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| CVE | Vendors | Products | Updated | CVSS v3.1 |
|---|---|---|---|---|
| CVE-2026-99999 | 1 Linux | 1 Linux Kernel | 2026-10-17 | 9.3 Critical |
| In the Linux kernel, the following vulnerability has been resolved: ipv4: validate checksum_start before completing checksum If a packet with bad checksum metadata gets into the ipv4 stack, skb_checksum_help can corrupt the network header and cause a bunch of mischief. This was discovered and reported by Paulos, and has been reporoduced by others independently since. We really shouldn't allow such packets in, but as a defence in depth measure, let's also check before we complete the checksum. A more complete validation at input is forthcoming, but needs more work. | ||||
| CVE-2026-98432 | 1 Linux | 1 Linux Kernel | 2026-10-17 | 5.9 Medium |
| In the Linux kernel, the following vulnerability has been resolved: ipv4: free inet_opt and ireq_opt after an RCU grace period tcp_v4_syn_recv_sock() transfers ownership of ireq->ireq_opt to the child socket (newinet->inet_opt) without copying it. Another cpu can concurrently process a retransmitted SYN for the same request socket, and send a SYNACK from tcp_check_req(). tcp_v4_send_synack() and inet_csk_route_req() read ireq->ireq_opt under rcu_read_lock() only, and ip_build_and_send_pkt() and ip_options_build() then read opt->optlen twice. Note that the SYNACK timer itself is not an issue: it holds a reference on its request socket, and inet_csk_reqsk_queue_drop() calls timer_delete_sync() before the child can be freed. Since commit 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table"), request sockets are processed without holding the listener lock, so nothing prevents the child socket from being freed while the SYNACK is still being built. TCP child sockets do not have SOCK_RCU_FREE, and inet_sock_destruct() frees inet_opt with a plain kfree(), leading to a use-after-free in ip_options_build(). A similar issue exists with request socket migration (net.ipv4.tcp_migrate_req=1, or a BPF_SK_REUSEPORT_SELECT_OR_MIGRATE program). reqsk_timer_handler() clones the request socket with inet_reqsk_clone(), so that the old request socket and its clone share the same ireq_opt, then reqsk_migrate_reset() clears the pointer in the old one. Another cpu holding a reference on the old request socket can still be using these options (sending a SYNACK, or creating a child in tcp_v4_syn_recv_sock()) when the clone is freed, and tcp_v4_reqsk_destructor() also uses a plain kfree(). Readers already use RCU, and other paths replacing inet_opt (do_ip_setsockopt(), cipso_v4_sock_setattr()...) already use kfree_rcu(). Use kfree_rcu() in inet_sock_destruct() and tcp_v4_reqsk_destructor() as well. IPv6 is not affected by the first issue, because tcp_v6_syn_recv_sock() duplicates the options. tcp_v6_reqsk_destructor() has the same migration issue with ipv6_opt, which is only set by CALIPSO. This will be addressed in a separate patch. | ||||
| CVE-2026-98418 | 1 Linux | 1 Linux Kernel | 2026-10-17 | 4.7 Medium |
| In the Linux kernel, the following vulnerability has been resolved: sched/core: Avoid false migration warning for proxy donors Proxy execution can move a blocked donor's scheduling context to the lock owner's CPU even when the donor is migration-disabled. The donor does not execute there, and its original execution CPU remains recorded in wake_cpu. set_task_cpu() warns unconditionally for migration-disabled tasks, so a subsequent proxy migration or the wakeup path returning the donor home triggers a false positive: moving a blocked scheduling context does not violate the migration-disabled execution context. For example, creating a mutex owner on CPU1 and a migration-disabled waiter on CPU0 can trigger the following warning: proxy_migrate_repro: donor blocking on CPU0 with migration disabled proxy_migrate_repro: donor moved from CPU0 to CPU1 WARNING: kernel/sched/core.c:3389 at set_task_cpu+0x1d3/0x280 ... Call Trace: try_to_wake_up+0x43f/0x780 __mutex_unlock_slowpath+0x330/0x540 owner_fn+0x9f/0xc0 [proxy_migrate_repro] ... proxy_migrate_repro: donor woke on CPU0, task_cpu=0 proxy_migrate_repro: completed Exclude blocked proxy donors from the warning. The proxy wakeup path restores an executable placement before clearing the blocked state. | ||||
| CVE-2026-98406 | 1 Linux | 1 Linux Kernel | 2026-10-17 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: avoid WARN in set_bitrate_mask when sdata not in driver ieee80211_set_bitrate_mask() checks if the interface is running via ieee80211_sdata_running(), but it does not check if the interface is still present in the driver. When sdata is running but IEEE80211_SDATA_IN_DRIVER is not set, the call reaches drv_set_bitrate_mask() in driver-ops.h which hits wlan1: Failed check-sdata-in-driver check, flags: 0x0 WARNING: net/mac80211/driver-ops.h:884 at drv_set_bitrate_mask Syzkaller triggers this via wext SIOCSIWRATE ioctl. The Call Trace shows wext_ioctl_dispatch() in wext-core.c dispatching the ioctl, calling ioctl_standard_call() for SIOCSIWRATE, which calls cfg80211_wext_siwrate() in wext-compat.c. That builds a bitrate mask and calls rdev_set_bitrate_mask() which ends up in ieee80211_set_bitrate_mask() in cfg.c. The interface is marked running via SDATA_STATE_RUNNING but flags is 0, so check_sdata_in_driver() fails. When the interface is being torn down, or when wext ioctl is issued during interface bringup before drv_add_interface() sets IN_DRIVER, the running check passes while IN_DRIVER is clear. Check IEEE80211_SDATA_IN_DRIVER in ieee80211_set_bitrate_mask() before calling the driver, returning -ENETDOWN. This avoids the WARN_ONCE in driver-ops.h and matches other cfg.c operations that bail early when not in driver. This change should be safe because wiphy mutex is held in cfg80211_wext_siwrate() via guard(wiphy), and IN_DRIVER is set/cleared under RTNL and wiphy paths in drv_add_interface() and drv_remove_interface() in driver-ops.c, so the check is race-free against driver add/remove. Returning -ENETDOWN is the same error other not-running paths use and does not introduce new locking. [also add second syzbot report] | ||||
| CVE-2026-98407 | 1 Linux | 1 Linux Kernel | 2026-10-17 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: wifi: rsi: fix heap OOB write on key removal When a key is removed (data == NULL), rsi_hal_load_key() runs: memset(&set_key[FRAME_DESC_SZ], 0, frame_len - FRAME_DESC_SZ); set_key is a struct rsi_set_key *, so the subscript is scaled by sizeof(struct rsi_set_key) (160 bytes): &set_key[FRAME_DESC_SZ] is skb->data + 2560, and the memset writes 144 zero bytes starting 2.4KB past the end of the 160-byte skb data buffer, corrupting unrelated heap objects. The intended byte offset would have been (u8 *)set_key + FRAME_DESC_SZ. The write fires on every DISABLE_KEY callback, so plain disconnects, roams and interface teardowns trigger it on real networks. The memset is redundant: the whole buffer is zeroed right after allocation, so the frame sent to the device is byte-identical without it. Drop the else branch; normal operation is unaffected. Discovered by Atuin - Automated Vulnerability Discovery Engine. | ||||
| CVE-2026-98401 | 1 Linux | 1 Linux Kernel | 2026-10-16 | 7.0 High |
| In the Linux kernel, the following vulnerability has been resolved: net: iptunnel: fix stale transport header during tunnel decapsulation Syzbot reported a crash in qdisc_pkt_len_segs_init() caused by a stale transport_header offset after tunnel decapsulation. BUG: unable to handle page fault for address: ffffed102091a42e Oops: Oops: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 340 Comm: qdisc_uaf_repro Not tainted 7.2.0-rc4-00061-g248951ddc14d #256 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:__asan_load2 <IRQ> qdisc_pkt_len_segs_init (net/core/dev.c:4145) __dev_queue_xmit (net/core/dev.c:4787) br_dev_queue_push_xmit (net/bridge/br_forward.c:53) br_handle_frame_finish (net/bridge/br_input.c:229) br_handle_frame (net/bridge/br_input.c:315) __netif_receive_skb_core.constprop.0 (net/core/dev.c:6099) __netif_receive_skb_list_core (net/core/dev.c:6287) netif_receive_skb_list_internal (net/core/dev.c:6445) napi_complete_done (net/core/dev.c:6813) gro_cell_poll (net/core/gro_cells.c:74) __napi_poll (net/core/dev.c:7735) net_rx_action (net/core/dev.c:7798 net/core/dev.c:7955) handle_softirqs (kernel/softirq.c:622) do_softirq (kernel/softirq.c:523 kernel/softirq.c:510 ) __local_bh_enable_ip (kernel/softirq.c:450) tun_get_user (drivers/net/tun.c:1986 (discriminator 1)) tun_chr_write_iter (drivers/net/tun.c:2032) The issue is completely latent until qdisc read transport header in commit 7fb4c1967011 ("net: pull headers in qdisc_pkt_len_segs_init()"). The crash requires four conditions to line up: 1. The incoming packet is encapsulated and carries GSO metadata. The outer transport header offset is stored in skb->transport_header while the packet is still in the outer tunnel context. 2. The tunnel receiver strips the outer headers. skb->data is advanced to the inner frame, but skb->transport_header is left pointing to the now-removed outer L4 header, so it becomes a negative offset relative to the new data. 3. The inner frame is not delivered to the local IP stack. Instead, it is forwarded at L2 by a bridge or HSR, so ip_rcv_core() never runs and the transport header is not reset to the inner L4 offset. 4. The forwarding path calls __dev_queue_xmit(), which enters qdisc_pkt_len_segs_init(). That function computes the GSO header length from skb_transport_offset(skb). Because the offset is negative, the unsigned cast overflows and pskb_may_pull(skb, hdr_len + sizeof(struct tcphdr)) reads past the end of the skb, triggering a KASAN fault or page fault. The issue specifically requires GSO packets (shinfo->gso_size != 0), which are processed/aggregated through gro_cells. Fix this by clearing transport_header to the ~0U sentinel in gro_cell for all tunnnel driver. GTP does not support GRO/GSO, drop the evil GSO packets in GTP directly. | ||||
| CVE-2026-98405 | 1 Linux | 1 Linux Kernel | 2026-10-16 | 7.0 High |
| In the Linux kernel, the following vulnerability has been resolved: smb: client: fix missing iov bounds check in parse_posix_sids() In parse_posix_sids(), sidsbuf_end is calculated using the server-supplied out_len without being validated against the actual length of the received iov (iov_len). If a server provides an inflated out_len, sidsbuf_end will point past the end of the iov. This defeats the bounds guards in posix_info_sid_size(), allowing out-of-bounds reads into adjacent kernel memory. Fix this by rejecting responses where the calculated sidsbuf_end would exceed the received iov boundaries or cause pointer wraparound. | ||||
| CVE-2026-98409 | 1 Linux | 1 Linux Kernel | 2026-10-16 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: watchdog: rtd119x: Avoid division by zero clk_get_rate() could return 0. Avoid a division by zero panic. | ||||
| CVE-2026-98417 | 1 Linux | 1 Linux Kernel | 2026-10-16 | 7.5 High |
| In the Linux kernel, the following vulnerability has been resolved: net: xfrm: reject unrepresentable espintcp transport headers ESP-in-TCP can hand xfrm packets whose transport header offset no longer fits after the stream parser trims the TCP envelope. The plain transport header reset truncates that offset and triggers the skb warning path. Use the careful transport-header helper and drop the skb through the existing XFRM error path when the offset cannot be represented. | ||||
| CVE-2026-98397 | 1 Linux | 1 Linux Kernel | 2026-10-16 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: platform/x86: x86-android-tablets: hold device reference for secondary fwnode teardown In gpio_secondary_fwnode_init(), acpi_bus_find_device_by_name() returns a device reference, but the local dev variable is declared with __free(put_device), dropping the reference at the end of each iteration. Meanwhile, devm_add_action_or_reset() saves the dev pointer for gpio_secondary_unset() without incrementing its reference count, which could lead to a use-after-free during driver teardown if the device is released in the interim. Acquire an explicit device reference with get_device() when registering the devres action, and drop it with put_device() inside gpio_secondary_unset(). | ||||
| CVE-2026-89912 | 1 Linux | 1 Linux Kernel | 2026-10-16 | 7.1 High |
| In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: vgic-its: Don't dereference a NULL collection on ITT save MAPC with V=0 drops ite->collection but leaves the ITE on the device's ITT list, and vgic_its_save_ite() dereferences it unconditionally. A guest that issues MAPD, MAPTI and then MAPC(V=0) therefore oopses the host when the VMM issues KVM_DEV_ARM_ITS_SAVE_TABLES to migrate it. That sequence is UNPREDICTABLE per the architecture, but KVM already handles the resulting state in the translate, MOVI and DISCARD paths. Save a zeroed entry, which vgic_its_restore_ite() reads back as invalid. Skipping the ITE instead would leave the ITT slot holding whatever is in guest memory, and restore rejects an entry naming a collection the restored collection table does not have. | ||||
| CVE-2026-89713 | 1 Linux | 1 Linux Kernel | 2026-10-16 | 9.1 Critical |
| In the Linux kernel, the following vulnerability has been resolved: NFSD: check truncate permission under inode lock nfsd_setattr() checks whether a size update needs NFSD_MAY_TRUNC before it takes inode_lock(). The comparison uses the file size sampled by that unlocked read, but the actual ATTR_SIZE update is applied later under inode_lock() by notify_change(). This leaves a TOCTOU window for append-only files. If a client sends a SETATTR that does not shrink the file at the time of the unlocked sample, a concurrent append can extend the file before nfsd_setattr() takes inode_lock(). notify_change() then applies a real truncation without the NFSD_MAY_TRUNC check that rejects IS_APPEND(inode). The VFS truncate syscall paths perform their own append-only checks before calling notify_change(), so NFSD must make this decision against the locked size it is about to change. Split the write-count acquisition from the truncation permission check. Keep get_write_access() before the locked setattr work, then recheck whether the requested size is below i_size_read(inode) after inode_lock() has been acquired and before notify_change(ATTR_SIZE). This also avoids the plain unlocked inode->i_size load. | ||||
| CVE-2026-89708 | 1 Linux | 1 Linux Kernel | 2026-10-16 | 9.8 Critical |
| In the Linux kernel, the following vulnerability has been resolved: nfsd: RCU-protect cl_cb_session to fix use-after-free on session teardown After a DESTROY_SESSION the per-session teardown path can free a session while rpciod still holds an inflight callback rpc_task that dereferences clp->cl_cb_session. nfsd4_probe_callback_sync() flushes cl_callback_wq, but once nfsd4_run_cb_work() has called rpc_call_async() the rpc_task lives on rpciod; flushing the workqueue does not wait for it. rpc_shutdown_client() does drain rpciod tasks, but uses a 1-second wait_event_timeout — tasks stuck in rpc_delay() (e.g. 2-second NFS4ERR_DELAY retries) can outlive the drain. destroy path rpciod ------------ ------ unhash_session(ses) nfsd4_probe_callback_sync(clp) flush_workqueue(cl_callback_wq) /* returns; rpc_task still live */ nfsd4_put_session_locked(ses) free_session(ses) -> kfree(ses) nfsd4_cb_sequence_done() reads cb_clp->cl_cb_session /* freed slab */ A second window exists in nfsd4_process_cb_update(). When __nfsd4_find_backchannel() returns NULL because unhash_session() has already removed the destroyed session from cl_sessions, setup_callback_client() takes the v4.1 early return so clp->cl_cb_session = ses never fires and the field retains a pointer to the about-to-be-freed session. Fix both by converting cl_cb_session to an RCU-protected pointer: - Move the cl_cb_session = ses assignment in setup_callback_client() to after rpc_create() succeeds, so it is only published when a working backchannel exists. Clear cl_cb_session on the error return in nfsd4_process_cb_update(). Both stores use rcu_assign_pointer(). - Annotate cl_cb_session with __rcu. All rpciod-side readers use rcu_read_lock()/rcu_dereference() and check for NULL, bailing to the appropriate error or requeue path: encode_cb_sequence4args(), decode_cb_sequence4resok(), nfsd41_cb_get_slot(), nfsd41_cb_release_slot(), nfsd4_cb_prepare(), and nfsd4_cb_sequence_done(). - Switch __free_session() from kfree() to kfree_rcu() so the session slab is not reclaimed until after an RCU grace period, guaranteeing that rpciod readers inside rcu_read_lock() never dereference freed memory. - Pass the session pointer to the nfsd_cb_seq_status and nfsd_cb_free_slot tracepoints instead of having them re-read cl_cb_session. - nfsd4_cb_prepare() calls rpc_exit() when the session is NULL, routing through the done/release path to requeue the callback. | ||||
| CVE-2026-89707 | 1 Linux | 1 Linux Kernel | 2026-10-16 | 7.5 High |
| In the Linux kernel, the following vulnerability has been resolved: nfsd: release path refs on follow_down() error nfsd_cross_mnt() initializes a local struct path with mntget() and dget() before calling follow_down(). On a negative return the error arm jumps to out without releasing those references: err = follow_down(&path, follow_flags); if (err < 0) goto out; follow_down() never drops the caller's entry-time refs on any error sub-case; for example a pre-cross d_manage() failure leaves path untouched, so the mntget()/dget() taken on entry survive the call. Every other early-exit arm in nfsd_cross_mnt() (other-namespace return, IS_ERR(exp2), and the success tail after the swap) already calls path_put(&path); the err < 0 arm is the lone omission. The leak inflates mnt_count and d_count on each failed cross-mount, blocking umount and pinning dentries against the shrinker, and is reachable by any authenticated NFS client through nfsd_lookup_dentry or the NFSv4 READDIR encode path. Fix by calling path_put(&path) before the goto out in the err < 0 arm so the entry-time refs are released on all follow_down() error returns. | ||||
| CVE-2026-89699 | 1 Linux | 1 Linux Kernel | 2026-10-16 | 7.5 High |
| In the Linux kernel, the following vulnerability has been resolved: nfsd: validate symlink target length in NFSv4 CREATE nfsd4_decode_create() accepts an unbounded cr_datalen from the wire for NF4LNK symlink targets, allowing a client to force a kmalloc of up to the maximum RPC payload size (several MiB) per COMPOUND op that persists until compound teardown. The VFS rejects oversized targets with ENAMETOOLONG, but the allocation has already occurred. Reject cr_datalen == 0 early with nfserr_inval and cr_datalen greater than NFS4_MAXPATHLEN (PATH_MAX) with nfserr_nametoolong to bound the allocation. | ||||
| CVE-2026-89697 | 1 Linux | 1 Linux Kernel | 2026-10-16 | 9.1 Critical |
| In the Linux kernel, the following vulnerability has been resolved: nfsd: add fh_want_write() for early-verified SETATTR in nfsd_proc_setattr() The BOTH_TIME_SET branch calls fh_verify() early so setattr_prepare() can inspect the dentry. This causes nfsd_setattr() to skip fh_want_write(), so notify_change() runs without a mount write reference. Add the missing fh_want_write() call after the early fh_verify(). | ||||
| CVE-2026-89686 | 1 Linux | 1 Linux Kernel | 2026-10-16 | 9.8 Critical |
| In the Linux kernel, the following vulnerability has been resolved: nfsd: fix BUG_ON in nfsd4_alloc_layout_stateid on racing delegation revoke nfsd4_alloc_layout_stateid reads fp->fi_deleg_file without holding fi_lock when the parent stateid is a delegation. A concurrent delegation revoke via the laundromat can clear fi_deleg_file under fi_lock, causing nfsd_file_get() to return NULL and triggering the BUG_ON. This race is client-reachable: two NFS clients can trigger it by having one hold a delegation while another opens the same file to force a recall. When the first client doesn't respond to the recall, the laundromat revokes it. A concurrent LAYOUTGET from any client using the delegation stateid hits the race window. Fix this by taking fi_lock around the fi_deleg_file read in the SC_TYPE_DELEG path, matching the locking discipline of the find_any_file() arm, and replacing the BUG_ON with a graceful error return that cleans up the partially-initialized layout stateid. | ||||
| CVE-2026-89685 | 1 Linux | 1 Linux Kernel | 2026-10-16 | 7.5 High |
| In the Linux kernel, the following vulnerability has been resolved: nfsd: fix clock domain mismatch in clients_still_reclaiming() clients_still_reclaiming() computes a deadline from nn->boot_time (CLOCK_REALTIME, ~1.7 billion) but compares it against ktime_get_boottime_seconds() (CLOCK_BOOTTIME, seconds since boot). The comparison is always false — it would take ~54 years of uptime for BOOTTIME to exceed the REALTIME-derived deadline. This means any client can hold the server in grace indefinitely by sending CLAIM_PREVIOUS OPEN requests, blocking all non-reclaim operations for all other clients. Add boot_time_bt (CLOCK_BOOTTIME) alongside the existing boot_time and use it for the deadline computation. boot_time (CLOCK_REALTIME) is preserved for its cl_boot clientid-nonce role. | ||||
| CVE-2026-89676 | 1 Linux | 1 Linux Kernel | 2026-10-16 | 9.8 Critical |
| In the Linux kernel, the following vulnerability has been resolved: nfsd: fix stale s2s_cp_stateids IDR entry for async COPY For an async COPY, nfsd4_copy() called nfs4_init_copy_state() before dup_copy_fields(), so the s2s_cp_stateids IDR was pointed at &u->copy->cp_stateid -- memory in the per-rqstp COMPOUND buffer that is reused by the next request. dup_copy_fields() copies only the value into async_copy, so the IDR slot dangled at the transient buffer for the whole background copy. Any IDR walker then dereferences reused request memory: the laundromat reads cs_type from it and, if the bytes look like an expired NFS4_COPYNOTIFY_STID, follows into refcount_dec()/idr_remove()/kfree() on garbage; manage_cpntf_state() has the same exposure via idr_find(). Duplicate the fields first, then register the stateid on the stable async_copy. result->cb_stateid is unchanged. | ||||
| CVE-2026-89675 | 1 Linux | 1 Linux Kernel | 2026-10-16 | 9.8 Critical |
| In the Linux kernel, the following vulnerability has been resolved: nfsd: fix UAF in async copy cancel and shutdown An async copy could be freed or used after free while a teardown caller (OFFLOAD_CANCEL, nfsd4_shutdown_copy, nfsd4_cancel_copy_by_sb) raced the copy kthread: - find_async_copy() bumped copy->refcount but left the copy on clp->async_copies, so the reaper's cleanup_async_copy() could run release_copy_files() concurrently with a cancel/shutdown caller. Both put and NULL nf_src/nf_dst without a common lock, double-putting the nfsd_file and freeing it early. - nfsd4_do_async_copy() set NFSD4_COPY_F_STOPPED before its final uses of the copy (nfsd_update_cmtime_attr() on copy->nf_dst, nfsd4_send_cb_offload()). nfsd4_stop_copy() treats a set STOPPED bit as "kthread done, skip kthread_stop()", so a teardown caller ran release_copy_files() -- which puts and NULLs nf_dst -- while the kthread still dereferenced it (NULL/UAF). - copy->copy_task was never pinned. The one-shot kthread self-reaps on return, so kthread_stop()'s get_task_struct() could touch a freed task_struct. - co_cb is embedded in the copy, but nfsd4_send_cb_offload() held a reference only on the client, so a concurrent teardown could free the copy while the CB_OFFLOAD callback was in flight. Fix the teardown lifetime as a whole: - find_async_copy() unlinks the copy (clear cp_clp, list_del_init) under async_lock; the cancel, shutdown, and sb-cancel paths drop the list-membership reference via nfs4_put_copy() after nfsd4_stop_copy(). Drop the now-redundant list_del fixup from cleanup_async_copy(). - Because unlinking hides the copy from the reaper, its cleanup_async_copy() can no longer remove the copy's s2s_cp_stateids entry; the cancel/shutdown/sb-cancel paths now call nfs4_free_copy_state() themselves (while cp_clp is still valid) so the entry does not dangle at freed memory for the laundromat and manage_cpntf_state() to dereference. - Give the kthread its own reference, taken in nfsd4_copy() before wake_up_process() and dropped at the end of nfsd4_do_async_copy(); call wake_up_process() before list_add(). - Pin the task_struct with get_task_struct() in nfsd4_copy(), released in nfs4_put_copy(), so kthread_stop() is safe whenever the kthread exits. Set NFSD4_COPY_F_STOPPED only in nfsd4_stop_copy(), which now always kthread_stop()s before release_copy_files(); completion is still reported via NFSD4_COPY_F_COMPLETED, so nfsd4_has_active_async_copies() is unaffected. Each teardown caller removes the copy from clp->async_copies first, so kthread_stop() runs exactly once. - Take a copy reference in nfsd4_send_cb_offload(), dropped in nfsd4_cb_offload_release(). The kthread still holds its own reference there, so the refcount_inc() cannot race the final free. - Read cp_clp with smp_load_acquire() to pair with the unordered set_bit()/clear_bit() writers (Documentation/atomic_bitops.rst). | ||||