Search Results (984 CVEs found)

CVE Vendors Products Updated CVSS v3.1
CVE-2026-74471 1 Linux 1 Linux Kernel 2026-08-18 7.8 High
In the Linux kernel, the following vulnerability has been resolved: tracing: Check return value of __register_event() in trace_module_add_events() trace_module_add_events() ignores the return value of __register_event() and unconditionally calls __add_event_to_tracers() for each event. If __register_event() fails (for example, if event_init() fails), the trace_event_call is not added to ftrace_events list, but __add_event_to_tracers() still creates a trace_event_file pointing to it. If module loading subsequently fails and module memory is freed, tracing state retains a stale trace_event_call pointer in trace_event_file, leading to a use-after-free when tracefs or tracing subsystem operations are later executed. Fix this by checking the return value of __register_event() and only calling __add_event_to_tracers() if event registration succeeded.
CVE-2026-72071 1 Linux 1 Linux Kernel 2026-08-17 7.8 High
In the Linux kernel, the following vulnerability has been resolved: tracing/user_events: Fix use-after-free in user_event_mm_dup() user_event_mm_dup() walks the parent mm's enabler list locklessly under rcu_read_lock() during fork() (from copy_process()); it does not take event_mutex: rcu_read_lock(); list_for_each_entry_rcu(enabler, &old_mm->enablers, mm_enablers_link) enabler->event = user_event_get(orig->event); user_event_enabler_destroy() removes an enabler from that list with list_del_rcu() and then, without waiting for a grace period, drops the enabler's user_event reference with user_event_put() and frees the enabler with kfree(). A reader that loaded the enabler before the list_del_rcu() can still be walking it, which leads to two use-after-frees: - kfree(enabler) frees the enabler while that reader dereferences enabler->event. - user_event_put() may drop the last reference to the user_event, which is then freed (via delayed_destroy_user_event() on a work queue), while the same reader does user_event_get(orig->event) on it. Both are reachable by an unprivileged task that can open user_events_data: one multithreaded process that registers an enabler and then concurrently unregisters it and calls fork() triggers the race. KASAN reports a slab-use-after-free in user_event_mm_dup() during clone(), with a "refcount_t: addition on 0" warning when the user_event is freed. The enabler use-after-free was found first; the user_event one was reported by XIAO WU, and the earlier enabler-only fix did not address it. Defer both the user_event_put() and the kfree(enabler) to a work item queued with queue_rcu_work(), so they run only after an RCU grace period, once all readers walking the enabler list have finished. The put must run in process context because user_event_put() takes event_mutex on the last reference, so a work queue is used rather than call_rcu(). The now-unlocked put lets the locked argument of user_event_enabler_destroy() be removed; all callers are updated.
CVE-2026-72024 1 Linux 1 Linux Kernel 2026-08-17 7.8 High
In the Linux kernel, the following vulnerability has been resolved: mac802154: remove interfaces with RCU list deletion Queue wake, stop, and disable paths walk local->interfaces under RCU. The bulk hardware teardown path removes entries with list_del(), so an asynchronous transmit completion can follow a poisoned list node in ieee802154_wake_queue(). Use list_del_rcu() as in the single-interface removal path. The following unregister_netdevice() waits for in-flight RCU readers before freeing the netdevice, so no separate grace-period wait is needed.
CVE-2026-72069 1 Linux 1 Linux Kernel 2026-08-17 9.8 Critical
In the Linux kernel, the following vulnerability has been resolved: locking/rt: Fix the incorrect RCU protection in rt_spin_unlock() rt_spin_unlock() releases the RCU protection before unlocking the lock. That opens the door for the following UAF scenario: T1 T2 spin_lock(&p->lock); rcu_read_lock(); invalidate(p); p = rcu_dereference(ptr); rcu_assign_pointer(ptr, NULL); if (!p) return; spin_unlock(&p->lock); spin_lock(&p->lock) lock(&lock->lock); rcu_read_lock(); kfree_rcu(p); rcu_read_unlock(); .... spin_unlock(&p->lock) rcu_read_unlock(); // Ends grace period rcu_do_batch() kfree(p); UAF -> rt_mutex_cmpxchg_release(&lock->lock...) Regular spinlocks keep preemption disabled accross the unlock operation, which provides full RCU protection, but the RT substitution fails to resemble that. Same applies for the rwlock substitution. Move the rcu_read_unlock() invocation past the unlock operations to match the non-RT semantics. This makes it asymmetric vs. rt_xxx_lock(), but that's harmless as the caller needs to hold RCU read lock across the lock operation. The migrate_enable() call stays before the unlock operation because there is no per CPU operation in the unlock path which would require migration to be kept disabled.
CVE-2026-72113 1 Linux 1 Linux Kernel 2026-08-17 7.8 High
In the Linux kernel, the following vulnerability has been resolved: can: bcm: add missing device refcount for CAN filter removal sashiko-bot remarked a problem with a concurrent device unregistration in isotp.c which also is present in the bcm.c code. A former fix for raw.c commit c275a176e4b6 ("can: raw: add missing refcount for memory leak fix") introduced a netdevice_tracker which solves the issue for bcm.c too. bcm_release(), bcm_delete_rx_op() and bcm_notifier() relied on dev_get_by_index(ifindex) to re-find the device for an rx_op before unregistering its filter. If a concurrent NETDEV_UNREGISTER has already unlisted the device from the ifindex table, that lookup fails and can_rx_unregister() is silently skipped, leaving a stale CAN filter pointing at the soon-to-be-freed bcm_op/socket. Hold a netdev_hold()/netdev_put() tracked reference on op->rx_reg_dev from the moment the rx filter is registered in bcm_rx_setup() until it is unregistered in bcm_rx_unreg(), and use that reference directly in bcm_release() and bcm_delete_rx_op() instead of re-looking the device up by ifindex.
CVE-2026-72151 1 Linux 1 Linux Kernel 2026-08-17 8.4 High
In the Linux kernel, the following vulnerability has been resolved: tpm: tpm2-sessions: wait for async KPP completion in tpm_buf_append_salt tpm_buf_append_salt() in drivers/char/tpm/tpm2-sessions.c calls crypto_kpp_generate_public_key() and crypto_kpp_compute_shared_secret() without installing a completion callback, discards both return values, and immediately frees the kpp_request via kpp_request_free(). When the resolved ecdh-nist-p256 KPP backend is asynchronous (atmel-ecc, HPRE, keembay-ocs), either operation returns -EINPROGRESS and the deferred completion worker dereferences the freed request. The path fires automatically from the hwrng_fillfn kernel thread via tpm_get_random -> tpm2_get_random -> tpm2_start_auth_session -> tpm_buf_append_salt on every entropy poll, without any userland action. Install crypto_req_done as the completion callback, wrap both KPP operations in crypto_wait_req(), and propagate errors to the caller. The wait is a no-op for synchronous backends.
CVE-2026-17523 2 Linux, Redhat 2 Linux Kernel, Enterprise Linux 2026-08-17 7.8 High
A flaw was found in the Linux kernel in net/can/bcm.c in can: bcm, where an unprivileged local user can exploit this vulnerability to execute arbitrary code within the kernel, which leads to a local privilege escalation (LPE). This allows the attacker to gain root privileges and take full control of the affected system.
CVE-2026-72125 1 Linux 1 Linux Kernel 2026-08-17 7.8 High
In the Linux kernel, the following vulnerability has been resolved: can: isotp: fix use-after-free race with concurrent NETDEV_UNREGISTER isotp_release() looked up the bound network device via dev_get_by_index() using the stored ifindex. During device unregistration the device is unlisted from the ifindex hash before the NETDEV_UNREGISTER notifier chain runs, so a concurrent isotp_release() could find no device, skip can_rx_unregister() entirely, and still proceed to free the socket. Since isotp_release() had already removed itself from the isotp notifier list at that point, isotp_notify() would never get a chance to clean up either, leaving a stale CAN filter that keeps pointing at the freed socket. Fix this the same way raw.c already does: hold a tracked reference to the bound net_device in the socket (so->dev/so->dev_tracker) from bind() onward instead of re-resolving it from the ifindex, and serialize bind()/release() with rtnl_lock() so that so->dev is always consistent with what the NETDEV_UNREGISTER notifier sees. so->dev stays valid regardless of ifindex-hash unlisting, and is only ever cleared by whichever of isotp_release()/isotp_notify() gets there first, so the filter is always removed exactly once. isotp_bind() now rejects a (re)bind with -EAGAIN while so->[tx|rx].state isn't ISOTP_IDLE yet, so a timer left running by a prior NETDEV_UNREGISTER can't act on a newly bound so->ifindex. Both checks share the same lock_sock() section, so there is no window in which a concurrent isotp_notify() clearing so->bound could be missed.
CVE-2026-72233 1 Linux 1 Linux Kernel 2026-08-17 8.8 High
In the Linux kernel, the following vulnerability has been resolved: batman-adv: bla: reacquire gw address after skb realloc The pskb_may_pull() called by batadv_bla_is_backbone_gw() could reallocate the buffer behind the skb. Variables which were pointing to the old buffer need to be reassigned to avoid an use-after-free.
CVE-2026-72323 1 Linux 1 Linux Kernel 2026-08-17 9.8 Critical
In the Linux kernel, the following vulnerability has been resolved: ipv4: igmp: Fix potential UAF in igmp_gq_start_timer() A race condition exists between device teardown (inetdev_destroy) and incoming IGMP query processing (igmp_rcv), leading to a Use-After-Free in the IGMP timer callback. During device destruction, inetdev_destroy() drops the primary reference to in_device, which can drop its refcount to 0. The actual freeing of in_device memory is deferred via RCU (using call_rcu()). Concurrently, igmp_rcv() runs under RCU read lock and obtains the in_device pointer. Because the memory is RCU-protected, CPU-0 can safely dereference in_device even if its refcount has hit 0. However, if CPU-0 calls igmp_gq_start_timer() and re-arms the timer, it attempts to acquire a reference using in_dev_hold(). This increments the refcount from 0 to 1, triggering a "refcount_t: addition on 0" warning. Since the in_device memory is still scheduled to be freed after the RCU grace period (as the free callback does not check the refcount again), the device is freed while the timer is still armed. When the timer expires, it accesses the freed memory, causing a kernel panic. Fix this by using refcount_inc_not_zero() (via a new helper in_dev_hold_safe()) to prevent acquiring a reference if the device is already being destroyed. If the refcount is 0, we do not arm the timer. A similar issue in IPv6 MLD is fixed in a subsequent patch.
CVE-2026-64245 1 Linux 1 Linux Kernel 2026-08-17 7.8 High
In the Linux kernel, the following vulnerability has been resolved: fbdev: modedb: fix a possible UAF in fb_find_mode() If mode_option is NULL, it is assigned from mode_option_buf: if (!mode_option) { fb_get_options(NULL, &mode_option_buf); mode_option = mode_option_buf; } Later, name is assigned from mode_option: const char *name = mode_option; However, mode_option_buf is freed before name is no longer used: kfree(mode_option_buf); while name is still accessed by: if ((name_matches(db[i], name, namelen) || Since name aliases mode_option_buf, this may result in a use-after-free. Fix this by extending the lifetime of mode_option_buf until the end of the function by using scope-based resource management for cleanup.
CVE-2026-72093 1 Linux 1 Linux Kernel 2026-08-17 7.8 High
In the Linux kernel, the following vulnerability has been resolved: accel/amdxdna: Fix use-after-free in amdxdna_gem_dmabuf_mmap() When vm_insert_pages() fails, the error path calls vma->vm_ops->close(vma) which internally calls drm_gem_vm_close() → drm_gem_object_put(), releasing the GEM object reference acquired at the start of the function. However, the close_vma label then falls through to put_obj, which calls drm_gem_object_put() a second time on the same object. If the first put releases the last reference, the object is freed and the second put accesses freed memory, causing a use-after-free. Fix by returning directly from close_vma instead of falling through to put_obj, since the close handler already performs all necessary cleanup including the object put.
CVE-2026-72234 1 Linux 1 Linux Kernel 2026-08-17 9.8 Critical
In the Linux kernel, the following vulnerability has been resolved: batman-adv: access unicast_ttvn skb->data only after skb realloc The pskb_may_pull() called by batadv_get_vid() could reallocate the buffer behind the skb. Variables which were pointing to the old buffer need to be reassigned to avoid an use-after-free. This was done correctly for the ethernet header but missed for the unicast_packet pointer.
CVE-2026-72235 1 Linux 1 Linux Kernel 2026-08-17 8.8 High
In the Linux kernel, the following vulnerability has been resolved: batman-adv: retrieve ethhdr after potential skb realloc on RX pskb_may_pull() in batadv_interface_rx() could reallocate the buffer behind the skb. Variables which were pointing to the old buffer need to be reassigned to avoid an use-after-free. This was done correctly for the VLAN header but missed for the ethernet header which is later used for the TT and AP isolation handling.
CVE-2026-72299 1 Linux 1 Linux Kernel 2026-08-17 9.8 Critical
In the Linux kernel, the following vulnerability has been resolved: tipc: restrict socket queue dumps in enqueue tracepoints tipc_sk_enqueue() runs with sk->sk_lock.slock held while the socket is owned by user context. The spinlock protects the backlog queue in this path, but it does not serialize against the socket owner consuming or purging sk_receive_queue. KASAN reported: CPU: 14 UID: 0 PID: 1050 Comm: tipc3 Not tainted 7.1.0-rc6+ #126 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x76/0xa0 lib/dump_stack.c:123 print_report+0xce/0x5b0 mm/kasan/report.c:482 kasan_report+0xc6/0x100 mm/kasan/report.c:597 __asan_report_load4_noabort+0x14/0x30 mm/kasan/report_generic.c:380 tipc_skb_dump+0x1327/0x16f0 net/tipc/trace.c:73 tipc_list_dump+0x208/0x2e0 net/tipc/trace.c:187 tipc_sk_dump+0xaf6/0xd60 net/tipc/socket.c:3996 trace_event_raw_event_tipc_sk_class+0x312/0x5a0 net/tipc/trace.h:188 tipc_sk_rcv+0xb1d/0x1d50 net/tipc/socket.c:2497 tipc_node_xmit+0x1c3/0x1440 net/tipc/node.c:1689 __tipc_sendmsg+0x97a/0x1440 net/tipc/socket.c:1512 tipc_sendmsg+0x52/0x80 net/tipc/socket.c:1400 sock_sendmsg+0x2f6/0x3e0 net/socket.c:825 splice_to_socket+0x7f9/0x1010 fs/splice.c:884 do_splice+0xe21/0x2330 fs/splice.c:936 __do_splice+0x153/0x260 fs/splice.c:1431 __x64_sys_splice+0x150/0x230 fs/splice.c:1616 x64_sys_call+0xeb5/0x2790 arch/x86/entry/syscall_64.c:41 do_syscall_64+0xf3/0x620 arch/x86/entry/syscall_64.c:63 entry_SYSCALL_64_after_hwframe+0x76/0x7e arch/x86/entry/entry_64.S:130 RIP: 0033:0x71624e8aafe2 Code: 08 0f 85 71 3a ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 66 2e 0f 1f 84 00 00 00 00 00 66 RSP: 002b:0000716157ffed68 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 0000716157fff6c0 RCX: 000071624e8aafe2 RDX: 000000000000005f RSI: 0000000000000000 RDI: 0000000000000066 RBP: 0000716157ffed90 R08: 0000000000008000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffff00 R13: 0000000000000021 R14: 0000000000000000 R15: 00007fff89799c40 </TASK> The TIPC_DUMP_ALL tracepoints in tipc_sk_enqueue() also dump sk_receive_queue and can therefore dereference skbs that the socket owner has already dequeued or freed. Restrict these dumps to TIPC_DUMP_SK_BKLGQ, which matches the queue protected by the held spinlock. Keep the change limited to the enqueue path, where the unsafe queue dump is reachable while the socket is owned by user context.
CVE-2026-72317 1 Linux 1 Linux Kernel 2026-08-17 9.8 Critical
In the Linux kernel, the following vulnerability has been resolved: SUNRPC: pin upper rpc_clnt across the TLS connect_worker The TLS connect path has a use-after-free: nothing pins the upper rpc_clnt across the delayed connect_worker. xs_connect() stores task->tk_client in sock_xprt::clnt as a raw pointer and queues the worker; for TLS-secured transports that worker is xs_tcp_tls_setup_socket(), which reads several fields out of the saved pointer (cl_timeout, cl_program, cl_prog, cl_vers, cl_cred, cl_stats) to construct the args for the inner handshake rpc_clnt. The xprt does not reference the rpc_clnt; the rpc_clnt references the xprt. xs_destroy() does cancel the connect_worker, but it runs only when the xprt's refcount drops to zero, which cannot happen until the rpc_clnt releases its cl_xprt reference in rpc_free_client_work(). When a TLS handshake fails fatally (for example, an mTLS mount whose client cert does not match the server), the connecting task is woken with -EACCES and exits, the mount caller invokes rpc_shutdown_client(), and the upper rpc_clnt is freed before the queued connect_worker fires. xs_tcp_tls_setup_socket() then dereferences the freed clnt, producing the refcount_t underflow Michael Nemanov reported. Take a reference on the upper rpc_clnt in xs_connect() for TLS transports via a new rpc_hold_client() helper, and drop it in the connect_worker's exit path with rpc_release_client(). The xprt_lock_connect() / xprt_unlock_connect() pairing already serialises xs_connect() with xs_tcp_tls_setup_socket(), so the take and release are balanced one-for-one. The non-TLS connect worker (xs_tcp_setup_socket) never reads sock_xprt::clnt, so leave that path alone and avoid the clnt-holds-xprt-holds-clnt cycle that would otherwise prevent xprt destruction.
CVE-2026-72331 1 Linux 1 Linux Kernel 2026-08-17 7.8 High
In the Linux kernel, the following vulnerability has been resolved: accel/amdxdna: Fix VMA access race aie2_populate_range() and amdxdna_umap_release() access a saved VMA pointer that may have already been freed, leading to a potential use-after-free. Remove the VMA accesses from these functions to avoid the race.
CVE-2026-72335 1 Linux 1 Linux Kernel 2026-08-17 7.8 High
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: Fix adv monitor add failure cleanup hci_add_adv_monitor() publishes a new adv_monitor in hdev->adv_monitors_idr before the powered MSFT setup step. The MSFT offload add path can then fail either locally before the controller add command completes, or in the MSFT add callback. In the current queued management add flow, hci_cmd_sync_work() still invokes mgmt_add_adv_patterns_monitor_complete() with the original pending command after msft_add_monitor_pattern() returns. The buggy scenario involves two paths, with each column showing the order within that path: MSFT add handling MGMT completion 1. insert monitor and handle 1. receive sync error 2. send MSFT add command 2. call add-monitor completion 3. callback sees bad response 3. load cmd->user_data 4. callback frees monitor 4. read monitor->handle Local MSFT setup failures have the other half of the same ownership bug: they return an error after the IDR insertion, but no later code removes the failed monitor from the IDR. Keep ownership with the pending management command until its completion. For normal management adds, the MSFT add callback now records successful controller state and returns errors to its caller. The management completion frees the monitor on non-success after copying the response handle, while resume/reregister callback-error cleanup remains in the MSFT callback. The success path keeps the existing bookkeeping. Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in mgmt_add_adv_patterns_monitor_complete+0xfb/0x260 [bluetooth] Call Trace: <TASK> dump_stack_lvl+0x66/0xa0 print_report+0xce/0x5f0 ? mgmt_add_adv_patterns_monitor_complete+0xfb/0x260 [bluetooth] ? srso_alias_return_thunk+0x5/0xfbef5 ? __virt_addr_valid+0x19f/0x330 ? mgmt_add_adv_patterns_monitor_complete+0xfb/0x260 [bluetooth] kasan_report+0xe0/0x110 ? mgmt_add_adv_patterns_monitor_complete+0xfb/0x260 [bluetooth] mgmt_add_adv_patterns_monitor_complete+0xfb/0x260 [bluetooth] ? srso_alias_return_thunk+0x5/0xfbef5 ? 0xffffffffc00d00da ? __pfx_mgmt_add_adv_patterns_monitor_complete+0x10/0x10 [bluetooth] ? __pfx_mgmt_add_adv_patterns_monitor_complete+0x10/0x10 [bluetooth] ? hci_cmd_sync_work+0x1ab/0x210 [bluetooth] hci_cmd_sync_work+0x1c0/0x210 [bluetooth] ? __pfx_mgmt_add_adv_patterns_monitor_complete+0x10/0x10 [bluetooth] process_one_work+0x4fd/0xbc0 ? __pfx_process_one_work+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? __list_add_valid_or_report+0x37/0xf0 ? __pfx_hci_cmd_sync_work+0x10/0x10 [bluetooth] ? srso_alias_return_thunk+0x5/0xfbef5 worker_thread+0x2d8/0x570 ? __pfx_worker_thread+0x10/0x10 kthread+0x1ad/0x1f0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x3c9/0x540 ? __pfx_ret_from_fork+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? __switch_to+0x2e9/0x730 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Allocated by task 471 on cpu 3 at 285.205389s: kasan_save_stack+0x33/0x60 kasan_save_track+0x17/0x60 __kasan_kmalloc+0xaa/0xb0 add_adv_patterns_monitor_rssi+0xd5/0x230 [bluetooth] hci_sock_sendmsg+0x96b/0xf80 [bluetooth] __sys_sendto+0x2bc/0x2d0 __x64_sys_sendto+0x76/0x90 do_syscall_64+0x115/0x6a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 454 on cpu 2 at 285.217112s: kasan_save_stack+0x33/0x60 kasan_save_track+0x17/0x60 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x5f/0x80 kfree+0x313/0x590 msft_add_monitor_sync+0x54a/0x570 [bluetooth] hci_add_adv_monitor+0x133/0x180 [bluetooth] hci_cmd_sync_work+0x187/0x210 [bluetooth] process_one_work+0x4fd/0xbc0 worker_thread+0x2d8/0x570 kthread+0x1ad/0x1f0 ret_from_fork+0x3c9/0x540 ret_from_fork_asm+0x1a/0x30
CVE-2026-72255 1 Linux 1 Linux Kernel 2026-08-17 7.8 High
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_queue: pin bridge device while NFQUEUE holds fake dst The br_netfilter fake rtable is embedded in struct net_bridge and is attached to bridged packets with skb_dst_set_noref(). If such a packet is queued to NFQUEUE, __nf_queue() upgrades that fake dst with skb_dst_force(). At that point the queued skb can hold a real dst reference after bridge teardown has started. The problem is not that every bridged packet needs its own dst reference. The problem is that NFQUEUE can keep the bridge private fake dst alive after unregister begins. Fix this by keeping the bridge fake dst model unchanged and pinning the bridge master device only while the packet sits in NFQUEUE. Record the bridge device in nf_queue_entry when the queued skb carries a bridge fake dst, take a device reference for the queue lifetime, and drop it when the queue entry is freed. Also make sure queued entries are reaped when that bridge device goes down, and drop the redundant nf_bridge_info_exists() test from the fake dst detection. This keeps netdev_priv(br->dev) alive until verdict completion, so the embedded fake rtable and its metrics backing storage cannot be freed out from under dst_release(). It also avoids the constant refcount bump and avoids using ipv4-specific dst helpers for IPv6 bridge traffic.
CVE-2026-72328 1 Linux 1 Linux Kernel 2026-08-17 7.8 High
In the Linux kernel, the following vulnerability has been resolved: accel/amdxdna: Fix potential amdxdna_umap lifetime race amdxdna_umap_release() calls the blocking mmu_interval_notifier_remove() before removing the object from abo->mem.umap_list. If aie2_populate_range() runs concurrently, it may obtain a reference to an amdxdna_umap that is being released, leading to a potential use-after-free. Use kref_get_unless_zero() in aie2_populate_range() when acquiring a reference. If the reference count has already dropped to zero, release is in progress and the entry is skipped.