In the Linux kernel, the following vulnerability has been resolved: drm/shmem-helper: Remove errant put in error path drm_gem_shmem_mmap() doesn't own this reference, resulting in the GEM object getting prematurely freed leading to a later use-after-free.

In the Linux kernel, the following vulnerability has been resolved: net: hisilicon: Fix potential use-after-free in hix5hd2_rx() The skb is delivered to napi_gro_receive() which may free it, after calling this, dereferencing skb may trigger use-after-free.

In the Linux kernel, the following vulnerability has been resolved: RDMA/hfi1: Fix use-after-free bug for mm struct Under certain conditions, such as MPI_Abort, the hfi1 cleanup code may represent the last reference held on the task mm. hfi1_mmu_rb_unregister() then drops the last reference and the mm is freed before the final use in hfi1_release_user_pages(). A new task may allocate the mm structure while it is still being used, resulting in problems. One manifestation is corruption of the mmap_sem counter leading to a hang in down_write(). Another is corruption of an mm struct that is in use by another task.

In the Linux kernel, the following vulnerability has been resolved: md: fix double free of io_acct_set bioset Now io_acct_set is alloc and free in personality. Remove the codes that free io_acct_set in md_free and md_stop.

In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: Fix races among concurrent prealloc proc writes We have no protection against concurrent PCM buffer preallocation changes via proc files, and it may potentially lead to UAF or some weird problem. This patch applies the PCM open_mutex to the proc write operation for avoiding the racy proc writes and the PCM stream open (and further operations).

In the Linux kernel, the following vulnerability has been resolved: scsi: mpt3sas: Fix use after free in _scsih_expander_node_remove() The function mpt3sas_transport_port_remove() called in _scsih_expander_node_remove() frees the port field of the sas_expander structure, leading to the following use-after-free splat from KASAN when the ioc_info() call following that function is executed (e.g. when doing rmmod of the driver module): [ 3479.371167] ================================================================== [ 3479.378496] BUG: KASAN: use-after-free in _scsih_expander_node_remove+0x710/0x750 [mpt3sas] [ 3479.386936] Read of size 1 at addr ffff8881c037691c by task rmmod/1531 [ 3479.393524] [ 3479.395035] CPU: 18 PID: 1531 Comm: rmmod Not tainted 5.17.0-rc8+ #1436 [ 3479.401712] Hardware name: Supermicro Super Server/H12SSL-NT, BIOS 2.1 06/02/2021 [ 3479.409263] Call Trace: [ 3479.411743] <TASK> [ 3479.413875] dump_stack_lvl+0x45/0x59 [ 3479.417582] print_address_description.constprop.0+0x1f/0x120 [ 3479.423389] ? _scsih_expander_node_remove+0x710/0x750 [mpt3sas] [ 3479.429469] kasan_report.cold+0x83/0xdf [ 3479.433438] ? _scsih_expander_node_remove+0x710/0x750 [mpt3sas] [ 3479.439514] _scsih_expander_node_remove+0x710/0x750 [mpt3sas] [ 3479.445411] ? _raw_spin_unlock_irqrestore+0x2d/0x40 [ 3479.452032] scsih_remove+0x525/0xc90 [mpt3sas] [ 3479.458212] ? mpt3sas_expander_remove+0x1d0/0x1d0 [mpt3sas] [ 3479.465529] ? down_write+0xde/0x150 [ 3479.470746] ? up_write+0x14d/0x460 [ 3479.475840] ? kernfs_find_ns+0x137/0x310 [ 3479.481438] pci_device_remove+0x65/0x110 [ 3479.487013] __device_release_driver+0x316/0x680 [ 3479.493180] driver_detach+0x1ec/0x2d0 [ 3479.498499] bus_remove_driver+0xe7/0x2d0 [ 3479.504081] pci_unregister_driver+0x26/0x250 [ 3479.510033] _mpt3sas_exit+0x2b/0x6cf [mpt3sas] [ 3479.516144] __x64_sys_delete_module+0x2fd/0x510 [ 3479.522315] ? free_module+0xaa0/0xaa0 [ 3479.527593] ? __cond_resched+0x1c/0x90 [ 3479.532951] ? lockdep_hardirqs_on_prepare+0x273/0x3e0 [ 3479.539607] ? syscall_enter_from_user_mode+0x21/0x70 [ 3479.546161] ? trace_hardirqs_on+0x1c/0x110 [ 3479.551828] do_syscall_64+0x35/0x80 [ 3479.556884] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 3479.563402] RIP: 0033:0x7f1fc482483b ... [ 3479.943087] ================================================================== Fix this by introducing the local variable port_id to store the port ID value before executing mpt3sas_transport_port_remove(). This local variable is then used in the call to ioc_info() instead of dereferencing the freed port structure.

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: Fix use after free in hci_send_acl This fixes the following trace caused by receiving HCI_EV_DISCONN_PHY_LINK_COMPLETE which does call hci_conn_del without first checking if conn->type is in fact AMP_LINK and in case it is do properly cleanup upper layers with hci_disconn_cfm: ================================================================== BUG: KASAN: use-after-free in hci_send_acl+0xaba/0xc50 Read of size 8 at addr ffff88800e404818 by task bluetoothd/142 CPU: 0 PID: 142 Comm: bluetoothd Not tainted 5.17.0-rc5-00006-gda4022eeac1a #7 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x45/0x59 print_address_description.constprop.0+0x1f/0x150 kasan_report.cold+0x7f/0x11b hci_send_acl+0xaba/0xc50 l2cap_do_send+0x23f/0x3d0 l2cap_chan_send+0xc06/0x2cc0 l2cap_sock_sendmsg+0x201/0x2b0 sock_sendmsg+0xdc/0x110 sock_write_iter+0x20f/0x370 do_iter_readv_writev+0x343/0x690 do_iter_write+0x132/0x640 vfs_writev+0x198/0x570 do_writev+0x202/0x280 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RSP: 002b:00007ffce8a099b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 Code: 0f 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 14 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10 RDX: 0000000000000001 RSI: 00007ffce8a099e0 RDI: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffce8a099e0 RCX: 00007f788fc3cf77 R10: 00007ffce8af7080 R11: 0000000000000246 R12: 000055e4ccf75580 RBP: 0000000000000015 R08: 0000000000000002 R09: 0000000000000001 </TASK> R13: 000055e4ccf754a0 R14: 000055e4ccf75cd0 R15: 000055e4ccf4a6b0 Allocated by task 45: kasan_save_stack+0x1e/0x40 __kasan_kmalloc+0x81/0xa0 hci_chan_create+0x9a/0x2f0 l2cap_conn_add.part.0+0x1a/0xdc0 l2cap_connect_cfm+0x236/0x1000 le_conn_complete_evt+0x15a7/0x1db0 hci_le_conn_complete_evt+0x226/0x2c0 hci_le_meta_evt+0x247/0x450 hci_event_packet+0x61b/0xe90 hci_rx_work+0x4d5/0xc50 process_one_work+0x8fb/0x15a0 worker_thread+0x576/0x1240 kthread+0x29d/0x340 ret_from_fork+0x1f/0x30 Freed by task 45: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_set_free_info+0x20/0x30 __kasan_slab_free+0xfb/0x130 kfree+0xac/0x350 hci_conn_cleanup+0x101/0x6a0 hci_conn_del+0x27e/0x6c0 hci_disconn_phylink_complete_evt+0xe0/0x120 hci_event_packet+0x812/0xe90 hci_rx_work+0x4d5/0xc50 process_one_work+0x8fb/0x15a0 worker_thread+0x576/0x1240 kthread+0x29d/0x340 ret_from_fork+0x1f/0x30 The buggy address belongs to the object at ffff88800c0f0500 The buggy address is located 24 bytes inside of which belongs to the cache kmalloc-128 of size 128 The buggy address belongs to the page: 128-byte region [ffff88800c0f0500, ffff88800c0f0580) flags: 0x100000000000200(slab|node=0|zone=1) page:00000000fe45cd86 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xc0f0 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 raw: 0100000000000200 ffffea00003a2c80 dead000000000004 ffff8880078418c0 page dumped because: kasan: bad access detected ffff88800c0f0400: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc Memory state around the buggy address: >ffff88800c0f0500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88800c0f0480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88800c0f0580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ---truncated---

In the Linux kernel, the following vulnerability has been resolved: mt76: fix tx status related use-after-free race on station removal There is a small race window where ongoing tx activity can lead to a skb getting added to the status tracking idr after that idr has already been cleaned up, which will keep the wcid linked in the status poll list. Fix this by only adding status skbs if the wcid pointer is still assigned in dev->wcid, which gets cleared early by mt76_sta_pre_rcu_remove

In the Linux kernel, the following vulnerability has been resolved: cgroup: Use separate src/dst nodes when preloading css_sets for migration Each cset (css_set) is pinned by its tasks. When we're moving tasks around across csets for a migration, we need to hold the source and destination csets to ensure that they don't go away while we're moving tasks about. This is done by linking cset->mg_preload_node on either the mgctx->preloaded_src_csets or mgctx->preloaded_dst_csets list. Using the same cset->mg_preload_node for both the src and dst lists was deemed okay as a cset can't be both the source and destination at the same time. Unfortunately, this overloading becomes problematic when multiple tasks are involved in a migration and some of them are identity noop migrations while others are actually moving across cgroups. For example, this can happen with the following sequence on cgroup1: #1> mkdir -p /sys/fs/cgroup/misc/a/b #2> echo $$ > /sys/fs/cgroup/misc/a/cgroup.procs #3> RUN_A_COMMAND_WHICH_CREATES_MULTIPLE_THREADS & #4> PID=$! #5> echo $PID > /sys/fs/cgroup/misc/a/b/tasks #6> echo $PID > /sys/fs/cgroup/misc/a/cgroup.procs the process including the group leader back into a. In this final migration, non-leader threads would be doing identity migration while the group leader is doing an actual one. After #3, let's say the whole process was in cset A, and that after #4, the leader moves to cset B. Then, during #6, the following happens: 1. cgroup_migrate_add_src() is called on B for the leader. 2. cgroup_migrate_add_src() is called on A for the other threads. 3. cgroup_migrate_prepare_dst() is called. It scans the src list. 4. It notices that B wants to migrate to A, so it tries to A to the dst list but realizes that its ->mg_preload_node is already busy. 5. and then it notices A wants to migrate to A as it's an identity migration, it culls it by list_del_init()'ing its ->mg_preload_node and putting references accordingly. 6. The rest of migration takes place with B on the src list but nothing on the dst list. This means that A isn't held while migration is in progress. If all tasks leave A before the migration finishes and the incoming task pins it, the cset will be destroyed leading to use-after-free. This is caused by overloading cset->mg_preload_node for both src and dst preload lists. We wanted to exclude the cset from the src list but ended up inadvertently excluding it from the dst list too. This patch fixes the issue by separating out cset->mg_preload_node into ->mg_src_preload_node and ->mg_dst_preload_node, so that the src and dst preloadings don't interfere with each other.

In the Linux kernel, the following vulnerability has been resolved: iwlwifi: fix use-after-free If no firmware was present at all (or, presumably, all of the firmware files failed to parse), we end up unbinding by calling device_release_driver(), which calls remove(), which then in iwlwifi calls iwl_drv_stop(), freeing the 'drv' struct. However the new code I added will still erroneously access it after it was freed. Set 'failure=false' in this case to avoid the access, all data was already freed anyway.

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix use-after-free after failure to create a snapshot At ioctl.c:create_snapshot(), we allocate a pending snapshot structure and then attach it to the transaction's list of pending snapshots. After that we call btrfs_commit_transaction(), and if that returns an error we jump to 'fail' label, where we kfree() the pending snapshot structure. This can result in a later use-after-free of the pending snapshot: 1) We allocated the pending snapshot and added it to the transaction's list of pending snapshots; 2) We call btrfs_commit_transaction(), and it fails either at the first call to btrfs_run_delayed_refs() or btrfs_start_dirty_block_groups(). In both cases, we don't abort the transaction and we release our transaction handle. We jump to the 'fail' label and free the pending snapshot structure. We return with the pending snapshot still in the transaction's list; 3) Another task commits the transaction. This time there's no error at all, and then during the transaction commit it accesses a pointer to the pending snapshot structure that the snapshot creation task has already freed, resulting in a user-after-free. This issue could actually be detected by smatch, which produced the following warning: fs/btrfs/ioctl.c:843 create_snapshot() warn: '&pending_snapshot->list' not removed from list So fix this by not having the snapshot creation ioctl directly add the pending snapshot to the transaction's list. Instead add the pending snapshot to the transaction handle, and then at btrfs_commit_transaction() we add the snapshot to the list only when we can guarantee that any error returned after that point will result in a transaction abort, in which case the ioctl code can safely free the pending snapshot and no one can access it anymore.

In the Linux kernel, the following vulnerability has been resolved: misc: fastrpc: Fix use-after-free and race in fastrpc_map_find Currently, there is a race window between the point when the mutex is unlocked in fastrpc_map_lookup and the reference count increasing (fastrpc_map_get) in fastrpc_map_find, which can also lead to use-after-free. So lets merge fastrpc_map_find into fastrpc_map_lookup which allows us to both protect the maps list by also taking the &fl->lock spinlock and the reference count, since the spinlock will be released only after. Add take_ref argument to make this suitable for all callers.

Guest triggered use-after-free in Linux xen-netback A malicious or buggy network PV frontend can force Linux netback to disable the interface and terminate the receive kernel thread associated with queue 0 in response to the frontend sending a malformed packet. Such kernel thread termination will lead to a use-after-free in Linux netback when the backend is destroyed, as the kernel thread associated with queue 0 will have already exited and thus the call to kthread_stop will be performed against a stale pointer.

In the Linux kernel 6.0.8, there is a use-after-free in run_unpack in fs/ntfs3/run.c, related to a difference between NTFS sector size and media sector size.

In the Linux kernel, the following vulnerability has been resolved: rtnetlink: make sure to refresh master_dev/m_ops in __rtnl_newlink() While looking at one unrelated syzbot bug, I found the replay logic in __rtnl_newlink() to potentially trigger use-after-free. It is better to clear master_dev and m_ops inside the loop, in case we have to replay it.

In the Linux kernel, the following vulnerability has been resolved: drm/vmwgfx: Fix stale file descriptors on failed usercopy A failing usercopy of the fence_rep object will lead to a stale entry in the file descriptor table as put_unused_fd() won't release it. This enables userland to refer to a dangling 'file' object through that still valid file descriptor, leading to all kinds of use-after-free exploitation scenarios. Fix this by deferring the call to fd_install() until after the usercopy has succeeded.

In the Linux kernel, the following vulnerability has been resolved: misc: fastrpc: Don't remove map on creater_process and device_release Do not remove the map from the list on error path in fastrpc_init_create_process, instead call fastrpc_map_put, to avoid use-after-free. Do not remove it on fastrpc_device_release either, call fastrpc_map_put instead. The fastrpc_free_map is the only proper place to remove the map. This is called only after the reference count is 0.

In the Linux kernel, the following vulnerability has been resolved: erofs: fix pcluster use-after-free on UP platforms During stress testing with CONFIG_SMP disabled, KASAN reports as below: ================================================================== BUG: KASAN: use-after-free in __mutex_lock+0xe5/0xc30 Read of size 8 at addr ffff8881094223f8 by task stress/7789 CPU: 0 PID: 7789 Comm: stress Not tainted 6.0.0-rc1-00002-g0d53d2e882f9 #3 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 Call Trace: <TASK> .. __mutex_lock+0xe5/0xc30 .. z_erofs_do_read_page+0x8ce/0x1560 .. z_erofs_readahead+0x31c/0x580 .. Freed by task 7787 kasan_save_stack+0x1e/0x40 kasan_set_track+0x20/0x30 kasan_set_free_info+0x20/0x40 __kasan_slab_free+0x10c/0x190 kmem_cache_free+0xed/0x380 rcu_core+0x3d5/0xc90 __do_softirq+0x12d/0x389 Last potentially related work creation: kasan_save_stack+0x1e/0x40 __kasan_record_aux_stack+0x97/0xb0 call_rcu+0x3d/0x3f0 erofs_shrink_workstation+0x11f/0x210 erofs_shrink_scan+0xdc/0x170 shrink_slab.constprop.0+0x296/0x530 drop_slab+0x1c/0x70 drop_caches_sysctl_handler+0x70/0x80 proc_sys_call_handler+0x20a/0x2f0 vfs_write+0x555/0x6c0 ksys_write+0xbe/0x160 do_syscall_64+0x3b/0x90 The root cause is that erofs_workgroup_unfreeze() doesn't reset to orig_val thus it causes a race that the pcluster reuses unexpectedly before freeing. Since UP platforms are quite rare now, such path becomes unnecessary. Let's drop such specific-designed path directly instead.

In the Linux kernel, the following vulnerability has been resolved: net: dsa: lantiq_gswip: fix use after free in gswip_remove() of_node_put(priv->ds->slave_mii_bus->dev.of_node) should be done before mdiobus_free(priv->ds->slave_mii_bus).

In the Linux kernel, the following vulnerability has been resolved: peci: cpu: Fix use-after-free in adev_release() When auxiliary_device_add() returns an error, auxiliary_device_uninit() is called, which causes refcount for device to be decremented and .release callback will be triggered. Because adev_release() re-calls auxiliary_device_uninit(), it will cause use-after-free: [ 1269.455172] WARNING: CPU: 0 PID: 14267 at lib/refcount.c:28 refcount_warn_saturate+0x110/0x15 [ 1269.464007] refcount_t: underflow; use-after-free.

In the Linux kernel, the following vulnerability has been resolved: net: arc_emac: Fix use after free in arc_mdio_probe() If bus->state is equal to MDIOBUS_ALLOCATED, mdiobus_free(bus) will free the "bus". But bus->name is still used in the next line, which will lead to a use after free. We can fix it by putting the name in a local variable and make the bus->name point to the rodata section "name",then use the name in the error message without referring to bus to avoid the uaf.

In the Linux kernel, the following vulnerability has been resolved: moxart: fix potential use-after-free on remove path It was reported that the mmc host structure could be accessed after it was freed in moxart_remove(), so fix this by saving the base register of the device and using it instead of the pointer dereference.

There is a use-after-free vulnerability in the Linux Kernel which can be exploited to achieve local privilege escalation. To reach the vulnerability kernel configuration flag CONFIG_TLS or CONFIG_XFRM_ESPINTCP has to be configured, but the operation does not require any privilege. There is a use-after-free bug of icsk_ulp_data of a struct inet_connection_sock. When CONFIG_TLS is enabled, user can install a tls context (struct tls_context) on a connected tcp socket. The context is not cleared if this socket is disconnected and reused as a listener. If a new socket is created from the listener, the context is inherited and vulnerable. The setsockopt TCP_ULP operation does not require any privilege. We recommend upgrading past commit 2c02d41d71f90a5168391b6a5f2954112ba2307c

In the Linux kernel, the following vulnerability has been resolved: hrtimers: Handle CPU state correctly on hotplug Consider a scenario where a CPU transitions from CPUHP_ONLINE to halfway through a CPU hotunplug down to CPUHP_HRTIMERS_PREPARE, and then back to CPUHP_ONLINE: Since hrtimers_prepare_cpu() does not run, cpu_base.hres_active remains set to 1 throughout. However, during a CPU unplug operation, the tick and the clockevents are shut down at CPUHP_AP_TICK_DYING. On return to the online state, for instance CFS incorrectly assumes that the hrtick is already active, and the chance of the clockevent device to transition to oneshot mode is also lost forever for the CPU, unless it goes back to a lower state than CPUHP_HRTIMERS_PREPARE once. This round-trip reveals another issue; cpu_base.online is not set to 1 after the transition, which appears as a WARN_ON_ONCE in enqueue_hrtimer(). Aside of that, the bulk of the per CPU state is not reset either, which means there are dangling pointers in the worst case. Address this by adding a corresponding startup() callback, which resets the stale per CPU state and sets the online flag. [ tglx: Make the new callback unconditionally available, remove the online modification in the prepare() callback and clear the remaining state in the starting callback instead of the prepare callback ]

In the Linux kernel, the following vulnerability has been resolved: nvme-tcp: fix UAF when detecting digest errors We should also bail from the io_work loop when we set rd_enabled to true, so we don't attempt to read data from the socket when the TCP stream is already out-of-sync or corrupted.

In the Linux kernel, the following vulnerability has been resolved: nvme-tcp: fix possible use-after-free in transport error_recovery work While nvme_tcp_submit_async_event_work is checking the ctrl and queue state before preparing the AER command and scheduling io_work, in order to fully prevent a race where this check is not reliable the error recovery work must flush async_event_work before continuing to destroy the admin queue after setting the ctrl state to RESETTING such that there is no race .submit_async_event and the error recovery handler itself changing the ctrl state.

In the Linux kernel, the following vulnerability has been resolved: HSI: ssi_protocol: Fix use after free vulnerability in ssi_protocol Driver Due to Race Condition In the ssi_protocol_probe() function, &ssi->work is bound with ssip_xmit_work(), In ssip_pn_setup(), the ssip_pn_xmit() function within the ssip_pn_ops structure is capable of starting the work. If we remove the module which will call ssi_protocol_remove() to make a cleanup, it will free ssi through kfree(ssi), while the work mentioned above will be used. The sequence of operations that may lead to a UAF bug is as follows: CPU0 CPU1 | ssip_xmit_work ssi_protocol_remove | kfree(ssi); | | struct hsi_client *cl = ssi->cl; | // use ssi Fix it by ensuring that the work is canceled before proceeding with the cleanup in ssi_protocol_remove().

In the Linux kernel, the following vulnerability has been resolved: scsi: mpt3sas: Fix use-after-free warning Fix the following use-after-free warning which is observed during controller reset: refcount_t: underflow; use-after-free. WARNING: CPU: 23 PID: 5399 at lib/refcount.c:28 refcount_warn_saturate+0xa6/0xf0

In the Linux kernel, the following vulnerability has been resolved: net/smc: fix LGR and link use-after-free issue We encountered a LGR/link use-after-free issue, which manifested as the LGR/link refcnt reaching 0 early and entering the clear process, making resource access unsafe. refcount_t: addition on 0; use-after-free. WARNING: CPU: 14 PID: 107447 at lib/refcount.c:25 refcount_warn_saturate+0x9c/0x140 Workqueue: events smc_lgr_terminate_work [smc] Call trace: refcount_warn_saturate+0x9c/0x140 __smc_lgr_terminate.part.45+0x2a8/0x370 [smc] smc_lgr_terminate_work+0x28/0x30 [smc] process_one_work+0x1b8/0x420 worker_thread+0x158/0x510 kthread+0x114/0x118 or refcount_t: underflow; use-after-free. WARNING: CPU: 6 PID: 93140 at lib/refcount.c:28 refcount_warn_saturate+0xf0/0x140 Workqueue: smc_hs_wq smc_listen_work [smc] Call trace: refcount_warn_saturate+0xf0/0x140 smcr_link_put+0x1cc/0x1d8 [smc] smc_conn_free+0x110/0x1b0 [smc] smc_conn_abort+0x50/0x60 [smc] smc_listen_find_device+0x75c/0x790 [smc] smc_listen_work+0x368/0x8a0 [smc] process_one_work+0x1b8/0x420 worker_thread+0x158/0x510 kthread+0x114/0x118 It is caused by repeated release of LGR/link refcnt. One suspect is that smc_conn_free() is called repeatedly because some smc_conn_free() from server listening path are not protected by sock lock. e.g. Calls under socklock | smc_listen_work ------------------------------------------------------- lock_sock(sk) | smc_conn_abort smc_conn_free | \- smc_conn_free \- smcr_link_put | \- smcr_link_put (duplicated) release_sock(sk) So here add sock lock protection in smc_listen_work() path, making it exclusive with other connection operations.

A use-after-free vulnerability in the Linux Kernel Performance Events system can be exploited to achieve local privilege escalation. The perf_group_detach function did not check the event's siblings' attach_state before calling add_event_to_groups(), but remove_on_exec made it possible to call list_del_event() on before detaching from their group, making it possible to use a dangling pointer causing a use-after-free vulnerability. We recommend upgrading past commit fd0815f632c24878e325821943edccc7fde947a2.

The block subsystem in the Linux kernel before 5.2 has a use-after-free that can lead to arbitrary code execution in the kernel context and privilege escalation, aka CID-c3e2219216c9. This is related to blk_mq_free_rqs and blk_cleanup_queue.

An issue was discovered in the Linux kernel before 5.0.19. The XFRM subsystem has a use-after-free, related to an xfrm_state_fini panic, aka CID-dbb2483b2a46.

A use-after-free vulnerability in the Linux Kernel io_uring subsystem can be exploited to achieve local privilege escalation. Both io_install_fixed_file and its callers call fput in a file in case of an error, causing a reference underflow which leads to a use-after-free vulnerability. We recommend upgrading past commit 9d94c04c0db024922e886c9fd429659f22f48ea4.

In the Linux kernel, the following vulnerability has been resolved: srcu: Tighten cleanup_srcu_struct() GP checks Currently, cleanup_srcu_struct() checks for a grace period in progress, but it does not check for a grace period that has not yet started but which might start at any time. Such a situation could result in a use-after-free bug, so this commit adds a check for a grace period that is needed but not yet started to cleanup_srcu_struct().

A use-after-free vulnerability in the Linux Kernel io_uring system can be exploited to achieve local privilege escalation. The io_file_get_fixed function lacks the presence of ctx->uring_lock which can lead to a Use-After-Free vulnerability due a race condition with fixed files getting unregistered. We recommend upgrading past commit da24142b1ef9fd5d36b76e36bab328a5b27523e8.

A use-after-free flaw was found in the Linux kernel’s Ext4 File System in how a user triggers several file operations simultaneously with the overlay FS usage. This flaw allows a local user to crash or potentially escalate their privileges on the system. Only if patch 9a2544037600 ("ovl: fix use after free in struct ovl_aio_req") not applied yet, the kernel could be affected.

In the Linux kernel, the following vulnerability has been resolved: RDMA/mlx5: Fix implicit ODP use after free Prevent double queueing of implicit ODP mr destroy work by using __xa_cmpxchg() to make sure this is the only time we are destroying this specific mr. Without this change, we could try to invalidate this mr twice, which in turn could result in queuing a MR work destroy twice, and eventually the second work could execute after the MR was freed due to the first work, causing a user after free and trace below. refcount_t: underflow; use-after-free. WARNING: CPU: 2 PID: 12178 at lib/refcount.c:28 refcount_warn_saturate+0x12b/0x130 Modules linked in: bonding ib_ipoib vfio_pci ip_gre geneve nf_tables ip6_gre gre ip6_tunnel tunnel6 ipip tunnel4 ib_umad rdma_ucm mlx5_vfio_pci vfio_pci_core vfio_iommu_type1 mlx5_ib vfio ib_uverbs mlx5_core iptable_raw openvswitch nsh rpcrdma ib_iser libiscsi scsi_transport_iscsi rdma_cm iw_cm ib_cm ib_core xt_conntrack xt_MASQUERADE nf_conntrack_netlink nfnetlink xt_addrtype iptable_nat nf_nat br_netfilter rpcsec_gss_krb5 auth_rpcgss oid_registry overlay zram zsmalloc fuse [last unloaded: ib_uverbs] CPU: 2 PID: 12178 Comm: kworker/u20:5 Not tainted 6.5.0-rc1_net_next_mlx5_58c644e #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Workqueue: events_unbound free_implicit_child_mr_work [mlx5_ib] RIP: 0010:refcount_warn_saturate+0x12b/0x130 Code: 48 c7 c7 38 95 2a 82 c6 05 bc c6 fe 00 01 e8 0c 66 aa ff 0f 0b 5b c3 48 c7 c7 e0 94 2a 82 c6 05 a7 c6 fe 00 01 e8 f5 65 aa ff <0f> 0b 5b c3 90 8b 07 3d 00 00 00 c0 74 12 83 f8 01 74 13 8d 50 ff RSP: 0018:ffff8881008e3e40 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000027 RDX: ffff88852c91b5c8 RSI: 0000000000000001 RDI: ffff88852c91b5c0 RBP: ffff8881dacd4e00 R08: 00000000ffffffff R09: 0000000000000019 R10: 000000000000072e R11: 0000000063666572 R12: ffff88812bfd9e00 R13: ffff8881c792d200 R14: ffff88810011c005 R15: ffff8881002099c0 FS: 0000000000000000(0000) GS:ffff88852c900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5694b5e000 CR3: 00000001153f6003 CR4: 0000000000370ea0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? refcount_warn_saturate+0x12b/0x130 free_implicit_child_mr_work+0x180/0x1b0 [mlx5_ib] process_one_work+0x1cc/0x3c0 worker_thread+0x218/0x3c0 kthread+0xc6/0xf0 ret_from_fork+0x1f/0x30 </TASK>

In the Linux kernel, the following vulnerability has been resolved: ftrace: Fix use-after-free for dynamic ftrace_ops KASAN reported a use-after-free with ftrace ops [1]. It was found from vmcore that perf had registered two ops with the same content successively, both dynamic. After unregistering the second ops, a use-after-free occurred. In ftrace_shutdown(), when the second ops is unregistered, the FTRACE_UPDATE_CALLS command is not set because there is another enabled ops with the same content. Also, both ops are dynamic and the ftrace callback function is ftrace_ops_list_func, so the FTRACE_UPDATE_TRACE_FUNC command will not be set. Eventually the value of 'command' will be 0 and ftrace_shutdown() will skip the rcu synchronization. However, ftrace may be activated. When the ops is released, another CPU may be accessing the ops. Add the missing synchronization to fix this problem. [1] BUG: KASAN: use-after-free in __ftrace_ops_list_func kernel/trace/ftrace.c:7020 [inline] BUG: KASAN: use-after-free in ftrace_ops_list_func+0x2b0/0x31c kernel/trace/ftrace.c:7049 Read of size 8 at addr ffff56551965bbc8 by task syz-executor.2/14468 CPU: 1 PID: 14468 Comm: syz-executor.2 Not tainted 5.10.0 #7 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x40c arch/arm64/kernel/stacktrace.c:132 show_stack+0x30/0x40 arch/arm64/kernel/stacktrace.c:196 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b4/0x248 lib/dump_stack.c:118 print_address_description.constprop.0+0x28/0x48c mm/kasan/report.c:387 __kasan_report mm/kasan/report.c:547 [inline] kasan_report+0x118/0x210 mm/kasan/report.c:564 check_memory_region_inline mm/kasan/generic.c:187 [inline] __asan_load8+0x98/0xc0 mm/kasan/generic.c:253 __ftrace_ops_list_func kernel/trace/ftrace.c:7020 [inline] ftrace_ops_list_func+0x2b0/0x31c kernel/trace/ftrace.c:7049 ftrace_graph_call+0x0/0x4 __might_sleep+0x8/0x100 include/linux/perf_event.h:1170 __might_fault mm/memory.c:5183 [inline] __might_fault+0x58/0x70 mm/memory.c:5171 do_strncpy_from_user lib/strncpy_from_user.c:41 [inline] strncpy_from_user+0x1f4/0x4b0 lib/strncpy_from_user.c:139 getname_flags+0xb0/0x31c fs/namei.c:149 getname+0x2c/0x40 fs/namei.c:209 [...] Allocated by task 14445: kasan_save_stack+0x24/0x50 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc mm/kasan/common.c:479 [inline] __kasan_kmalloc.constprop.0+0x110/0x13c mm/kasan/common.c:449 kasan_kmalloc+0xc/0x14 mm/kasan/common.c:493 kmem_cache_alloc_trace+0x440/0x924 mm/slub.c:2950 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:675 [inline] perf_event_alloc.part.0+0xb4/0x1350 kernel/events/core.c:11230 perf_event_alloc kernel/events/core.c:11733 [inline] __do_sys_perf_event_open kernel/events/core.c:11831 [inline] __se_sys_perf_event_open+0x550/0x15f4 kernel/events/core.c:11723 __arm64_sys_perf_event_open+0x6c/0x80 kernel/events/core.c:11723 [...] Freed by task 14445: kasan_save_stack+0x24/0x50 mm/kasan/common.c:48 kasan_set_track+0x24/0x34 mm/kasan/common.c:56 kasan_set_free_info+0x20/0x40 mm/kasan/generic.c:358 __kasan_slab_free.part.0+0x11c/0x1b0 mm/kasan/common.c:437 __kasan_slab_free mm/kasan/common.c:445 [inline] kasan_slab_free+0x2c/0x40 mm/kasan/common.c:446 slab_free_hook mm/slub.c:1569 [inline] slab_free_freelist_hook mm/slub.c:1608 [inline] slab_free mm/slub.c:3179 [inline] kfree+0x12c/0xc10 mm/slub.c:4176 perf_event_alloc.part.0+0xa0c/0x1350 kernel/events/core.c:11434 perf_event_alloc kernel/events/core.c:11733 [inline] __do_sys_perf_event_open kernel/events/core.c:11831 [inline] __se_sys_perf_event_open+0x550/0x15f4 kernel/events/core.c:11723 [...]

In the Linux kernel, the following vulnerability has been resolved: net: do not leave a dangling sk pointer, when socket creation fails It is possible to trigger a use-after-free by: * attaching an fentry probe to __sock_release() and the probe calling the bpf_get_socket_cookie() helper * running traceroute -I 1.1.1.1 on a freshly booted VM A KASAN enabled kernel will log something like below (decoded and stripped): ================================================================== BUG: KASAN: slab-use-after-free in __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29) Read of size 8 at addr ffff888007110dd8 by task traceroute/299 CPU: 2 PID: 299 Comm: traceroute Tainted: G E 6.10.0-rc2+ #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:117 (discriminator 1)) print_report (mm/kasan/report.c:378 mm/kasan/report.c:488) ? __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29) kasan_report (mm/kasan/report.c:603) ? __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29) kasan_check_range (mm/kasan/generic.c:183 mm/kasan/generic.c:189) __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29) bpf_get_socket_ptr_cookie (./arch/x86/include/asm/preempt.h:94 ./include/linux/sock_diag.h:42 net/core/filter.c:5094 net/core/filter.c:5092) bpf_prog_875642cf11f1d139___sock_release+0x6e/0x8e bpf_trampoline_6442506592+0x47/0xaf __sock_release (net/socket.c:652) __sock_create (net/socket.c:1601) ... Allocated by task 299 on cpu 2 at 78.328492s: kasan_save_stack (mm/kasan/common.c:48) kasan_save_track (mm/kasan/common.c:68) __kasan_slab_alloc (mm/kasan/common.c:312 mm/kasan/common.c:338) kmem_cache_alloc_noprof (mm/slub.c:3941 mm/slub.c:4000 mm/slub.c:4007) sk_prot_alloc (net/core/sock.c:2075) sk_alloc (net/core/sock.c:2134) inet_create (net/ipv4/af_inet.c:327 net/ipv4/af_inet.c:252) __sock_create (net/socket.c:1572) __sys_socket (net/socket.c:1660 net/socket.c:1644 net/socket.c:1706) __x64_sys_socket (net/socket.c:1718) do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Freed by task 299 on cpu 2 at 78.328502s: kasan_save_stack (mm/kasan/common.c:48) kasan_save_track (mm/kasan/common.c:68) kasan_save_free_info (mm/kasan/generic.c:582) poison_slab_object (mm/kasan/common.c:242) __kasan_slab_free (mm/kasan/common.c:256) kmem_cache_free (mm/slub.c:4437 mm/slub.c:4511) __sk_destruct (net/core/sock.c:2117 net/core/sock.c:2208) inet_create (net/ipv4/af_inet.c:397 net/ipv4/af_inet.c:252) __sock_create (net/socket.c:1572) __sys_socket (net/socket.c:1660 net/socket.c:1644 net/socket.c:1706) __x64_sys_socket (net/socket.c:1718) do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Fix this by clearing the struct socket reference in sk_common_release() to cover all protocol families create functions, which may already attached the reference to the sk object with sock_init_data().

There is a logic error in io_uring's implementation which can be used to trigger a use-after-free vulnerability leading to privilege escalation. In the io_prep_async_work function the assumption that the last io_grab_identity call cannot return false is not true, and in this case the function will use the init_cred or the previous linked requests identity to do operations instead of using the current identity. This can lead to reference counting issues causing use-after-free. We recommend upgrading past version 5.10.161.

A double-free flaw was found in the Linux kernel’s TUN/TAP device driver functionality in how a user registers the device when the register_netdevice function fails (NETDEV_REGISTER notifier). This flaw allows a local user to crash or potentially escalate their privileges on the system.

A flaw was found in the Nosy driver in the Linux kernel. This issue allows a device to be inserted twice into a doubly-linked list, leading to a use-after-free when one of these devices is removed. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability. Versions before kernel 5.12-rc6 are affected

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix UAF due to race between btf_try_get_module and load_module While working on code to populate kfunc BTF ID sets for module BTF from its initcall, I noticed that by the time the initcall is invoked, the module BTF can already be seen by userspace (and the BPF verifier). The existing btf_try_get_module calls try_module_get which only fails if mod->state == MODULE_STATE_GOING, i.e. it can increment module reference when module initcall is happening in parallel. Currently, BTF parsing happens from MODULE_STATE_COMING notifier callback. At this point, the module initcalls have not been invoked. The notifier callback parses and prepares the module BTF, allocates an ID, which publishes it to userspace, and then adds it to the btf_modules list allowing the kernel to invoke btf_try_get_module for the BTF. However, at this point, the module has not been fully initialized (i.e. its initcalls have not finished). The code in module.c can still fail and free the module, without caring for other users. However, nothing stops btf_try_get_module from succeeding between the state transition from MODULE_STATE_COMING to MODULE_STATE_LIVE. This leads to a use-after-free issue when BPF program loads successfully in the state transition, load_module's do_init_module call fails and frees the module, and BPF program fd on close calls module_put for the freed module. Future patch has test case to verify we don't regress in this area in future. There are multiple points after prepare_coming_module (in load_module) where failure can occur and module loading can return error. We illustrate and test for the race using the last point where it can practically occur (in module __init function). An illustration of the race: CPU 0 CPU 1 load_module notifier_call(MODULE_STATE_COMING) btf_parse_module btf_alloc_id // Published to userspace list_add(&btf_mod->list, btf_modules) mod->init(...) ... ^ bpf_check | check_pseudo_btf_id | btf_try_get_module | returns true | ... ... | module __init in progress return prog_fd | ... ... V if (ret < 0) free_module(mod) ... close(prog_fd) ... bpf_prog_free_deferred module_put(used_btf.mod) // use-after-free We fix this issue by setting a flag BTF_MODULE_F_LIVE, from the notifier callback when MODULE_STATE_LIVE state is reached for the module, so that we return NULL from btf_try_get_module for modules that are not fully formed. Since try_module_get already checks that module is not in MODULE_STATE_GOING state, and that is the only transition a live module can make before being removed from btf_modules list, this is enough to close the race and prevent the bug. A later selftest patch crafts the race condition artifically to verify that it has been fixed, and that verifier fails to load program (with ENXIO). Lastly, a couple of comments: 1. Even if this race didn't exist, it seems more appropriate to only access resources (ksyms and kfuncs) of a fully formed module which has been initialized completely. 2. This patch was born out of need for synchronization against module initcall for the next patch, so it is needed for correctness even without the aforementioned race condition. The BTF resources initialized by module initcall are set up once and then only looked up, so just waiting until the initcall has finished ensures correct behavior.

In the Linux kernel, the following vulnerability has been resolved: btrfs: do not clean up repair bio if submit fails The submit helper will always run bio_endio() on the bio if it fails to submit, so cleaning up the bio just leads to a variety of use-after-free and NULL pointer dereference bugs because we race with the endio function that is cleaning up the bio. Instead just return BLK_STS_OK as the repair function has to continue to process the rest of the pages, and the endio for the repair bio will do the appropriate cleanup for the page that it was given.

In the Linux kernel, the following vulnerability has been resolved: ext4: fix use-after-free in ext4_rename_dir_prepare We got issue as follows: EXT4-fs (loop0): mounted filesystem without journal. Opts: ,errors=continue ext4_get_first_dir_block: bh->b_data=0xffff88810bee6000 len=34478 ext4_get_first_dir_block: *parent_de=0xffff88810beee6ae bh->b_data=0xffff88810bee6000 ext4_rename_dir_prepare: [1] parent_de=0xffff88810beee6ae ================================================================== BUG: KASAN: use-after-free in ext4_rename_dir_prepare+0x152/0x220 Read of size 4 at addr ffff88810beee6ae by task rep/1895 CPU: 13 PID: 1895 Comm: rep Not tainted 5.10.0+ #241 Call Trace: dump_stack+0xbe/0xf9 print_address_description.constprop.0+0x1e/0x220 kasan_report.cold+0x37/0x7f ext4_rename_dir_prepare+0x152/0x220 ext4_rename+0xf44/0x1ad0 ext4_rename2+0x11c/0x170 vfs_rename+0xa84/0x1440 do_renameat2+0x683/0x8f0 __x64_sys_renameat+0x53/0x60 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f45a6fc41c9 RSP: 002b:00007ffc5a470218 EFLAGS: 00000246 ORIG_RAX: 0000000000000108 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f45a6fc41c9 RDX: 0000000000000005 RSI: 0000000020000180 RDI: 0000000000000005 RBP: 00007ffc5a470240 R08: 00007ffc5a470160 R09: 0000000020000080 R10: 00000000200001c0 R11: 0000000000000246 R12: 0000000000400bb0 R13: 00007ffc5a470320 R14: 0000000000000000 R15: 0000000000000000 The buggy address belongs to the page: page:00000000440015ce refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x10beee flags: 0x200000000000000() raw: 0200000000000000 ffffea00043ff4c8 ffffea0004325608 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88810beee580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88810beee600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88810beee680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88810beee700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88810beee780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== Disabling lock debugging due to kernel taint ext4_rename_dir_prepare: [2] parent_de->inode=3537895424 ext4_rename_dir_prepare: [3] dir=0xffff888124170140 ext4_rename_dir_prepare: [4] ino=2 ext4_rename_dir_prepare: ent->dir->i_ino=2 parent=-757071872 Reason is first directory entry which 'rec_len' is 34478, then will get illegal parent entry. Now, we do not check directory entry after read directory block in 'ext4_get_first_dir_block'. To solve this issue, check directory entry in 'ext4_get_first_dir_block'. [ Trigger an ext4_error() instead of just warning if the directory is missing a '.' or '..' entry. Also make sure we return an error code if the file system is corrupted. -TYT ]

In the Linux kernel, the following vulnerability has been resolved: scsi: lpfc: Resolve NULL ptr dereference after an ELS LOGO is aborted A use-after-free crash can occur after an ELS LOGO is aborted. Specifically, a nodelist structure is freed and then ndlp->vport->cfg_log_verbose is dereferenced in lpfc_nlp_get() when the discovery state machine is mistakenly called a second time with NLP_EVT_DEVICE_RM argument. Rework lpfc_cmpl_els_logo() to prevent the duplicate calls to release a nodelist structure.

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: fix dangling sco_conn and use-after-free in sco_sock_timeout Connecting the same socket twice consecutively in sco_sock_connect() could lead to a race condition where two sco_conn objects are created but only one is associated with the socket. If the socket is closed before the SCO connection is established, the timer associated with the dangling sco_conn object won't be canceled. As the sock object is being freed, the use-after-free problem happens when the timer callback function sco_sock_timeout() accesses the socket. Here's the call trace: dump_stack+0x107/0x163 ? refcount_inc+0x1c/ print_address_description.constprop.0+0x1c/0x47e ? refcount_inc+0x1c/0x7b kasan_report+0x13a/0x173 ? refcount_inc+0x1c/0x7b check_memory_region+0x132/0x139 refcount_inc+0x1c/0x7b sco_sock_timeout+0xb2/0x1ba process_one_work+0x739/0xbd1 ? cancel_delayed_work+0x13f/0x13f ? __raw_spin_lock_init+0xf0/0xf0 ? to_kthread+0x59/0x85 worker_thread+0x593/0x70e kthread+0x346/0x35a ? drain_workqueue+0x31a/0x31a ? kthread_bind+0x4b/0x4b ret_from_fork+0x1f/0x30

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_conn: Fix UAF in hci_enhanced_setup_sync This checks if the ACL connection remains valid as it could be destroyed while hci_enhanced_setup_sync is pending on cmd_sync leading to the following trace: BUG: KASAN: slab-use-after-free in hci_enhanced_setup_sync+0x91b/0xa60 Read of size 1 at addr ffff888002328ffd by task kworker/u5:2/37 CPU: 0 UID: 0 PID: 37 Comm: kworker/u5:2 Not tainted 6.11.0-rc6-01300-g810be445d8d6 #7099 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014 Workqueue: hci0 hci_cmd_sync_work Call Trace: <TASK> dump_stack_lvl+0x5d/0x80 ? hci_enhanced_setup_sync+0x91b/0xa60 print_report+0x152/0x4c0 ? hci_enhanced_setup_sync+0x91b/0xa60 ? __virt_addr_valid+0x1fa/0x420 ? hci_enhanced_setup_sync+0x91b/0xa60 kasan_report+0xda/0x1b0 ? hci_enhanced_setup_sync+0x91b/0xa60 hci_enhanced_setup_sync+0x91b/0xa60 ? __pfx_hci_enhanced_setup_sync+0x10/0x10 ? __pfx___mutex_lock+0x10/0x10 hci_cmd_sync_work+0x1c2/0x330 process_one_work+0x7d9/0x1360 ? __pfx_lock_acquire+0x10/0x10 ? __pfx_process_one_work+0x10/0x10 ? assign_work+0x167/0x240 worker_thread+0x5b7/0xf60 ? __kthread_parkme+0xac/0x1c0 ? __pfx_worker_thread+0x10/0x10 ? __pfx_worker_thread+0x10/0x10 kthread+0x293/0x360 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2f/0x70 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Allocated by task 34: kasan_save_stack+0x30/0x50 kasan_save_track+0x14/0x30 __kasan_kmalloc+0x8f/0xa0 __hci_conn_add+0x187/0x17d0 hci_connect_sco+0x2e1/0xb90 sco_sock_connect+0x2a2/0xb80 __sys_connect+0x227/0x2a0 __x64_sys_connect+0x6d/0xb0 do_syscall_64+0x71/0x140 entry_SYSCALL_64_after_hwframe+0x76/0x7e Freed by task 37: kasan_save_stack+0x30/0x50 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x101/0x160 kfree+0xd0/0x250 device_release+0x9a/0x210 kobject_put+0x151/0x280 hci_conn_del+0x448/0xbf0 hci_abort_conn_sync+0x46f/0x980 hci_cmd_sync_work+0x1c2/0x330 process_one_work+0x7d9/0x1360 worker_thread+0x5b7/0xf60 kthread+0x293/0x360 ret_from_fork+0x2f/0x70 ret_from_fork_asm+0x1a/0x30

There exists a use-after-free vulnerability in the Linux kernel through io_uring and the IORING_OP_SPLICE operation. If IORING_OP_SPLICE is missing the IO_WQ_WORK_FILES flag, which signals that the operation won't use current->nsproxy, so its reference counter is not increased. This assumption is not always true as calling io_splice on specific files will call the get_uts function which will use current->nsproxy leading to invalidly decreasing its reference counter later causing the use-after-free vulnerability. We recommend upgrading to version 5.10.160 or above

In the Linux kernel, the following vulnerability has been resolved: netfilter: Fix use-after-free in get_info() ip6table_nat module unload has refcnt warning for UAF. call trace is: WARNING: CPU: 1 PID: 379 at kernel/module/main.c:853 module_put+0x6f/0x80 Modules linked in: ip6table_nat(-) CPU: 1 UID: 0 PID: 379 Comm: ip6tables Not tainted 6.12.0-rc4-00047-gc2ee9f594da8-dirty #205 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:module_put+0x6f/0x80 Call Trace: <TASK> get_info+0x128/0x180 do_ip6t_get_ctl+0x6a/0x430 nf_getsockopt+0x46/0x80 ipv6_getsockopt+0xb9/0x100 rawv6_getsockopt+0x42/0x190 do_sock_getsockopt+0xaa/0x180 __sys_getsockopt+0x70/0xc0 __x64_sys_getsockopt+0x20/0x30 do_syscall_64+0xa2/0x1a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Concurrent execution of module unload and get_info() trigered the warning. The root cause is as follows: cpu0 cpu1 module_exit //mod->state = MODULE_STATE_GOING ip6table_nat_exit xt_unregister_template kfree(t) //removed from templ_list getinfo() t = xt_find_table_lock list_for_each_entry(tmpl, &xt_templates[af]...) if (strcmp(tmpl->name, name)) continue; //table not found try_module_get list_for_each_entry(t, &xt_net->tables[af]...) return t; //not get refcnt module_put(t->me) //uaf unregister_pernet_subsys //remove table from xt_net list While xt_table module was going away and has been removed from xt_templates list, we couldnt get refcnt of xt_table->me. Check module in xt_net->tables list re-traversal to fix it.