Use After Free
CWE-416
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
We track 4,465 vulnerabilities of this type. 100% are rated high or critical, and the average CVSS score is 8.3. 109 have been exploited in real attacks.
How this weakness is prevented
- Architecture and Design: Choose a language that provides automatic memory management.
- Implementation: When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Latest Use After Free vulnerabilities
- 9.8 Critical severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: crypto: krb5 - filter out async aead implementations at alloc krb5_aead_encrypt(), krb5_aead_decrypt() in rfc3961_simplified.c and rfc8009_encrypt(), rfc8009_decrypt() in rfc8009_aes2.c set a
- 8.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: crypto: qat - fix VF2PF work teardown race in adf_disable_sriov() The VF2PF interrupt handler queues PF-side response work that stores a raw pointer to per-VF state (struct adf_accel_vf_info).
- 8.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free of a deferred file_lock on SMB2_CLOSE then SMB2_CANCEL Commit f580d27e8928 ("ksmbd: fix use-after-free of a deferred file_lock on double SMB2_CANCEL") made smb2_cance
- 8.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix UAF in channel timeout by holding conn ref l2cap_chan_timeout() runs asynchronously and accesses chan->conn. If the connection is torn down while the timer is running or
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: Fix UAF of hci_conn_params in add_device_complete add_device_complete() runs from the hci_cmd_sync_work kworker, which holds only hci_req_sync_lock and *not* hci_dev_lock. It
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: netpoll: fix a use-after-free on shutdown path There is a use-after-free error on netpoll, which is clearly detected by KASAN. BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x3b/0x
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: ipv4: igmp: remove multicast group from hash table on device destruction When a device is destroyed under RTNL, ip_mc_destroy_dev() iterates through the multicast list and calls ip_ma_put() on
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: media: nxp: imx8-isi: Fix use-after-free on remove KASAN reports a slab-use-after-free in __media_entity_remove_link() during rmmod of imx8_isi: BUG: KASAN: slab-use-after-free in __media_enti
- 7.0 High severity
Linux: NULL Pointer Dereference
In the Linux kernel, the following vulnerability has been resolved: mfd: cros_ec: Delay dev_set_drvdata() until probe success If ec_device_probe() fails, cros_ec_class_release releases memory for the cros_ec_dev structure. However, because the drvdata was alre
- 8.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: bnep: pin L2CAP connection during netdev registration bnep_add_connection() reads the L2CAP connection without holding the channel lock, then passes its HCI device to register_netde
- 8.0 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: fix UAF in bt_accept_dequeue() bt_accept_get() takes a temporary reference before dropping the accept queue lock. bt_accept_dequeue() currently drops that reference before bt_accept
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: smb: client: resolve SWN tcon from live registrations cifs_swn_notify() looks up a witness registration by id under cifs_swnreg_idr_mutex, drops the mutex, and then uses the registration's cac
- 9.8 Critical severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: ksmbd: serialize QUERY_DIRECTORY requests per file smb2_query_dir() stores a pointer to its stack-allocated private data in the ksmbd_file readdir_data. Concurrent QUERY_DIRECTORY requests usi
- 8.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix UAF of struct file_lock in SMB2_LOCK deferred-lock cancellation When a blocking byte-range lock request is deferred in the FILE_LOCK_DEFERRED path, ksmbd registers the asynchronous
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: cpufreq: pcc: fix use-after-free and double free in _OSC evaluation pcc_cpufreq_do_osc() calls acpi_evaluate_object() twice for the two-phase _OSC negotiation. Between the two calls it freed o
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: HID: letsketch: fix UAF on inrange_timer at driver unbind letsketch_driver does not provide a .remove callback, but letsketch_probe() arms a per-device timer: timer_setup(&data->inrange_timer,
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: HID: appleir: fix UAF on pending key_up_timer in remove() appleir_remove() runs hid_hw_stop() before timer_delete_sync(). hid_hw_stop() synchronously unregisters the HID input device via hid_d
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: HID: lg-g15: cancel pending work on remove to fix a use-after-free lg_g15_data is allocated with devm and holds a work item. The report handlers schedule that work straight from device input.
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: bpf: Allow LPM map access from sleepable BPF programs trie_lookup_elem() annotates its rcu_dereference_check() walks with only rcu_read_lock_bh_held(). Because rcu_dereference_check(p, c) reso
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: usb: free iso schedules on failed submit EHCI and FOTG210 isochronous submits build an ehci_iso_sched before linking the URB to the endpoint queue, and keep the staged schedule in urb->hcpriv
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: udc: Fix use-after-free in gadget_match_driver The udc structure acts as the management structure for the gadget, but their lifecycles are decoupled. A race condition exists where
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: USB: idmouse: fix use-after-free on disconnect race mutex_unlock() may access the mutex structure after releasing the lock and therefore cannot be used to manage lifetime of objects directly (
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: USB: ldusb: fix use-after-free on disconnect race mutex_unlock() may access the mutex structure after releasing the lock and therefore cannot be used to manage lifetime of objects directly (un
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: USB: iowarrior: fix use-after-free on disconnect Submitted write URBs are not stopped on close() and therefore need to be stopped unconditionally on disconnect() to avoid use-after-free in the
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: USB: iowarrior: fix use-after-free on disconnect race mutex_unlock() may access the mutex structure after releasing the lock and therefore cannot be used to manage lifetime of objects directly
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: USB: legousbtower: fix use-after-free on disconnect race mutex_unlock() may access the mutex structure after releasing the lock and therefore cannot be used to manage lifetime of objects direc
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: usb: typec: ucsi: ccg: Fix use-after-free of ucsi on remove The threaded IRQ handler ccg_irq_handler() calls ucsi_notify_common(), which on a connector-change event calls ucsi_connector_change
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: crypto: loongson - Remove broken and unused loongson-rng The loongson-rng rng_alg has several vulnerabilities, including not providing forward security, and a use-after-free bug due to the use
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: crypto: qat - protect service table iterations with service_lock The service_table list is protected by service_lock when entries are added or removed (in adf_service_add() and adf_service_rem
- 9.8 Critical severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: spi: fsl-lpspi: terminate the RX channel on TX prepare failure path When dmaengine_prep_slave_sg() fails for the TX channel, the error path terminates the TX DMA channel but leaves the RX chan
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: perf/aux: Fix page UAF in map_range() map_range() reads rb->aux_pages[], rb->aux_nr_pages and rb->aux_pgoff via perf_mmap_to_page() while holding only event->mmap_mutex. Those fields are seria
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: fuse: re-lock request before returning from fuse_ref_folio() fuse_ref_folio() unlocks the request but does not re-lock it before returning. fuse_chan_abort() can end the request and the async
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: fuse: clear intr_entry in fuse_resend and fuse_remove_pending_req When fuse_resend() moves a request from fpq->processing back to fiq->pending, it sets FR_PENDING and clears FR_SENT but does n
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: fuse-uring: Avoid use-after-free in fuse_uring_async_stop_queues fuse_uring_async_stop_queues() might run when the last reference on ring->queue_refs was already dropped. In order to avoid an
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: fuse-uring: make a fuse_req on SQE commit only findable after memcpy Bad userspace might try to trick us and send commit SQEs request unique / commit-id of requests that are not even send to f
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next() pwrseq_debugfs_seq_next() declares 'next' with __free(put_device), which causes put_device() to be called on the returned pointer
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: fpga: region: fix use-after-free in child_regions_with_firmware() Move of_node_put(child_region) after the error print to avoid accessing freed memory when pr_err() references child_region. [
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: power: reset: linkstation-poweroff: fix use-after-free in the linkstation_poweroff_init() Move of_node_put(dn) after the of_match_node() call, which still needs the node pointer. The node refe
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: fbdev: modedb: fix a possible UAF in fb_find_mode() If mode_option is NULL, it is assigned from mode_option_buf: if (!mode_option) { fb_get_options(NULL, &mode_option_buf); mode_option = mode_
- 7.8 High severity
Linux: Use After Free
In the Linux kernel, the following vulnerability has been resolved: mm/damon/sysfs-schemes: delete tried region in regions_rmdirs() DAMON sysfs maintains the DAMOS tried region directory objects via a linked list. When the user requests refresh of the director