In the Linux kernel, the following vulnerability has been resolved: media: mediatek: vcodec: Can't set dst buffer to done when lat decode error Core thread will call v4l2_m2m_buf_done to set dst buffer done for lat architecture. If lat call v4l2_m2m_buf_done_and_job_finish to free dst buffer when lat decode error, core thread will access kernel NULL pointer dereference, then crash.

In the Linux kernel, the following vulnerability has been resolved: drm/vkms: Fix null-ptr-deref in vkms_release() A null-ptr-deref is triggered when it tries to destroy the workqueue in vkms->output.composer_workq in vkms_release(). KASAN: null-ptr-deref in range [0x0000000000000118-0x000000000000011f] CPU: 5 PID: 17193 Comm: modprobe Not tainted 6.0.0-11331-gd465bff130bf #24 RIP: 0010:destroy_workqueue+0x2f/0x710 ... Call Trace: <TASK> ? vkms_config_debugfs_init+0x50/0x50 [vkms] __devm_drm_dev_alloc+0x15a/0x1c0 [drm] vkms_init+0x245/0x1000 [vkms] do_one_initcall+0xd0/0x4f0 do_init_module+0x1a4/0x680 load_module+0x6249/0x7110 __do_sys_finit_module+0x140/0x200 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 The reason is that an OOM happened which triggers the destroy of the workqueue, however, the workqueue is alloced in the later process, thus a null-ptr-deref happened. A simple call graph is shown as below: vkms_init() vkms_create() devm_drm_dev_alloc() __devm_drm_dev_alloc() devm_drm_dev_init() devm_add_action_or_reset() devm_add_action() # an error happened devm_drm_dev_init_release() drm_dev_put() kref_put() drm_dev_release() vkms_release() destroy_workqueue() # null-ptr-deref happened vkms_modeset_init() vkms_output_init() vkms_crtc_init() # where the workqueue get allocated Fix this by checking if composer_workq is NULL before passing it to the destroy_workqueue() in vkms_release().

In the Linux kernel, the following vulnerability has been resolved: net: sched: cake: fix null pointer access issue when cake_init() fails When the default qdisc is cake, if the qdisc of dev_queue fails to be inited during mqprio_init(), cake_reset() is invoked to clear resources. In this case, the tins is NULL, and it will cause gpf issue. The process is as follows: qdisc_create_dflt() cake_init() q->tins = kvcalloc(...) --->failed, q->tins is NULL ... qdisc_put() ... cake_reset() ... cake_dequeue_one() b = &q->tins[...] --->q->tins is NULL The following is the Call Trace information: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:cake_dequeue_one+0xc9/0x3c0 Call Trace: <TASK> cake_reset+0xb1/0x140 qdisc_reset+0xed/0x6f0 qdisc_destroy+0x82/0x4c0 qdisc_put+0x9e/0xb0 qdisc_create_dflt+0x2c3/0x4a0 mqprio_init+0xa71/0x1760 qdisc_create+0x3eb/0x1000 tc_modify_qdisc+0x408/0x1720 rtnetlink_rcv_msg+0x38e/0xac0 netlink_rcv_skb+0x12d/0x3a0 netlink_unicast+0x4a2/0x740 netlink_sendmsg+0x826/0xcc0 sock_sendmsg+0xc5/0x100 ____sys_sendmsg+0x583/0x690 ___sys_sendmsg+0xe8/0x160 __sys_sendmsg+0xbf/0x160 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f89e5122d04 </TASK>

In the Linux kernel, the following vulnerability has been resolved: cxl: fix possible null-ptr-deref in cxl_guest_init_afu|adapter() If device_register() fails in cxl_register_afu|adapter(), the device is not added, device_unregister() can not be called in the error path, otherwise it will cause a null-ptr-deref because of removing not added device. As comment of device_register() says, it should use put_device() to give up the reference in the error path. So split device_unregister() into device_del() and put_device(), then goes to put dev when register fails.

In the Linux kernel, the following vulnerability has been resolved: drbd: only clone bio if we have a backing device Commit c347a787e34cb (drbd: set ->bi_bdev in drbd_req_new) moved a bio_set_dev call (which has since been removed) to "earlier", from drbd_request_prepare to drbd_req_new. The problem is that this accesses device->ldev->backing_bdev, which is not NULL-checked at this point. When we don't have an ldev (i.e. when the DRBD device is diskless), this leads to a null pointer deref. So, only allocate the private_bio if we actually have a disk. This is also a small optimization, since we don't clone the bio to only to immediately free it again in the diskless case.

In the Linux kernel, the following vulnerability has been resolved: drm/bridge: megachips: Fix a null pointer dereference bug When removing the module we will get the following warning: [ 31.911505] i2c-core: driver [stdp2690-ge-b850v3-fw] unregistered [ 31.912484] general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN PTI [ 31.913338] KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] [ 31.915280] RIP: 0010:drm_bridge_remove+0x97/0x130 [ 31.921825] Call Trace: [ 31.922533] stdp4028_ge_b850v3_fw_remove+0x34/0x60 [megachips_stdpxxxx_ge_b850v3_fw] [ 31.923139] i2c_device_remove+0x181/0x1f0 The two bridges (stdp2690, stdp4028) do not probe at the same time, so the driver does not call ge_b850v3_resgiter() when probing, causing the driver to try to remove the object that has not been initialized. Fix this by checking whether both the bridges are probed.

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_conn: Fix crash on hci_create_cis_sync When attempting to connect multiple ISO sockets without using DEFER_SETUP may result in the following crash: BUG: KASAN: null-ptr-deref in hci_create_cis_sync+0x18b/0x2b0 Read of size 2 at addr 0000000000000036 by task kworker/u3:1/50 CPU: 0 PID: 50 Comm: kworker/u3:1 Not tainted 6.0.0-rc7-02243-gb84a13ff4eda #4373 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-1.fc36 04/01/2014 Workqueue: hci0 hci_cmd_sync_work Call Trace: <TASK> dump_stack_lvl+0x19/0x27 kasan_report+0xbc/0xf0 ? hci_create_cis_sync+0x18b/0x2b0 hci_create_cis_sync+0x18b/0x2b0 ? get_link_mode+0xd0/0xd0 ? __ww_mutex_lock_slowpath+0x10/0x10 ? mutex_lock+0xe0/0xe0 ? get_link_mode+0xd0/0xd0 hci_cmd_sync_work+0x111/0x190 process_one_work+0x427/0x650 worker_thread+0x87/0x750 ? process_one_work+0x650/0x650 kthread+0x14e/0x180 ? kthread_exit+0x50/0x50 ret_from_fork+0x22/0x30 </TASK>

In the Linux kernel, the following vulnerability has been resolved: power: supply: fix null pointer dereferencing in power_supply_get_battery_info when kmalloc() fail to allocate memory in kasprintf(), propname will be NULL, strcmp() called by of_get_property() will cause null pointer dereference. So return ENOMEM if kasprintf() return NULL pointer.

In the Linux kernel, the following vulnerability has been resolved: media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer() Wei Chen reports a kernel bug as blew: general protection fault, probably for non-canonical address KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] ... Call Trace: <TASK> __i2c_transfer+0x77e/0x1930 drivers/i2c/i2c-core-base.c:2109 i2c_transfer+0x1d5/0x3d0 drivers/i2c/i2c-core-base.c:2170 i2cdev_ioctl_rdwr+0x393/0x660 drivers/i2c/i2c-dev.c:297 i2cdev_ioctl+0x75d/0x9f0 drivers/i2c/i2c-dev.c:458 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fd834a8bded In az6027_i2c_xfer(), if msg[i].addr is 0x99, a null-ptr-deref will caused when accessing msg[i].buf. For msg[i].len is 0 and msg[i].buf is null. Fix this by checking msg[i].len in az6027_i2c_xfer().

In the Linux kernel, the following vulnerability has been resolved: drivers/md/md-bitmap: check the return value of md_bitmap_get_counter() Check the return value of md_bitmap_get_counter() in case it returns NULL pointer, which will result in a null pointer dereference. v2: update the check to include other dereference

In the Linux kernel, the following vulnerability has been resolved: io_uring/msg_ring: Fix NULL pointer dereference in io_msg_send_fd() Syzkaller produced the below call trace: BUG: KASAN: null-ptr-deref in io_msg_ring+0x3cb/0x9f0 Write of size 8 at addr 0000000000000070 by task repro/16399 CPU: 0 PID: 16399 Comm: repro Not tainted 6.1.0-rc1 #28 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 Call Trace: <TASK> dump_stack_lvl+0xcd/0x134 ? io_msg_ring+0x3cb/0x9f0 kasan_report+0xbc/0xf0 ? io_msg_ring+0x3cb/0x9f0 kasan_check_range+0x140/0x190 io_msg_ring+0x3cb/0x9f0 ? io_msg_ring_prep+0x300/0x300 io_issue_sqe+0x698/0xca0 io_submit_sqes+0x92f/0x1c30 __do_sys_io_uring_enter+0xae4/0x24b0 .... RIP: 0033:0x7f2eaf8f8289 RSP: 002b:00007fff40939718 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f2eaf8f8289 RDX: 0000000000000000 RSI: 0000000000006f71 RDI: 0000000000000004 RBP: 00007fff409397a0 R08: 0000000000000000 R09: 0000000000000039 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004006d0 R13: 00007fff40939880 R14: 0000000000000000 R15: 0000000000000000 </TASK> Kernel panic - not syncing: panic_on_warn set ... We don't have a NULL check on file_ptr in io_msg_send_fd() function, so when file_ptr is NUL src_file is also NULL and get_file() dereferences a NULL pointer and leads to above crash. Add a NULL check to fix this issue.

In the Linux kernel, the following vulnerability has been resolved: media: coda: Add check for kmalloc As the kmalloc may return NULL pointer, it should be better to check the return value in order to avoid NULL poineter dereference, same as the others.

In the Linux kernel, the following vulnerability has been resolved: pnode: terminate at peers of source The propagate_mnt() function handles mount propagation when creating mounts and propagates the source mount tree @source_mnt to all applicable nodes of the destination propagation mount tree headed by @dest_mnt. Unfortunately it contains a bug where it fails to terminate at peers of @source_mnt when looking up copies of the source mount that become masters for copies of the source mount tree mounted on top of slaves in the destination propagation tree causing a NULL dereference. Once the mechanics of the bug are understood it's easy to trigger. Because of unprivileged user namespaces it is available to unprivileged users. While fixing this bug we've gotten confused multiple times due to unclear terminology or missing concepts. So let's start this with some clarifications: * The terms "master" or "peer" denote a shared mount. A shared mount belongs to a peer group. * A peer group is a set of shared mounts that propagate to each other. They are identified by a peer group id. The peer group id is available in @shared_mnt->mnt_group_id. Shared mounts within the same peer group have the same peer group id. The peers in a peer group can be reached via @shared_mnt->mnt_share. * The terms "slave mount" or "dependent mount" denote a mount that receives propagation from a peer in a peer group. IOW, shared mounts may have slave mounts and slave mounts have shared mounts as their master. Slave mounts of a given peer in a peer group are listed on that peers slave list available at @shared_mnt->mnt_slave_list. * The term "master mount" denotes a mount in a peer group. IOW, it denotes a shared mount or a peer mount in a peer group. The term "master mount" - or "master" for short - is mostly used when talking in the context of slave mounts that receive propagation from a master mount. A master mount of a slave identifies the closest peer group a slave mount receives propagation from. The master mount of a slave can be identified via @slave_mount->mnt_master. Different slaves may point to different masters in the same peer group. * Multiple peers in a peer group can have non-empty ->mnt_slave_lists. Non-empty ->mnt_slave_lists of peers don't intersect. Consequently, to ensure all slave mounts of a peer group are visited the ->mnt_slave_lists of all peers in a peer group have to be walked. * Slave mounts point to a peer in the closest peer group they receive propagation from via @slave_mnt->mnt_master (see above). Together with these peers they form a propagation group (see below). The closest peer group can thus be identified through the peer group id @slave_mnt->mnt_master->mnt_group_id of the peer/master that a slave mount receives propagation from. * A shared-slave mount is a slave mount to a peer group pg1 while also a peer in another peer group pg2. IOW, a peer group may receive propagation from another peer group. If a peer group pg1 is a slave to another peer group pg2 then all peers in peer group pg1 point to the same peer in peer group pg2 via ->mnt_master. IOW, all peers in peer group pg1 appear on the same ->mnt_slave_list. IOW, they cannot be slaves to different peer groups. * A pure slave mount is a slave mount that is a slave to a peer group but is not a peer in another peer group. * A propagation group denotes the set of mounts consisting of a single peer group pg1 and all slave mounts and shared-slave mounts that point to a peer in that peer group via ->mnt_master. IOW, all slave mounts such that @slave_mnt->mnt_master->mnt_group_id is equal to @shared_mnt->mnt_group_id. The concept of a propagation group makes it easier to talk about a single propagation level in a propagation tree. For example, in propagate_mnt() the immediate peers of @dest_mnt and all slaves of @dest_mnt's peer group form a propagation group pr ---truncated---

In the Linux kernel, the following vulnerability has been resolved: net: sched: sfb: fix null pointer access issue when sfb_init() fails When the default qdisc is sfb, if the qdisc of dev_queue fails to be inited during mqprio_init(), sfb_reset() is invoked to clear resources. In this case, the q->qdisc is NULL, and it will cause gpf issue. The process is as follows: qdisc_create_dflt() sfb_init() tcf_block_get() --->failed, q->qdisc is NULL ... qdisc_put() ... sfb_reset() qdisc_reset(q->qdisc) --->q->qdisc is NULL ops = qdisc->ops The following is the Call Trace information: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] RIP: 0010:qdisc_reset+0x2b/0x6f0 Call Trace: <TASK> sfb_reset+0x37/0xd0 qdisc_reset+0xed/0x6f0 qdisc_destroy+0x82/0x4c0 qdisc_put+0x9e/0xb0 qdisc_create_dflt+0x2c3/0x4a0 mqprio_init+0xa71/0x1760 qdisc_create+0x3eb/0x1000 tc_modify_qdisc+0x408/0x1720 rtnetlink_rcv_msg+0x38e/0xac0 netlink_rcv_skb+0x12d/0x3a0 netlink_unicast+0x4a2/0x740 netlink_sendmsg+0x826/0xcc0 sock_sendmsg+0xc5/0x100 ____sys_sendmsg+0x583/0x690 ___sys_sendmsg+0xe8/0x160 __sys_sendmsg+0xbf/0x160 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f2164122d04 </TASK>

In the Linux kernel, the following vulnerability has been resolved: i2c: mux: reg: check return value after calling platform_get_resource() It will cause null-ptr-deref in resource_size(), if platform_get_resource() returns NULL, move calling resource_size() after devm_ioremap_resource() that will check 'res' to avoid null-ptr-deref. And use devm_platform_get_and_ioremap_resource() to simplify code.

In the Linux kernel, the following vulnerability has been resolved: cxl: fix possible null-ptr-deref in cxl_pci_init_afu|adapter() If device_register() fails in cxl_pci_afu|adapter(), the device is not added, device_unregister() can not be called in the error path, otherwise it will cause a null-ptr-deref because of removing not added device. As comment of device_register() says, it should use put_device() to give up the reference in the error path. So split device_unregister() into device_del() and put_device(), then goes to put dev when register fails.

In the Linux kernel, the following vulnerability has been resolved: ACPI: processor: idle: Check acpi_fetch_acpi_dev() return value The return value of acpi_fetch_acpi_dev() could be NULL, which would cause a NULL pointer dereference to occur in acpi_device_hid(). [ rjw: Subject and changelog edits, added empty line after if () ]

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: Fix kfd_process_device_init_vm error handling Should only destroy the ib_mem and let process cleanup worker to free the outstanding BOs. Reset the pointer in pdd->qpd structure, to avoid NULL pointer access in process destroy worker. BUG: kernel NULL pointer dereference, address: 0000000000000010 Call Trace: amdgpu_amdkfd_gpuvm_unmap_gtt_bo_from_kernel+0x46/0xb0 [amdgpu] kfd_process_device_destroy_cwsr_dgpu+0x40/0x70 [amdgpu] kfd_process_destroy_pdds+0x71/0x190 [amdgpu] kfd_process_wq_release+0x2a2/0x3b0 [amdgpu] process_one_work+0x2a1/0x600 worker_thread+0x39/0x3d0

In the Linux kernel, the following vulnerability has been resolved: mmc: rtsx_pci: fix return value check of mmc_add_host() mmc_add_host() may return error, if we ignore its return value, the memory that allocated in mmc_alloc_host() will be leaked and it will lead a kernel crash because of deleting not added device in the remove path. So fix this by checking the return value and calling mmc_free_host() in the error path, beside, runtime PM also needs be disabled.

In the Linux kernel, the following vulnerability has been resolved: media: coda: Add check for dcoda_iram_alloc As the coda_iram_alloc may return NULL pointer, it should be better to check the return value in order to avoid NULL poineter dereference, same as the others.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix size validation for non-exclusive domains (v4) Fix amdgpu_bo_validate_size() to check whether the TTM domain manager for the requested memory exists, else we get a kernel oops when dereferencing "man". v2: Make the patch standalone, i.e. not dependent on local patches. v3: Preserve old behaviour and just check that the manager pointer is not NULL. v4: Complain if GTT domain requested and it is uninitialized--most likely a bug.

In the Linux kernel, the following vulnerability has been resolved: iommu/mediatek: Check return value after calling platform_get_resource() platform_get_resource() may return NULL pointer, we need check its return value to avoid null-ptr-deref in resource_size().

In the Linux kernel, the following vulnerability has been resolved: parisc: led: Fix potential null-ptr-deref in start_task() start_task() calls create_singlethread_workqueue() and not checked the ret value, which may return NULL. And a null-ptr-deref may happen: start_task() create_singlethread_workqueue() # failed, led_wq is NULL queue_delayed_work() queue_delayed_work_on() __queue_delayed_work() # warning here, but continue __queue_work() # access wq->flags, null-ptr-deref Check the ret value and return -ENOMEM if it is NULL.

In the Linux kernel, the following vulnerability has been resolved: tipc: fix a null-ptr-deref in tipc_topsrv_accept syzbot found a crash in tipc_topsrv_accept: KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] Workqueue: tipc_rcv tipc_topsrv_accept RIP: 0010:kernel_accept+0x22d/0x350 net/socket.c:3487 Call Trace: <TASK> tipc_topsrv_accept+0x197/0x280 net/tipc/topsrv.c:460 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 It was caused by srv->listener that might be set to null by tipc_topsrv_stop() in net .exit whereas it's still used in tipc_topsrv_accept() worker. srv->listener is protected by srv->idr_lock in tipc_topsrv_stop(), so add a check for srv->listener under srv->idr_lock in tipc_topsrv_accept() to avoid the null-ptr-deref. To ensure the lsock is not released during the tipc_topsrv_accept(), move sock_release() after tipc_topsrv_work_stop() where it's waiting until the tipc_topsrv_accept worker to be done. Note that sk_callback_lock is used to protect sk->sk_user_data instead of srv->listener, and it should check srv in tipc_topsrv_listener_data_ready() instead. This also ensures that no more tipc_topsrv_accept worker will be started after tipc_conn_close() is called in tipc_topsrv_stop() where it sets sk->sk_user_data to null.

In the Linux kernel, the following vulnerability has been resolved: gpiolib: cdev: fix NULL-pointer dereferences There are several places where we can crash the kernel by requesting lines, unbinding the GPIO device, then calling any of the system calls relevant to the GPIO character device's annonymous file descriptors: ioctl(), read(), poll(). While I observed it with the GPIO simulator, it will also happen for any of the GPIO devices that can be hot-unplugged - for instance any HID GPIO expander (e.g. CP2112). This affects both v1 and v2 uAPI. This fixes it partially by checking if gdev->chip is not NULL but it doesn't entirely remedy the situation as we still have a race condition in which another thread can remove the device after the check.

In the Linux kernel, the following vulnerability has been resolved: iio: light: isl29028: Fix the warning in isl29028_remove() The driver use the non-managed form of the register function in isl29028_remove(). To keep the release order as mirroring the ordering in probe, the driver should use non-managed form in probe, too. The following log reveals it: [ 32.374955] isl29028 0-0010: remove [ 32.376861] general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] PREEMPT SMP KASAN PTI [ 32.377676] KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037] [ 32.379432] RIP: 0010:kernfs_find_and_get_ns+0x28/0xe0 [ 32.385461] Call Trace: [ 32.385807] sysfs_unmerge_group+0x59/0x110 [ 32.386110] dpm_sysfs_remove+0x58/0xc0 [ 32.386391] device_del+0x296/0xe50 [ 32.386959] cdev_device_del+0x1d/0xd0 [ 32.387231] devm_iio_device_unreg+0x27/0xb0 [ 32.387542] devres_release_group+0x319/0x3d0 [ 32.388162] i2c_device_remove+0x93/0x1f0

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: mlme: fix null-ptr deref on failed assoc If association to an AP without a link 0 fails, then we crash in tracing because it assumes that either ap_mld_addr or link 0 BSS is valid, since we clear sdata->vif.valid_links and then don't add the ap_mld_addr to the struct. Since we clear also sdata->vif.cfg.ap_addr, keep a local copy of it and assign it earlier, before clearing valid_links, to fix this.

In the Linux kernel, the following vulnerability has been resolved: vme: Fix error not catched in fake_init() In fake_init(), __root_device_register() is possible to fail but it's ignored, which can cause unregistering vme_root fail when exit. general protection fault, probably for non-canonical address 0xdffffc000000008c KASAN: null-ptr-deref in range [0x0000000000000460-0x0000000000000467] RIP: 0010:root_device_unregister+0x26/0x60 Call Trace: <TASK> __x64_sys_delete_module+0x34f/0x540 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Return error when __root_device_register() fails.

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix NULL dereference in nfs3svc_encode_getaclres In error cases the dentry may be NULL. Before 20798dfe249a, the encoder also checked dentry and d_really_is_positive(dentry), but that looks like overkill to me--zero status should be enough to guarantee a positive dentry. This isn't the first time we've seen an error-case NULL dereference hidden in the initialization of a local variable in an xdr encoder. But I went back through the other recent rewrites and didn't spot any similar bugs.

In the Linux kernel, the following vulnerability has been resolved: scsi: lpfc: Fix null ndlp ptr dereference in abnormal exit path for GFT_ID An error case exit from lpfc_cmpl_ct_cmd_gft_id() results in a call to lpfc_nlp_put() with a null pointer to a nodelist structure. Changed lpfc_cmpl_ct_cmd_gft_id() to initialize nodelist pointer upon entry.

In the Linux kernel, the following vulnerability has been resolved: HID: amd_sfh: Fix potential NULL pointer dereference devm_add_action_or_reset() can suddenly invoke amd_mp2_pci_remove() at registration that will cause NULL pointer dereference since corresponding data is not initialized yet. The patch moves initialization of data before devm_add_action_or_reset(). Found by Linux Driver Verification project (linuxtesting.org). [jkosina@suse.cz: rebase]

In the Linux kernel, the following vulnerability has been resolved: ext4: don't allow journal inode to have encrypt flag Mounting a filesystem whose journal inode has the encrypt flag causes a NULL dereference in fscrypt_limit_io_blocks() when the 'inlinecrypt' mount option is used. The problem is that when jbd2_journal_init_inode() calls bmap(), it eventually finds its way into ext4_iomap_begin(), which calls fscrypt_limit_io_blocks(). fscrypt_limit_io_blocks() requires that if the inode is encrypted, then its encryption key must already be set up. That's not the case here, since the journal inode is never "opened" like a normal file would be. Hence the crash. A reproducer is: mkfs.ext4 -F /dev/vdb debugfs -w /dev/vdb -R "set_inode_field <8> flags 0x80808" mount /dev/vdb /mnt -o inlinecrypt To fix this, make ext4 consider journal inodes with the encrypt flag to be invalid. (Note, maybe other flags should be rejected on the journal inode too. For now, this is just the minimal fix for the above issue.) I've marked this as fixing the commit that introduced the call to fscrypt_limit_io_blocks(), since that's what made an actual crash start being possible. But this fix could be applied to any version of ext4 that supports the encrypt feature.

In the Linux kernel, the following vulnerability has been resolved: media: cx88: Fix a null-ptr-deref bug in buffer_prepare() When the driver calls cx88_risc_buffer() to prepare the buffer, the function call may fail, resulting in a empty buffer and null-ptr-deref later in buffer_queue(). The following log can reveal it: [ 41.822762] general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN PTI [ 41.824488] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] [ 41.828027] RIP: 0010:buffer_queue+0xc2/0x500 [ 41.836311] Call Trace: [ 41.836945] __enqueue_in_driver+0x141/0x360 [ 41.837262] vb2_start_streaming+0x62/0x4a0 [ 41.838216] vb2_core_streamon+0x1da/0x2c0 [ 41.838516] __vb2_init_fileio+0x981/0xbc0 [ 41.839141] __vb2_perform_fileio+0xbf9/0x1120 [ 41.840072] vb2_fop_read+0x20e/0x400 [ 41.840346] v4l2_read+0x215/0x290 [ 41.840603] vfs_read+0x162/0x4c0 Fix this by checking the return value of cx88_risc_buffer() [hverkuil: fix coding style issues]

In the Linux kernel, the following vulnerability has been resolved: bnxt_en: Fix possible crash in bnxt_hwrm_set_coal() During the error recovery sequence, the rtnl_lock is not held for the entire duration and some datastructures may be freed during the sequence. Check for the BNXT_STATE_OPEN flag instead of netif_running() to ensure that the device is fully operational before proceeding to reconfigure the coalescing settings. This will fix a possible crash like this: BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 PGD 0 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 10 PID: 181276 Comm: ethtool Kdump: loaded Tainted: G IOE --------- - - 4.18.0-348.el8.x86_64 #1 Hardware name: Dell Inc. PowerEdge R740/0F9N89, BIOS 2.3.10 08/15/2019 RIP: 0010:bnxt_hwrm_set_coal+0x1fb/0x2a0 [bnxt_en] Code: c2 66 83 4e 22 08 66 89 46 1c e8 10 cb 00 00 41 83 c6 01 44 39 b3 68 01 00 00 0f 8e a3 00 00 00 48 8b 93 c8 00 00 00 49 63 c6 <48> 8b 2c c2 48 8b 85 b8 02 00 00 48 85 c0 74 2e 48 8b 74 24 08 f6 RSP: 0018:ffffb11c8dcaba50 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8d168a8b0ac0 RCX: 00000000000000c5 RDX: 0000000000000000 RSI: ffff8d162f72c000 RDI: ffff8d168a8b0b28 RBP: 0000000000000000 R08: b6e1f68a12e9a7eb R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000037 R12: ffff8d168a8b109c R13: ffff8d168a8b10aa R14: 0000000000000000 R15: ffffffffc01ac4e0 FS: 00007f3852e4c740(0000) GS:ffff8d24c0080000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000041b3ee003 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: ethnl_set_coalesce+0x3ce/0x4c0 genl_family_rcv_msg_doit.isra.15+0x10f/0x150 genl_family_rcv_msg+0xb3/0x160 ? coalesce_fill_reply+0x480/0x480 genl_rcv_msg+0x47/0x90 ? genl_family_rcv_msg+0x160/0x160 netlink_rcv_skb+0x4c/0x120 genl_rcv+0x24/0x40 netlink_unicast+0x196/0x230 netlink_sendmsg+0x204/0x3d0 sock_sendmsg+0x4c/0x50 __sys_sendto+0xee/0x160 ? syscall_trace_enter+0x1d3/0x2c0 ? __audit_syscall_exit+0x249/0x2a0 __x64_sys_sendto+0x24/0x30 do_syscall_64+0x5b/0x1a0 entry_SYSCALL_64_after_hwframe+0x65/0xca RIP: 0033:0x7f38524163bb

In the Linux kernel, the following vulnerability has been resolved: usb: cdns3: change place of 'priv_ep' assignment in cdns3_gadget_ep_dequeue(), cdns3_gadget_ep_enable() If 'ep' is NULL, result of ep_to_cdns3_ep(ep) is invalid pointer and its dereference with priv_ep->cdns3_dev may cause panic. Found by Linux Verification Center (linuxtesting.org) with SVACE.

In the Linux kernel, the following vulnerability has been resolved: tracing/eprobes: Have event probes be consistent with kprobes and uprobes Currently, if a symbol "@" is attempted to be used with an event probe (eprobes), it will cause a NULL pointer dereference crash. Both kprobes and uprobes can reference data other than the main registers. Such as immediate address, symbols and the current task name. Have eprobes do the same thing. For "comm", if "comm" is used and the event being attached to does not have the "comm" field, then make it the "$comm" that kprobes has. This is consistent to the way histograms and filters work.

In the Linux kernel, the following vulnerability has been resolved: sfc: fix kernel panic when creating VF When creating VFs a kernel panic can happen when calling to efx_ef10_try_update_nic_stats_vf. When releasing a DMA coherent buffer, sometimes, I don't know in what specific circumstances, it has to unmap memory with vunmap. It is disallowed to do that in IRQ context or with BH disabled. Otherwise, we hit this line in vunmap, causing the crash: BUG_ON(in_interrupt()); This patch reenables BH to release the buffer. Log messages when the bug is hit: kernel BUG at mm/vmalloc.c:2727! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 6 PID: 1462 Comm: NetworkManager Kdump: loaded Tainted: G I --------- --- 5.14.0-119.el9.x86_64 #1 Hardware name: Dell Inc. PowerEdge R740/06WXJT, BIOS 2.8.2 08/27/2020 RIP: 0010:vunmap+0x2e/0x30 ...skip... Call Trace: __iommu_dma_free+0x96/0x100 efx_nic_free_buffer+0x2b/0x40 [sfc] efx_ef10_try_update_nic_stats_vf+0x14a/0x1c0 [sfc] efx_ef10_update_stats_vf+0x18/0x40 [sfc] efx_start_all+0x15e/0x1d0 [sfc] efx_net_open+0x5a/0xe0 [sfc] __dev_open+0xe7/0x1a0 __dev_change_flags+0x1d7/0x240 dev_change_flags+0x21/0x60 ...skip...

In the Linux kernel, the following vulnerability has been resolved: rose: Fix NULL pointer dereference in rose_send_frame() The syzkaller reported an issue: KASAN: null-ptr-deref in range [0x0000000000000380-0x0000000000000387] CPU: 0 PID: 4069 Comm: kworker/0:15 Not tainted 6.0.0-syzkaller-02734-g0326074ff465 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 Workqueue: rcu_gp srcu_invoke_callbacks RIP: 0010:rose_send_frame+0x1dd/0x2f0 net/rose/rose_link.c:101 Call Trace: <IRQ> rose_transmit_clear_request+0x1d5/0x290 net/rose/rose_link.c:255 rose_rx_call_request+0x4c0/0x1bc0 net/rose/af_rose.c:1009 rose_loopback_timer+0x19e/0x590 net/rose/rose_loopback.c:111 call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers.part.0+0x674/0xa80 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803 __do_softirq+0x1d0/0x9c8 kernel/softirq.c:571 [...] </IRQ> It triggers NULL pointer dereference when 'neigh->dev->dev_addr' is called in the rose_send_frame(). It's the first occurrence of the `neigh` is in rose_loopback_timer() as `rose_loopback_neigh', and the 'dev' in 'rose_loopback_neigh' is initialized sa nullptr. It had been fixed by commit 3b3fd068c56e3fbea30090859216a368398e39bf ("rose: Fix Null pointer dereference in rose_send_frame()") ever. But it's introduced by commit 3c53cd65dece47dd1f9d3a809f32e59d1d87b2b8 ("rose: check NULL rose_loopback_neigh->loopback") again. We fix it by add NULL check in rose_transmit_clear_request(). When the 'dev' in 'neigh' is NULL, we don't reply the request and just clear it. syzkaller don't provide repro, and I provide a syz repro like: r0 = syz_init_net_socket$bt_sco(0x1f, 0x5, 0x2) ioctl$sock_inet_SIOCSIFFLAGS(r0, 0x8914, &(0x7f0000000180)={'rose0\x00', 0x201}) r1 = syz_init_net_socket$rose(0xb, 0x5, 0x0) bind$rose(r1, &(0x7f00000000c0)=@full={0xb, @dev, @null, 0x0, [@null, @null, @netrom, @netrom, @default, @null]}, 0x40) connect$rose(r1, &(0x7f0000000240)=@short={0xb, @dev={0xbb, 0xbb, 0xbb, 0x1, 0x0}, @remote={0xcc, 0xcc, 0xcc, 0xcc, 0xcc, 0xcc, 0x1}, 0x1, @netrom={0xbb, 0xbb, 0xbb, 0xbb, 0xbb, 0x0, 0x0}}, 0x1c)

In the Linux kernel, the following vulnerability has been resolved: xprtrdma: treat all calls not a bcall when bc_serv is NULL When a rdma server returns a fault format reply, nfs v3 client may treats it as a bcall when bc service is not exist. The debug message at rpcrdma_bc_receive_call are, [56579.837169] RPC: rpcrdma_bc_receive_call: callback XID 00000001, length=20 [56579.837174] RPC: rpcrdma_bc_receive_call: 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 04 After that, rpcrdma_bc_receive_call will meets NULL pointer as, [ 226.057890] BUG: unable to handle kernel NULL pointer dereference at 00000000000000c8 ... [ 226.058704] RIP: 0010:_raw_spin_lock+0xc/0x20 ... [ 226.059732] Call Trace: [ 226.059878] rpcrdma_bc_receive_call+0x138/0x327 [rpcrdma] [ 226.060011] __ib_process_cq+0x89/0x170 [ib_core] [ 226.060092] ib_cq_poll_work+0x26/0x80 [ib_core] [ 226.060257] process_one_work+0x1a7/0x360 [ 226.060367] ? create_worker+0x1a0/0x1a0 [ 226.060440] worker_thread+0x30/0x390 [ 226.060500] ? create_worker+0x1a0/0x1a0 [ 226.060574] kthread+0x116/0x130 [ 226.060661] ? kthread_flush_work_fn+0x10/0x10 [ 226.060724] ret_from_fork+0x35/0x40 ...

In the Linux kernel, the following vulnerability has been resolved: drm/msm/mdp5: Return error code in mdp5_mixer_release when deadlock is detected There is a possibility for mdp5_get_global_state to return -EDEADLK when acquiring the modeset lock, but currently global_state in mdp5_mixer_release doesn't check for if an error is returned. To avoid a NULL dereference error, let's have mdp5_mixer_release check if an error is returned and propagate that error. Patchwork: https://patchwork.freedesktop.org/patch/485181/

In the Linux kernel, the following vulnerability has been resolved: igc: Reinstate IGC_REMOVED logic and implement it properly The initially merged version of the igc driver code (via commit 146740f9abc4, "igc: Add support for PF") contained the following IGC_REMOVED checks in the igc_rd32/wr32() MMIO accessors: u32 igc_rd32(struct igc_hw *hw, u32 reg) { u8 __iomem *hw_addr = READ_ONCE(hw->hw_addr); u32 value = 0; if (IGC_REMOVED(hw_addr)) return ~value; value = readl(&hw_addr[reg]); /* reads should not return all F's */ if (!(~value) && (!reg || !(~readl(hw_addr)))) hw->hw_addr = NULL; return value; } And: #define wr32(reg, val) \ do { \ u8 __iomem *hw_addr = READ_ONCE((hw)->hw_addr); \ if (!IGC_REMOVED(hw_addr)) \ writel((val), &hw_addr[(reg)]); \ } while (0) E.g. igb has similar checks in its MMIO accessors, and has a similar macro E1000_REMOVED, which is implemented as follows: #define E1000_REMOVED(h) unlikely(!(h)) These checks serve to detect and take note of an 0xffffffff MMIO read return from the device, which can be caused by a PCIe link flap or some other kind of PCI bus error, and to avoid performing MMIO reads and writes from that point onwards. However, the IGC_REMOVED macro was not originally implemented: #ifndef IGC_REMOVED #define IGC_REMOVED(a) (0) #endif /* IGC_REMOVED */ This led to the IGC_REMOVED logic to be removed entirely in a subsequent commit (commit 3c215fb18e70, "igc: remove IGC_REMOVED function"), with the rationale that such checks matter only for virtualization and that igc does not support virtualization -- but a PCIe device can become detached even without virtualization being in use, and without proper checks, a PCIe bus error affecting an igc adapter will lead to various NULL pointer dereferences, as the first access after the error will set hw->hw_addr to NULL, and subsequent accesses will blindly dereference this now-NULL pointer. This patch reinstates the IGC_REMOVED checks in igc_rd32/wr32(), and implements IGC_REMOVED the way it is done for igb, by checking for the unlikely() case of hw_addr being NULL. This change prevents the oopses seen when a PCIe link flap occurs on an igc adapter.

In the Linux kernel, the following vulnerability has been resolved: HID: nintendo: fix rumble worker null pointer deref We can dereference a null pointer trying to queue work to a destroyed workqueue. If the device is disconnected, nintendo_hid_remove is called, in which the rumble_queue is destroyed. Avoid using that queue to defer rumble work once the controller state is set to JOYCON_CTLR_STATE_REMOVED. This eliminates the null pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: net: phy: at803x: fix NULL pointer dereference on AR9331 PHY Latest kernel will explode on the PHY interrupt config, since it depends now on allocated priv. So, run probe to allocate priv to fix it. ar9331_switch ethernet.1:10 lan0 (uninitialized): PHY [!ahb!ethernet@1a000000!mdio!switch@10:00] driver [Qualcomm Atheros AR9331 built-in PHY] (irq=13) CPU 0 Unable to handle kernel paging request at virtual address 0000000a, epc == 8050e8a8, ra == 80504b34 ... Call Trace: [<8050e8a8>] at803x_config_intr+0x5c/0xd0 [<80504b34>] phy_request_interrupt+0xa8/0xd0 [<8050289c>] phylink_bringup_phy+0x2d8/0x3ac [<80502b68>] phylink_fwnode_phy_connect+0x118/0x130 [<8074d8ec>] dsa_slave_create+0x270/0x420 [<80743b04>] dsa_port_setup+0x12c/0x148 [<8074580c>] dsa_register_switch+0xaf0/0xcc0 [<80511344>] ar9331_sw_probe+0x370/0x388 [<8050cb78>] mdio_probe+0x44/0x70 [<804df300>] really_probe+0x200/0x424 [<804df7b4>] __driver_probe_device+0x290/0x298 [<804df810>] driver_probe_device+0x54/0xe4 [<804dfd50>] __device_attach_driver+0xe4/0x130 [<804dcb00>] bus_for_each_drv+0xb4/0xd8 [<804dfac4>] __device_attach+0x104/0x1a4 [<804ddd24>] bus_probe_device+0x48/0xc4 [<804deb44>] deferred_probe_work_func+0xf0/0x10c [<800a0ffc>] process_one_work+0x314/0x4d4 [<800a17fc>] worker_thread+0x2a4/0x354 [<800a9a54>] kthread+0x134/0x13c [<8006306c>] ret_from_kernel_thread+0x14/0x1c Same Issue would affect some other PHYs (QCA8081, QCA9561), so fix it too.

In the Linux kernel, the following vulnerability has been resolved: drm/ttm: Fix dummy res NULL ptr deref bug Check the bo->resource value before accessing the resource mem_type. v2: Fix commit description unwrapped warning <log snip> [ 40.191227][ T184] general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] SMP KASAN PTI [ 40.192995][ T184] KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] [ 40.194411][ T184] CPU: 1 PID: 184 Comm: systemd-udevd Not tainted 5.19.0-rc4-00721-gb297c22b7070 #1 [ 40.196063][ T184] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-4 04/01/2014 [ 40.199605][ T184] RIP: 0010:ttm_bo_validate+0x1b3/0x240 [ttm] [ 40.200754][ T184] Code: e8 72 c5 ff ff 83 f8 b8 74 d4 85 c0 75 54 49 8b 9e 58 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 10 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 04 3c 03 7e 44 8b 53 10 31 c0 85 d2 0f 85 58 [ 40.203685][ T184] RSP: 0018:ffffc900006df0c8 EFLAGS: 00010202 [ 40.204630][ T184] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff1102f4bb71b [ 40.205864][ T184] RDX: 0000000000000002 RSI: ffffc900006df208 RDI: 0000000000000010 [ 40.207102][ T184] RBP: 1ffff920000dbe1a R08: ffffc900006df208 R09: 0000000000000000 [ 40.208394][ T184] R10: ffff88817a5f0000 R11: 0000000000000001 R12: ffffc900006df110 [ 40.209692][ T184] R13: ffffc900006df0f0 R14: ffff88817a5db800 R15: ffffc900006df208 [ 40.210862][ T184] FS: 00007f6b1d16e8c0(0000) GS:ffff88839d700000(0000) knlGS:0000000000000000 [ 40.212250][ T184] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 40.213275][ T184] CR2: 000055a1001d4ff0 CR3: 00000001700f4000 CR4: 00000000000006e0 [ 40.214469][ T184] Call Trace: [ 40.214974][ T184] <TASK> [ 40.215438][ T184] ? ttm_bo_bounce_temp_buffer+0x140/0x140 [ttm] [ 40.216572][ T184] ? mutex_spin_on_owner+0x240/0x240 [ 40.217456][ T184] ? drm_vma_offset_add+0xaa/0x100 [drm] [ 40.218457][ T184] ttm_bo_init_reserved+0x3d6/0x540 [ttm] [ 40.219410][ T184] ? shmem_get_inode+0x744/0x980 [ 40.220231][ T184] ttm_bo_init_validate+0xb1/0x200 [ttm] [ 40.221172][ T184] ? bo_driver_evict_flags+0x340/0x340 [drm_vram_helper] [ 40.222530][ T184] ? ttm_bo_init_reserved+0x540/0x540 [ttm] [ 40.223643][ T184] ? __do_sys_finit_module+0x11a/0x1c0 [ 40.224654][ T184] ? __shmem_file_setup+0x102/0x280 [ 40.234764][ T184] drm_gem_vram_create+0x305/0x480 [drm_vram_helper] [ 40.235766][ T184] ? bo_driver_evict_flags+0x340/0x340 [drm_vram_helper] [ 40.236846][ T184] ? __kasan_slab_free+0x108/0x180 [ 40.237650][ T184] drm_gem_vram_fill_create_dumb+0x134/0x340 [drm_vram_helper] [ 40.238864][ T184] ? local_pci_probe+0xdf/0x180 [ 40.239674][ T184] ? drmm_vram_helper_init+0x400/0x400 [drm_vram_helper] [ 40.240826][ T184] drm_client_framebuffer_create+0x19c/0x400 [drm] [ 40.241955][ T184] ? drm_client_buffer_delete+0x200/0x200 [drm] [ 40.243001][ T184] ? drm_client_pick_crtcs+0x554/0xb80 [drm] [ 40.244030][ T184] drm_fb_helper_generic_probe+0x23f/0x940 [drm_kms_helper] [ 40.245226][ T184] ? __cond_resched+0x1c/0xc0 [ 40.245987][ T184] ? drm_fb_helper_memory_range_to_clip+0x180/0x180 [drm_kms_helper] [ 40.247316][ T184] ? mutex_unlock+0x80/0x100 [ 40.248005][ T184] ? __mutex_unlock_slowpath+0x2c0/0x2c0 [ 40.249083][ T184] drm_fb_helper_single_fb_probe+0x907/0xf00 [drm_kms_helper] [ 40.250314][ T184] ? drm_fb_helper_check_var+0x1180/0x1180 [drm_kms_helper] [ 40.251540][ T184] ? __cond_resched+0x1c/0xc0 [ 40.252321][ T184] ? mutex_lock+0x9f/0x100 [ 40.253062][ T184] __drm_fb_helper_initial_config_and_unlock+0xb9/0x2c0 [drm_kms_helper] [ 40.254394][ T184] drm_fbdev_client_hotplug+0x56f/0x840 [drm_kms_helper] [ 40.255477][ T184] drm_fbdev_generic_setup+0x165/0x3c0 [drm_kms_helper] [ 40.256607][ T184] bochs_pci_probe+0x6b7/0x900 [bochs] [ ---truncated---

In the Linux kernel, the following vulnerability has been resolved: md/bitmap: don't set sb values if can't pass sanity check If bitmap area contains invalid data, kernel will crash then mdadm triggers "Segmentation fault". This is cluster-md speical bug. In non-clustered env, mdadm will handle broken metadata case. In clustered array, only kernel space handles bitmap slot info. But even this bug only happened in clustered env, current sanity check is wrong, the code should be changed. How to trigger: (faulty injection) dd if=/dev/zero bs=1M count=1 oflag=direct of=/dev/sda dd if=/dev/zero bs=1M count=1 oflag=direct of=/dev/sdb mdadm -C /dev/md0 -b clustered -e 1.2 -n 2 -l mirror /dev/sda /dev/sdb mdadm -Ss echo aaa > magic.txt == below modifying slot 2 bitmap data == dd if=magic.txt of=/dev/sda seek=16384 bs=1 count=3 <== destroy magic dd if=/dev/zero of=/dev/sda seek=16436 bs=1 count=4 <== ZERO chunksize mdadm -A /dev/md0 /dev/sda /dev/sdb == kernel crashes. mdadm outputs "Segmentation fault" == Reason of kernel crash: In md_bitmap_read_sb (called by md_bitmap_create), bad bitmap magic didn't block chunksize assignment, and zero value made DIV_ROUND_UP_SECTOR_T() trigger "divide error". Crash log: kernel: md: md0 stopped. kernel: md/raid1:md0: not clean -- starting background reconstruction kernel: md/raid1:md0: active with 2 out of 2 mirrors kernel: dlm: ... ... kernel: md-cluster: Joined cluster 44810aba-38bb-e6b8-daca-bc97a0b254aa slot 1 kernel: md0: invalid bitmap file superblock: bad magic kernel: md_bitmap_copy_from_slot can't get bitmap from slot 2 kernel: md-cluster: Could not gather bitmaps from slot 2 kernel: divide error: 0000 [#1] SMP NOPTI kernel: CPU: 0 PID: 1603 Comm: mdadm Not tainted 5.14.6-1-default kernel: Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) kernel: RIP: 0010:md_bitmap_create+0x1d1/0x850 [md_mod] kernel: RSP: 0018:ffffc22ac0843ba0 EFLAGS: 00010246 kernel: ... ... kernel: Call Trace: kernel: ? dlm_lock_sync+0xd0/0xd0 [md_cluster 77fe..7a0] kernel: md_bitmap_copy_from_slot+0x2c/0x290 [md_mod 24ea..d3a] kernel: load_bitmaps+0xec/0x210 [md_cluster 77fe..7a0] kernel: md_bitmap_load+0x81/0x1e0 [md_mod 24ea..d3a] kernel: do_md_run+0x30/0x100 [md_mod 24ea..d3a] kernel: md_ioctl+0x1290/0x15a0 [md_mod 24ea....d3a] kernel: ? mddev_unlock+0xaa/0x130 [md_mod 24ea..d3a] kernel: ? blkdev_ioctl+0xb1/0x2b0 kernel: block_ioctl+0x3b/0x40 kernel: __x64_sys_ioctl+0x7f/0xb0 kernel: do_syscall_64+0x59/0x80 kernel: ? exit_to_user_mode_prepare+0x1ab/0x230 kernel: ? syscall_exit_to_user_mode+0x18/0x40 kernel: ? do_syscall_64+0x69/0x80 kernel: entry_SYSCALL_64_after_hwframe+0x44/0xae kernel: RIP: 0033:0x7f4a15fa722b kernel: ... ... kernel: ---[ end trace 8afa7612f559c868 ]--- kernel: RIP: 0010:md_bitmap_create+0x1d1/0x850 [md_mod]

In the Linux kernel, the following vulnerability has been resolved: drm/msm/hdmi: check return value after calling platform_get_resource_byname() It will cause null-ptr-deref if platform_get_resource_byname() returns NULL, we need check the return value. Patchwork: https://patchwork.freedesktop.org/patch/482992/

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: Fix missing i_op in ntfs_read_mft There is null pointer dereference because i_op == NULL. The bug happens because we don't initialize i_op for records in $Extend.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/cs: make commands with 0 chunks illegal behaviour. Submitting a cs with 0 chunks, causes an oops later, found trying to execute the wrong userspace driver. MESA_LOADER_DRIVER_OVERRIDE=v3d glxinfo [172536.665184] BUG: kernel NULL pointer dereference, address: 00000000000001d8 [172536.665188] #PF: supervisor read access in kernel mode [172536.665189] #PF: error_code(0x0000) - not-present page [172536.665191] PGD 6712a0067 P4D 6712a0067 PUD 5af9ff067 PMD 0 [172536.665195] Oops: 0000 [#1] SMP NOPTI [172536.665197] CPU: 7 PID: 2769838 Comm: glxinfo Tainted: P O 5.10.81 #1-NixOS [172536.665199] Hardware name: To be filled by O.E.M. To be filled by O.E.M./CROSSHAIR V FORMULA-Z, BIOS 2201 03/23/2015 [172536.665272] RIP: 0010:amdgpu_cs_ioctl+0x96/0x1ce0 [amdgpu] [172536.665274] Code: 75 18 00 00 4c 8b b2 88 00 00 00 8b 46 08 48 89 54 24 68 49 89 f7 4c 89 5c 24 60 31 d2 4c 89 74 24 30 85 c0 0f 85 c0 01 00 00 <48> 83 ba d8 01 00 00 00 48 8b b4 24 90 00 00 00 74 16 48 8b 46 10 [172536.665276] RSP: 0018:ffffb47c0e81bbe0 EFLAGS: 00010246 [172536.665277] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [172536.665278] RDX: 0000000000000000 RSI: ffffb47c0e81be28 RDI: ffffb47c0e81bd68 [172536.665279] RBP: ffff936524080010 R08: 0000000000000000 R09: ffffb47c0e81be38 [172536.665281] R10: ffff936524080010 R11: ffff936524080000 R12: ffffb47c0e81bc40 [172536.665282] R13: ffffb47c0e81be28 R14: ffff9367bc410000 R15: ffffb47c0e81be28 [172536.665283] FS: 00007fe35e05d740(0000) GS:ffff936c1edc0000(0000) knlGS:0000000000000000 [172536.665284] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [172536.665286] CR2: 00000000000001d8 CR3: 0000000532e46000 CR4: 00000000000406e0 [172536.665287] Call Trace: [172536.665322] ? amdgpu_cs_find_mapping+0x110/0x110 [amdgpu] [172536.665332] drm_ioctl_kernel+0xaa/0xf0 [drm] [172536.665338] drm_ioctl+0x201/0x3b0 [drm] [172536.665369] ? amdgpu_cs_find_mapping+0x110/0x110 [amdgpu] [172536.665372] ? selinux_file_ioctl+0x135/0x230 [172536.665399] amdgpu_drm_ioctl+0x49/0x80 [amdgpu] [172536.665403] __x64_sys_ioctl+0x83/0xb0 [172536.665406] do_syscall_64+0x33/0x40 [172536.665409] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/2018

In the Linux kernel, the following vulnerability has been resolved: netfs: Fix missing xas_retry() calls in xarray iteration netfslib has a number of places in which it performs iteration of an xarray whilst being under the RCU read lock. It *should* call xas_retry() as the first thing inside of the loop and do "continue" if it returns true in case the xarray walker passed out a special value indicating that the walk needs to be redone from the root[*]. Fix this by adding the missing retry checks. [*] I wonder if this should be done inside xas_find(), xas_next_node() and suchlike, but I'm told that's not an simple change to effect. This can cause an oops like that below. Note the faulting address - this is an internal value (|0x2) returned from xarray. BUG: kernel NULL pointer dereference, address: 0000000000000402 ... RIP: 0010:netfs_rreq_unlock+0xef/0x380 [netfs] ... Call Trace: netfs_rreq_assess+0xa6/0x240 [netfs] netfs_readpage+0x173/0x3b0 [netfs] ? init_wait_var_entry+0x50/0x50 filemap_read_page+0x33/0xf0 filemap_get_pages+0x2f2/0x3f0 filemap_read+0xaa/0x320 ? do_filp_open+0xb2/0x150 ? rmqueue+0x3be/0xe10 ceph_read_iter+0x1fe/0x680 [ceph] ? new_sync_read+0x115/0x1a0 new_sync_read+0x115/0x1a0 vfs_read+0xf3/0x180 ksys_read+0x5f/0xe0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae Changes: ======== ver #2) - Changed an unsigned int to a size_t to reduce the likelihood of an overflow as per Willy's suggestion. - Added an additional patch to fix the maths.

In the Linux kernel, the following vulnerability has been resolved: xhci: Fix null pointer dereference in remove if xHC has only one roothub The remove path in xhci platform driver tries to remove and put both main and shared hcds even if only a main hcd exists (one roothub) This causes a null pointer dereference in reboot for those controllers. Check that the shared_hcd exists before trying to remove it.