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: perf: hisi: Fix use-after-free when register pmu fails When we fail to register the uncore pmu, the pmu context may not been allocated. The error handing will call cpuhp_state_remove_instance() to call uncore pmu offline callback, which migrate the pmu context. Since that's liable to lead to some kind of use-after-free. 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 failed to register.

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/mediatek: Fix coverity issue with unintentional integer overflow 1. Instead of multiplying 2 variable of different types. Change to assign a value of one variable and then multiply the other variable. 2. Add a int variable for multiplier calculation instead of calculating different types multiplier with dma_addr_t variable directly.

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: padata: Fix refcnt handling in padata_free_shell() In a high-load arm64 environment, the pcrypt_aead01 test in LTP can lead to system UAF (Use-After-Free) issues. Due to the lengthy analysis of the pcrypt_aead01 function call, I'll describe the problem scenario using a simplified model: Suppose there's a user of padata named `user_function` that adheres to the padata requirement of calling `padata_free_shell` after `serial()` has been invoked, as demonstrated in the following code: ```c struct request { struct padata_priv padata; struct completion *done; }; void parallel(struct padata_priv *padata) { do_something(); } void serial(struct padata_priv *padata) { struct request *request = container_of(padata, struct request, padata); complete(request->done); } void user_function() { DECLARE_COMPLETION(done) padata->parallel = parallel; padata->serial = serial; padata_do_parallel(); wait_for_completion(&done); padata_free_shell(); } ``` In the corresponding padata.c file, there's the following code: ```c static void padata_serial_worker(struct work_struct *serial_work) { ... cnt = 0; while (!list_empty(&local_list)) { ... padata->serial(padata); cnt++; } local_bh_enable(); if (refcount_sub_and_test(cnt, &pd->refcnt)) padata_free_pd(pd); } ``` Because of the high system load and the accumulation of unexecuted softirq at this moment, `local_bh_enable()` in padata takes longer to execute than usual. Subsequently, when accessing `pd->refcnt`, `pd` has already been released by `padata_free_shell()`, resulting in a UAF issue with `pd->refcnt`. The fix is straightforward: add `refcount_dec_and_test` before calling `padata_free_pd` in `padata_free_shell`.

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: f2fs: compress: fix to avoid use-after-free on dic Call trace: __memcpy+0x128/0x250 f2fs_read_multi_pages+0x940/0xf7c f2fs_mpage_readpages+0x5a8/0x624 f2fs_readahead+0x5c/0x110 page_cache_ra_unbounded+0x1b8/0x590 do_sync_mmap_readahead+0x1dc/0x2e4 filemap_fault+0x254/0xa8c f2fs_filemap_fault+0x2c/0x104 __do_fault+0x7c/0x238 do_handle_mm_fault+0x11bc/0x2d14 do_mem_abort+0x3a8/0x1004 el0_da+0x3c/0xa0 el0t_64_sync_handler+0xc4/0xec el0t_64_sync+0x1b4/0x1b8 In f2fs_read_multi_pages(), once f2fs_decompress_cluster() was called if we hit cached page in compress_inode's cache, dic may be released, it needs break the loop rather than continuing it, in order to avoid accessing invalid dic pointer.

In the Linux kernel, the following vulnerability has been resolved: IB/mlx5: Fix init stage error handling to avoid double free of same QP and UAF In the unlikely event that workqueue allocation fails and returns NULL in mlx5_mkey_cache_init(), delete the call to mlx5r_umr_resource_cleanup() (which frees the QP) in mlx5_ib_stage_post_ib_reg_umr_init(). This will avoid attempted double free of the same QP when __mlx5_ib_add() does its cleanup. Resolves a splat: Syzkaller reported a UAF in ib_destroy_qp_user workqueue: Failed to create a rescuer kthread for wq "mkey_cache": -EINTR infiniband mlx5_0: mlx5_mkey_cache_init:981:(pid 1642): failed to create work queue infiniband mlx5_0: mlx5_ib_stage_post_ib_reg_umr_init:4075:(pid 1642): mr cache init failed -12 ================================================================== BUG: KASAN: slab-use-after-free in ib_destroy_qp_user (drivers/infiniband/core/verbs.c:2073) Read of size 8 at addr ffff88810da310a8 by task repro_upstream/1642 Call Trace: <TASK> kasan_report (mm/kasan/report.c:590) ib_destroy_qp_user (drivers/infiniband/core/verbs.c:2073) mlx5r_umr_resource_cleanup (drivers/infiniband/hw/mlx5/umr.c:198) __mlx5_ib_add (drivers/infiniband/hw/mlx5/main.c:4178) mlx5r_probe (drivers/infiniband/hw/mlx5/main.c:4402) ... </TASK> Allocated by task 1642: __kmalloc (./include/linux/kasan.h:198 mm/slab_common.c:1026 mm/slab_common.c:1039) create_qp (./include/linux/slab.h:603 ./include/linux/slab.h:720 ./include/rdma/ib_verbs.h:2795 drivers/infiniband/core/verbs.c:1209) ib_create_qp_kernel (drivers/infiniband/core/verbs.c:1347) mlx5r_umr_resource_init (drivers/infiniband/hw/mlx5/umr.c:164) mlx5_ib_stage_post_ib_reg_umr_init (drivers/infiniband/hw/mlx5/main.c:4070) __mlx5_ib_add (drivers/infiniband/hw/mlx5/main.c:4168) mlx5r_probe (drivers/infiniband/hw/mlx5/main.c:4402) ... Freed by task 1642: __kmem_cache_free (mm/slub.c:1826 mm/slub.c:3809 mm/slub.c:3822) ib_destroy_qp_user (drivers/infiniband/core/verbs.c:2112) mlx5r_umr_resource_cleanup (drivers/infiniband/hw/mlx5/umr.c:198) mlx5_ib_stage_post_ib_reg_umr_init (drivers/infiniband/hw/mlx5/main.c:4076 drivers/infiniband/hw/mlx5/main.c:4065) __mlx5_ib_add (drivers/infiniband/hw/mlx5/main.c:4168) mlx5r_probe (drivers/infiniband/hw/mlx5/main.c:4402) ...

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: f2fs: fix to drop meta_inode's page cache in f2fs_put_super() syzbot reports a kernel bug as below: F2FS-fs (loop1): detect filesystem reference count leak during umount, type: 10, count: 1 kernel BUG at fs/f2fs/super.c:1639! CPU: 0 PID: 15451 Comm: syz-executor.1 Not tainted 6.5.0-syzkaller-09338-ge0152e7481c6 #0 RIP: 0010:f2fs_put_super+0xce1/0xed0 fs/f2fs/super.c:1639 Call Trace: generic_shutdown_super+0x161/0x3c0 fs/super.c:693 kill_block_super+0x3b/0x70 fs/super.c:1646 kill_f2fs_super+0x2b7/0x3d0 fs/f2fs/super.c:4879 deactivate_locked_super+0x9a/0x170 fs/super.c:481 deactivate_super+0xde/0x100 fs/super.c:514 cleanup_mnt+0x222/0x3d0 fs/namespace.c:1254 task_work_run+0x14d/0x240 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x210/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x60 kernel/entry/common.c:296 do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd In f2fs_put_super(), it tries to do sanity check on dirty and IO reference count of f2fs, once there is any reference count leak, it will trigger panic. The root case is, during f2fs_put_super(), if there is any IO error in f2fs_wait_on_all_pages(), we missed to truncate meta_inode's page cache later, result in panic, fix this case.

In the Linux kernel, the following vulnerability has been resolved: media: bttv: fix use after free error due to btv->timeout timer There may be some a race condition between timer function bttv_irq_timeout and bttv_remove. The timer is setup in probe and there is no timer_delete operation in remove function. When it hit kfree btv, the function might still be invoked, which will cause use after free bug. This bug is found by static analysis, it may be false positive. Fix it by adding del_timer_sync invoking to the remove function. cpu0 cpu1 bttv_probe ->timer_setup ->bttv_set_dma ->mod_timer; bttv_remove ->kfree(btv); ->bttv_irq_timeout ->USE btv

In the Linux kernel, the following vulnerability has been resolved: hsr: Prevent use after free in prp_create_tagged_frame() The prp_fill_rct() function can fail. In that situation, it frees the skb and returns NULL. Meanwhile on the success path, it returns the original skb. So it's straight forward to fix bug by using the returned value.

In the Linux kernel, the following vulnerability has been resolved: tipc: Change nla_policy for bearer-related names to NLA_NUL_STRING syzbot reported the following uninit-value access issue [1]: ===================================================== BUG: KMSAN: uninit-value in strlen lib/string.c:418 [inline] BUG: KMSAN: uninit-value in strstr+0xb8/0x2f0 lib/string.c:756 strlen lib/string.c:418 [inline] strstr+0xb8/0x2f0 lib/string.c:756 tipc_nl_node_reset_link_stats+0x3ea/0xb50 net/tipc/node.c:2595 genl_family_rcv_msg_doit net/netlink/genetlink.c:971 [inline] genl_family_rcv_msg net/netlink/genetlink.c:1051 [inline] genl_rcv_msg+0x11ec/0x1290 net/netlink/genetlink.c:1066 netlink_rcv_skb+0x371/0x650 net/netlink/af_netlink.c:2545 genl_rcv+0x40/0x60 net/netlink/genetlink.c:1075 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline] netlink_unicast+0xf47/0x1250 net/netlink/af_netlink.c:1368 netlink_sendmsg+0x1238/0x13d0 net/netlink/af_netlink.c:1910 sock_sendmsg_nosec net/socket.c:730 [inline] sock_sendmsg net/socket.c:753 [inline] ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2541 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2595 __sys_sendmsg net/socket.c:2624 [inline] __do_sys_sendmsg net/socket.c:2633 [inline] __se_sys_sendmsg net/socket.c:2631 [inline] __x64_sys_sendmsg+0x307/0x490 net/socket.c:2631 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Uninit was created at: slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767 slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:559 __alloc_skb+0x318/0x740 net/core/skbuff.c:650 alloc_skb include/linux/skbuff.h:1286 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1214 [inline] netlink_sendmsg+0xb34/0x13d0 net/netlink/af_netlink.c:1885 sock_sendmsg_nosec net/socket.c:730 [inline] sock_sendmsg net/socket.c:753 [inline] ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2541 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2595 __sys_sendmsg net/socket.c:2624 [inline] __do_sys_sendmsg net/socket.c:2633 [inline] __se_sys_sendmsg net/socket.c:2631 [inline] __x64_sys_sendmsg+0x307/0x490 net/socket.c:2631 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd TIPC bearer-related names including link names must be null-terminated strings. If a link name which is not null-terminated is passed through netlink, strstr() and similar functions can cause buffer overrun. This causes the above issue. This patch changes the nla_policy for bearer-related names from NLA_STRING to NLA_NUL_STRING. This resolves the issue by ensuring that only null-terminated strings are accepted as bearer-related names. syzbot reported similar uninit-value issue related to bearer names [2]. The root cause of this issue is that a non-null-terminated bearer name was passed. This patch also resolved this issue.

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.