecessary work. In __release_metadata_snap, clear pmd->held_root before btree deletion so partial failure leaks blocks rather than leaving a stale reference, and unlock the snapshot block before decrementing its refcount.