In the Linux kernel, the following vulnerability has been resolved: media: xc2028: avoid use-after-free in load_firmware_cb() syzkaller reported use-after-free in load_firmware_cb() [1]. The reason is because the module allocated a struct tuner in tuner_probe(), and then the module initialization failed, the struct tuner was released. A worker which created during module initialization accesses this struct tuner later, it caused use-after-free. The process is as follows: task-6504 worker_thread tuner_probe <= alloc dvb_frontend [2] ... request_firmware_nowait <= create a worker ... tuner_remove <= free dvb_frontend ... request_firmware_work_func <= the firmware is ready load_firmware_cb <= but now the dvb_frontend has been freed To fix the issue, check the dvd_frontend in load_firmware_cb(), if it is null, report a warning and just return. [1]: ================================================================== BUG: KASAN: use-after-free in load_firmware_cb+0x1310/0x17a0 Read of size 8 at addr ffff8000d7ca2308 by task kworker/2:3/6504 Call trace: load_firmware_cb+0x1310/0x17a0 request_firmware_work_func+0x128/0x220 process_one_work+0x770/0x1824 worker_thread+0x488/0xea0 kthread+0x300/0x430 ret_from_fork+0x10/0x20 Allocated by task 6504: kzalloc tuner_probe+0xb0/0x1430 i2c_device_probe+0x92c/0xaf0 really_probe+0x678/0xcd0 driver_probe_device+0x280/0x370 __device_attach_driver+0x220/0x330 bus_for_each_drv+0x134/0x1c0 __device_attach+0x1f4/0x410 device_initial_probe+0x20/0x30 bus_probe_device+0x184/0x200 device_add+0x924/0x12c0 device_register+0x24/0x30 i2c_new_device+0x4e0/0xc44 v4l2_i2c_new_subdev_board+0xbc/0x290 v4l2_i2c_new_subdev+0xc8/0x104 em28xx_v4l2_init+0x1dd0/0x3770 Freed by task 6504: kfree+0x238/0x4e4 tuner_remove+0x144/0x1c0 i2c_device_remove+0xc8/0x290 __device_release_driver+0x314/0x5fc device_release_driver+0x30/0x44 bus_remove_device+0x244/0x490 device_del+0x350/0x900 device_unregister+0x28/0xd0 i2c_unregister_device+0x174/0x1d0 v4l2_device_unregister+0x224/0x380 em28xx_v4l2_init+0x1d90/0x3770 The buggy address belongs to the object at ffff8000d7ca2000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 776 bytes inside of 2048-byte region [ffff8000d7ca2000, ffff8000d7ca2800) The buggy address belongs to the page: page:ffff7fe00035f280 count:1 mapcount:0 mapping:ffff8000c001f000 index:0x0 flags: 0x7ff800000000100(slab) raw: 07ff800000000100 ffff7fe00049d880 0000000300000003 ffff8000c001f000 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8000d7ca2200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8000d7ca2280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8000d7ca2300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8000d7ca2380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8000d7ca2400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== [2] Actually, it is allocated for struct tuner, and dvb_frontend is inside.

In the Linux kernel, the following vulnerability has been resolved: PCI/DPC: Fix use-after-free on concurrent DPC and hot-removal Keith reports a use-after-free when a DPC event occurs concurrently to hot-removal of the same portion of the hierarchy: The dpc_handler() awaits readiness of the secondary bus below the Downstream Port where the DPC event occurred. To do so, it polls the config space of the first child device on the secondary bus. If that child device is concurrently removed, accesses to its struct pci_dev cause the kernel to oops. That's because pci_bridge_wait_for_secondary_bus() neglects to hold a reference on the child device. Before v6.3, the function was only called on resume from system sleep or on runtime resume. Holding a reference wasn't necessary back then because the pciehp IRQ thread could never run concurrently. (On resume from system sleep, IRQs are not enabled until after the resume_noirq phase. And runtime resume is always awaited before a PCI device is removed.) However starting with v6.3, pci_bridge_wait_for_secondary_bus() is also called on a DPC event. Commit 53b54ad074de ("PCI/DPC: Await readiness of secondary bus after reset"), which introduced that, failed to appreciate that pci_bridge_wait_for_secondary_bus() now needs to hold a reference on the child device because dpc_handler() and pciehp may indeed run concurrently. The commit was backported to v5.10+ stable kernels, so that's the oldest one affected. Add the missing reference acquisition. Abridged stack trace: BUG: unable to handle page fault for address: 00000000091400c0 CPU: 15 PID: 2464 Comm: irq/53-pcie-dpc 6.9.0 RIP: pci_bus_read_config_dword+0x17/0x50 pci_dev_wait() pci_bridge_wait_for_secondary_bus() dpc_reset_link() pcie_do_recovery() dpc_handler()

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix extent map use-after-free when adding pages to compressed bio At add_ra_bio_pages() we are accessing the extent map to calculate 'add_size' after we dropped our reference on the extent map, resulting in a use-after-free. Fix this by computing 'add_size' before dropping our extent map reference.

In the Linux kernel, the following vulnerability has been resolved: net/iucv: fix use after free in iucv_sock_close() iucv_sever_path() is called from process context and from bh context. iucv->path is used as indicator whether somebody else is taking care of severing the path (or it is already removed / never existed). This needs to be done with atomic compare and swap, otherwise there is a small window where iucv_sock_close() will try to work with a path that has already been severed and freed by iucv_callback_connrej() called by iucv_tasklet_fn(). Example: [452744.123844] Call Trace: [452744.123845] ([<0000001e87f03880>] 0x1e87f03880) [452744.123966] [<00000000d593001e>] iucv_path_sever+0x96/0x138 [452744.124330] [<000003ff801ddbca>] iucv_sever_path+0xc2/0xd0 [af_iucv] [452744.124336] [<000003ff801e01b6>] iucv_sock_close+0xa6/0x310 [af_iucv] [452744.124341] [<000003ff801e08cc>] iucv_sock_release+0x3c/0xd0 [af_iucv] [452744.124345] [<00000000d574794e>] __sock_release+0x5e/0xe8 [452744.124815] [<00000000d5747a0c>] sock_close+0x34/0x48 [452744.124820] [<00000000d5421642>] __fput+0xba/0x268 [452744.124826] [<00000000d51b382c>] task_work_run+0xbc/0xf0 [452744.124832] [<00000000d5145710>] do_notify_resume+0x88/0x90 [452744.124841] [<00000000d5978096>] system_call+0xe2/0x2c8 [452744.125319] Last Breaking-Event-Address: [452744.125321] [<00000000d5930018>] iucv_path_sever+0x90/0x138 [452744.125324] [452744.125325] Kernel panic - not syncing: Fatal exception in interrupt Note that bh_lock_sock() is not serializing the tasklet context against process context, because the check for sock_owned_by_user() and corresponding handling is missing. Ideas for a future clean-up patch: A) Correct usage of bh_lock_sock() in tasklet context, as described in Re-enqueue, if needed. This may require adding return values to the tasklet functions and thus changes to all users of iucv. B) Change iucv tasklet into worker and use only lock_sock() in af_iucv.

In the Linux kernel, the following vulnerability has been resolved: net: txgbe: free isb resources at the right time When using MSI/INTx interrupt, the shared interrupts are still being handled in the device remove routine, before free IRQs. So isb memory is still read after it is freed. Thus move wx_free_isb_resources() from txgbe_close() to txgbe_remove(). And fix the improper isb free action in txgbe_open() error handling path.

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.

In the Linux kernel, the following vulnerability has been resolved: mISDN: Fix a use after free in hfcmulti_tx() Don't dereference *sp after calling dev_kfree_skb(*sp).

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().

In the Linux kernel, the following vulnerability has been resolved: cachefiles: Set object to close if ondemand_id < 0 in copen If copen is maliciously called in the user mode, it may delete the request corresponding to the random id. And the request may have not been read yet. Note that when the object is set to reopen, the open request will be done with the still reopen state in above case. As a result, the request corresponding to this object is always skipped in select_req function, so the read request is never completed and blocks other process. Fix this issue by simply set object to close if its id < 0 in copen.

In the Linux kernel, the following vulnerability has been resolved: cachefiles: cyclic allocation of msg_id to avoid reuse Reusing the msg_id after a maliciously completed reopen request may cause a read request to remain unprocessed and result in a hung, as shown below: t1 | t2 | t3 ------------------------------------------------- cachefiles_ondemand_select_req cachefiles_ondemand_object_is_close(A) cachefiles_ondemand_set_object_reopening(A) queue_work(fscache_object_wq, &info->work) ondemand_object_worker cachefiles_ondemand_init_object(A) cachefiles_ondemand_send_req(OPEN) // get msg_id 6 wait_for_completion(&req_A->done) cachefiles_ondemand_daemon_read // read msg_id 6 req_A cachefiles_ondemand_get_fd copy_to_user // Malicious completion msg_id 6 copen 6,-1 cachefiles_ondemand_copen complete(&req_A->done) // will not set the object to close // because ondemand_id && fd is valid. // ondemand_object_worker() is done // but the object is still reopening. // new open req_B cachefiles_ondemand_init_object(B) cachefiles_ondemand_send_req(OPEN) // reuse msg_id 6 process_open_req copen 6,A.size // The expected failed copen was executed successfully Expect copen to fail, and when it does, it closes fd, which sets the object to close, and then close triggers reopen again. However, due to msg_id reuse resulting in a successful copen, the anonymous fd is not closed until the daemon exits. Therefore read requests waiting for reopen to complete may trigger hung task. To avoid this issue, allocate the msg_id cyclically to avoid reusing the msg_id for a very short duration of time.

In the Linux kernel, the following vulnerability has been resolved: usb: typec: tcpm: fix use-after-free case in tcpm_register_source_caps There could be a potential use-after-free case in tcpm_register_source_caps(). This could happen when: * new (say invalid) source caps are advertised * the existing source caps are unregistered * tcpm_register_source_caps() returns with an error as usb_power_delivery_register_capabilities() fails This causes port->partner_source_caps to hold on to the now freed source caps. Reset port->partner_source_caps value to NULL after unregistering existing source caps.

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Disassociate vcpus from redistributor region on teardown When tearing down a redistributor region, make sure we don't have any dangling pointer to that region stored in a vcpu.

In the Linux kernel, the following vulnerability has been resolved: cachefiles: wait for ondemand_object_worker to finish when dropping object When queuing ondemand_object_worker() to re-open the object, cachefiles_object is not pinned. The cachefiles_object may be freed when the pending read request is completed intentionally and the related erofs is umounted. If ondemand_object_worker() runs after the object is freed, it will incur use-after-free problem as shown below. process A processs B process C process D cachefiles_ondemand_send_req() // send a read req X // wait for its completion // close ondemand fd cachefiles_ondemand_fd_release() // set object as CLOSE cachefiles_ondemand_daemon_read() // set object as REOPENING queue_work(fscache_wq, &info->ondemand_work) // close /dev/cachefiles cachefiles_daemon_release cachefiles_flush_reqs complete(&req->done) // read req X is completed // umount the erofs fs cachefiles_put_object() // object will be freed cachefiles_ondemand_deinit_obj_info() kmem_cache_free(object) // both info and object are freed ondemand_object_worker() When dropping an object, it is no longer necessary to reopen the object, so use cancel_work_sync() to cancel or wait for ondemand_object_worker() to finish.

In the Linux kernel, the following vulnerability has been resolved: xhci: Handle TD clearing for multiple streams case When multiple streams are in use, multiple TDs might be in flight when an endpoint is stopped. We need to issue a Set TR Dequeue Pointer for each, to ensure everything is reset properly and the caches cleared. Change the logic so that any N>1 TDs found active for different streams are deferred until after the first one is processed, calling xhci_invalidate_cancelled_tds() again from xhci_handle_cmd_set_deq() to queue another command until we are done with all of them. Also change the error/"should never happen" paths to ensure we at least clear any affected TDs, even if we can't issue a command to clear the hardware cache, and complain loudly with an xhci_warn() if this ever happens. This problem case dates back to commit e9df17eb1408 ("USB: xhci: Correct assumptions about number of rings per endpoint.") early on in the XHCI driver's life, when stream support was first added. It was then identified but not fixed nor made into a warning in commit 674f8438c121 ("xhci: split handling halted endpoints into two steps"), which added a FIXME comment for the problem case (without materially changing the behavior as far as I can tell, though the new logic made the problem more obvious). Then later, in commit 94f339147fc3 ("xhci: Fix failure to give back some cached cancelled URBs."), it was acknowledged again. [Mathias: commit 94f339147fc3 ("xhci: Fix failure to give back some cached cancelled URBs.") was a targeted regression fix to the previously mentioned patch. Users reported issues with usb stuck after unmounting/disconnecting UAS devices. This rolled back the TD clearing of multiple streams to its original state.] Apparently the commit author was aware of the problem (yet still chose to submit it): It was still mentioned as a FIXME, an xhci_dbg() was added to log the problem condition, and the remaining issue was mentioned in the commit description. The choice of making the log type xhci_dbg() for what is, at this point, a completely unhandled and known broken condition is puzzling and unfortunate, as it guarantees that no actual users would see the log in production, thereby making it nigh undebuggable (indeed, even if you turn on DEBUG, the message doesn't really hint at there being a problem at all). It took me *months* of random xHC crashes to finally find a reliable repro and be able to do a deep dive debug session, which could all have been avoided had this unhandled, broken condition been actually reported with a warning, as it should have been as a bug intentionally left in unfixed (never mind that it shouldn't have been left in at all). > Another fix to solve clearing the caches of all stream rings with > cancelled TDs is needed, but not as urgent. 3 years after that statement and 14 years after the original bug was introduced, I think it's finally time to fix it. And maybe next time let's not leave bugs unfixed (that are actually worse than the original bug), and let's actually get people to review kernel commits please. Fixes xHC crashes and IOMMU faults with UAS devices when handling errors/faults. Easiest repro is to use `hdparm` to mark an early sector (e.g. 1024) on a disk as bad, then `cat /dev/sdX > /dev/null` in a loop. At least in the case of JMicron controllers, the read errors end up having to cancel two TDs (for two queued requests to different streams) and the one that didn't get cleared properly ends up faulting the xHC entirely when it tries to access DMA pages that have since been unmapped, referred to by the stale TDs. This normally happens quickly (after two or three loops). After this fix, I left the `cat` in a loop running overnight and experienced no xHC failures, with all read errors recovered properly. Repro'd and tested on an Apple M1 Mac Mini (dwc3 host). On systems without an IOMMU, this bug would instead silently corrupt freed memory, making this a ---truncated---

In the Linux kernel, the following vulnerability has been resolved: ASoC: topology: Fix references to freed memory Most users after parsing a topology file, release memory used by it, so having pointer references directly into topology file contents is wrong. Use devm_kmemdup(), to allocate memory as needed.

In the Linux kernel, the following vulnerability has been resolved: net: bridge: mst: fix suspicious rcu usage in br_mst_set_state I converted br_mst_set_state to RCU to avoid a vlan use-after-free but forgot to change the vlan group dereference helper. Switch to vlan group RCU deref helper to fix the suspicious rcu usage warning.

In the Linux kernel, the following vulnerability has been resolved: block: avoid to reuse `hctx` not removed from cpuhp callback list If the 'hctx' isn't removed from cpuhp callback list, we can't reuse it, otherwise use-after-free may be triggered.

In the Linux kernel, the following vulnerability has been resolved: drm/i915/gt: Fix potential UAF by revoke of fence registers CI has been sporadically reporting the following issue triggered by igt@i915_selftest@live@hangcheck on ADL-P and similar machines: <6> [414.049203] i915: Running intel_hangcheck_live_selftests/igt_reset_evict_fence ... <6> [414.068804] i915 0000:00:02.0: [drm] GT0: GUC: submission enabled <6> [414.068812] i915 0000:00:02.0: [drm] GT0: GUC: SLPC enabled <3> [414.070354] Unable to pin Y-tiled fence; err:-4 <3> [414.071282] i915_vma_revoke_fence:301 GEM_BUG_ON(!i915_active_is_idle(&fence->active)) ... <4>[ 609.603992] ------------[ cut here ]------------ <2>[ 609.603995] kernel BUG at drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c:301! <4>[ 609.604003] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI <4>[ 609.604006] CPU: 0 PID: 268 Comm: kworker/u64:3 Tainted: G U W 6.9.0-CI_DRM_14785-g1ba62f8cea9c+ #1 <4>[ 609.604008] Hardware name: Intel Corporation Alder Lake Client Platform/AlderLake-P DDR4 RVP, BIOS RPLPFWI1.R00.4035.A00.2301200723 01/20/2023 <4>[ 609.604010] Workqueue: i915 __i915_gem_free_work [i915] <4>[ 609.604149] RIP: 0010:i915_vma_revoke_fence+0x187/0x1f0 [i915] ... <4>[ 609.604271] Call Trace: <4>[ 609.604273] <TASK> ... <4>[ 609.604716] __i915_vma_evict+0x2e9/0x550 [i915] <4>[ 609.604852] __i915_vma_unbind+0x7c/0x160 [i915] <4>[ 609.604977] force_unbind+0x24/0xa0 [i915] <4>[ 609.605098] i915_vma_destroy+0x2f/0xa0 [i915] <4>[ 609.605210] __i915_gem_object_pages_fini+0x51/0x2f0 [i915] <4>[ 609.605330] __i915_gem_free_objects.isra.0+0x6a/0xc0 [i915] <4>[ 609.605440] process_scheduled_works+0x351/0x690 ... In the past, there were similar failures reported by CI from other IGT tests, observed on other platforms. Before commit 63baf4f3d587 ("drm/i915/gt: Only wait for GPU activity before unbinding a GGTT fence"), i915_vma_revoke_fence() was waiting for idleness of vma->active via fence_update(). That commit introduced vma->fence->active in order for the fence_update() to be able to wait selectively on that one instead of vma->active since only idleness of fence registers was needed. But then, another commit 0d86ee35097a ("drm/i915/gt: Make fence revocation unequivocal") replaced the call to fence_update() in i915_vma_revoke_fence() with only fence_write(), and also added that GEM_BUG_ON(!i915_active_is_idle(&fence->active)) in front. No justification was provided on why we might then expect idleness of vma->fence->active without first waiting on it. The issue can be potentially caused by a race among revocation of fence registers on one side and sequential execution of signal callbacks invoked on completion of a request that was using them on the other, still processed in parallel to revocation of those fence registers. Fix it by waiting for idleness of vma->fence->active in i915_vma_revoke_fence(). (cherry picked from commit 24bb052d3dd499c5956abad5f7d8e4fd07da7fb1)

In the Linux kernel, the following vulnerability has been resolved: cachefiles: defer exposing anon_fd until after copy_to_user() succeeds After installing the anonymous fd, we can now see it in userland and close it. However, at this point we may not have gotten the reference count of the cache, but we will put it during colse fd, so this may cause a cache UAF. So grab the cache reference count before fd_install(). In addition, by kernel convention, fd is taken over by the user land after fd_install(), and the kernel should not call close_fd() after that, i.e., it should call fd_install() after everything is ready, thus fd_install() is called after copy_to_user() succeeds.

In the Linux kernel, the following vulnerability has been resolved: cachefiles: remove requests from xarray during flushing requests Even with CACHEFILES_DEAD set, we can still read the requests, so in the following concurrency the request may be used after it has been freed: mount | daemon_thread1 | daemon_thread2 ------------------------------------------------------------ cachefiles_ondemand_init_object cachefiles_ondemand_send_req REQ_A = kzalloc(sizeof(*req) + data_len) wait_for_completion(&REQ_A->done) cachefiles_daemon_read cachefiles_ondemand_daemon_read // close dev fd cachefiles_flush_reqs complete(&REQ_A->done) kfree(REQ_A) xa_lock(&cache->reqs); cachefiles_ondemand_select_req req->msg.opcode != CACHEFILES_OP_READ // req use-after-free !!! xa_unlock(&cache->reqs); xa_destroy(&cache->reqs) Hence remove requests from cache->reqs when flushing them to avoid accessing freed requests.

In the Linux kernel, the following vulnerability has been resolved: PCI/MSI: Fix UAF in msi_capability_init KFENCE reports the following UAF: BUG: KFENCE: use-after-free read in __pci_enable_msi_range+0x2c0/0x488 Use-after-free read at 0x0000000024629571 (in kfence-#12): __pci_enable_msi_range+0x2c0/0x488 pci_alloc_irq_vectors_affinity+0xec/0x14c pci_alloc_irq_vectors+0x18/0x28 kfence-#12: 0x0000000008614900-0x00000000e06c228d, size=104, cache=kmalloc-128 allocated by task 81 on cpu 7 at 10.808142s: __kmem_cache_alloc_node+0x1f0/0x2bc kmalloc_trace+0x44/0x138 msi_alloc_desc+0x3c/0x9c msi_domain_insert_msi_desc+0x30/0x78 msi_setup_msi_desc+0x13c/0x184 __pci_enable_msi_range+0x258/0x488 pci_alloc_irq_vectors_affinity+0xec/0x14c pci_alloc_irq_vectors+0x18/0x28 freed by task 81 on cpu 7 at 10.811436s: msi_domain_free_descs+0xd4/0x10c msi_domain_free_locked.part.0+0xc0/0x1d8 msi_domain_alloc_irqs_all_locked+0xb4/0xbc pci_msi_setup_msi_irqs+0x30/0x4c __pci_enable_msi_range+0x2a8/0x488 pci_alloc_irq_vectors_affinity+0xec/0x14c pci_alloc_irq_vectors+0x18/0x28 Descriptor allocation done in: __pci_enable_msi_range msi_capability_init msi_setup_msi_desc msi_insert_msi_desc msi_domain_insert_msi_desc msi_alloc_desc ... Freed in case of failure in __msi_domain_alloc_locked() __pci_enable_msi_range msi_capability_init pci_msi_setup_msi_irqs msi_domain_alloc_irqs_all_locked msi_domain_alloc_locked __msi_domain_alloc_locked => fails msi_domain_free_locked ... That failure propagates back to pci_msi_setup_msi_irqs() in msi_capability_init() which accesses the descriptor for unmasking in the error exit path. Cure it by copying the descriptor and using the copy for the error exit path unmask operation. [ tglx: Massaged change log ]

In the Linux kernel, the following vulnerability has been resolved: cachefiles: fix slab-use-after-free in fscache_withdraw_volume() We got the following issue in our fault injection stress test: ================================================================== BUG: KASAN: slab-use-after-free in fscache_withdraw_volume+0x2e1/0x370 Read of size 4 at addr ffff88810680be08 by task ondemand-04-dae/5798 CPU: 0 PID: 5798 Comm: ondemand-04-dae Not tainted 6.8.0-dirty #565 Call Trace: kasan_check_range+0xf6/0x1b0 fscache_withdraw_volume+0x2e1/0x370 cachefiles_withdraw_volume+0x31/0x50 cachefiles_withdraw_cache+0x3ad/0x900 cachefiles_put_unbind_pincount+0x1f6/0x250 cachefiles_daemon_release+0x13b/0x290 __fput+0x204/0xa00 task_work_run+0x139/0x230 Allocated by task 5820: __kmalloc+0x1df/0x4b0 fscache_alloc_volume+0x70/0x600 __fscache_acquire_volume+0x1c/0x610 erofs_fscache_register_volume+0x96/0x1a0 erofs_fscache_register_fs+0x49a/0x690 erofs_fc_fill_super+0x6c0/0xcc0 vfs_get_super+0xa9/0x140 vfs_get_tree+0x8e/0x300 do_new_mount+0x28c/0x580 [...] Freed by task 5820: kfree+0xf1/0x2c0 fscache_put_volume.part.0+0x5cb/0x9e0 erofs_fscache_unregister_fs+0x157/0x1b0 erofs_kill_sb+0xd9/0x1c0 deactivate_locked_super+0xa3/0x100 vfs_get_super+0x105/0x140 vfs_get_tree+0x8e/0x300 do_new_mount+0x28c/0x580 [...] ================================================================== Following is the process that triggers the issue: mount failed | daemon exit ------------------------------------------------------------ deactivate_locked_super cachefiles_daemon_release erofs_kill_sb erofs_fscache_unregister_fs fscache_relinquish_volume __fscache_relinquish_volume fscache_put_volume(fscache_volume, fscache_volume_put_relinquish) zero = __refcount_dec_and_test(&fscache_volume->ref, &ref); cachefiles_put_unbind_pincount cachefiles_daemon_unbind cachefiles_withdraw_cache cachefiles_withdraw_volumes list_del_init(&volume->cache_link) fscache_free_volume(fscache_volume) cache->ops->free_volume cachefiles_free_volume list_del_init(&cachefiles_volume->cache_link); kfree(fscache_volume) cachefiles_withdraw_volume fscache_withdraw_volume fscache_volume->n_accesses // fscache_volume UAF !!! The fscache_volume in cache->volumes must not have been freed yet, but its reference count may be 0. So use the new fscache_try_get_volume() helper function try to get its reference count. If the reference count of fscache_volume is 0, fscache_put_volume() is freeing it, so wait for it to be removed from cache->volumes. If its reference count is not 0, call cachefiles_withdraw_volume() with reference count protection to avoid the above issue.

In the Linux kernel, the following vulnerability has been resolved: cachefiles: flush all requests after setting CACHEFILES_DEAD In ondemand mode, when the daemon is processing an open request, if the kernel flags the cache as CACHEFILES_DEAD, the cachefiles_daemon_write() will always return -EIO, so the daemon can't pass the copen to the kernel. Then the kernel process that is waiting for the copen triggers a hung_task. Since the DEAD state is irreversible, it can only be exited by closing /dev/cachefiles. Therefore, after calling cachefiles_io_error() to mark the cache as CACHEFILES_DEAD, if in ondemand mode, flush all requests to avoid the above hungtask. We may still be able to read some of the cached data before closing the fd of /dev/cachefiles. Note that this relies on the patch that adds reference counting to the req, otherwise it may UAF.

In the Linux kernel, the following vulnerability has been resolved: ionic: fix use after netif_napi_del() When queues are started, netif_napi_add() and napi_enable() are called. If there are 4 queues and only 3 queues are used for the current configuration, only 3 queues' napi should be registered and enabled. The ionic_qcq_enable() checks whether the .poll pointer is not NULL for enabling only the using queue' napi. Unused queues' napi will not be registered by netif_napi_add(), so the .poll pointer indicates NULL. But it couldn't distinguish whether the napi was unregistered or not because netif_napi_del() doesn't reset the .poll pointer to NULL. So, ionic_qcq_enable() calls napi_enable() for the queue, which was unregistered by netif_napi_del(). Reproducer: ethtool -L <interface name> rx 1 tx 1 combined 0 ethtool -L <interface name> rx 0 tx 0 combined 1 ethtool -L <interface name> rx 0 tx 0 combined 4 Splat looks like: kernel BUG at net/core/dev.c:6666! Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 3 PID: 1057 Comm: kworker/3:3 Not tainted 6.10.0-rc2+ #16 Workqueue: events ionic_lif_deferred_work [ionic] RIP: 0010:napi_enable+0x3b/0x40 Code: 48 89 c2 48 83 e2 f6 80 b9 61 09 00 00 00 74 0d 48 83 bf 60 01 00 00 00 74 03 80 ce 01 f0 4f RSP: 0018:ffffb6ed83227d48 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff97560cda0828 RCX: 0000000000000029 RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff97560cda0a28 RBP: ffffb6ed83227d50 R08: 0000000000000400 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000 R13: ffff97560ce3c1a0 R14: 0000000000000000 R15: ffff975613ba0a20 FS: 0000000000000000(0000) GS:ffff975d5f780000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8f734ee200 CR3: 0000000103e50000 CR4: 00000000007506f0 PKRU: 55555554 Call Trace: <TASK> ? die+0x33/0x90 ? do_trap+0xd9/0x100 ? napi_enable+0x3b/0x40 ? do_error_trap+0x83/0xb0 ? napi_enable+0x3b/0x40 ? napi_enable+0x3b/0x40 ? exc_invalid_op+0x4e/0x70 ? napi_enable+0x3b/0x40 ? asm_exc_invalid_op+0x16/0x20 ? napi_enable+0x3b/0x40 ionic_qcq_enable+0xb7/0x180 [ionic 59bdfc8a035436e1c4224ff7d10789e3f14643f8] ionic_start_queues+0xc4/0x290 [ionic 59bdfc8a035436e1c4224ff7d10789e3f14643f8] ionic_link_status_check+0x11c/0x170 [ionic 59bdfc8a035436e1c4224ff7d10789e3f14643f8] ionic_lif_deferred_work+0x129/0x280 [ionic 59bdfc8a035436e1c4224ff7d10789e3f14643f8] process_one_work+0x145/0x360 worker_thread+0x2bb/0x3d0 ? __pfx_worker_thread+0x10/0x10 kthread+0xcc/0x100 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2d/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30

In the Linux kernel, the following vulnerability has been resolved: cachefiles: fix slab-use-after-free in cachefiles_ondemand_daemon_read() We got the following issue in a fuzz test of randomly issuing the restore command: ================================================================== BUG: KASAN: slab-use-after-free in cachefiles_ondemand_daemon_read+0xb41/0xb60 Read of size 8 at addr ffff888122e84088 by task ondemand-04-dae/963 CPU: 13 PID: 963 Comm: ondemand-04-dae Not tainted 6.8.0-dirty #564 Call Trace: kasan_report+0x93/0xc0 cachefiles_ondemand_daemon_read+0xb41/0xb60 vfs_read+0x169/0xb50 ksys_read+0xf5/0x1e0 Allocated by task 116: kmem_cache_alloc+0x140/0x3a0 cachefiles_lookup_cookie+0x140/0xcd0 fscache_cookie_state_machine+0x43c/0x1230 [...] Freed by task 792: kmem_cache_free+0xfe/0x390 cachefiles_put_object+0x241/0x480 fscache_cookie_state_machine+0x5c8/0x1230 [...] ================================================================== Following is the process that triggers the issue: mount | daemon_thread1 | daemon_thread2 ------------------------------------------------------------ cachefiles_withdraw_cookie cachefiles_ondemand_clean_object(object) cachefiles_ondemand_send_req REQ_A = kzalloc(sizeof(*req) + data_len) wait_for_completion(&REQ_A->done) cachefiles_daemon_read cachefiles_ondemand_daemon_read REQ_A = cachefiles_ondemand_select_req msg->object_id = req->object->ondemand->ondemand_id ------ restore ------ cachefiles_ondemand_restore xas_for_each(&xas, req, ULONG_MAX) xas_set_mark(&xas, CACHEFILES_REQ_NEW) cachefiles_daemon_read cachefiles_ondemand_daemon_read REQ_A = cachefiles_ondemand_select_req copy_to_user(_buffer, msg, n) xa_erase(&cache->reqs, id) complete(&REQ_A->done) ------ close(fd) ------ cachefiles_ondemand_fd_release cachefiles_put_object cachefiles_put_object kmem_cache_free(cachefiles_object_jar, object) REQ_A->object->ondemand->ondemand_id // object UAF !!! When we see the request within xa_lock, req->object must not have been freed yet, so grab the reference count of object before xa_unlock to avoid the above issue.

In the Linux kernel, the following vulnerability has been resolved: btrfs: zoned: fix use-after-free due to race with dev replace While loading a zone's info during creation of a block group, we can race with a device replace operation and then trigger a use-after-free on the device that was just replaced (source device of the replace operation). This happens because at btrfs_load_zone_info() we extract a device from the chunk map into a local variable and then use the device while not under the protection of the device replace rwsem. So if there's a device replace operation happening when we extract the device and that device is the source of the replace operation, we will trigger a use-after-free if before we finish using the device the replace operation finishes and frees the device. Fix this by enlarging the critical section under the protection of the device replace rwsem so that all uses of the device are done inside the critical section.

In the Linux kernel, the following vulnerability has been resolved: 9p: add missing locking around taking dentry fid list Fix a use-after-free on dentry's d_fsdata fid list when a thread looks up a fid through dentry while another thread unlinks it: UAF thread: refcount_t: addition on 0; use-after-free. p9_fid_get linux/./include/net/9p/client.h:262 v9fs_fid_find+0x236/0x280 linux/fs/9p/fid.c:129 v9fs_fid_lookup_with_uid linux/fs/9p/fid.c:181 v9fs_fid_lookup+0xbf/0xc20 linux/fs/9p/fid.c:314 v9fs_vfs_getattr_dotl+0xf9/0x360 linux/fs/9p/vfs_inode_dotl.c:400 vfs_statx+0xdd/0x4d0 linux/fs/stat.c:248 Freed by: p9_fid_destroy (inlined) p9_client_clunk+0xb0/0xe0 linux/net/9p/client.c:1456 p9_fid_put linux/./include/net/9p/client.h:278 v9fs_dentry_release+0xb5/0x140 linux/fs/9p/vfs_dentry.c:55 v9fs_remove+0x38f/0x620 linux/fs/9p/vfs_inode.c:518 vfs_unlink+0x29a/0x810 linux/fs/namei.c:4335 The problem is that d_fsdata was not accessed under d_lock, because d_release() normally is only called once the dentry is otherwise no longer accessible but since we also call it explicitly in v9fs_remove that lock is required: move the hlist out of the dentry under lock then unref its fids once they are no longer accessible.

In the Linux kernel, the following vulnerability has been resolved: RDMA/hns: Fix UAF for cq async event The refcount of CQ is not protected by locks. When CQ asynchronous events and CQ destruction are concurrent, CQ may have been released, which will cause UAF. Use the xa_lock() to protect the CQ refcount.

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix use-after-free of timer for log writer thread Patch series "nilfs2: fix log writer related issues". This bug fix series covers three nilfs2 log writer-related issues, including a timer use-after-free issue and potential deadlock issue on unmount, and a potential freeze issue in event synchronization found during their analysis. Details are described in each commit log. This patch (of 3): A use-after-free issue has been reported regarding the timer sc_timer on the nilfs_sc_info structure. The problem is that even though it is used to wake up a sleeping log writer thread, sc_timer is not shut down until the nilfs_sc_info structure is about to be freed, and is used regardless of the thread's lifetime. Fix this issue by limiting the use of sc_timer only while the log writer thread is alive.

In the Linux kernel, the following vulnerability has been resolved: net: fix __dst_negative_advice() race __dst_negative_advice() does not enforce proper RCU rules when sk->dst_cache must be cleared, leading to possible UAF. RCU rules are that we must first clear sk->sk_dst_cache, then call dst_release(old_dst). Note that sk_dst_reset(sk) is implementing this protocol correctly, while __dst_negative_advice() uses the wrong order. Given that ip6_negative_advice() has special logic against RTF_CACHE, this means each of the three ->negative_advice() existing methods must perform the sk_dst_reset() themselves. Note the check against NULL dst is centralized in __dst_negative_advice(), there is no need to duplicate it in various callbacks. Many thanks to Clement Lecigne for tracking this issue. This old bug became visible after the blamed commit, using UDP sockets.

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: check/clear fast rx for non-4addr sta VLAN changes When moving a station out of a VLAN and deleting the VLAN afterwards, the fast_rx entry still holds a pointer to the VLAN's netdev, which can cause use-after-free bugs. Fix this by immediately calling ieee80211_check_fast_rx after the VLAN change.

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix potential UAF in smb2_is_network_name_deleted() Skip sessions that are being teared down (status == SES_EXITING) to avoid UAF.

In the Linux kernel, the following vulnerability has been resolved: raid1: fix use-after-free for original bio in raid1_write_request() r1_bio->bios[] is used to record new bios that will be issued to underlying disks, however, in raid1_write_request(), r1_bio->bios[] will set to the original bio temporarily. Meanwhile, if blocked rdev is set, free_r1bio() will be called causing that all r1_bio->bios[] to be freed: raid1_write_request() r1_bio = alloc_r1bio(mddev, bio); -> r1_bio->bios[] is NULL for (i = 0; i < disks; i++) -> for each rdev in conf // first rdev is normal r1_bio->bios[0] = bio; -> set to original bio // second rdev is blocked if (test_bit(Blocked, &rdev->flags)) break if (blocked_rdev) free_r1bio() put_all_bios() bio_put(r1_bio->bios[0]) -> original bio is freed Test scripts: mdadm -CR /dev/md0 -l1 -n4 /dev/sd[abcd] --assume-clean fio -filename=/dev/md0 -ioengine=libaio -rw=write -bs=4k -numjobs=1 \ -iodepth=128 -name=test -direct=1 echo blocked > /sys/block/md0/md/rd2/state Test result: BUG bio-264 (Not tainted): Object already free ----------------------------------------------------------------------------- Allocated in mempool_alloc_slab+0x24/0x50 age=1 cpu=1 pid=869 kmem_cache_alloc+0x324/0x480 mempool_alloc_slab+0x24/0x50 mempool_alloc+0x6e/0x220 bio_alloc_bioset+0x1af/0x4d0 blkdev_direct_IO+0x164/0x8a0 blkdev_write_iter+0x309/0x440 aio_write+0x139/0x2f0 io_submit_one+0x5ca/0xb70 __do_sys_io_submit+0x86/0x270 __x64_sys_io_submit+0x22/0x30 do_syscall_64+0xb1/0x210 entry_SYSCALL_64_after_hwframe+0x6c/0x74 Freed in mempool_free_slab+0x1f/0x30 age=1 cpu=1 pid=869 kmem_cache_free+0x28c/0x550 mempool_free_slab+0x1f/0x30 mempool_free+0x40/0x100 bio_free+0x59/0x80 bio_put+0xf0/0x220 free_r1bio+0x74/0xb0 raid1_make_request+0xadf/0x1150 md_handle_request+0xc7/0x3b0 md_submit_bio+0x76/0x130 __submit_bio+0xd8/0x1d0 submit_bio_noacct_nocheck+0x1eb/0x5c0 submit_bio_noacct+0x169/0xd40 submit_bio+0xee/0x1d0 blkdev_direct_IO+0x322/0x8a0 blkdev_write_iter+0x309/0x440 aio_write+0x139/0x2f0 Since that bios for underlying disks are not allocated yet, fix this problem by using mempool_free() directly to free the r1_bio.

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix potential UAF in is_valid_oplock_break() Skip sessions that are being teared down (status == SES_EXITING) to avoid UAF.

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix potential UAF in cifs_dump_full_key() Skip sessions that are being teared down (status == SES_EXITING) to avoid UAF.

In the Linux kernel, the following vulnerability has been resolved: ax25: fix use-after-free bugs caused by ax25_ds_del_timer When the ax25 device is detaching, the ax25_dev_device_down() calls ax25_ds_del_timer() to cleanup the slave_timer. When the timer handler is running, the ax25_ds_del_timer() that calls del_timer() in it will return directly. As a result, the use-after-free bugs could happen, one of the scenarios is shown below: (Thread 1) | (Thread 2) | ax25_ds_timeout() ax25_dev_device_down() | ax25_ds_del_timer() | del_timer() | ax25_dev_put() //FREE | | ax25_dev-> //USE In order to mitigate bugs, when the device is detaching, use timer_shutdown_sync() to stop the timer.

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix potential UAF in cifs_signal_cifsd_for_reconnect() Skip sessions that are being teared down (status == SES_EXITING) to avoid UAF.

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix potential UAF in cifs_stats_proc_show() Skip sessions that are being teared down (status == SES_EXITING) to avoid UAF.

In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Flush pages under kvm->lock to fix UAF in svm_register_enc_region() Do the cache flush of converted pages in svm_register_enc_region() before dropping kvm->lock to fix use-after-free issues where region and/or its array of pages could be freed by a different task, e.g. if userspace has __unregister_enc_region_locked() already queued up for the region. Note, the "obvious" alternative of using local variables doesn't fully resolve the bug, as region->pages is also dynamically allocated. I.e. the region structure itself would be fine, but region->pages could be freed. Flushing multiple pages under kvm->lock is unfortunate, but the entire flow is a rare slow path, and the manual flush is only needed on CPUs that lack coherency for encrypted memory.

In the Linux kernel, the following vulnerability has been resolved: mlxsw: spectrum_acl_tcam: Fix possible use-after-free during activity update The rule activity update delayed work periodically traverses the list of configured rules and queries their activity from the device. As part of this task it accesses the entry pointed by 'ventry->entry', but this entry can be changed concurrently by the rehash delayed work, leading to a use-after-free [1]. Fix by closing the race and perform the activity query under the 'vregion->lock' mutex. [1] BUG: KASAN: slab-use-after-free in mlxsw_sp_acl_tcam_flower_rule_activity_get+0x121/0x140 Read of size 8 at addr ffff8881054ed808 by task kworker/0:18/181 CPU: 0 PID: 181 Comm: kworker/0:18 Not tainted 6.9.0-rc2-custom-00781-gd5ab772d32f7 #2 Hardware name: Mellanox Technologies Ltd. MSN3700/VMOD0005, BIOS 5.11 01/06/2019 Workqueue: mlxsw_core mlxsw_sp_acl_rule_activity_update_work Call Trace: <TASK> dump_stack_lvl+0xc6/0x120 print_report+0xce/0x670 kasan_report+0xd7/0x110 mlxsw_sp_acl_tcam_flower_rule_activity_get+0x121/0x140 mlxsw_sp_acl_rule_activity_update_work+0x219/0x400 process_one_work+0x8eb/0x19b0 worker_thread+0x6c9/0xf70 kthread+0x2c9/0x3b0 ret_from_fork+0x4d/0x80 ret_from_fork_asm+0x1a/0x30 </TASK> Allocated by task 1039: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 __kasan_kmalloc+0x8f/0xa0 __kmalloc+0x19c/0x360 mlxsw_sp_acl_tcam_entry_create+0x7b/0x1f0 mlxsw_sp_acl_tcam_vchunk_migrate_all+0x30d/0xb50 mlxsw_sp_acl_tcam_vregion_rehash_work+0x157/0x1300 process_one_work+0x8eb/0x19b0 worker_thread+0x6c9/0xf70 kthread+0x2c9/0x3b0 ret_from_fork+0x4d/0x80 ret_from_fork_asm+0x1a/0x30 Freed by task 1039: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x60 poison_slab_object+0x102/0x170 __kasan_slab_free+0x14/0x30 kfree+0xc1/0x290 mlxsw_sp_acl_tcam_vchunk_migrate_all+0x3d7/0xb50 mlxsw_sp_acl_tcam_vregion_rehash_work+0x157/0x1300 process_one_work+0x8eb/0x19b0 worker_thread+0x6c9/0xf70 kthread+0x2c9/0x3b0 ret_from_fork+0x4d/0x80 ret_from_fork_asm+0x1a/0x30

A use-after-free vulnerability in the Linux kernel's net/sched: cls_fw component can be exploited to achieve local privilege escalation. If tcf_change_indev() fails, fw_set_parms() will immediately return an error after incrementing or decrementing the reference counter in tcf_bind_filter(). If an attacker can control the reference counter and set it to zero, they can cause the reference to be freed, leading to a use-after-free vulnerability. We recommend upgrading past commit 0323bce598eea038714f941ce2b22541c46d488f.

In the Linux kernel, the following vulnerability has been resolved: cxl/acpi: Fix a use-after-free in cxl_parse_cfmws() KASAN and KFENCE detected an user-after-free in the CXL driver. This happens in the cxl_decoder_add() fail path. KASAN prints the following error: BUG: KASAN: slab-use-after-free in cxl_parse_cfmws (drivers/cxl/acpi.c:299) This happens in cxl_parse_cfmws(), where put_device() is called, releasing cxld, which is accessed later. Use the local variables in the dev_err() instead of pointing to the released memory. Since the dev_err() is printing a resource, change the open coded print format to use the %pr format specifier.

A use-after-free vulnerability in the Linux kernel's net/sched: cls_u32 component can be exploited to achieve local privilege escalation. If tcf_change_indev() fails, u32_set_parms() will immediately return an error after incrementing or decrementing the reference counter in tcf_bind_filter(). If an attacker can control the reference counter and set it to zero, they can cause the reference to be freed, leading to a use-after-free vulnerability. We recommend upgrading past commit 04c55383fa5689357bcdd2c8036725a55ed632bc.

A use-after-free vulnerability in the Linux kernel's netfilter: nf_tables component can be exploited to achieve local privilege escalation. Flaw in the error handling of bound chains causes a use-after-free in the abort path of NFT_MSG_NEWRULE. The vulnerability requires CAP_NET_ADMIN to be triggered. We recommend upgrading past commit 4bedf9eee016286c835e3d8fa981ddece5338795.

A use-after-free vulnerability was found in the Linux kernel's netfilter subsystem in net/netfilter/nf_tables_api.c. Mishandled error handling with NFT_MSG_NEWRULE makes it possible to use a dangling pointer in the same transaction causing a use-after-free vulnerability. This flaw allows a local attacker with user access to cause a privilege escalation issue. We recommend upgrading past commit 1240eb93f0616b21c675416516ff3d74798fdc97.

In Ubuntu's accountsservice an unprivileged local attacker can trigger a use-after-free vulnerability in accountsservice by sending a D-Bus message to the accounts-daemon process.

In the Linux kernel, the following vulnerability has been resolved: um: virtio_uml: Fix use-after-free after put_device in probe When register_virtio_device() fails in virtio_uml_probe(), the code sets vu_dev->registered = 1 even though the device was not successfully registered. This can lead to use-after-free or other issues.

A vulnerability exists in the memory management subsystem of the Linux kernel. The lock handling for accessing and updating virtual memory areas (VMAs) is incorrect, leading to use-after-free problems. This issue can be successfully exploited to execute arbitrary kernel code, escalate containers, and gain root privileges.

In the Linux kernel, the following vulnerability has been resolved: HID: multitouch: Correct devm device reference for hidinput input_dev name Reference the HID device rather than the input device for the devm allocation of the input_dev name. Referencing the input_dev would lead to a use-after-free when the input_dev was unregistered and subsequently fires a uevent that depends on the name. At the point of firing the uevent, the name would be freed by devres management. Use devm_kasprintf to simplify the logic for allocating memory and formatting the input_dev name string.

In the Linux kernel, the following vulnerability has been resolved: cifs: prevent use-after-free by freeing the cfile later In smb2_compound_op we have a possible use-after-free which can cause hard to debug problems later on. This was revealed during stress testing with KASAN enabled kernel. Fixing it by moving the cfile free call to a few lines below, after the usage.