CVE Database

In the Linux kernel, the following vulnerability has been resolved: s390/zcrypt: Improve EP11 CPRB domain handling with ASN.1 parsing The zcrypt_msgtype6_send_ep11_cprb() function uses fragile struct overlays to access and modify the domain field in the EP11 CPRB payload, creating maintainability and security concerns: 1. Struct overlay approach (pld_hdr) assumes fixed payload structure and doesn't validate the actual ASN.1 encoding. 2. Complex length format detection logic is error-prone and doesn't properly validate bounds at each parsing step. 3. Direct struct member access bypasses proper ASN.1 validation. Fix by replacing struct overlays with explicit ASN.1 parsing that validates each field (payload tag/length, function tag/length/value, optional domain tag/length/value) with proper bounds checking at every step. Add asn1_int_encode() helper function to safely write integer values with correct endianness conversion. This makes the code consistent with the validation pattern introduced with the rework of the xcrb_msg_to_type6_ep11cprb_msgx() function.

In the Linux kernel, the following vulnerability has been resolved: s390/zcrypt: Pad trailing CCA or EP11 message with zeros The both functions xcrb_msg_to_type6cprb_msgx() and xcrb_msg_to_type6_ep11cprb_msgx() copy the user space message into a kernel buffer based on the message length. But on further processing the message is supposed to be 4 byte length adjusted. Thus up to 3 bytes of uninitialized kernel memory are forwarded to further processing steps and may unwanted expose kernel memory to the crypto card firmware. This patch contains code to pad the gap between user space copied message and message buffer length sent down to further processing of the CCA or EP11 message to zeros.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix NULL pointer dereference in amdgpu_dm_crtc_set_vblank() amdgpu_dm_crtc_set_vblank() dereferences acrtc_state->stream when vblank is enabled/queried from DRM_IOCTL_MODE_CRTC_GET_SEQUENCE before a stream is attached to it. BUG: kernel NULL pointer dereference, address: 0000000000000008 RIP: amdgpu_dm_crtc_set_vblank+0x6b/0x4d0 [amdgpu] Call Trace: drm_vblank_enable drm_vblank_get drm_crtc_get_sequence_ioctl drm_ioctl_kernel drm_ioctl Reproduced by running VKCTS with WSI tests enabled on RADV. Guard the enable path on acrtc_state->stream being non-NULL, matching the existing checks in this function. (cherry picked from commit 7b1b31bf6942e6f43509b48da23f8e27269aac39)

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: validate GEM_CREATE domain combinations AMDGPU_GEM_CREATE checked domain bits against AMDGPU_GEM_DOMAIN_MASK, but did not validate domain combinations. Userspace could combine CPU|GTT|VRAM with DOORBELL, GDS, GWS, or OA, making amdgpu_bo_placement_from_domain() exceed AMDGPU_BO_MAX_PLACEMENTS and hit BUG_ON(). Allow combinations only within CPU/GTT/VRAM, and require non-CPU/GTT/ VRAM domains to be specified one at a time. Return -EINVAL for invalid combinations in amdgpu_gem_create_ioctl(). v2: Rename helper from amdgpu_gem_domain_valid() to amdgpu_gem_are_domains_valid() (Christian) (cherry picked from commit db39852d0c39843cb02048dfb47e4b8c703e9080)

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix UVD decode image min size calculation This needs to use pitch instead of width. Also reject pitch over 4096 to avoid overflow. (cherry picked from commit b41c8cb12e202b220353332ab87dc01a11f69304)

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: disallow multiple FENCE chunks in one submit amdgpu_cs_pass1() dispatches on chunk_id once per chunk without rejecting repeated ids. p->uf_bo is a single-slot field, so a submission carrying two AMDGPU_CHUNK_ID_FENCE chunks runs amdgpu_cs_p1_user_fence() twice, and the second run overwrites p->uf_bo with a freshly referenced BO without dropping the reference taken by the first. amdgpu_cs_parser_fini() only unrefs the final p->uf_bo, so every FENCE chunk but the last leaks a BO reference. The leaked BO outlives handle close and process exit. Reject duplicate FENCE chunks the same way commit fec5f8e8c6bc ("drm/amdgpu: disallow multiple BO_HANDLES chunks in one submit") did for p->bo_list. (cherry picked from commit 665b1fc2a1845206408f9a2c6da67101789edb82)

In the Linux kernel, the following vulnerability has been resolved: xfs: propagate errors from xfs_rtginode_load xfs_rtginode_ensure() treats every xfs_rtginode_load() error other than -ENOENT as success. This can leave the realtime group inode unset after an I/O, allocation, or corruption error. Growfs then continues as though the inode had been loaded. Only -ENOENT means that the inode needs to be created. Return all other errors to the growfs caller.

In the Linux kernel, the following vulnerability has been resolved: xfs: fix off-by-one in rtrefcount btree root level validation xfs_rtrefcountbt_compute_maxlevels() sets mp->m_rtrefc_maxlevels = min(d_maxlevels, r_maxlevels) + 1; where the trailing "+ 1" already accounts for the inode-root level, so the deepest valid on-disk root level is m_rtrefc_maxlevels - 1 and a cursor must satisfy bc_nlevels <= bc_maxlevels (= m_rtrefc_maxlevels). The two on-disk validation paths, xfs_rtrefcountbt_verify() and xfs_iformat_rtrefcount(), check the root level with ">" instead of ">=", so a crafted rtreflink (metadir + realtime + reflink) image whose /rtgroups/N.refcount inode has bb_level == m_rtrefc_maxlevels is accepted on mount. xfs_rtrefcountbt_init_cursor() then sets bc_nlevels = bb_level + 1, exceeding bc_maxlevels by one. Since the xfs_rtrefcountbt_cur slab object is sized for exactly bc_maxlevels entries, the first btree op on such a cursor indexes bc_levels[m_rtrefc_maxlevels] past the end of the object. This is reached by the first rtrefcount cursor built after mount, via log/CoW recovery (xfs_reflink_recover_cow() during xfs_mountfs()) or an FS_IOC_GETFSMAP over the realtime device. Reject a root level equal to m_rtrefc_maxlevels, matching the ">=" form already used by the sibling data-device refcount/rmap verifiers and the in-memory rtrmap verifier. BUG: KASAN: slab-out-of-bounds in xfs_btree_lookup (fs/xfs/libxfs/xfs_btree.c:2101) Write of size 2 at addr ffff888018391658 by task exploit/144 xfs_btree_lookup (fs/xfs/libxfs/xfs_btree.c:2101) xfs_btree_query_range (fs/xfs/libxfs/xfs_btree.c:5308) xfs_refcount_recover_cow_leftovers (fs/xfs/libxfs/xfs_refcount.c:2113) xfs_reflink_recover_cow (fs/xfs/xfs_reflink.c:1085) xlog_recover_finish (fs/xfs/xfs_log_recover.c:3551) xfs_mountfs (fs/xfs/xfs_mount.c:1158) xfs_fs_fill_super (fs/xfs/xfs_super.c:1940) get_tree_bdev_flags (fs/super.c:1634) vfs_get_tree (fs/super.c:1694) path_mount (fs/namespace.c:4161) __x64_sys_mount (fs/namespace.c:4367) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) The buggy address belongs to the cache xfs_rtrefcountbt_cur of size 216 The buggy address is located 8 bytes to the right of allocated 216-byte region [ffff888018391578, ffff888018391650) Kernel panic - not syncing: Fatal exception

In the Linux kernel, the following vulnerability has been resolved: xfs: bounds-check buffer log item's dirty bitmap xlog_recover_do_reg_buffer() replays each dirty region described by a buffer log item's bitmap into the buffer read for that item: memcpy(xfs_buf_offset(bp, (uint)bit << XFS_BLF_SHIFT), item->ri_buf[i].iov_base, nbits << XFS_BLF_SHIFT); The destination offset (bit/nbits, from the logged dirty bitmap) and the buffer size (from the logged blf_len) are both attacker-controlled and otherwise unrelated, yet the only thing bounding the copy is an ASSERT(), which compiles away on production kernels. A crafted image logging a small blf_len together with a bitmap bit past the end of that buffer drives the memcpy() past the buffer's allocation, corrupting adjacent kernel heap during mount-time log recovery. This is reachable by anyone who can get a crafted image mounted -- the malicious-filesystem threat model XFS already guards against elsewhere. Turn the ASSERT() into a real XFS_IS_CORRUPT() check that aborts recovery of the buffer with -EFSCORRUPTED, consistent with the validate-and-fail idiom already used in xlog_recover_do_inode_buffer() and xfs_dquot_item_recover.c. xlog_recover_do_reg_buffer() therefore becomes STATIC int and its three callers propagate the error. Found and confirmed with KASAN on a CONFIG_XFS_DEBUG=n build: the crafted image trips a slab-out-of-bounds write before this change and fails recovery cleanly with -EFSCORRUPTED after it.

In the Linux kernel, the following vulnerability has been resolved: xfs: don't double-lock when deleting a self-referential directory LOLLM notices that the dirtree scrubber can detect a directory that refers to itself. In this case, it's not correct for the directory tree repair code to try to iolock/ilock both sc->ip and dp, because they're the same inode. Fix this by detecting that corner case and handling it appropriately.

In the Linux kernel, the following vulnerability has been resolved: xfs: fix ilock leak on error in xfs_dq_get_next_id xfs_dq_get_next_id() takes the quota inode ILOCK before calling xfs_iread_extents(). If xfs_iread_extents() fails, the function returns immediately without releasing the lock, leaking the quota inode ILOCK. This can leave the quota inode locked and cause subsequent quota operations to hang. Fix this by jumping to a common unlock path on error instead of returning directly.

In the Linux kernel, the following vulnerability has been resolved: xfs: don't walk off the end of a null sc->sa.agi_bp in AGI repair LOLLM noticed a longstanding bug where xrep_iunlink_walk_ondisk_bucket tries to walk ragi->sc->sa.agi_bp to rebuild the unlinked inode lists. Unfortunately, it's possible for agi_bp to be null if the buffer verifier fails, so we have to use ragi->agi_bp (which skips verifier checks) instead.

In the Linux kernel, the following vulnerability has been resolved: xfs: fix another iunlink infinite loop bug in online fsck xrep_iunlink_resolve_bucket is supposed to reconstruct as much of the incore prev and next unlinked list pointers based on what it finds on disk and in memory before we move on to relinking the truly lost inodes back into the unlinked list. However, it's still vulnerable to infinite loops that come in via the next_unlinked pointers. Fix this problem by remembering which inodes we've already seen and checking new agino pointers against that. If a bit is already set, either this is a loop or the inode has nonzero link count. We'll deal with the second case in a subsequent patch.

In the Linux kernel, the following vulnerability has been resolved: xfs: avoid UAF on sc->tempip in xrep_tempfile_create LOLLM noticed a potential UAF if the tempfile creation code fails after it set sc->tempip. Fix that.

In the Linux kernel, the following vulnerability has been resolved: xfs: fix exchange-range reflink flag clearing issue with INO1_WRITTEN When exchanging two full-file ranges, xmi_can_exchange_reflink_flags() can move the reflink inode flag from the file that currently has it to the other file, as long as exactly one side is marked. This assumes that the file contents, and therefore all shared extents, are exchanged. That assumption is not true when XFS_EXCHMAPS_INO1_WRITTEN is set. xfs_exchmaps_can_skip_mapping() can skip hole and unwritten mappings from file1, so an exchange can complete without moving every mapping that the earlier flag-swap decision accounted for. In that case the post-operation cleanup can clear the reflink flag from an inode that still owns shared written extents. Later writes then take the non-reflink write path and may update blocks that should still have been protected by CoW, which shows up as data corruption between reflink-related files. Fix this by disabling the reflink flag exchange whenever XFS_EXCHMAPS_INO1_WRITTEN is requested. The contents exchange can still proceed; the conservative outcome is that both inodes keep the reflink flag. The regular reflink flag cleanup path can drop the extra flag later once the inode no longer has shared extents.

In the Linux kernel, the following vulnerability has been resolved: xfs: don't swallow dquot recovery verification errors xlog_recover_dquot_commit_pass2() validates the recovered dquot with xfs_dqblk_verify() and, on failure, sets error = -EFSCORRUPTED and jumps to out_release. But out_release unconditionally returns 0, so the corruption error is discarded: the caller xlog_recover_items_pass2() sees success, log recovery proceeds as if the dquot were valid, and the corrupt quota buffer can be written back to disk.

In the Linux kernel, the following vulnerability has been resolved: ceph: avoid fs reclaim while using current->journal_info handle_reply() stores a `ceph_mds_request` pointer in `current->journal_info` while filling the inode and dentry cache from an MDS reply. An allocation in this section can enter direct reclaim and prune dentries from another filesystem. If this dirties an ext4 inode, ext4 starts a JBD2 transaction. JBD2 interprets the Ceph request in `current->journal_info` as a journal handle and dereferences the request's `r_tid` as `h_transaction`, causing a kernel crash, e.g.: Unable to handle kernel paging request at virtual address 00000000077b4818 [...] Internal error: Oops: 0000000096000004 [#1] SMP Modules linked in: CPU: 6 UID: 0 PID: 2699135 Comm: kworker/6:3 Tainted: G W 6.18.38-i3 #1113 NONE [...] Workqueue: ceph-msgr ceph_con_workfn pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : jbd2__journal_start+0x2c/0x208 lr : __ext4_journal_start_sb+0x100/0x178 [...] Call trace: jbd2__journal_start+0x2c/0x208 (P) __ext4_journal_start_sb+0x100/0x178 ext4_dirty_inode+0x3c/0x90 __mark_inode_dirty+0x58/0x400 iput.part.0+0x2b0/0x370 iput+0x18/0x30 dentry_unlink_inode+0xc0/0x158 __dentry_kill+0x80/0x250 shrink_dentry_list+0x90/0x130 prune_dcache_sb+0x60/0x98 super_cache_scan+0xe8/0x190 do_shrink_slab+0x174/0x388 shrink_slab+0xd8/0x4c0 shrink_node+0x31c/0x908 do_try_to_free_pages+0xd0/0x508 try_to_free_pages+0x11c/0x238 __alloc_frozen_pages_noprof+0x4d0/0xdd0 __folio_alloc_noprof+0x18/0x70 __filemap_get_folio+0x248/0x440 ceph_readdir_prepopulate+0x570/0x9e8 mds_dispatch+0x1424/0x1ba0 ceph_con_process_message+0x74/0xa0 ceph_con_v1_try_read+0x3a0/0x1510 ceph_con_workfn+0x260/0x460 Enter a scoped NOFS allocation context and leave it after clearing `journal_info`. This prevents filesystem reclaim from recursing into another filesystem while the field contains Ceph-private data.

In the Linux kernel, the following vulnerability has been resolved: ceph: fix hanging __ceph_get_caps() with stale mds_wanted A reader can hang forever in __ceph_get_caps() when the client no longer holds `FILE_RD`, but local cap state still says that the capability is already wanted (via `mds_wanted`). One way to trigger this is through MDS cap revocation. If another client performs a conflicting operation, the MDS can revoke `FILE_RD` from the reader; the next read then has to reacquire `FILE_RD`. If the cap update that should request `FILE_RD` never reaches the MDS after `cap->mds_wanted` was raised, the reader is left holding only non-file caps while local `mds_wanted` still includes the file read caps. In that state, try_get_cap_refs() sees `need <= mds_wanted` and returns 0, so __ceph_get_caps() just waits on `i_cap_wq`. If the cap update that was supposed to request `FILE_RD never reaches the MDS after `cap->mds_wanted was` raised, no further request is sent and the waiter can sleep indefinitely until unrelated cap traffic happens to wake it up. The ordering issue is that `cap->mds_wanted` is updated in __prep_cap() before the `CEPH_MSG_CLIENT_CAPS message` is actually queued for send. That makes one field serve two different meanings at once: what this client wants, and what the client believes the MDS already knows it wants. A proper fix would be to split those states and track whether a cap update is actually in flight or has been observed by the MDS. However, simply moving the `cap->mds_wanted assignment` later would not be sufficient: queueing the message in the messenger does not guarantee that the MDS processed that specific wanted set, and reconnect or message loss can still invalidate that assumption. Fixing that properly would require a larger rework of the cap state machine. To allow simpler backports to stable kernels, this patch implements a simpler workaround: - stop waiting forever in __ceph_get_caps(); after a bounded wait, fall back to the renew path - make ceph_renew_caps() issue a synchronous `OPEN` request whenever the inode still does not actually hold the wanted caps, instead of only calling ceph_check_caps() The extra issued-vs-wanted check in ceph_renew_caps() is necessary because the previous test only checked whether the inode still had any real caps at all. That is not enough after revocation: the client can still hold something like `pLs` and yet be missing `FILE_RD` completely. In that case, falling back to ceph_check_caps() is not sufficient, because it still trusts `cap->mds_wanted` and may resend nothing. By requiring `(issued & wanted) == wanted` before taking the asynchronous path, the code only uses ceph_check_caps() when the `wanted caps` are already actually issued. Otherwise, it sends the synchronous `OPEN` renew. This preserves the existing asynchronous fast path when the wanted caps are already issued, avoids changing cap-state semantics, and fixes the hang by guaranteeing that a stalled waiter eventually retries through a path that does not rely on the stale `mds_wanted` state. [ idryomov: move CEPH_GET_CAPS_WAIT_TIMEOUT from libceph.h to mds_client.h, formatting ]

In the Linux kernel, the following vulnerability has been resolved: ASoC: tas2562: Validate values for volume writes tas2562_volume_control_put() does not do any validation of the control value written by userspace, it uses it to look up a value in a fixed size array which can easily be overflowed and then writes whatever value it gets back to the device. Add validation that we are loading a value we have in the array.

In the Linux kernel, the following vulnerability has been resolved: ASoC: SOF: ipc4-topology: Refresh copier IPC payload before widget setup The ipc_config_data buffer for copier widgets is built once during ipc_prepare (called from sof_pcm_setup_connected_widgets) and cached for reuse. For host copiers this buffer contains the copier_data with gtw_cfg.node_id (host DMA ID). For DAI copiers it additionally includes a dma_config_tlv trailer with stream_id and dma_channel_id for HDA link DMA. On suspend/resume, both host and link DMA streams are released and re-allocated with potentially different stream tags. The underlying copier_data and dma_config_tlv structures are correctly updated by host_config and sdw_hda_dai_hw_params respectively. However, since the widget list (spcm->stream[].list) persists across suspend, sof_pcm_hw_params skips sof_pcm_setup_connected_widgets and ipc_prepare never runs again to rebuild ipc_config_data. The stale cached payload is then sent to firmware with boot-time DMA channel assignments, causing DMA channel conflicts that lead to firmware errors and crashes. Fix this by refreshing copier_data and dma_config_tlv portions of ipc_config_data in sof_ipc4_widget_setup right before the IPC message is sent. This ensures the payload always reflects the current DMA state regardless of whether ipc_prepare ran. For DAI copiers, the gtw_cfg.config_length in copier_data is temporarily inflated to include the TLV size (matching the ipc_config_data layout) before copying, then restored, mirroring what sof_ipc4_prepare_copier_module does when first building the buffer.

In the Linux kernel, the following vulnerability has been resolved: optee: ffa: Add NULL check in optee_ffa_lend_protmem Sashiko (locally) reports a possible null dereference under memory pressure due to the lack of validation of the allocated pointer. Fix that by adding the missing check.

In the Linux kernel, the following vulnerability has been resolved: clk: spacemit: k3: set hdma clock as critical HDMA clock is responsible for the internal TCM access path of X100 RISC-V core, so set the clock flag as critical to prevent it from being shut off, otherwise the Linux system will hang, for example in the case of a vector instruction access generates a page fault.

In the Linux kernel, the following vulnerability has been resolved: crypto: tegra - fix rctx->cryptlen calculation in tegra_gcm_do_one_req() Perform rctx->cryptlen calculation in tegra_gcm_do_one_req() the same way it is done in tegra_ccm_crypt_init(). The current formulae may lead to a crash if a caller does not call tegra_gcm_setauthsize() and so ctx->authsize remains zero. Then a decrypt operation with incorrect rctx->cryptlen will lead to a write beyound rctx->dst_sg buffer. As a follow-up cleanup delete struct tegra_aead_ctx->authsize field since it appears to be completely unused. Also simplify tegra_ccm_setauthsize() and tegra_gcm_setauthsize() functions respectively.

In the Linux kernel, the following vulnerability has been resolved: af_unix: Unlink scc_entry in unix_del_edge(). Kyle Zeng reported that GC could free a dead SCC partially. The scenario is as follows: 1) Create two SCCs: X -. A <-> B ^--' 2) Run the following concurrently: 2-1) send() sk-B to sk-B from sk-X 2-2) close() both A and B At 2-1), there is a small window where unix_add_edges() publishes a new edge (B <-> B) to GC but its skb is not queued by skb_queue_tail(). If 2-2) completes before skb_queue_tail() and GC is triggered, it judges A <-> B as dead, but B is not freed because GC cannot collect the not-yet-queued skb holding the B <-> B edge. X -. A <-> B -. This edge is visible ^--' ^..' but skb is not This itself is not a problem since the next GC run will judge B as dead as well and free it finally. X -. A <.> B -. ^--' ^--' However, X's SCC forces the next GC to call unix_walk_scc_fast(), and it iterates over A through B's scc_entry. Let's unlink scc_entry before freeing the vertex in unix_del_edge().

In the Linux kernel, the following vulnerability has been resolved: ovpn: fix NULL dereference when killing missing key ovpn_crypto_kill_key assumes both crypto slots are populated and dereferences each slot before checking it. That is not guaranteed: a peer can have only one installed key, and the kill path may be asked to remove a key that is not present. Read each slot once while holding the crypto state lock, check for NULL before looking at key_id, and only replace the slot that actually matches.

In the Linux kernel, the following vulnerability has been resolved: ovpn: finish crypto callback cleanup before peer release Crypto completion callbacks hold both key-slot and peer references. The peer reference pins the netdev, and dropping the last peer reference can let netdev unregistration and module removal make progress. Do not release that peer reference before the callback has finished its own cleanup. If ovpn_crypto_key_slot_put runs after ovpn_peer_put, it can schedule an RCU callback backed by module text after ovpn_cleanup rcu_barrier has already run. The TX error path also freed the remaining skb after ovpn_peer_put, leaving callback cleanup outside the peer/netdev lifetime window. Release the key slot and free any remaining skb first, then drop the peer reference as the last callback action.

Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection') in the default lf.query Python protocol in Google langfun versions prior to 0.1.2 allows remote unauthenticated attackers to execute arbitrary Python code in the context of the host application via crafted prompt inputs that cause the model to generate executable Python expressions evaluated without a sandbox.

In the Linux kernel, the following vulnerability has been resolved: scsi: core: pair EH runtime PM get and put shost->eh_noresume is currently consulted twice in one error handling iteration: once before scsi_autopm_get_host() and once again before scsi_autopm_put_host(). That is racy when a PM-triggered error path flips shost->eh_noresume while the SCSI EH thread is still running. The problem flow looks like this: PM path ufshcd_set_dev_pwr_mode() shost->eh_noresume = 1 ufshcd_execute_start_stop <-- trigger EH ... shost->eh_noresume = 0 EH path scsi_error_handler() if (!shost->eh_noresume) scsi_autopm_get_host() <-- skipped ... if (!shost->eh_noresume) scsi_autopm_put_host() <-- executed later In that case one EH iteration can skip autoresume on entry and still drop a runtime PM reference on exit. That leaves an unmatched runtime PM put and can trigger a runtime PM usage count underflow. Fix this by making eh_noresume a regular bool so it can be accessed with READ_ONCE() and WRITE_ONCE(). Snapshot it once per EH iteration and use that snapshot for both runtime PM get and put decisions.

In the Linux kernel, the following vulnerability has been resolved: perf: Reject exited events as group leaders perf_event_remove_on_exec() sets remove-on-exec events to the EXIT state and detaches their group relationships. The event's file descriptor can remain open, however, and perf_event_open() currently accepts that event as a group leader because its early validation rejects only REVOKED and DEAD events. A new sibling can consequently be linked to the detached leader. When the leader is closed, perf_group_detach() observes that its PERF_ATTACH_GROUP bit is already clear and skips the new sibling. The sibling then retains a group_leader pointer to the freed event. Reject group leaders in the EXIT state. Perform the check while holding the shared context mutex so that an exec in the target task cannot detach the leader between validation and group attachment. [peterz: make the earlier test fully consistent]

In the Linux kernel, the following vulnerability has been resolved: sctp: validate cookie AUTH state before use When cookie authentication is disabled, COOKIE_ECHO restores fixed-size AUTH fields directly from peer-controlled cookie bytes. A forged RANDOM length, HMAC list, or CHUNKS list can then reach association consumers with lengths or identifiers that were never validated against the local backing arrays. A forged RANDOM length can cause out-of-bounds reads during key-vector construction. A forged HMAC identifier also caused a 32-byte write past a zero-length AUTH chunk, providing a primitive for a local privilege escalation chain. Validate the cookie's RANDOM, HMACS, and CHUNKS parameters at the cookie trust boundary before copying them into the association. Reject invalid types, malformed lengths, unsupported HMAC identifiers, HMAC lists without SHA1, and forbidden chunk ids.