Double Free

In the Linux kernel, the following vulnerability has been resolved: bpf: Cancel the running bpf_timer through kworker for PREEMPT_RT During the update procedure, when overwrite element in a pre-allocated htab, the freeing of old_element is protected by the bucket lock. The reason why the bucket lock is necessary is that the old_element has already been stashed in htab->extra_elems after alloc_htab_elem() returns. If freeing the old_element after the bucket lock is unlocked, the stashed element may be reused by concurrent update procedure and the freeing of old_element will run concurrently with the reuse of the old_element. However, the invocation of check_and_free_fields() may acquire a spin-lock which violates the lockdep rule because its caller has already held a raw-spin-lock (bucket lock). The following warning will be reported when such race happens: BUG: scheduling while atomic: test_progs/676/0x00000003 3 locks held by test_progs/676: #0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830 #1: ffff88810e961188 (&htab->lockdep_key){....}-{2:2}, at: htab_map_update_elem+0x306/0x1500 #2: ffff8881f4eac1b8 (&base->softirq_expiry_lock){....}-{2:2}, at: hrtimer_cancel_wait_running+0xe9/0x1b0 Modules linked in: bpf_testmod(O) Preemption disabled at: [<ffffffff817837a3>] htab_map_update_elem+0x293/0x1500 CPU: 0 UID: 0 PID: 676 Comm: test_progs Tainted: G ... 6.12.0+ #11 Tainted: [W]=WARN, [O]=OOT_MODULE Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)... Call Trace: <TASK> dump_stack_lvl+0x57/0x70 dump_stack+0x10/0x20 __schedule_bug+0x120/0x170 __schedule+0x300c/0x4800 schedule_rtlock+0x37/0x60 rtlock_slowlock_locked+0x6d9/0x54c0 rt_spin_lock+0x168/0x230 hrtimer_cancel_wait_running+0xe9/0x1b0 hrtimer_cancel+0x24/0x30 bpf_timer_delete_work+0x1d/0x40 bpf_timer_cancel_and_free+0x5e/0x80 bpf_obj_free_fields+0x262/0x4a0 check_and_free_fields+0x1d0/0x280 htab_map_update_elem+0x7fc/0x1500 bpf_prog_9f90bc20768e0cb9_overwrite_cb+0x3f/0x43 bpf_prog_ea601c4649694dbd_overwrite_timer+0x5d/0x7e bpf_prog_test_run_syscall+0x322/0x830 __sys_bpf+0x135d/0x3ca0 __x64_sys_bpf+0x75/0xb0 x64_sys_call+0x1b5/0xa10 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 ... </TASK> It seems feasible to break the reuse and refill of per-cpu extra_elems into two independent parts: reuse the per-cpu extra_elems with bucket lock being held and refill the old_element as per-cpu extra_elems after the bucket lock is unlocked. However, it will make the concurrent overwrite procedures on the same CPU return unexpected -E2BIG error when the map is full. Therefore, the patch fixes the lock problem by breaking the cancelling of bpf_timer into two steps for PREEMPT_RT: 1) use hrtimer_try_to_cancel() and check its return value 2) if the timer is running, use hrtimer_cancel() through a kworker to cancel it again Considering that the current implementation of hrtimer_cancel() will try to acquire a being held softirq_expiry_lock when the current timer is running, these steps above are reasonable. However, it also has downside. When the timer is running, the cancelling of the timer is delayed when releasing the last map uref. The delay is also fixable (e.g., break the cancelling of bpf timer into two parts: one part in locked scope, another one in unlocked scope), it can be revised later if necessary. It is a bit hard to decide the right fix tag. One reason is that the problem depends on PREEMPT_RT which is enabled in v6.12. Considering the softirq_expiry_lock lock exists since v5.4 and bpf_timer is introduced in v5.15, the bpf_timer commit is used in the fixes tag and an extra depends-on tag is added to state the dependency on PREEMPT_RT. Depends-on: v6.12+ with PREEMPT_RT enabledShow less

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_tcm: Don't free command immediately Don't prematurely free the command. Wait for the status completion of the sense status. It can be freed then. Otherwise we will double-free the command.Show less

In the Linux kernel, the following vulnerability has been resolved: media: uvcvideo: Fix double free in error path If the uvc_status_init() function fails to allocate the int_urb, it will free the dev->status pointer but doesn't reset the pointer to NULL. This results in the kfree() call in uvc_status_cleanup() trying to double-free the memory. Fix it by resetting the dev->status pointer to NULL after freeing it. Reviewed by: Ricardo Ribalda <ribalda@chromium.org>Show less

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: uvc: fix list double add in uvcg_video_pump A panic can occur if the endpoint becomes disabled and the uvcg_video_pump adds the request back to the req_free list after it has already been queued to the endpoint. The endpoint complete will add the request back to the req_free list. Invalidate the local request handle once it's been queued. <6>[ 246.796704][T13726] configfs-gadget gadget: uvc: uvc_function_set_alt(1, 0) <3>[ 246.797078][ T26] list_add double add: new=ffffff878bee5c40, prev=ffffff878bee5c40, next=ffffff878b0f0a90. <6>[ 246.797213][ T26] ------------[ cut here ]------------ <2>[ 246.797224][ T26] kernel BUG at lib/list_debug.c:31! <6>[ 246.807073][ T26] Call trace: <6>[ 246.807180][ T26] uvcg_video_pump+0x364/0x38c <6>[ 246.807366][ T26] process_one_work+0x2a4/0x544 <6>[ 246.807394][ T26] worker_thread+0x350/0x784 <6>[ 246.807442][ T26] kthread+0x2ac/0x320Show less

In the Linux kernel, the following vulnerability has been resolved: drm/amd/pm: fix double free in si_parse_power_table() In function si_parse_power_table(), array adev->pm.dpm.ps and its member is allocated. If the allocation of each member fails, the array itself is freed and returned with an error code. However, the array is later freed again in si_dpm_fini() function which is called when the function returns an error. This leads to potential double free of the array adev->pm.dpm.ps, as well as leak of its array members, since the members are not freed in the allocation function and the array is not nulled when freed. In addition adev->pm.dpm.num_ps, which keeps track of the allocated array member, is not updated until the member allocation is successfully finished, this could also lead to either use after free, or uninitialized variable access in si_dpm_fini(). Fix this by postponing the free of the array until si_dpm_fini() and increment adev->pm.dpm.num_ps everytime the array member is allocated.Show less

In the Linux kernel, the following vulnerability has been resolved: ath10k: skip ath10k_halt during suspend for driver state RESTARTING Double free crash is observed when FW recovery(caused by wmi timeout/crash) is followed by immediate suspend event. The FW recovery is triggered by ath10k_core_restart() which calls driver clean up via ath10k_halt(). When the suspend event occurs between the FW recovery, the restart worker thread is put into frozen state until suspend completes. The suspend event triggers ath10k_stop() which again triggers ath10k_halt() The double invocation of ath10k_halt() causes ath10k_htt_rx_free() to be called twice(Note: ath10k_htt_rx_alloc was not called by restart worker thread because of its frozen state), causing the crash. To fix this, during the suspend flow, skip call to ath10k_halt() in ath10k_stop() when the current driver state is ATH10K_STATE_RESTARTING. Also, for driver state ATH10K_STATE_RESTARTING, call ath10k_wait_for_suspend() in ath10k_stop(). This is because call to ath10k_wait_for_suspend() is skipped later in [ath10k_halt() > ath10k_core_stop()] for the driver state ATH10K_STATE_RESTARTING. The frozen restart worker thread will be cancelled during resume when the device comes out of suspend. Below is the crash stack for reference: [ 428.469167] ------------[ cut here ]------------ [ 428.469180] kernel BUG at mm/slub.c:4150! [ 428.469193] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [ 428.469219] Workqueue: events_unbound async_run_entry_fn [ 428.469230] RIP: 0010:kfree+0x319/0x31b [ 428.469241] RSP: 0018:ffffa1fac015fc30 EFLAGS: 00010246 [ 428.469247] RAX: ffffedb10419d108 RBX: ffff8c05262b0000 [ 428.469252] RDX: ffff8c04a8c07000 RSI: 0000000000000000 [ 428.469256] RBP: ffffa1fac015fc78 R08: 0000000000000000 [ 428.469276] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 428.469285] Call Trace: [ 428.469295] ? dma_free_attrs+0x5f/0x7d [ 428.469320] ath10k_core_stop+0x5b/0x6f [ 428.469336] ath10k_halt+0x126/0x177 [ 428.469352] ath10k_stop+0x41/0x7e [ 428.469387] drv_stop+0x88/0x10e [ 428.469410] __ieee80211_suspend+0x297/0x411 [ 428.469441] rdev_suspend+0x6e/0xd0 [ 428.469462] wiphy_suspend+0xb1/0x105 [ 428.469483] ? name_show+0x2d/0x2d [ 428.469490] dpm_run_callback+0x8c/0x126 [ 428.469511] ? name_show+0x2d/0x2d [ 428.469517] __device_suspend+0x2e7/0x41b [ 428.469523] async_suspend+0x1f/0x93 [ 428.469529] async_run_entry_fn+0x3d/0xd1 [ 428.469535] process_one_work+0x1b1/0x329 [ 428.469541] worker_thread+0x213/0x372 [ 428.469547] kthread+0x150/0x15f [ 428.469552] ? pr_cont_work+0x58/0x58 [ 428.469558] ? kthread_blkcg+0x31/0x31 Tested-on: QCA6174 hw3.2 PCI WLAN.RM.4.4.1-00288-QCARMSWPZ-1Show less

In the Linux kernel, the following vulnerability has been resolved: HID: elan: Fix potential double free in elan_input_configured 'input' is a managed resource allocated with devm_input_allocate_device(), so there is no need to call input_free_device() explicitly or there will be a double free. According to the doc of devm_input_allocate_device(): * Managed input devices do not need to be explicitly unregistered or * freed as it will be done automatically when owner device unbinds from * its driver (or binding fails).Show less

In the Linux kernel, the following vulnerability has been resolved: misc: ocxl: fix possible double free in ocxl_file_register_afu info_release() will be called in device_unregister() when info->dev's reference count is 0. So there is no need to call ocxl_afu_put() and kfree() again. Fix this by adding free_minor() and return to err_unregister error path.Show less

In the Linux kernel, the following vulnerability has been resolved: tracing: Fix potential double free in create_var_ref() In create_var_ref(), init_var_ref() is called to initialize the fields of variable ref_field, which is allocated in the previous function call to create_hist_field(). Function init_var_ref() allocates the corresponding fields such as ref_field->system, but frees these fields when the function encounters an error. The caller later calls destroy_hist_field() to conduct error handling, which frees the fields and the variable itself. This results in double free of the fields which are already freed in the previous function. Fix this by storing NULL to the corresponding fields when they are freed in init_var_ref().Show less

In the Linux kernel, the following vulnerability has been resolved: remoteproc: mtk_scp: Fix a potential double free 'scp->rproc' is allocated using devm_rproc_alloc(), so there is no need to free it explicitly in the remove function.Show less

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.Show less

In the Linux kernel, the following vulnerability has been resolved: mac80211: fix potential double free on mesh join While commit 6a01afcf8468 ("mac80211: mesh: Free ie data when leaving mesh") fixed a memory leak on mesh leave / teardown it introduced a potential memory corruption caused by a double free when rejoining the mesh: ieee80211_leave_mesh() -> kfree(sdata->u.mesh.ie); ... ieee80211_join_mesh() -> copy_mesh_setup() -> old_ie = ifmsh->ie; -> kfree(old_ie); This double free / kernel panics can be reproduced by using wpa_supplicant with an encrypted mesh (if set up without encryption via "iw" then ifmsh->ie is always NULL, which avoids this issue). And then calling: $ iw dev mesh0 mesh leave $ iw dev mesh0 mesh join my-mesh Note that typically these commands are not used / working when using wpa_supplicant. And it seems that wpa_supplicant or wpa_cli are going through a NETDEV_DOWN/NETDEV_UP cycle between a mesh leave and mesh join where the NETDEV_UP resets the mesh.ie to NULL via a memcpy of default_mesh_setup in cfg80211_netdev_notifier_call, which then avoids the memory corruption, too. The issue was first observed in an application which was not using wpa_supplicant but "Senf" instead, which implements its own calls to nl80211. Fixing the issue by removing the kfree()'ing of the mesh IE in the mesh join function and leaving it solely up to the mesh leave to free the mesh IE.Show less

In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: Fix double uncharge the mem of sk_msg If tcp_bpf_sendmsg is running during a tear down operation, psock may be freed. tcp_bpf_sendmsg() tcp_bpf_send_verdict() sk_msg_return() tcp_bpf_sendmsg_redir() unlikely(!psock)) sk_msg_free() The mem of msg has been uncharged in tcp_bpf_send_verdict() by sk_msg_return(), and would be uncharged by sk_msg_free() again. When psock is null, we can simply returning an error code, this would then trigger the sk_msg_free_nocharge in the error path of __SK_REDIRECT and would have the side effect of throwing an error up to user space. This would be a slight change in behavior from user side but would look the same as an error if the redirect on the socket threw an error. This issue can cause the following info: WARNING: CPU: 0 PID: 2136 at net/ipv4/af_inet.c:155 inet_sock_destruct+0x13c/0x260 Call Trace: <TASK> __sk_destruct+0x24/0x1f0 sk_psock_destroy+0x19b/0x1c0 process_one_work+0x1b3/0x3c0 worker_thread+0x30/0x350 ? process_one_work+0x3c0/0x3c0 kthread+0xe6/0x110 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x22/0x30 </TASK>Show less

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix double free during GPU reset on DC streams [Why] The issue only occurs during the GPU reset code path. We first backup the current state prior to commiting 0 streams internally from DM to DC. This state backup contains valid link encoder assignments. DC will clear the link encoder assignments as part of current state (but not the backup, since it was a copied before the commit) and free the extra stream reference it held. DC requires that the link encoder assignments remain cleared/invalid prior to commiting. Since the backup still has valid assignments we call the interface post reset to clear them. This routine also releases the extra reference that the link encoder interface held - resulting in a double free (and eventually a NULL pointer dereference). [How] We'll have to do a full DC commit anyway after GPU reset because the stream count previously went to 0. We don't need to retain the assignment that we had backed up, so just copy off of the now clean current state assignment after the reset has occcurred with the new link_enc_cfg_copy() interface.Show less

In the Linux kernel, the following vulnerability has been resolved: ubifs: rename_whiteout: Fix double free for whiteout_ui->data 'whiteout_ui->data' will be freed twice if space budget fail for rename whiteout operation as following process: rename_whiteout dev = kmalloc whiteout_ui->data = dev kfree(whiteout_ui->data) // Free first time iput(whiteout) ubifs_free_inode kfree(ui->data) // Double free! KASAN reports: ================================================================== BUG: KASAN: double-free or invalid-free in ubifs_free_inode+0x4f/0x70 Call Trace: kfree+0x117/0x490 ubifs_free_inode+0x4f/0x70 [ubifs] i_callback+0x30/0x60 rcu_do_batch+0x366/0xac0 __do_softirq+0x133/0x57f Allocated by task 1506: kmem_cache_alloc_trace+0x3c2/0x7a0 do_rename+0x9b7/0x1150 [ubifs] ubifs_rename+0x106/0x1f0 [ubifs] do_syscall_64+0x35/0x80 Freed by task 1506: kfree+0x117/0x490 do_rename.cold+0x53/0x8a [ubifs] ubifs_rename+0x106/0x1f0 [ubifs] do_syscall_64+0x35/0x80 The buggy address belongs to the object at ffff88810238bed8 which belongs to the cache kmalloc-8 of size 8 ================================================================== Let ubifs_free_inode() free 'whiteout_ui->data'. BTW, delete unused assignment 'whiteout_ui->data_len = 0', process 'ubifs_evict_inode() -> ubifs_jnl_delete_inode() -> ubifs_jnl_write_inode()' doesn't need it (because 'inc_nlink(whiteout)' won't be excuted by 'goto out_release', and the nlink of whiteout inode is 0).Show less

This is a similar, but different vulnerability than the issue reported as CVE-2024-39549. A double-free vulnerability in the routing process daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an attacker to send a malformed BGP Path attribute update which allocates memory used to log the bad path attribute. This double free of memory is causing an rpd crash, leading to a Denial of Service (DoS). This issue affects: Junos OS:  * from 22.4 before 22.4R3-S4. Junos OS Evolved: * from 22.4 before 22.4R3-S4-EVO.Show less