In the Linux kernel, the following vulnerability has been resolved: dm: fix mempool NULL pointer race when completing IO dm_io_dec_pending() calls end_io_acct() first and will then dec md in-flight pending count. But if a task is swapping DM table at same time this can result in a crash due to mempool->elements being NULL: task1 task2 do_resume ->do_suspend ->dm_wait_for_completion bio_endio ->clone_endio ->dm_io_dec_pending ->end_io_acct ->wakeup task1 ->dm_swap_table ->__bind ->__bind_mempools ->bioset_exit ->mempool_exit ->free_io [ 67.330330] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 ...... [ 67.330494] pstate: 80400085 (Nzcv daIf +PAN -UAO) [ 67.330510] pc : mempool_free+0x70/0xa0 [ 67.330515] lr : mempool_free+0x4c/0xa0 [ 67.330520] sp : ffffff8008013b20 [ 67.330524] x29: ffffff8008013b20 x28: 0000000000000004 [ 67.330530] x27: ffffffa8c2ff40a0 x26: 00000000ffff1cc8 [ 67.330535] x25: 0000000000000000 x24: ffffffdada34c800 [ 67.330541] x23: 0000000000000000 x22: ffffffdada34c800 [ 67.330547] x21: 00000000ffff1cc8 x20: ffffffd9a1304d80 [ 67.330552] x19: ffffffdada34c970 x18: 000000b312625d9c [ 67.330558] x17: 00000000002dcfbf x16: 00000000000006dd [ 67.330563] x15: 000000000093b41e x14: 0000000000000010 [ 67.330569] x13: 0000000000007f7a x12: 0000000034155555 [ 67.330574] x11: 0000000000000001 x10: 0000000000000001 [ 67.330579] x9 : 0000000000000000 x8 : 0000000000000000 [ 67.330585] x7 : 0000000000000000 x6 : ffffff80148b5c1a [ 67.330590] x5 : ffffff8008013ae0 x4 : 0000000000000001 [ 67.330596] x3 : ffffff80080139c8 x2 : ffffff801083bab8 [ 67.330601] x1 : 0000000000000000 x0 : ffffffdada34c970 [ 67.330609] Call trace: [ 67.330616] mempool_free+0x70/0xa0 [ 67.330627] bio_put+0xf8/0x110 [ 67.330638] dec_pending+0x13c/0x230 [ 67.330644] clone_endio+0x90/0x180 [ 67.330649] bio_endio+0x198/0x1b8 [ 67.330655] dec_pending+0x190/0x230 [ 67.330660] clone_endio+0x90/0x180 [ 67.330665] bio_endio+0x198/0x1b8 [ 67.330673] blk_update_request+0x214/0x428 [ 67.330683] scsi_end_request+0x2c/0x300 [ 67.330688] scsi_io_completion+0xa0/0x710 [ 67.330695] scsi_finish_command+0xd8/0x110 [ 67.330700] scsi_softirq_done+0x114/0x148 [ 67.330708] blk_done_softirq+0x74/0xd0 [ 67.330716] __do_softirq+0x18c/0x374 [ 67.330724] irq_exit+0xb4/0xb8 [ 67.330732] __handle_domain_irq+0x84/0xc0 [ 67.330737] gic_handle_irq+0x148/0x1b0 [ 67.330744] el1_irq+0xe8/0x190 [ 67.330753] lpm_cpuidle_enter+0x4f8/0x538 [ 67.330759] cpuidle_enter_state+0x1fc/0x398 [ 67.330764] cpuidle_enter+0x18/0x20 [ 67.330772] do_idle+0x1b4/0x290 [ 67.330778] cpu_startup_entry+0x20/0x28 [ 67.330786] secondary_start_kernel+0x160/0x170 Fix this by: 1) Establishing pointers to 'struct dm_io' members in dm_io_dec_pending() so that they may be passed into end_io_acct() _after_ free_io() is called. 2) Moving end_io_acct() after free_io().

In the Linux kernel, the following vulnerability has been resolved: tracing: Have trace_event_file have ref counters The following can crash the kernel: # cd /sys/kernel/tracing # echo 'p:sched schedule' > kprobe_events # exec 5>>events/kprobes/sched/enable # > kprobe_events # exec 5>&- The above commands: 1. Change directory to the tracefs directory 2. Create a kprobe event (doesn't matter what one) 3. Open bash file descriptor 5 on the enable file of the kprobe event 4. Delete the kprobe event (removes the files too) 5. Close the bash file descriptor 5 The above causes a crash! BUG: kernel NULL pointer dereference, address: 0000000000000028 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 6 PID: 877 Comm: bash Not tainted 6.5.0-rc4-test-00008-g2c6b6b1029d4-dirty #186 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:tracing_release_file_tr+0xc/0x50 What happens here is that the kprobe event creates a trace_event_file "file" descriptor that represents the file in tracefs to the event. It maintains state of the event (is it enabled for the given instance?). Opening the "enable" file gets a reference to the event "file" descriptor via the open file descriptor. When the kprobe event is deleted, the file is also deleted from the tracefs system which also frees the event "file" descriptor. But as the tracefs file is still opened by user space, it will not be totally removed until the final dput() is called on it. But this is not true with the event "file" descriptor that is already freed. If the user does a write to or simply closes the file descriptor it will reference the event "file" descriptor that was just freed, causing a use-after-free bug. To solve this, add a ref count to the event "file" descriptor as well as a new flag called "FREED". The "file" will not be freed until the last reference is released. But the FREE flag will be set when the event is removed to prevent any more modifications to that event from happening, even if there's still a reference to the event "file" descriptor.

In the Linux kernel, the following vulnerability has been resolved: usb: typec: tcpm: Fix NULL pointer dereference in tcpm_pd_svdm() It is possible that typec_register_partner() returns ERR_PTR on failure. When port->partner is an error, a NULL pointer dereference may occur as shown below. [91222.095236][ T319] typec port0: failed to register partner (-17) ... [91225.061491][ T319] Unable to handle kernel NULL pointer dereference at virtual address 000000000000039f [91225.274642][ T319] pc : tcpm_pd_data_request+0x310/0x13fc [91225.274646][ T319] lr : tcpm_pd_data_request+0x298/0x13fc [91225.308067][ T319] Call trace: [91225.308070][ T319] tcpm_pd_data_request+0x310/0x13fc [91225.308073][ T319] tcpm_pd_rx_handler+0x100/0x9e8 [91225.355900][ T319] kthread_worker_fn+0x178/0x58c [91225.355902][ T319] kthread+0x150/0x200 [91225.355905][ T319] ret_from_fork+0x10/0x30 Add a check for port->partner to avoid dereferencing a NULL pointer.

In the Linux kernel, the following vulnerability has been resolved: clk: mediatek: clk-mt7629-eth: Add check for mtk_alloc_clk_data Add the check for the return value of mtk_alloc_clk_data() in order to avoid NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: clk: mediatek: clk-mt2701: Add check for mtk_alloc_clk_data Add the check for the return value of mtk_alloc_clk_data() in order to avoid NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: clk: mediatek: clk-mt6779: Add check for mtk_alloc_clk_data Add the check for the return value of mtk_alloc_clk_data() in order to avoid NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: clk: mediatek: clk-mt6765: Add check for mtk_alloc_clk_data Add the check for the return value of mtk_alloc_clk_data() in order to avoid NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: pstore/platform: Add check for kstrdup Add check for the return value of kstrdup() and return the error if it fails in order to avoid NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: clk: mediatek: clk-mt6797: Add check for mtk_alloc_clk_data Add the check for the return value of mtk_alloc_clk_data() in order to avoid NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: hwmon: (axi-fan-control) Fix possible NULL pointer dereference axi_fan_control_irq_handler(), dependent on the private axi_fan_control_data structure, might be called before the hwmon device is registered. That will cause an "Unable to handle kernel NULL pointer dereference" error.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix null pointer dereference in error message This patch fixes a null pointer dereference in the error message that is printed when the Display Core (DC) fails to initialize. The original message includes the DC version number, which is undefined if the DC is not initialized.

In the Linux kernel, the following vulnerability has been resolved: drm: bridge: it66121: Fix invalid connector dereference Fix the NULL pointer dereference when no monitor is connected, and the sound card is opened from userspace. Instead return an empty buffer (of zeroes) as the EDID information to the sound framework if there is no connector attached.

In the Linux kernel, the following vulnerability has been resolved: drivers/perf: hisi: use cpuhp_state_remove_instance_nocalls() for hisi_hns3_pmu uninit process When tearing down a 'hisi_hns3' PMU, we mistakenly run the CPU hotplug callbacks after the device has been unregistered, leading to fireworks when we try to execute empty function callbacks within the driver: | Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 | CPU: 0 PID: 15 Comm: cpuhp/0 Tainted: G W O 5.12.0-rc4+ #1 | Hardware name: , BIOS KpxxxFPGA 1P B600 V143 04/22/2021 | pstate: 80400009 (Nzcv daif +PAN -UAO -TCO BTYPE=--) | pc : perf_pmu_migrate_context+0x98/0x38c | lr : perf_pmu_migrate_context+0x94/0x38c | | Call trace: | perf_pmu_migrate_context+0x98/0x38c | hisi_hns3_pmu_offline_cpu+0x104/0x12c [hisi_hns3_pmu] Use cpuhp_state_remove_instance_nocalls() instead of cpuhp_state_remove_instance() so that the notifiers don't execute after the PMU device has been unregistered. [will: Rewrote commit message]

In the Linux kernel, the following vulnerability has been resolved: clk: mediatek: clk-mt7629: Add check for mtk_alloc_clk_data Add the check for the return value of mtk_alloc_clk_data() in order to avoid NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: drm/bridge: lt8912b: Fix crash on bridge detach The lt8912b driver, in its bridge detach function, calls drm_connector_unregister() and drm_connector_cleanup(). drm_connector_unregister() should be called only for connectors explicitly registered with drm_connector_register(), which is not the case in lt8912b. The driver's drm_connector_funcs.destroy hook is set to drm_connector_cleanup(). Thus the driver should not call either drm_connector_unregister() nor drm_connector_cleanup() in its lt8912_bridge_detach(), as they cause a crash on bridge detach: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 Mem abort info: ESR = 0x0000000096000006 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x06: level 2 translation fault Data abort info: ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 user pgtable: 4k pages, 48-bit VAs, pgdp=00000000858f3000 [0000000000000000] pgd=0800000085918003, p4d=0800000085918003, pud=0800000085431003, pmd=0000000000000000 Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP Modules linked in: tidss(-) display_connector lontium_lt8912b tc358768 panel_lvds panel_simple drm_dma_helper drm_kms_helper drm drm_panel_orientation_quirks CPU: 3 PID: 462 Comm: rmmod Tainted: G W 6.5.0-rc2+ #2 Hardware name: Toradex Verdin AM62 on Verdin Development Board (DT) pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : drm_connector_cleanup+0x78/0x2d4 [drm] lr : lt8912_bridge_detach+0x54/0x6c [lontium_lt8912b] sp : ffff800082ed3a90 x29: ffff800082ed3a90 x28: ffff0000040c1940 x27: 0000000000000000 x26: 0000000000000000 x25: dead000000000122 x24: dead000000000122 x23: dead000000000100 x22: ffff000003fb6388 x21: 0000000000000000 x20: 0000000000000000 x19: ffff000003fb6260 x18: fffffffffffe56e8 x17: 0000000000000000 x16: 0010000000000000 x15: 0000000000000038 x14: 0000000000000000 x13: ffff800081914b48 x12: 000000000000040e x11: 000000000000015a x10: ffff80008196ebb8 x9 : ffff800081914b48 x8 : 00000000ffffefff x7 : ffff0000040c1940 x6 : ffff80007aa649d0 x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff80008159e008 x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: drm_connector_cleanup+0x78/0x2d4 [drm] lt8912_bridge_detach+0x54/0x6c [lontium_lt8912b] drm_bridge_detach+0x44/0x84 [drm] drm_encoder_cleanup+0x40/0xb8 [drm] drmm_encoder_alloc_release+0x1c/0x30 [drm] drm_managed_release+0xac/0x148 [drm] drm_dev_put.part.0+0x88/0xb8 [drm] devm_drm_dev_init_release+0x14/0x24 [drm] devm_action_release+0x14/0x20 release_nodes+0x5c/0x90 devres_release_all+0x8c/0xe0 device_unbind_cleanup+0x18/0x68 device_release_driver_internal+0x208/0x23c driver_detach+0x4c/0x94 bus_remove_driver+0x70/0xf4 driver_unregister+0x30/0x60 platform_driver_unregister+0x14/0x20 tidss_platform_driver_exit+0x18/0xb2c [tidss] __arm64_sys_delete_module+0x1a0/0x2b4 invoke_syscall+0x48/0x110 el0_svc_common.constprop.0+0x60/0x10c do_el0_svc_compat+0x1c/0x40 el0_svc_compat+0x40/0xac el0t_32_sync_handler+0xb0/0x138 el0t_32_sync+0x194/0x198 Code: 9104a276 f2fbd5b7 aa0203e1 91008af8 (f85c0420)

In the Linux kernel, the following vulnerability has been resolved: usb: dwc2: fix possible NULL pointer dereference caused by driver concurrency In _dwc2_hcd_urb_enqueue(), "urb->hcpriv = NULL" is executed without holding the lock "hsotg->lock". In _dwc2_hcd_urb_dequeue(): spin_lock_irqsave(&hsotg->lock, flags); ... if (!urb->hcpriv) { dev_dbg(hsotg->dev, "## urb->hcpriv is NULL ##\n"); goto out; } rc = dwc2_hcd_urb_dequeue(hsotg, urb->hcpriv); // Use urb->hcpriv ... out: spin_unlock_irqrestore(&hsotg->lock, flags); When _dwc2_hcd_urb_enqueue() and _dwc2_hcd_urb_dequeue() are concurrently executed, the NULL check of "urb->hcpriv" can be executed before "urb->hcpriv = NULL". After urb->hcpriv is NULL, it can be used in the function call to dwc2_hcd_urb_dequeue(), which can cause a NULL pointer dereference. This possible bug is found by an experimental static analysis tool developed by myself. This tool analyzes the locking APIs to extract function pairs that can be concurrently executed, and then analyzes the instructions in the paired functions to identify possible concurrency bugs including data races and atomicity violations. The above possible bug is reported, when my tool analyzes the source code of Linux 6.5. To fix this possible bug, "urb->hcpriv = NULL" should be executed with holding the lock "hsotg->lock". After using this patch, my tool never reports the possible bug, with the kernelconfiguration allyesconfig for x86_64. Because I have no associated hardware, I cannot test the patch in runtime testing, and just verify it according to the code logic.

In the Linux kernel, the following vulnerability has been resolved: hid: cp2112: Fix duplicate workqueue initialization Previously the cp2112 driver called INIT_DELAYED_WORK within cp2112_gpio_irq_startup, resulting in duplicate initilizations of the workqueue on subsequent IRQ startups following an initial request. This resulted in a warning in set_work_data in workqueue.c, as well as a rare NULL dereference within process_one_work in workqueue.c. Initialize the workqueue within _probe instead.

In the Linux kernel, the following vulnerability has been resolved: media: hantro: Check whether reset op is defined before use The i.MX8MM/N/P does not define the .reset op since reset of the VPU is done by genpd. Check whether the .reset op is defined before calling it to avoid NULL pointer dereference. Note that the Fixes tag is set to the commit which removed the reset op from i.MX8M Hantro G2 implementation, this is because before this commit all the implementations did define the .reset op.

In the Linux kernel, the following vulnerability has been resolved: cxl/mem: Fix shutdown order Ira reports that removing cxl_mock_mem causes a crash with the following trace: BUG: kernel NULL pointer dereference, address: 0000000000000044 [..] RIP: 0010:cxl_region_decode_reset+0x7f/0x180 [cxl_core] [..] Call Trace: <TASK> cxl_region_detach+0xe8/0x210 [cxl_core] cxl_decoder_kill_region+0x27/0x40 [cxl_core] cxld_unregister+0x29/0x40 [cxl_core] devres_release_all+0xb8/0x110 device_unbind_cleanup+0xe/0x70 device_release_driver_internal+0x1d2/0x210 bus_remove_device+0xd7/0x150 device_del+0x155/0x3e0 device_unregister+0x13/0x60 devm_release_action+0x4d/0x90 ? __pfx_unregister_port+0x10/0x10 [cxl_core] delete_endpoint+0x121/0x130 [cxl_core] devres_release_all+0xb8/0x110 device_unbind_cleanup+0xe/0x70 device_release_driver_internal+0x1d2/0x210 bus_remove_device+0xd7/0x150 device_del+0x155/0x3e0 ? lock_release+0x142/0x290 cdev_device_del+0x15/0x50 cxl_memdev_unregister+0x54/0x70 [cxl_core] This crash is due to the clearing out the cxl_memdev's driver context (@cxlds) before the subsystem is done with it. This is ultimately due to the region(s), that this memdev is a member, being torn down and expecting to be able to de-reference @cxlds, like here: static int cxl_region_decode_reset(struct cxl_region *cxlr, int count) ... if (cxlds->rcd) goto endpoint_reset; ... Fix it by keeping the driver context valid until memdev-device unregistration, and subsequently the entire stack of related dependencies, unwinds.

In the Linux kernel, the following vulnerability has been resolved: media: vidtv: psi: Add check for kstrdup Add check for the return value of kstrdup() and return the error if it fails in order to avoid NULL pointer dereference.