In the Linux kernel, the following vulnerability has been resolved: iio: gyro: mpu3050: Move iio_device_register() to correct location iio_device_register() should be at the end of the probe function to prevent race conditions. Place iio_device_register() at the end of the probe function and place iio_device_unregister() accordingly.
In the Linux kernel, the following vulnerability has been resolved: xfrm: prevent policy_hthresh.work from racing with netns teardown A XFRM_MSG_NEWSPDINFO request can queue the per-net work item policy_hthresh.work onto the system workqueue. The queued callback, xfrm_hash_rebuild(), retrieves the enclosing struct net via container_of(). If the net namespace is torn down before that work runs, the associated struct net may already have been freed, and xfrm_hash_rebuild() may then dereference stale memory. xfrm_policy_fini() already flushes policy_hash_work during teardown, but it does not synchronize policy_hthresh.work. Synchronize policy_hthresh.work in xfrm_policy_fini() as well, so the queued work cannot outlive the net namespace teardown and access a freed struct net.
In the Linux kernel, the following vulnerability has been resolved: bridge: cfm: Fix race condition in peer_mep deletion When a peer MEP is being deleted, cancel_delayed_work_sync() is called on ccm_rx_dwork before freeing. However, br_cfm_frame_rx() runs in softirq context under rcu_read_lock (without RTNL) and can re-schedule ccm_rx_dwork via ccm_rx_timer_start() between cancel_delayed_work_sync() returning and kfree_rcu() being called. The following is a simple race scenario: cpu0 cpu1 mep_delete_implementation() cancel_delayed_work_sync(ccm_rx_dwork); br_cfm_frame_rx() // peer_mep still in hlist if (peer_mep->ccm_defect) ccm_rx_timer_start() queue_delayed_work(ccm_rx_dwork) hlist_del_rcu(&peer_mep->head); kfree_rcu(peer_mep, rcu); ccm_rx_work_expired() // on freed peer_mep To prevent this, cancel_delayed_work_sync() is replaced with disable_delayed_work_sync() in both peer MEP deletion paths, so that subsequent queue_delayed_work() calls from br_cfm_frame_rx() are silently rejected. The cc_peer_disable() helper retains cancel_delayed_work_sync() because it is also used for the CC enable/disable toggle path where the work must remain re-schedulable.
In the Linux kernel, the following vulnerability has been resolved: um: Fix potential race condition in TLB sync During the TLB sync, we need to traverse and modify the page table, so we should hold the page table lock. Since full SMP support for threads within the same process is still missing, let's disable the split page table lock for simplicity.
In the Linux kernel, the following vulnerability has been resolved: sched/psi: fix race between file release and pressure write A potential race condition exists between pressure write and cgroup file release regarding the priv member of struct kernfs_open_file, which triggers the uaf reported in [1]. Consider the following scenario involving execution on two separate CPUs: CPU0 CPU1 ==== ==== vfs_rmdir() kernfs_iop_rmdir() cgroup_rmdir() cgroup_kn_lock_live() cgroup_destroy_locked() cgroup_addrm_files() cgroup_rm_file() kernfs_remove_by_name() kernfs_remove_by_name_ns() vfs_write() __kernfs_remove() new_sync_write() kernfs_drain() kernfs_fop_write_iter() kernfs_drain_open_files() cgroup_file_write() kernfs_release_file() pressure_write() cgroup_file_release() ctx = of->priv; kfree(ctx); of->priv = NULL; cgroup_kn_unlock() cgroup_kn_lock_live() cgroup_get(cgrp) cgroup_kn_unlock() if (ctx->psi.trigger) // here, trigger uaf for ctx, that is of->priv The cgroup_rmdir() is protected by the cgroup_mutex, it also safeguards the memory deallocation of of->priv performed within cgroup_file_release(). However, the operations involving of->priv executed within pressure_write() are not entirely covered by the protection of cgroup_mutex. Consequently, if the code in pressure_write(), specifically the section handling the ctx variable executes after cgroup_file_release() has completed, a uaf vulnerability involving of->priv is triggered. Therefore, the issue can be resolved by extending the scope of the cgroup_mutex lock within pressure_write() to encompass all code paths involving of->priv, thereby properly synchronizing the race condition occurring between cgroup_file_release() and pressure_write(). And, if an live kn lock can be successfully acquired while executing the pressure write operation, it indicates that the cgroup deletion process has not yet reached its final stage; consequently, the priv pointer within open_file cannot be NULL. Therefore, the operation to retrieve the ctx value must be moved to a point *after* the live kn lock has been successfully acquired. In another situation, specifically after entering cgroup_kn_lock_live() but before acquiring cgroup_mutex, there exists a different class of race condition: CPU0: write memory.pressure CPU1: write cgroup.pressure=0 =========================== ============================= kernfs_fop_write_iter() kernfs_get_active_of(of) pressure_write() cgroup_kn_lock_live(memory.pressure) cgroup_tryget(cgrp) kernfs_break_active_protection(kn) ... blocks on cgroup_mutex cgroup_pressure_write() cgroup_kn_lock_live(cgroup.pressure) cgroup_file_show(memory.pressure, false) kernfs_show(false) kernfs_drain_open_files() cgroup_file_release(of) kfree(ctx) of->priv = NULL cgroup_kn_unlock() ... acquires cgroup_mutex ctx = of->priv; // may now be NULL if (ctx->psi.trigger) // NULL dereference Consequently, there is a possibility that of->priv is NULL, the pressure write needs to check for this. Now that the scope of the cgroup_mutex has been expanded, the original explicit cgroup_get/put operations are no longer necessary, this is because acquiring/releasing the live kn lock inherently executes a cgroup get/put operation. [1] BUG: KASAN: slab-use-after-free in pressure_write+0xa4/0x210 kernel/cgroup/cgroup.c:4011 Call Trace: pressure_write+0xa4/0x210 kernel/cgroup/cgroup.c:4011 cgroup_file_write+0x36f/0x790 kernel/cgroup/cgroup.c:43 ---truncated---
In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Fix race condition in QP timer handlers I encontered the following warning: WARNING: drivers/infiniband/sw/rxe/rxe_task.c:249 at rxe_sched_task+0x1c8/0x238 [rdma_rxe], CPU#0: swapper/0/0 ... libsha1 [last unloaded: ip6_udp_tunnel] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G C 6.19.0-rc5-64k-v8+ #37 PREEMPT Tainted: [C]=CRAP Hardware name: Raspberry Pi 4 Model B Rev 1.2 Call trace: rxe_sched_task+0x1c8/0x238 [rdma_rxe] (P) retransmit_timer+0x130/0x188 [rdma_rxe] call_timer_fn+0x68/0x4d0 __run_timers+0x630/0x888 ... WARNING: drivers/infiniband/sw/rxe/rxe_task.c:38 at rxe_sched_task+0x1c0/0x238 [rdma_rxe], CPU#0: swapper/0/0 ... WARNING: drivers/infiniband/sw/rxe/rxe_task.c:111 at do_work+0x488/0x5c8 [rdma_rxe], CPU#3: kworker/u17:4/93400 ... refcount_t: underflow; use-after-free. WARNING: lib/refcount.c:28 at refcount_warn_saturate+0x138/0x1a0, CPU#3: kworker/u17:4/93400 The issue is caused by a race condition between retransmit_timer() and rxe_destroy_qp, leading to the Queue Pair's (QP) reference count dropping to zero during timer handler execution. It seems this warning is harmless because rxe_qp_do_cleanup() will flush all pending timers and requests. Example of flow causing the issue: CPU0 CPU1 retransmit_timer() { spin_lock_irqsave rxe_destroy_qp() __rxe_cleanup() __rxe_put() // qp->ref_count decrease to 0 rxe_qp_do_cleanup() { if (qp->valid) { rxe_sched_task() { WARN_ON(rxe_read(task->qp) <= 0); } } spin_unlock_irqrestore } spin_lock_irqsave qp->valid = 0 spin_unlock_irqrestore } Ensure the QP's reference count is maintained and its validity is checked within the timer callbacks by adding calls to rxe_get(qp) and corresponding rxe_put(qp) after use.
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: SCO: fix race conditions in sco_sock_connect() sco_sock_connect() checks sk_state and sk_type without holding the socket lock. Two concurrent connect() syscalls on the same socket can both pass the check and enter sco_connect(), leading to use-after-free. The buggy scenario involves three participants and was confirmed with additional logging instrumentation: Thread A (connect): HCI disconnect: Thread B (connect): sco_sock_connect(sk) sco_sock_connect(sk) sk_state==BT_OPEN sk_state==BT_OPEN (pass, no lock) (pass, no lock) sco_connect(sk): sco_connect(sk): hci_dev_lock hci_dev_lock hci_connect_sco <- blocked -> hcon1 sco_conn_add->conn1 lock_sock(sk) sco_chan_add: conn1->sk = sk sk->conn = conn1 sk_state=BT_CONNECT release_sock hci_dev_unlock hci_dev_lock sco_conn_del: lock_sock(sk) sco_chan_del: sk->conn=NULL conn1->sk=NULL sk_state= BT_CLOSED SOCK_ZAPPED release_sock hci_dev_unlock (unblocked) hci_connect_sco -> hcon2 sco_conn_add -> conn2 lock_sock(sk) sco_chan_add: sk->conn=conn2 sk_state= BT_CONNECT // zombie sk! release_sock hci_dev_unlock Thread B revives a BT_CLOSED + SOCK_ZAPPED socket back to BT_CONNECT. Subsequent cleanup triggers double sock_put() and use-after-free. Meanwhile conn1 is leaked as it was orphaned when sco_conn_del() cleared the association. Fix this by: - Moving lock_sock() before the sk_state/sk_type checks in sco_sock_connect() to serialize concurrent connect attempts - Fixing the sk_type != SOCK_SEQPACKET check to actually return the error instead of just assigning it - Adding a state re-check in sco_connect() after lock_sock() to catch state changes during the window between the locks - Adding sco_pi(sk)->conn check in sco_chan_add() to prevent double-attach of a socket to multiple connections - Adding hci_conn_drop() on sco_chan_add failure to prevent HCI connection leaks
In the Linux kernel, the following vulnerability has been resolved: apparmor: fix race on rawdata dereference There is a race condition that leads to a use-after-free situation: because the rawdata inodes are not refcounted, an attacker can start open()ing one of the rawdata files, and at the same time remove the last reference to this rawdata (by removing the corresponding profile, for example), which frees its struct aa_loaddata; as a result, when seq_rawdata_open() is reached, i_private is a dangling pointer and freed memory is accessed. The rawdata inodes weren't refcounted to avoid a circular refcount and were supposed to be held by the profile rawdata reference. However during profile removal there is a window where the vfs and profile destruction race, resulting in the use after free. Fix this by moving to a double refcount scheme. Where the profile refcount on rawdata is used to break the circular dependency. Allowing for freeing of the rawdata once all inode references to the rawdata are put.
In the Linux kernel, the following vulnerability has been resolved: dst: fix races in rt6_uncached_list_del() and rt_del_uncached_list() syzbot was able to crash the kernel in rt6_uncached_list_flush_dev() in an interesting way [1] Crash happens in list_del_init()/INIT_LIST_HEAD() while writing list->prev, while the prior write on list->next went well. static inline void INIT_LIST_HEAD(struct list_head *list) { WRITE_ONCE(list->next, list); // This went well WRITE_ONCE(list->prev, list); // Crash, @list has been freed. } Issue here is that rt6_uncached_list_del() did not attempt to lock ul->lock, as list_empty(&rt->dst.rt_uncached) returned true because the WRITE_ONCE(list->next, list) happened on the other CPU. We might use list_del_init_careful() and list_empty_careful(), or make sure rt6_uncached_list_del() always grabs the spinlock whenever rt->dst.rt_uncached_list has been set. A similar fix is neeed for IPv4. [1] BUG: KASAN: slab-use-after-free in INIT_LIST_HEAD include/linux/list.h:46 [inline] BUG: KASAN: slab-use-after-free in list_del_init include/linux/list.h:296 [inline] BUG: KASAN: slab-use-after-free in rt6_uncached_list_flush_dev net/ipv6/route.c:191 [inline] BUG: KASAN: slab-use-after-free in rt6_disable_ip+0x633/0x730 net/ipv6/route.c:5020 Write of size 8 at addr ffff8880294cfa78 by task kworker/u8:14/3450 CPU: 0 UID: 0 PID: 3450 Comm: kworker/u8:14 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: netns cleanup_net Call Trace: <TASK> dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 INIT_LIST_HEAD include/linux/list.h:46 [inline] list_del_init include/linux/list.h:296 [inline] rt6_uncached_list_flush_dev net/ipv6/route.c:191 [inline] rt6_disable_ip+0x633/0x730 net/ipv6/route.c:5020 addrconf_ifdown+0x143/0x18a0 net/ipv6/addrconf.c:3853 addrconf_notify+0x1bc/0x1050 net/ipv6/addrconf.c:-1 notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] netif_close_many+0x29c/0x410 net/core/dev.c:1785 unregister_netdevice_many_notify+0xb50/0x2330 net/core/dev.c:12353 ops_exit_rtnl_list net/core/net_namespace.c:187 [inline] ops_undo_list+0x3dc/0x990 net/core/net_namespace.c:248 cleanup_net+0x4de/0x7b0 net/core/net_namespace.c:696 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 </TASK> Allocated by task 803: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x18d/0x6c0 mm/slub.c:5270 dst_alloc+0x105/0x170 net/core/dst.c:89 ip6_dst_alloc net/ipv6/route.c:342 [inline] icmp6_dst_alloc+0x75/0x460 net/ipv6/route.c:3333 mld_sendpack+0x683/0xe60 net/ipv6/mcast.c:1844 mld_send_cr net/ipv6/mcast.c:2154 [inline] mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entr ---truncated---
In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: oss: Fix data race at accessing runtime.oss.trigger Currently the runtime.oss.trigger field may be accessed concurrently without protection, which may lead to the data race. And, in this case, it may lead to more severe problem because it's a bit field; as writing the data, it may overwrite other bit fields as well, which confuses the operation completely, as spotted by fuzzing. Fix it by covering runtime.oss.trigger bit fled also with the existing params_lock mutex in both snd_pcm_oss_get_trigger() and snd_pcm_oss_poll().
In the Linux kernel, the following vulnerability has been resolved: media: amphion: Fix race between m2m job_abort and device_run Fix kernel panic caused by race condition where v4l2_m2m_ctx_release() frees m2m_ctx while v4l2_m2m_try_run() is about to call device_run with the same context. Race sequence: v4l2_m2m_try_run(): v4l2_m2m_ctx_release(): lock/unlock v4l2_m2m_cancel_job() job_abort() v4l2_m2m_job_finish() kfree(m2m_ctx) <- frees ctx device_run() <- use-after-free crash at 0x538 Crash trace: Unable to handle kernel read from unreadable memory at virtual address 0000000000000538 v4l2_m2m_try_run+0x78/0x138 v4l2_m2m_device_run_work+0x14/0x20 The amphion vpu driver does not rely on the m2m framework's device_run callback to perform encode/decode operations. Fix the race by preventing m2m framework job scheduling entirely: - Add job_ready callback returning 0 (no jobs ready for m2m framework) - Remove job_abort callback to avoid the race condition
In the Linux kernel, the following vulnerability has been resolved: i3c: mipi-i3c-hci: Fix race in DMA ring dequeue The HCI DMA dequeue path (hci_dma_dequeue_xfer()) may be invoked for multiple transfers that timeout around the same time. However, the function is not serialized and can race with itself. When a timeout occurs, hci_dma_dequeue_xfer() stops the ring, processes incomplete transfers, and then restarts the ring. If another timeout triggers a parallel call into the same function, the two instances may interfere with each other - stopping or restarting the ring at unexpected times. Add a mutex so that hci_dma_dequeue_xfer() is serialized with respect to itself.
In the Linux kernel, the following vulnerability has been resolved: netfilter: ctnetlink: ensure safe access to master conntrack Holding reference on the expectation is not sufficient, the master conntrack object can just go away, making exp->master invalid. To access exp->master safely: - Grab the nf_conntrack_expect_lock, this gets serialized with clean_from_lists() which also holds this lock when the master conntrack goes away. - Hold reference on master conntrack via nf_conntrack_find_get(). Not so easy since the master tuple to look up for the master conntrack is not available in the existing problematic paths. This patch goes for extending the nf_conntrack_expect_lock section to address this issue for simplicity, in the cases that are described below this is just slightly extending the lock section. The add expectation command already holds a reference to the master conntrack from ctnetlink_create_expect(). However, the delete expectation command needs to grab the spinlock before looking up for the expectation. Expand the existing spinlock section to address this to cover the expectation lookup. Note that, the nf_ct_expect_iterate_net() calls already grabs the spinlock while iterating over the expectation table, which is correct. The get expectation command needs to grab the spinlock to ensure master conntrack does not go away. This also expands the existing spinlock section to cover the expectation lookup too. I needed to move the netlink skb allocation out of the spinlock to keep it GFP_KERNEL. For the expectation events, the IPEXP_DESTROY event is already delivered under the spinlock, just move the delivery of IPEXP_NEW under the spinlock too because the master conntrack event cache is reached through exp->master. While at it, add lockdep notations to help identify what codepaths need to grab the spinlock.
In the Linux kernel, the following vulnerability has been resolved: net: avoid potential UAF in default_operstate() syzbot reported an UAF in default_operstate() [1] Issue is a race between device and netns dismantles. After calling __rtnl_unlock() from netdev_run_todo(), we can not assume the netns of each device is still alive. Make sure the device is not in NETREG_UNREGISTERED state, and add an ASSERT_RTNL() before the call to __dev_get_by_index(). We might move this ASSERT_RTNL() in __dev_get_by_index() in the future. [1] BUG: KASAN: slab-use-after-free in __dev_get_by_index+0x5d/0x110 net/core/dev.c:852 Read of size 8 at addr ffff888043eba1b0 by task syz.0.0/5339 CPU: 0 UID: 0 PID: 5339 Comm: syz.0.0 Not tainted 6.12.0-syzkaller-10296-gaaf20f870da0 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x169/0x550 mm/kasan/report.c:489 kasan_report+0x143/0x180 mm/kasan/report.c:602 __dev_get_by_index+0x5d/0x110 net/core/dev.c:852 default_operstate net/core/link_watch.c:51 [inline] rfc2863_policy+0x224/0x300 net/core/link_watch.c:67 linkwatch_do_dev+0x3e/0x170 net/core/link_watch.c:170 netdev_run_todo+0x461/0x1000 net/core/dev.c:10894 rtnl_unlock net/core/rtnetlink.c:152 [inline] rtnl_net_unlock include/linux/rtnetlink.h:133 [inline] rtnl_dellink+0x760/0x8d0 net/core/rtnetlink.c:3520 rtnetlink_rcv_msg+0x791/0xcf0 net/core/rtnetlink.c:6911 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2541 netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1347 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1891 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:726 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2583 ___sys_sendmsg net/socket.c:2637 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2669 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2a3cb80809 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2a3d9cd058 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f2a3cd45fa0 RCX: 00007f2a3cb80809 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000008 RBP: 00007f2a3cbf393e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f2a3cd45fa0 R15: 00007ffd03bc65c8 </TASK> Allocated by task 5339: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4314 kmalloc_noprof include/linux/slab.h:901 [inline] kmalloc_array_noprof include/linux/slab.h:945 [inline] netdev_create_hash net/core/dev.c:11870 [inline] netdev_init+0x10c/0x250 net/core/dev.c:11890 ops_init+0x31e/0x590 net/core/net_namespace.c:138 setup_net+0x287/0x9e0 net/core/net_namespace.c:362 copy_net_ns+0x33f/0x570 net/core/net_namespace.c:500 create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228 ksys_unshare+0x57d/0xa70 kernel/fork.c:3314 __do_sys_unshare kernel/fork.c:3385 [inline] __se_sys_unshare kernel/fork.c:3383 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3383 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x8 ---truncated---
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in SMB request handling A race condition exists between SMB request handling in `ksmbd_conn_handler_loop()` and the freeing of `ksmbd_conn` in the workqueue handler `handle_ksmbd_work()`. This leads to a UAF. - KASAN: slab-use-after-free Read in handle_ksmbd_work - KASAN: slab-use-after-free in rtlock_slowlock_locked This race condition arises as follows: - `ksmbd_conn_handler_loop()` waits for `conn->r_count` to reach zero: `wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);` - Meanwhile, `handle_ksmbd_work()` decrements `conn->r_count` using `atomic_dec_return(&conn->r_count)`, and if it reaches zero, calls `ksmbd_conn_free()`, which frees `conn`. - However, after `handle_ksmbd_work()` decrements `conn->r_count`, it may still access `conn->r_count_q` in the following line: `waitqueue_active(&conn->r_count_q)` or `wake_up(&conn->r_count_q)` This results in a UAF, as `conn` has already been freed. The discovery of this UAF can be referenced in the following PR for syzkaller's support for SMB requests.
In the Linux kernel, the following vulnerability has been resolved: net/packet: fix TOCTOU race on mmap'd vnet_hdr in tpacket_snd() In tpacket_snd(), when PACKET_VNET_HDR is enabled, vnet_hdr points directly into the mmap'd TX ring buffer shared with userspace. The kernel validates the header via __packet_snd_vnet_parse() but then re-reads all fields later in virtio_net_hdr_to_skb(). A concurrent userspace thread can modify the vnet_hdr fields between validation and use, bypassing all safety checks. The non-TPACKET path (packet_snd()) already correctly copies vnet_hdr to a stack-local variable. All other vnet_hdr consumers in the kernel (tun.c, tap.c, virtio_net.c) also use stack copies. The TPACKET TX path is the only caller of virtio_net_hdr_to_skb() that reads directly from user-controlled shared memory. Fix this by copying vnet_hdr from the mmap'd ring buffer to a stack-local variable before validation and use, consistent with the approach used in packet_snd() and all other callers.
In the Linux kernel, the following vulnerability has been resolved: mptcp: fix race in mptcp_pm_nl_flush_addrs_doit() syzbot and Eulgyu Kim reported crashes in mptcp_pm_nl_get_local_id() and/or mptcp_pm_nl_is_backup() Root cause is list_splice_init() in mptcp_pm_nl_flush_addrs_doit() which is not RCU ready. list_splice_init_rcu() can not be called here while holding pernet->lock spinlock. Many thanks to Eulgyu Kim for providing a repro and testing our patches.
In the Linux kernel, the following vulnerability has been resolved: apparmor: fix race between freeing data and fs accessing it AppArmor was putting the reference to i_private data on its end after removing the original entry from the file system. However the inode can aand does live beyond that point and it is possible that some of the fs call back functions will be invoked after the reference has been put, which results in a race between freeing the data and accessing it through the fs. While the rawdata/loaddata is the most likely candidate to fail the race, as it has the fewest references. If properly crafted it might be possible to trigger a race for the other types stored in i_private. Fix this by moving the put of i_private referenced data to the correct place which is during inode eviction.
In the Linux kernel, the following vulnerability has been resolved: espintcp: Fix race condition in espintcp_close() This issue was discovered during a code audit. After cancel_work_sync() is called from espintcp_close(), espintcp_tx_work() can still be scheduled from paths such as the Delayed ACK handler or ksoftirqd. As a result, the espintcp_tx_work() worker may dereference a freed espintcp ctx or sk. The following is a simple race scenario: cpu0 cpu1 espintcp_close() cancel_work_sync(&ctx->work); espintcp_write_space() schedule_work(&ctx->work); To prevent this race condition, cancel_work_sync() is replaced with disable_work_sync().
In the Linux kernel, the following vulnerability has been resolved: perf: Fix __perf_event_overflow() vs perf_remove_from_context() race Make sure that __perf_event_overflow() runs with IRQs disabled for all possible callchains. Specifically the software events can end up running it with only preemption disabled. This opens up a race vs perf_event_exit_event() and friends that will go and free various things the overflow path expects to be present, like the BPF program.
Race condition in the netlink_dump function in net/netlink/af_netlink.c in the Linux kernel before 4.6.3 allows local users to cause a denial of service (double free) or possibly have unspecified other impact via a crafted application that makes sendmsg system calls, leading to a free operation associated with a new dump that started earlier than anticipated.
Race condition in the snd_pcm_period_elapsed function in sound/core/pcm_lib.c in the ALSA subsystem in the Linux kernel before 4.7 allows local users to cause a denial of service (use-after-free) or possibly have unspecified other impact via a crafted SNDRV_PCM_TRIGGER_START command.
Race condition in net/packet/af_packet.c in the Linux kernel through 4.8.12 allows local users to gain privileges or cause a denial of service (use-after-free) by leveraging the CAP_NET_RAW capability to change a socket version, related to the packet_set_ring and packet_setsockopt functions.
Race condition in the ip4_datagram_release_cb function in net/ipv4/datagram.c in the Linux kernel before 3.15.2 allows local users to gain privileges or cause a denial of service (use-after-free) by leveraging incorrect expectations about locking during multithreaded access to internal data structures for IPv4 UDP sockets.
In the Linux kernel, the following vulnerability has been resolved: binder: fix node UAF in binder_add_freeze_work() In binder_add_freeze_work() we iterate over the proc->nodes with the proc->inner_lock held. However, this lock is temporarily dropped in order to acquire the node->lock first (lock nesting order). This can race with binder_node_release() and trigger a use-after-free: ================================================================== BUG: KASAN: slab-use-after-free in _raw_spin_lock+0xe4/0x19c Write of size 4 at addr ffff53c04c29dd04 by task freeze/640 CPU: 5 UID: 0 PID: 640 Comm: freeze Not tainted 6.11.0-07343-ga727812a8d45 #17 Hardware name: linux,dummy-virt (DT) Call trace: _raw_spin_lock+0xe4/0x19c binder_add_freeze_work+0x148/0x478 binder_ioctl+0x1e70/0x25ac __arm64_sys_ioctl+0x124/0x190 Allocated by task 637: __kmalloc_cache_noprof+0x12c/0x27c binder_new_node+0x50/0x700 binder_transaction+0x35ac/0x6f74 binder_thread_write+0xfb8/0x42a0 binder_ioctl+0x18f0/0x25ac __arm64_sys_ioctl+0x124/0x190 Freed by task 637: kfree+0xf0/0x330 binder_thread_read+0x1e88/0x3a68 binder_ioctl+0x16d8/0x25ac __arm64_sys_ioctl+0x124/0x190 ================================================================== Fix the race by taking a temporary reference on the node before releasing the proc->inner lock. This ensures the node remains alive while in use.
NVIDIA Resiliency Extension for Linux contains a vulnerability in the checkpointing core, where an attacker may cause a race condition. A successful exploit of this vulnerability might lead to information disclosure, data tampering, denial of service, or escalation of privileges.
A double-free flaw was found in the Linux kernel’s NTFS3 subsystem in how a user triggers remount and umount simultaneously. This flaw allows a local user to crash or potentially escalate their privileges on the system.
IBM DB2 High Performance Unload load for LUW 6.1 and 6.5 is vulnerable to a buffer overflow, caused by improper bounds checking which could allow a local attacker to execute arbitrary code on the system with root privileges. IBM X-Force ID: 165481.
The overlayfs implementation in the Linux kernel through 4.5.2 does not properly maintain POSIX ACL xattr data, which allows local users to gain privileges by leveraging a group-writable setgid directory.
In drivers/char/virtio_console.c in the Linux kernel before 5.13.4, data corruption or loss can be triggered by an untrusted device that supplies a buf->len value exceeding the buffer size. NOTE: the vendor indicates that the cited data corruption is not a vulnerability in any existing use case; the length validation was added solely for robustness in the face of anomalous host OS behavior
arch/powerpc/kvm/book3s_rtas.c in the Linux kernel through 5.13.5 on the powerpc platform allows KVM guest OS users to cause host OS memory corruption via rtas_args.nargs, aka CID-f62f3c20647e.
An issue was discovered in fs/gfs2/rgrp.c in the Linux kernel before 4.8. A use-after-free is caused by the functions gfs2_clear_rgrpd and read_rindex_entry.
The qdisc_notify function in net/sched/sch_api.c in the Linux kernel before 2.6.35 does not prevent tc_fill_qdisc function calls referencing builtin (aka CQ_F_BUILTIN) Qdisc structures, which allows local users to cause a denial of service (NULL pointer dereference and OOPS) or possibly have unspecified other impact via a crafted call.
Improper Verification of Cryptographic Signature vulnerability in Snow Software Inventory Agent on MacOS, Snow Software Inventory Agent on Windows, Snow Software Inventory Agent on Linux allows File Manipulation through Snow Update Packages.This issue affects Inventory Agent: through 6.12.0; Inventory Agent: through 6.14.5; Inventory Agent: through 6.7.2.
In the Linux kernel, the following vulnerability has been resolved: media: iris: fix use-after-free of fmt_src during MBPF check During concurrency testing, multiple instances can run in parallel, and each instance uses its own inst->lock while the core->lock protects the list of active instances. The race happens because these locks cover different scopes, inst->lock protects only the internals of a single instance, while the Macro Blocks Per Frame (MBPF) checker walks the core list under core->lock and reads fields like fmt_src->width and fmt_src->height. At the same time, iris_close() may free fmt_src and fmt_dst under inst->lock while the instance is still present in the core list. This allows a situation where the MBPF checker, still iterating through the core list, reaches an instance whose fmt_src was already freed by another thread and ends up dereferencing a dangling pointer, resulting in a use-after-free. This happens because the MBPF checker assumes that any instance in the core list is fully valid, but the freeing of fmt_src and fmt_dst without removing the instance from the core list is not correct. The correct ordering is to defer freeing fmt_src and fmt_dst until after the instance has been removed from the core list and all teardown under the core lock has completed, ensuring that no dangling pointers are ever exposed during MBPF checks.
The Linux kernel before 5.1-rc5 allows page->_refcount reference count overflow, with resultant use-after-free issues, if about 140 GiB of RAM exists. This is related to fs/fuse/dev.c, fs/pipe.c, fs/splice.c, include/linux/mm.h, include/linux/pipe_fs_i.h, kernel/trace/trace.c, mm/gup.c, and mm/hugetlb.c. It can occur with FUSE requests.
A use-after-free vulnerability in the Linux kernel's netfilter: nf_tables component can be exploited to achieve local privilege escalation. The nft_verdict_init() function allows positive values as drop error within the hook verdict, and hence the nf_hook_slow() function can cause a double free vulnerability when NF_DROP is issued with a drop error which resembles NF_ACCEPT. We recommend upgrading past commit f342de4e2f33e0e39165d8639387aa6c19dff660.
In the Linux kernel, the following vulnerability has been resolved: ext4: fix dirtyclusters double decrement on fs shutdown fstests test generic/388 occasionally reproduces a warning in ext4_put_super() associated with the dirty clusters count: WARNING: CPU: 7 PID: 76064 at fs/ext4/super.c:1324 ext4_put_super+0x48c/0x590 [ext4] Tracing the failure shows that the warning fires due to an s_dirtyclusters_counter value of -1. IOW, this appears to be a spurious decrement as opposed to some sort of leak. Further tracing of the dirty cluster count deltas and an LLM scan of the resulting output identified the cause as a double decrement in the error path between ext4_mb_mark_diskspace_used() and the caller ext4_mb_new_blocks(). First, note that generic/388 is a shutdown vs. fsstress test and so produces a random set of operations and shutdown injections. In the problematic case, the shutdown triggers an error return from the ext4_handle_dirty_metadata() call(s) made from ext4_mb_mark_context(). The changed value is non-zero at this point, so ext4_mb_mark_diskspace_used() does not exit after the error bubbles up from ext4_mb_mark_context(). Instead, the former decrements both cluster counters and returns the error up to ext4_mb_new_blocks(). The latter falls into the !ar->len out path which decrements the dirty clusters counter a second time, creating the inconsistency. To avoid this problem and simplify ownership of the cluster reservation in this codepath, lift the counter reduction to a single place in the caller. This makes it more clear that ext4_mb_new_blocks() is responsible for acquiring cluster reservation (via ext4_claim_free_clusters()) in the !delalloc case as well as releasing it, regardless of whether it ends up consumed or returned due to failure.
A use-after-free vulnerability in the Linux kernel's netfilter: nf_tables component can be exploited to achieve local privilege escalation. The nft_setelem_catchall_deactivate() function checks whether the catch-all set element is active in the current generation instead of the next generation before freeing it, but only flags it inactive in the next generation, making it possible to free the element multiple times, leading to a double free vulnerability. We recommend upgrading past commit b1db244ffd041a49ecc9618e8feb6b5c1afcdaa7.
Integer overflow in lib/asn1_decoder.c in the Linux kernel before 4.6 allows local users to gain privileges via crafted ASN.1 data.
The aio_mount function in fs/aio.c in the Linux kernel before 4.7.7 does not properly restrict execute access, which makes it easier for local users to bypass intended SELinux W^X policy restrictions, and consequently gain privileges, via an io_setup system call.
The load_flat_shared_library function in fs/binfmt_flat.c in the flat subsystem in the Linux kernel before 2.6.31-rc6 allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly have unspecified other impact by executing a shared flat binary, which triggers an access of an "uninitialized cred pointer."
A flaw was found in the Linux kernel. A use-after-free vulnerability in the NFC stack can lead to a threat to confidentiality, integrity, and system availability.
IBM DB2 High Performance Unload load for LUW 6.1, 6.1.0.1, 6.1.0.1 IF1, 6.1.0.2, 6.1.0.2 IF1, and 6.1.0.1 IF2 db2hpum and db2hpum_debug binaries are setuid root and have built-in options that allow an low privileged user the ability to load arbitrary db2 libraries from a privileged context. This results in arbitrary code being executed with root authority. IBM X-Force ID: 163489.
The join_session_keyring function in security/keys/process_keys.c in the Linux kernel before 4.4.1 mishandles object references in a certain error case, which allows local users to gain privileges or cause a denial of service (integer overflow and use-after-free) via crafted keyctl commands.
IBM DB2 High Performance Unload load for LUW 6.1, 6.1.0.1, 6.1.0.1 IF1, 6.1.0.2, 6.1.0.2 IF1, and 6.1.0.1 IF2 db2hpum_debug is a setuid root binary which trusts the PATH environment variable. A low privileged user can execute arbitrary commands as root by altering the PATH variable to point to a user controlled location. When a crash is induced the trojan gdb command is executed. IBM X-Force ID: 163488.
IBM DB2 for Linux, UNIX and Windows (includes DB2 Connect Server) 9.7, 10.1, 10.5, and 11.1 is vulnerable to a buffer overflow, which could allow an authenticated local attacker to execute arbitrary code on the system as root. IBM X-Force ID: 158519.
A null pointer dereference flaw was found in the hugetlbfs_fill_super function in the Linux kernel hugetlbfs (HugeTLB pages) functionality. This issue may allow a local user to crash the system or potentially escalate their privileges on the system.
In kernel/bpf/hashtab.c in the Linux kernel through 5.13.8, there is an integer overflow and out-of-bounds write when many elements are placed in a single bucket. NOTE: exploitation might be impractical without the CAP_SYS_ADMIN capability.
In the Linux kernel, the following vulnerability has been resolved: RDMA/iwcm: Fix a use-after-free related to destroying CM IDs iw_conn_req_handler() associates a new struct rdma_id_private (conn_id) with an existing struct iw_cm_id (cm_id) as follows: conn_id->cm_id.iw = cm_id; cm_id->context = conn_id; cm_id->cm_handler = cma_iw_handler; rdma_destroy_id() frees both the cm_id and the struct rdma_id_private. Make sure that cm_work_handler() does not trigger a use-after-free by only freeing of the struct rdma_id_private after all pending work has finished.