Double Free

In the Linux kernel, the following vulnerability has been resolved: crypto: amlogic - avoid double cleanup in meson_crypto_probe() When meson_allocate_chanlist() fails after a partial allocation, it already unwinds the allocated chanlist state through its local error path. meson_crypto_probe() then jump to error_flow and calls meson_free_chanlist() again, causing the same per-flow resources to be torn down twice. In the reproduced failure path, the second teardown re-entered crypto_engine_exit() on an already destroyed worker and KASAN reported a slab-use-after-free in kthread_destroy_worker(). Prevent double-free by handling partial allocation failures locally within meson_allocate_chanlist() and skipping the outer cleanup path. The bug was first flagged by an experimental analysis tool we are developing for kernel memory-management bugs while analyzing v6.13-rc1. The tool is still under development and is not yet publicly available. The bug was reproduced in a QEMU x86_64 guest booted with KASAN on v7.1, using the reproducer under tools/testing/meson_crypto_probe. The reproducer forces the second dma_alloc_attrs() call in the gxl-crypto probe path to return NULL, making meson_allocate_chanlist() fail after partial initialization. On the unpatched kernel this reliably triggered a slab-use-after-free. With this fix applied, the same reproducer no longer emits any KASAN report and the probe fails cleanly with -ENOMEM. ================================================================== BUG: KASAN: slab-use-after-free in kthread_destroy_worker+0xb2/0xd0 Read of size 8 at addr ff1100010c057a68 by task insmod/265 CPU: 1 UID: 0 PID: 265 Comm: insmod Tainted: G O 7.1.0-rc2-00376-g810af9adc907-dirty #10 PREEMPT(lazy) Tainted: [O]=OOT_MODULE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x68/0xa0 print_report+0xcb/0x5e0 ? __virt_addr_valid+0x21d/0x3f0 ? kthread_destroy_worker+0xb2/0xd0 ? kthread_destroy_worker+0xb2/0xd0 kasan_report+0xca/0x100 ? kthread_destroy_worker+0xb2/0xd0 kthread_destroy_worker+0xb2/0xd0 meson_crypto_probe+0x4d0/0xc10 [amlogic_gxl_crypto] platform_probe+0x99/0x140 really_probe+0x1c6/0x6a0 ? __pfx___device_attach_driver+0x10/0x10 __driver_probe_device+0x248/0x310 ? acpi_driver_match_device+0xb0/0x100 driver_probe_device+0x48/0x210 ? __pfx___device_attach_driver+0x10/0x10 __device_attach_driver+0x160/0x320 bus_for_each_drv+0x104/0x190 ? __pfx_bus_for_each_drv+0x10/0x10 ? _raw_spin_unlock_irqrestore+0x2c/0x50 __device_attach+0x19d/0x3b0 ? __pfx___device_attach+0x10/0x10 ? do_raw_spin_unlock+0x53/0x220 device_initial_probe+0x78/0xa0 bus_probe_device+0x5b/0x130 device_add+0xcfd/0x1430 ? __pfx_device_add+0x10/0x10 ? insert_resource+0x34/0x50 ? lock_release+0xc9/0x290 platform_device_add+0x24e/0x590 ? __pfx_meson_crypto_probe_repro_init+0x10/0x10 [meson_crypto_probe_repro] meson_crypto_probe_repro_init+0x330/0xff0 [meson_crypto_probe_repro] do_one_initcall+0xc0/0x450 ? __pfx_do_one_initcall+0x10/0x10 ? _raw_spin_unlock_irqrestore+0x2c/0x50 ? __create_object+0x59/0x80 ? kasan_unpoison+0x27/0x60 do_init_module+0x27b/0x7d0 ? __pfx_do_init_module+0x10/0x10 ? kasan_quarantine_put+0x84/0x1d0 ? kfree+0x32c/0x510 ? load_module+0x561e/0x5ff0 load_module+0x54fe/0x5ff0 ? __pfx_load_module+0x10/0x10 ? security_file_permission+0x20/0x40 ? kernel_read_file+0x23d/0x6e0 ? mmap_region+0x235/0x4a0 ? __pfx_kernel_read_file+0x10/0x10 ? __file_has_perm+0x2c0/0x3e0 init_module_from_file+0x158/0x180 ? __pfx_init_module_from_file+0x10/0x10 ? __lock_acquire+0x45a/0x1ba0 ? idempotent_init_module+0x315/0x610 ? lock_release+0xc9/0x290 ? lock ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2_close() replay A response-bearing attempt can return a replayable error and free its response buffer. If SMB2_close_init() fails before the next send, cleanup retains the previous buffer type and frees that response again. Reset response bookkeeping before each attempt to prevent the stale free.Show less

In the Linux kernel, the following vulnerability has been resolved: xfrm6: clear dst.dev on error to avoid double netdev_put in xfrm6_fill_dst() On the error path where in6_dev_get(dev) returns NULL, xfrm6_fill_dst() releases the device reference with netdev_put() but leaves xdst->u.dst.dev set. dst_destroy() later calls netdev_put(dst->dev) again, so the same net_device reference is released twice, underflowing its refcount (ref_tracker WARNING + "unregister_netdevice: waiting for <dev> to become free"). Clear xdst->u.dst.dev after the netdev_put(), the same way the XFRM device-offload paths xfrm_dev_state_add() and xfrm_dev_policy_add() in net/xfrm/xfrm_device.c NULL ->dev when releasing the reference on error. ref_tracker: reference already released. ref_tracker: allocated in: xfrm6_fill_dst (net/ipv6/xfrm6_policy.c:86) ... udpv6_sendmsg (net/ipv6/udp.c:1696) ... ref_tracker: freed in: xfrm6_fill_dst (net/ipv6/xfrm6_policy.c:90) ... WARNING: lib/ref_tracker.c:322 at ref_tracker_free+0x58b/0x780 dst_destroy (net/core/dst.c:115) rcu_core handle_softirqs ...Show less

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: fix fils_discovery double free on alloc failure ieee80211_set_fils_discovery() calls kfree_rcu() on the old template before allocating the replacement. If the kzalloc() then fails, it returns -ENOMEM while link->u.ap.fils_discovery still points at the object already queued for freeing. A later update or AP teardown (ieee80211_stop_ap()) re-queues that same rcu_head; the second free is caught by KASAN when the RCU sheaf is processed in softirq: BUG: KASAN: double-free in rcu_free_sheaf (mm/slub.c:5850) Free of addr ffff88800c065280 by task swapper/0/0 ... __rcu_free_sheaf_prepare (mm/slub.c:2634 mm/slub.c:2940) rcu_free_sheaf (mm/slub.c:5850) rcu_core (kernel/rcu/tree.c:2617 kernel/rcu/tree.c:2869) handle_softirqs (kernel/softirq.c:622) The buggy address belongs to the cache kmalloc-96 of size 96 Queue the old object for kfree_rcu() only after the new one is published, matching ieee80211_set_probe_resp() and ieee80211_set_s1g_short_beacon().Show less

In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: Fix potential UAF when ddgst mismatch Shivam Kumar found via vulnerability testing: When data digest is enabled on an NVMe/TCP connection and a digest mismatch occurs on a non-final H2C_DATA PDU during an R2T-based data transfer, the digest error handler in nvmet_tcp_try_recv_ddgst() calls nvmet_req_uninit() — which performs percpu_ref_put() on the submission queue — but does NOT mark the command as completed. It does not set cqe->status, does not modify rbytes_done, and does not clear any flag. When the subsequent fatal error triggers queue teardown, nvmet_tcp_uninit_data_in_cmds() iterates all commands, checks nvmet_tcp_need_data_in() for each one, and finds that the already-uninited command still appears to need data (because rbytes_done < transfer_len and cqe->status == 0). It therefore calls nvmet_req_uninit() a second time on the same command — a double percpu_ref_put against a single percpu_ref_get.Show less

In the Linux kernel, the following vulnerability has been resolved: staging: media: ipu7: fix double-free and use-after-free in error paths In both ipu7_isys_init() and ipu7_psys_init(), pdata is allocated and then passed to ipu7_bus_initialize_device(), which stores it in adev->pdata. The ipu7_bus_release() function frees adev->pdata when the device's reference count drops to zero. Two error paths incorrectly call kfree(pdata) after the device teardown has already freed it: 1. When ipu7_mmu_init() fails: put_device() is called, which drops the reference count to zero and triggers ipu7_bus_release() -> kfree(pdata). The subsequent kfree(pdata) is a double-free. 2. When ipu7_bus_add_device() fails: it calls auxiliary_device_uninit() internally, which calls put_device() -> ipu7_bus_release() -> kfree(pdata). The subsequent kfree(pdata) is again a double-free. Note that the kfree(pdata) when ipu7_bus_initialize_device() itself fails is correct, because in that case auxiliary_device_init() failed and the release function was never set up, so pdata must be freed manually. Additionally, the error code was not saved before calling put_device(), causing ERR_CAST() to dereference the already-freed adev pointer when constructing the return value. Fix this by saving the error from dev_err_probe() before put_device() and returning ERR_PTR() instead. Remove the redundant kfree(pdata) calls and fix the use-after-free in the return values of the two affected error paths.Show less

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix query directory replay double-free A response-bearing attempt can return a replayable error and free its response buffer. If SMB2_query_directory_init() fails before the next send, cleanup retains the previous buffer type and frees that response again. Reset response bookkeeping before each attempt to prevent the stale free.Show less

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix query_info() replay double-free A response-bearing attempt can return a replayable error and free its response buffer. If SMB2_query_info_init() fails before the next send, cleanup retains the previous buffer type and frees that response again. Reset response bookkeeping before each attempt to prevent the stale free.Show less

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2_ioctl() replay A response-bearing attempt can return a replayable error and free its response buffer. If SMB2_ioctl_init() fails before the next send, cleanup retains the previous buffer type and frees that response again. Reset response bookkeeping before each attempt to prevent the stale free.Show less

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix change notify replay double-free A response-bearing attempt can return a replayable error and free its response buffer. If SMB2_notify_init() fails before the next send, cleanup retains the previous buffer type and frees that response again. Reset response bookkeeping before each attempt to prevent the stale free.Show less

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2_flush() replay SMB2_flush() keeps its response buffer bookkeeping across replay attempts. If a replayable flush response is received and the retry then fails before cifs_send_recv() stores a replacement response, flush_exit will free the stale response pointer a second time. Reinitialize resp_buftype and rsp_iov at the top of the replay loop so cleanup only acts on response state produced by the current attempt. This fixes a double-free without changing replay handling for successful requests.Show less

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2_open() replay A response-bearing attempt can return a replayable error and free its response buffer. If SMB2_open_init() fails before the next send, cleanup retains the previous buffer type and frees that response again. Reset response bookkeeping before each attempt to prevent the stale free.Show less

In the Linux kernel, the following vulnerability has been resolved: cpufreq: qcom-cpufreq-hw: Fix possible double free qcom_cpufreq.data is allocated with devm_kzalloc() in probe() as an array of per-domain data. qcom_cpufreq_hw_cpu_init() stores a pointer to one element of this array in policy->driver_data. qcom_cpufreq_hw_cpu_exit() currently calls kfree() on policy->driver_data. This is not valid because the memory is devm-managed. For the first domain, this can free the devm-managed allocation while the devres entry is still active, leading to a possible double free when the platform device is later detached. For other domains, the pointer may refer to an element inside the array rather than the allocation base. Remove the kfree(data) call and let devres release qcom_cpufreq.data. This issue was found by a static analysis tool I am developing.Show less

Redis before 8.8.0, in the unusual case where an authenticated attacker can execute RESTORE, allows remote code execution via a RESTORE payload where the same NACK (pending entry) is referenced by more than one consumer, because deleting both consumers via XGROUP DELCONSUMER leads to a double free. NOTE: this issue exists because of an incomplete fix for CVE-2026-25243.Show less

libssh2 through 1.11.1, fixed in commit 5e47761, contains a double-free vulnerability in the sftp_open() function in src/sftp.c that allows a malicious SSH server to corrupt the heap of any authenticated client opening an SFTP session. When a server responds to SSH_FXP_OPEN with SSH_FXP_STATUS containing FX_OK, the response data buffer is freed, and if a subsequent sftp_packet_require() call returns a specific error such as LIBSSH2_ERROR_CHANNEL_PACKET_EXCEEDED, the same pointer is freed a second time, enabling tcache dup conditions on glibc systems that allow overlapping allocations and function pointer overwrites.Show less

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: net2280: Fix double free in probe error path usb_initialize_gadget() installs gadget_release() as the release callback for the embedded gadget device. The struct net2280 instance is therefore released through gadget_release() when the gadget device's last reference is dropped. The probe error path calls net2280_remove(), which tears down the partially initialized device and drops the gadget reference with usb_put_gadget(). Calling kfree(dev) afterwards can free the same object again. Drop the explicit kfree() and let the gadget device release callback handle the final free. This issue was found by a static analysis tool I am developing.Show less

In the Linux kernel, the following vulnerability has been resolved: octeontx2-pf: fix double free in rvu_rep_rsrc_init() rvu_rep_rsrc_init() allocates queue memory before calling otx2_init_hw_resources(). When hardware resource setup fails, otx2_init_hw_resources() already unwinds the partially initialized SQ, CQ, and aura state before returning an error. The representor error path then calls otx2_free_hw_resources() again and can free the same resources a second time. Fix this by splitting the cleanup labels so that a failure from otx2_init_hw_resources() only releases queue memory. Keep the otx2_free_hw_resources() call for failures that happen after hardware resource initialization completed successfully. The bug was first flagged by an experimental analysis tool we are developing for kernel memory-management bugs while analyzing v6.13-rc1. The tool is still under development and is not yet publicly available. Manual inspection confirms that the bug is still present in v7.1-rc3. Runtime validation was not performed because reproducing this path requires OcteonTX2 representor hardware.Show less

In the Linux kernel, the following vulnerability has been resolved: octeontx2-pf: avoid double free of pool->stack on AQ init failure otx2_pool_aq_init() frees pool->stack when mailbox sync or retry allocation fails, but leaves the pointer unchanged. Later, otx2_sq_aura_pool_init() unwinds the partial setup through otx2_aura_pool_free(), which frees pool->stack again. The CN20K-specific cn20k_pool_aq_init() implementation has the same bug in its corresponding error path. Set pool->stack to NULL immediately after the local free so the shared cleanup path does not free the same stack again while cleaning up partially initialized pool state. The bug was first flagged by an experimental analysis tool we are developing for kernel memory-management bugs while analyzing v6.13-rc1. The tool is still under development and is not yet publicly available. Manual inspection confirms that the bug is still present in v7.1-rc3. Runtime validation was not performed because reproducing this path requires OcteonTX2/CN20K hardware.Show less