In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Fix possible NULL pointer dereference in snd_usb_pcm_has_fixed_rate() The subs function argument may be NULL, so do not use it before the NULL check.

In the Linux kernel, the following vulnerability has been resolved: net: rds: Fix possible NULL-pointer dereference In rds_rdma_cm_event_handler_cmn() check, if conn pointer exists before dereferencing it as rdma_set_service_type() argument Found by Linux Verification Center (linuxtesting.org) with SVACE.

In the Linux kernel, the following vulnerability has been resolved: usb: typec: ucsi: Don't attempt to resume the ports before they exist This will fix null pointer dereference that was caused by the driver attempting to resume ports that were not yet registered.

In the Linux kernel, the following vulnerability has been resolved: media: dvb-usb-v2: af9035: Fix null-ptr-deref in af9035_i2c_master_xfer In af9035_i2c_master_xfer, msg is controlled by user. When msg[i].buf is null and msg[i].len is zero, former checks on msg[i].buf would be passed. Malicious data finally reach af9035_i2c_master_xfer. If accessing msg[i].buf[0] without sanity check, null ptr deref would happen. We add check on msg[i].len to prevent crash. Similar commit: commit 0ed554fd769a ("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()")

In the Linux kernel, the following vulnerability has been resolved: power: supply: Fix null pointer dereference in smb2_probe devm_kasprintf and devm_kzalloc return a pointer to dynamically allocated memory which can be NULL upon failure.

In the Linux kernel, the following vulnerability has been resolved: mfd: syscon: Fix null pointer dereference in of_syscon_register() kasprintf() returns a pointer to dynamically allocated memory which can be NULL upon failure.

In the Linux kernel, the following vulnerability has been resolved: tty: vcc: Add check for kstrdup() in vcc_probe() 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: powerpc/mm: Fix null-pointer dereference in pgtable_cache_add kasprintf() returns a pointer to dynamically allocated memory which can be NULL upon failure. Ensure the allocation was successful by checking the pointer validity.

In the Linux kernel, the following vulnerability has been resolved: net: wangxun: fix kernel panic due to null pointer When the device uses a custom subsystem vendor ID, the function wx_sw_init() returns before the memory of 'wx->mac_table' is allocated. The null pointer will causes the kernel panic.

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

In the Linux kernel, the following vulnerability has been resolved: serial: 8250_port: Check IRQ data before use In case the leaf driver wants to use IRQ polling (irq = 0) and IIR register shows that an interrupt happened in the 8250 hardware the IRQ data can be NULL. In such a case we need to skip the wake event as we came to this path from the timer interrupt and quite likely system is already awake. Without this fix we have got an Oops: serial8250: ttyS0 at I/O 0x3f8 (irq = 0, base_baud = 115200) is a 16550A ... BUG: kernel NULL pointer dereference, address: 0000000000000010 RIP: 0010:serial8250_handle_irq+0x7c/0x240 Call Trace: ? serial8250_handle_irq+0x7c/0x240 ? __pfx_serial8250_timeout+0x10/0x10

In the Linux kernel, the following vulnerability has been resolved: aio: fix mremap after fork null-deref Commit e4a0d3e720e7 ("aio: Make it possible to remap aio ring") introduced a null-deref if mremap is called on an old aio mapping after fork as mm->ioctx_table will be set to NULL. [jmoyer@redhat.com: fix 80 column issue]

In the Linux kernel, the following vulnerability has been resolved: gsmi: fix null-deref in gsmi_get_variable We can get EFI variables without fetching the attribute, so we must allow for that in gsmi. commit 859748255b43 ("efi: pstore: Omit efivars caching EFI varstore access layer") added a new get_variable call with attr=NULL, which triggers panic in gsmi.

In the Linux kernel, the following vulnerability has been resolved: RDMA/irdma: Fix potential NULL-ptr-dereference in_dev_get() can return NULL which will cause a failure once idev is dereferenced in in_dev_for_each_ifa_rtnl(). This patch adds a check for NULL value in idev beforehand. Found by Linux Verification Center (linuxtesting.org) with SVACE.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix NULL pointer dereference at hibernate During hibernate sequence the source context might not have a clk_mgr. So don't use it to look for DML2 support.

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: Add NULL ptr dereference checking at the end of attr_allocate_frame() It is preferable to exit through the out: label because internal debugging functions are located there.

In the Linux kernel, the following vulnerability has been resolved: iio: adc: ad7091r: Allow users to configure device events AD7091R-5 devices are supported by the ad7091r-5 driver together with the ad7091r-base driver. Those drivers declared iio events for notifying user space when ADC readings fall bellow the thresholds of low limit registers or above the values set in high limit registers. However, to configure iio events and their thresholds, a set of callback functions must be implemented and those were not present until now. The consequence of trying to configure ad7091r-5 events without the proper callback functions was a null pointer dereference in the kernel because the pointers to the callback functions were not set. Implement event configuration callbacks allowing users to read/write event thresholds and enable/disable event generation. Since the event spec structs are generic to AD7091R devices, also move those from the ad7091r-5 driver the base driver so they can be reused when support for ad7091r-2/-4/-8 be added.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/vkms: fix a possible null pointer dereference In amdgpu_vkms_conn_get_modes(), the return value of drm_cvt_mode() is assigned to mode, which will lead to a NULL pointer dereference on failure of drm_cvt_mode(). Add a check 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: x86/i8259: Mark legacy PIC interrupts with IRQ_LEVEL Baoquan reported that after triggering a crash the subsequent crash-kernel fails to boot about half of the time. It triggers a NULL pointer dereference in the periodic tick code. This happens because the legacy timer interrupt (IRQ0) is resent in software which happens in soft interrupt (tasklet) context. In this context get_irq_regs() returns NULL which leads to the NULL pointer dereference. The reason for the resend is a spurious APIC interrupt on the IRQ0 vector which is captured and leads to a resend when the legacy timer interrupt is enabled. This is wrong because the legacy PIC interrupts are level triggered and therefore should never be resent in software, but nothing ever sets the IRQ_LEVEL flag on those interrupts, so the core code does not know about their trigger type. Ensure that IRQ_LEVEL is set when the legacy PCI interrupts are set up.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix possible NULL dereference in amdgpu_ras_query_error_status_helper() Return invalid error code -EINVAL for invalid block id. Fixes the below: drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c:1183 amdgpu_ras_query_error_status_helper() error: we previously assumed 'info' could be null (see line 1176)

In the Linux kernel, the following vulnerability has been resolved: drm/panel: fix a possible null pointer dereference In versatile_panel_get_modes(), the return value of drm_mode_duplicate() is assigned to mode, which will lead to a NULL pointer dereference on failure of drm_mode_duplicate(). Add a check to avoid npd.

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: 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: f2fs: split initial and dynamic conditions for extent_cache Let's allocate the extent_cache tree without dynamic conditions to avoid a missing condition causing a panic as below. # create a file w/ a compressed flag # disable the compression # panic while updating extent_cache F2FS-fs (dm-64): Swapfile: last extent is not aligned to section F2FS-fs (dm-64): Swapfile (3) is not align to section: 1) creat(), 2) ioctl(F2FS_IOC_SET_PIN_FILE), 3) fallocate(2097152 * N) Adding 124996k swap on ./swap-file. Priority:0 extents:2 across:17179494468k ================================================================== BUG: KASAN: null-ptr-deref in instrument_atomic_read_write out/common/include/linux/instrumented.h:101 [inline] BUG: KASAN: null-ptr-deref in atomic_try_cmpxchg_acquire out/common/include/asm-generic/atomic-instrumented.h:705 [inline] BUG: KASAN: null-ptr-deref in queued_write_lock out/common/include/asm-generic/qrwlock.h:92 [inline] BUG: KASAN: null-ptr-deref in __raw_write_lock out/common/include/linux/rwlock_api_smp.h:211 [inline] BUG: KASAN: null-ptr-deref in _raw_write_lock+0x5a/0x110 out/common/kernel/locking/spinlock.c:295 Write of size 4 at addr 0000000000000030 by task syz-executor154/3327 CPU: 0 PID: 3327 Comm: syz-executor154 Tainted: G O 5.10.185 #1 Hardware name: emulation qemu-x86/qemu-x86, BIOS 2023.01-21885-gb3cc1cd24d 01/01/2023 Call Trace: __dump_stack out/common/lib/dump_stack.c:77 [inline] dump_stack_lvl+0x17e/0x1c4 out/common/lib/dump_stack.c:118 __kasan_report+0x16c/0x260 out/common/mm/kasan/report.c:415 kasan_report+0x51/0x70 out/common/mm/kasan/report.c:428 kasan_check_range+0x2f3/0x340 out/common/mm/kasan/generic.c:186 __kasan_check_write+0x14/0x20 out/common/mm/kasan/shadow.c:37 instrument_atomic_read_write out/common/include/linux/instrumented.h:101 [inline] atomic_try_cmpxchg_acquire out/common/include/asm-generic/atomic-instrumented.h:705 [inline] queued_write_lock out/common/include/asm-generic/qrwlock.h:92 [inline] __raw_write_lock out/common/include/linux/rwlock_api_smp.h:211 [inline] _raw_write_lock+0x5a/0x110 out/common/kernel/locking/spinlock.c:295 __drop_extent_tree+0xdf/0x2f0 out/common/fs/f2fs/extent_cache.c:1155 f2fs_drop_extent_tree+0x17/0x30 out/common/fs/f2fs/extent_cache.c:1172 f2fs_insert_range out/common/fs/f2fs/file.c:1600 [inline] f2fs_fallocate+0x19fd/0x1f40 out/common/fs/f2fs/file.c:1764 vfs_fallocate+0x514/0x9b0 out/common/fs/open.c:310 ksys_fallocate out/common/fs/open.c:333 [inline] __do_sys_fallocate out/common/fs/open.c:341 [inline] __se_sys_fallocate out/common/fs/open.c:339 [inline] __x64_sys_fallocate+0xb8/0x100 out/common/fs/open.c:339 do_syscall_64+0x35/0x50 out/common/arch/x86/entry/common.c:46

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix potential null pointer derefernce The amdgpu_ras_get_context may return NULL if device not support ras feature, so add check before using.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix potential NULL dereference Fix potential NULL dereference, in the case when "man", the resource manager might be NULL, when/if we print debug information.

In the Linux kernel, the following vulnerability has been resolved: crypto: rsa - add a check for allocation failure Static checkers insist that the mpi_alloc() allocation can fail so add a check to prevent a NULL dereference. Small allocations like this can't actually fail in current kernels, but adding a check is very simple and makes the static checkers happy.

In the Linux kernel, the following vulnerability has been resolved: drm/panel/panel-tpo-tpg110: fix a possible null pointer dereference In tpg110_get_modes(), the return value of drm_mode_duplicate() is assigned to mode, which will lead to a NULL pointer dereference on failure of drm_mode_duplicate(). Add a check to avoid npd.

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: media: vidtv: mux: Add check and kfree for kstrdup Add check for the return value of kstrdup() and return the error if it fails in order to avoid NULL pointer dereference. Moreover, use kfree() in the later error handling in order to avoid memory leak.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Avoid NULL dereference of timing generator [Why & How] Check whether assigned timing generator is NULL or not before accessing its funcs to prevent NULL dereference.

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_ncm: fix potential NULL ptr deref in ncm_bitrate() In Google internal bug 265639009 we've received an (as yet) unreproducible crash report from an aarch64 GKI 5.10.149-android13 running device. AFAICT the source code is at: https://android.googlesource.com/kernel/common/+/refs/tags/ASB-2022-12-05_13-5.10 The call stack is: ncm_close() -> ncm_notify() -> ncm_do_notify() with the crash at: ncm_do_notify+0x98/0x270 Code: 79000d0b b9000a6c f940012a f9400269 (b9405d4b) Which I believe disassembles to (I don't know ARM assembly, but it looks sane enough to me...): // halfword (16-bit) store presumably to event->wLength (at offset 6 of struct usb_cdc_notification) 0B 0D 00 79 strh w11, [x8, #6] // word (32-bit) store presumably to req->Length (at offset 8 of struct usb_request) 6C 0A 00 B9 str w12, [x19, #8] // x10 (NULL) was read here from offset 0 of valid pointer x9 // IMHO we're reading 'cdev->gadget' and getting NULL // gadget is indeed at offset 0 of struct usb_composite_dev 2A 01 40 F9 ldr x10, [x9] // loading req->buf pointer, which is at offset 0 of struct usb_request 69 02 40 F9 ldr x9, [x19] // x10 is null, crash, appears to be attempt to read cdev->gadget->max_speed 4B 5D 40 B9 ldr w11, [x10, #0x5c] which seems to line up with ncm_do_notify() case NCM_NOTIFY_SPEED code fragment: event->wLength = cpu_to_le16(8); req->length = NCM_STATUS_BYTECOUNT; /* SPEED_CHANGE data is up/down speeds in bits/sec */ data = req->buf + sizeof *event; data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget)); My analysis of registers and NULL ptr deref crash offset (Unable to handle kernel NULL pointer dereference at virtual address 000000000000005c) heavily suggests that the crash is due to 'cdev->gadget' being NULL when executing: data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget)); which calls: ncm_bitrate(NULL) which then calls: gadget_is_superspeed(NULL) which reads ((struct usb_gadget *)NULL)->max_speed and hits a panic. AFAICT, if I'm counting right, the offset of max_speed is indeed 0x5C. (remember there's a GKI KABI reservation of 16 bytes in struct work_struct) It's not at all clear to me how this is all supposed to work... but returning 0 seems much better than panic-ing...

In the Linux kernel, the following vulnerability has been resolved: wifi: wfx: fix possible NULL pointer dereference in wfx_set_mfp_ap() Since 'ieee80211_beacon_get()' can return NULL, 'wfx_set_mfp_ap()' should check the return value before examining skb data. So convert the latter to return an appropriate error code and propagate it to return from 'wfx_start_ap()' as well. Compile tested only.

In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel/uncore: Fix NULL pointer dereference issue in upi_fill_topology() Get logical socket id instead of physical id in discover_upi_topology() to avoid out-of-bound access on 'upi = &type->topology[nid][idx];' line that leads to NULL pointer dereference in upi_fill_topology()

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: drm/msm: another fix for the headless Adreno GPU Fix another oops reproducible when rebooting the board with the Adreno GPU working in the headless mode (e.g. iMX platforms). Unable to handle kernel NULL pointer dereference at virtual address 00000000 when read [00000000] *pgd=74936831, *pte=00000000, *ppte=00000000 Internal error: Oops: 17 [#1] ARM CPU: 0 PID: 51 Comm: reboot Not tainted 6.2.0-rc1-dirty #11 Hardware name: Freescale i.MX53 (Device Tree Support) PC is at msm_atomic_commit_tail+0x50/0x970 LR is at commit_tail+0x9c/0x188 pc : [<c06aa430>] lr : [<c067a214>] psr: 600e0013 sp : e0851d30 ip : ee4eb7eb fp : 00090acc r10: 00000058 r9 : c2193014 r8 : c4310000 r7 : c4759380 r6 : 07bef61d r5 : 00000000 r4 : 00000000 r3 : c44cc440 r2 : 00000000 r1 : 00000000 r0 : 00000000 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 10c5387d Table: 74910019 DAC: 00000051 Register r0 information: NULL pointer Register r1 information: NULL pointer Register r2 information: NULL pointer Register r3 information: slab kmalloc-1k start c44cc400 pointer offset 64 size 1024 Register r4 information: NULL pointer Register r5 information: NULL pointer Register r6 information: non-paged memory Register r7 information: slab kmalloc-128 start c4759380 pointer offset 0 size 128 Register r8 information: slab kmalloc-2k start c4310000 pointer offset 0 size 2048 Register r9 information: non-slab/vmalloc memory Register r10 information: non-paged memory Register r11 information: non-paged memory Register r12 information: non-paged memory Process reboot (pid: 51, stack limit = 0xc80046d9) Stack: (0xe0851d30 to 0xe0852000) 1d20: c4759380 fbd77200 000005ff 002b9c70 1d40: c4759380 c4759380 00000000 07bef61d 00000600 c0d6fe7c c2193014 00000058 1d60: 00090acc c067a214 00000000 c4759380 c4310000 00000000 c44cc854 c067a89c 1d80: 00000000 00000000 00000000 c4310468 00000000 c4759380 c4310000 c4310468 1da0: c4310470 c0643258 c4759380 00000000 00000000 c0c4ee24 00000000 c44cc810 1dc0: 00000000 c0c4ee24 00000000 c44cc810 00000000 0347d2a8 e0851e00 e0851e00 1de0: c4759380 c067ad20 c4310000 00000000 c44cc810 c27f8718 c44cc854 c067adb8 1e00: c4933000 00000002 00000001 00000000 00000000 c2130850 00000000 c2130854 1e20: c25fc488 00000000 c0ff162c 00000000 00000001 00000002 00000000 00000000 1e40: c43102c0 c43102c0 00000000 0347d2a8 c44cc810 c44cc814 c2133da8 c06d1a60 1e60: 00000000 00000000 00079028 c2012f24 fee1dead c4933000 00000058 c01431e4 1e80: 01234567 c0143a20 00000000 00000000 00000000 00000000 00000000 00000000 1ea0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1ec0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1ee0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1f00: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1f20: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1f40: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1f60: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1f80: 00000000 00000000 00000000 0347d2a8 00000002 00000004 00000078 00000058 1fa0: c010028c c0100060 00000002 00000004 fee1dead 28121969 01234567 00079028 1fc0: 00000002 00000004 00000078 00000058 0002fdc5 00000000 00000000 00090acc 1fe0: 00000058 becc9c64 b6e97e05 b6e0e5f6 600e0030 fee1dead 00000000 00000000 msm_atomic_commit_tail from commit_tail+0x9c/0x188 commit_tail from drm_atomic_helper_commit+0x160/0x188 drm_atomic_helper_commit from drm_atomic_commit+0xac/0xe0 drm_atomic_commit from drm_atomic_helper_disable_all+0x1b0/0x1c0 drm_atomic_helper_disable_all from drm_atomic_helper_shutdown+0x88/0x140 drm_atomic_helper_shutdown from device_shutdown+0x16c/0x240 device_shutdown from kernel_restart+0x38/0x90 kernel_restart from __do_sys_reboot+0x ---truncated---

In the Linux kernel, the following vulnerability has been resolved: Revert "tty: n_gsm: fix UAF in gsm_cleanup_mux" This reverts commit 9b9c8195f3f0d74a826077fc1c01b9ee74907239. The commit above is reverted as it did not solve the original issue. gsm_cleanup_mux() tries to free up the virtual ttys by calling gsm_dlci_release() for each available DLCI. There, dlci_put() is called to decrease the reference counter for the DLCI via tty_port_put() which finally calls gsm_dlci_free(). This already clears the pointer which is being checked in gsm_cleanup_mux() before calling gsm_dlci_release(). Therefore, it is not necessary to clear this pointer in gsm_cleanup_mux() as done in the reverted commit. The commit introduces a null pointer dereference: <TASK> ? __die+0x1f/0x70 ? page_fault_oops+0x156/0x420 ? search_exception_tables+0x37/0x50 ? fixup_exception+0x21/0x310 ? exc_page_fault+0x69/0x150 ? asm_exc_page_fault+0x26/0x30 ? tty_port_put+0x19/0xa0 gsmtty_cleanup+0x29/0x80 [n_gsm] release_one_tty+0x37/0xe0 process_one_work+0x1e6/0x3e0 worker_thread+0x4c/0x3d0 ? __pfx_worker_thread+0x10/0x10 kthread+0xe1/0x110 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2f/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 </TASK> The actual issue is that nothing guards dlci_put() from being called multiple times while the tty driver was triggered but did not yet finished calling gsm_dlci_free().

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: acpi: Fix suspend with Xen PV Commit f1e525009493 ("x86/boot: Skip realmode init code when running as Xen PV guest") missed one code path accessing real_mode_header, leading to dereferencing NULL when suspending the system under Xen: [ 348.284004] PM: suspend entry (deep) [ 348.289532] Filesystems sync: 0.005 seconds [ 348.291545] Freezing user space processes ... (elapsed 0.000 seconds) done. [ 348.292457] OOM killer disabled. [ 348.292462] Freezing remaining freezable tasks ... (elapsed 0.104 seconds) done. [ 348.396612] printk: Suspending console(s) (use no_console_suspend to debug) [ 348.749228] PM: suspend devices took 0.352 seconds [ 348.769713] ACPI: EC: interrupt blocked [ 348.816077] BUG: kernel NULL pointer dereference, address: 000000000000001c [ 348.816080] #PF: supervisor read access in kernel mode [ 348.816081] #PF: error_code(0x0000) - not-present page [ 348.816083] PGD 0 P4D 0 [ 348.816086] Oops: 0000 [#1] PREEMPT SMP NOPTI [ 348.816089] CPU: 0 PID: 6764 Comm: systemd-sleep Not tainted 6.1.3-1.fc32.qubes.x86_64 #1 [ 348.816092] Hardware name: Star Labs StarBook/StarBook, BIOS 8.01 07/03/2022 [ 348.816093] RIP: e030:acpi_get_wakeup_address+0xc/0x20 Fix that by adding an optional acpi callback allowing to skip setting the wakeup address, as in the Xen PV case this will be handled by the hypervisor anyway.

In the Linux kernel, the following vulnerability has been resolved: usb: xhci: Check endpoint is valid before dereferencing it When the host controller is not responding, all URBs queued to all endpoints need to be killed. This can cause a kernel panic if we dereference an invalid endpoint. Fix this by using xhci_get_virt_ep() helper to find the endpoint and checking if the endpoint is valid before dereferencing it. [233311.853271] xhci-hcd xhci-hcd.1.auto: xHCI host controller not responding, assume dead [233311.853393] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000e8 [233311.853964] pc : xhci_hc_died+0x10c/0x270 [233311.853971] lr : xhci_hc_died+0x1ac/0x270 [233311.854077] Call trace: [233311.854085] xhci_hc_died+0x10c/0x270 [233311.854093] xhci_stop_endpoint_command_watchdog+0x100/0x1a4 [233311.854105] call_timer_fn+0x50/0x2d4 [233311.854112] expire_timers+0xac/0x2e4 [233311.854118] run_timer_softirq+0x300/0xabc [233311.854127] __do_softirq+0x148/0x528 [233311.854135] irq_exit+0x194/0x1a8 [233311.854143] __handle_domain_irq+0x164/0x1d0 [233311.854149] gic_handle_irq.22273+0x10c/0x188 [233311.854156] el1_irq+0xfc/0x1a8 [233311.854175] lpm_cpuidle_enter+0x25c/0x418 [msm_pm] [233311.854185] cpuidle_enter_state+0x1f0/0x764 [233311.854194] do_idle+0x594/0x6ac [233311.854201] cpu_startup_entry+0x7c/0x80 [233311.854209] secondary_start_kernel+0x170/0x198

In the Linux kernel, the following vulnerability has been resolved: net: phy: dp83822: Fix null pointer access on DP83825/DP83826 devices The probe() function is only used for the DP83822 PHY, leaving the private data pointer uninitialized for the smaller DP83825/26 models. While all uses of the private data structure are hidden in 82822 specific callbacks, configuring the interrupt is shared across all models. This causes a NULL pointer dereference on the smaller PHYs as it accesses the private data unchecked. Verifying the pointer avoids that.

In the Linux kernel, the following vulnerability has been resolved: nfc: nci: fix possible NULL pointer dereference in send_acknowledge() Handle memory allocation failure from nci_skb_alloc() (calling alloc_skb()) to avoid possible 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: nvme-fc: Prevent null pointer dereference in nvme_fc_io_getuuid() The nvme_fc_fcp_op structure describing an AEN operation is initialized with a null request structure pointer. An FC LLDD may make a call to nvme_fc_io_getuuid passing a pointer to an nvmefc_fcp_req for an AEN operation. Add validation of the request structure pointer before dereference.

In the Linux kernel, the following vulnerability has been resolved: usb: hub: Guard against accesses to uninitialized BOS descriptors Many functions in drivers/usb/core/hub.c and drivers/usb/core/hub.h access fields inside udev->bos without checking if it was allocated and initialized. If usb_get_bos_descriptor() fails for whatever reason, udev->bos will be NULL and those accesses will result in a crash: BUG: kernel NULL pointer dereference, address: 0000000000000018 PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 5 PID: 17818 Comm: kworker/5:1 Tainted: G W 5.15.108-18910-gab0e1cb584e1 #1 <HASH:1f9e 1> Hardware name: Google Kindred/Kindred, BIOS Google_Kindred.12672.413.0 02/03/2021 Workqueue: usb_hub_wq hub_event RIP: 0010:hub_port_reset+0x193/0x788 Code: 89 f7 e8 20 f7 15 00 48 8b 43 08 80 b8 96 03 00 00 03 75 36 0f b7 88 92 03 00 00 81 f9 10 03 00 00 72 27 48 8b 80 a8 03 00 00 <48> 83 78 18 00 74 19 48 89 df 48 8b 75 b0 ba 02 00 00 00 4c 89 e9 RSP: 0018:ffffab740c53fcf8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffa1bc5f678000 RCX: 0000000000000310 RDX: fffffffffffffdff RSI: 0000000000000286 RDI: ffffa1be9655b840 RBP: ffffab740c53fd70 R08: 00001b7d5edaa20c R09: ffffffffb005e060 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: ffffab740c53fd3e R14: 0000000000000032 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffffa1be96540000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000018 CR3: 000000022e80c005 CR4: 00000000003706e0 Call Trace: hub_event+0x73f/0x156e ? hub_activate+0x5b7/0x68f process_one_work+0x1a2/0x487 worker_thread+0x11a/0x288 kthread+0x13a/0x152 ? process_one_work+0x487/0x487 ? kthread_associate_blkcg+0x70/0x70 ret_from_fork+0x1f/0x30 Fall back to a default behavior if the BOS descriptor isn't accessible and skip all the functionalities that depend on it: LPM support checks, Super Speed capabilitiy checks, U1/U2 states setup.

In the Linux kernel, the following vulnerability has been resolved: team: fix null-ptr-deref when team device type is changed Get a null-ptr-deref bug as follows with reproducer [1]. BUG: kernel NULL pointer dereference, address: 0000000000000228 ... RIP: 0010:vlan_dev_hard_header+0x35/0x140 [8021q] ... Call Trace: <TASK> ? __die+0x24/0x70 ? page_fault_oops+0x82/0x150 ? exc_page_fault+0x69/0x150 ? asm_exc_page_fault+0x26/0x30 ? vlan_dev_hard_header+0x35/0x140 [8021q] ? vlan_dev_hard_header+0x8e/0x140 [8021q] neigh_connected_output+0xb2/0x100 ip6_finish_output2+0x1cb/0x520 ? nf_hook_slow+0x43/0xc0 ? ip6_mtu+0x46/0x80 ip6_finish_output+0x2a/0xb0 mld_sendpack+0x18f/0x250 mld_ifc_work+0x39/0x160 process_one_work+0x1e6/0x3f0 worker_thread+0x4d/0x2f0 ? __pfx_worker_thread+0x10/0x10 kthread+0xe5/0x120 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x34/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 [1] $ teamd -t team0 -d -c '{"runner": {"name": "loadbalance"}}' $ ip link add name t-dummy type dummy $ ip link add link t-dummy name t-dummy.100 type vlan id 100 $ ip link add name t-nlmon type nlmon $ ip link set t-nlmon master team0 $ ip link set t-nlmon nomaster $ ip link set t-dummy up $ ip link set team0 up $ ip link set t-dummy.100 down $ ip link set t-dummy.100 master team0 When enslave a vlan device to team device and team device type is changed from non-ether to ether, header_ops of team device is changed to vlan_header_ops. That is incorrect and will trigger null-ptr-deref for vlan->real_dev in vlan_dev_hard_header() because team device is not a vlan device. Cache eth_header_ops in team_setup(), then assign cached header_ops to header_ops of team net device when its type is changed from non-ether to ether to fix the bug.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix a null pointer access when the smc_rreg pointer is NULL In certain types of chips, such as VEGA20, reading the amdgpu_regs_smc file could result in an abnormal null pointer access when the smc_rreg pointer is NULL. Below are the steps to reproduce this issue and the corresponding exception log: 1. Navigate to the directory: /sys/kernel/debug/dri/0 2. Execute command: cat amdgpu_regs_smc 3. Exception Log:: [4005007.702554] BUG: kernel NULL pointer dereference, address: 0000000000000000 [4005007.702562] #PF: supervisor instruction fetch in kernel mode [4005007.702567] #PF: error_code(0x0010) - not-present page [4005007.702570] PGD 0 P4D 0 [4005007.702576] Oops: 0010 [#1] SMP NOPTI [4005007.702581] CPU: 4 PID: 62563 Comm: cat Tainted: G OE 5.15.0-43-generic #46-Ubunt u [4005007.702590] RIP: 0010:0x0 [4005007.702598] Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. [4005007.702600] RSP: 0018:ffffa82b46d27da0 EFLAGS: 00010206 [4005007.702605] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffa82b46d27e68 [4005007.702609] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff9940656e0000 [4005007.702612] RBP: ffffa82b46d27dd8 R08: 0000000000000000 R09: ffff994060c07980 [4005007.702615] R10: 0000000000020000 R11: 0000000000000000 R12: 00007f5e06753000 [4005007.702618] R13: ffff9940656e0000 R14: ffffa82b46d27e68 R15: 00007f5e06753000 [4005007.702622] FS: 00007f5e0755b740(0000) GS:ffff99479d300000(0000) knlGS:0000000000000000 [4005007.702626] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [4005007.702629] CR2: ffffffffffffffd6 CR3: 00000003253fc000 CR4: 00000000003506e0 [4005007.702633] Call Trace: [4005007.702636] <TASK> [4005007.702640] amdgpu_debugfs_regs_smc_read+0xb0/0x120 [amdgpu] [4005007.703002] full_proxy_read+0x5c/0x80 [4005007.703011] vfs_read+0x9f/0x1a0 [4005007.703019] ksys_read+0x67/0xe0 [4005007.703023] __x64_sys_read+0x19/0x20 [4005007.703028] do_syscall_64+0x5c/0xc0 [4005007.703034] ? do_user_addr_fault+0x1e3/0x670 [4005007.703040] ? exit_to_user_mode_prepare+0x37/0xb0 [4005007.703047] ? irqentry_exit_to_user_mode+0x9/0x20 [4005007.703052] ? irqentry_exit+0x19/0x30 [4005007.703057] ? exc_page_fault+0x89/0x160 [4005007.703062] ? asm_exc_page_fault+0x8/0x30 [4005007.703068] entry_SYSCALL_64_after_hwframe+0x44/0xae [4005007.703075] RIP: 0033:0x7f5e07672992 [4005007.703079] Code: c0 e9 b2 fe ff ff 50 48 8d 3d fa b2 0c 00 e8 c5 1d 02 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 e c 28 48 89 54 24 [4005007.703083] RSP: 002b:00007ffe03097898 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [4005007.703088] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f5e07672992 [4005007.703091] RDX: 0000000000020000 RSI: 00007f5e06753000 RDI: 0000000000000003 [4005007.703094] RBP: 00007f5e06753000 R08: 00007f5e06752010 R09: 00007f5e06752010 [4005007.703096] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000022000 [4005007.703099] R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000 [4005007.703105] </TASK> [4005007.703107] Modules linked in: nf_tables libcrc32c nfnetlink algif_hash af_alg binfmt_misc nls_ iso8859_1 ipmi_ssif ast intel_rapl_msr intel_rapl_common drm_vram_helper drm_ttm_helper amd64_edac t tm edac_mce_amd kvm_amd ccp mac_hid k10temp kvm acpi_ipmi ipmi_si rapl sch_fq_codel ipmi_devintf ipm i_msghandler msr parport_pc ppdev lp parport mtd pstore_blk efi_pstore ramoops pstore_zone reed_solo mon ip_tables x_tables autofs4 ib_uverbs ib_core amdgpu(OE) amddrm_ttm_helper(OE) amdttm(OE) iommu_v 2 amd_sched(OE) amdkcl(OE) drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec rc_core drm igb ahci xhci_pci libahci i2c_piix4 i2c_algo_bit xhci_pci_renesas dca [4005007.703184] CR2: 0000000000000000 [4005007.703188] ---[ en ---truncated---

In the Linux kernel, the following vulnerability has been resolved: mtd: Fix gluebi NULL pointer dereference caused by ftl notifier If both ftl.ko and gluebi.ko are loaded, the notifier of ftl triggers NULL pointer dereference when trying to access ‘gluebi->desc’ in gluebi_read(). ubi_gluebi_init ubi_register_volume_notifier ubi_enumerate_volumes ubi_notify_all gluebi_notify nb->notifier_call() gluebi_create mtd_device_register mtd_device_parse_register add_mtd_device blktrans_notify_add not->add() ftl_add_mtd tr->add_mtd() scan_header mtd_read mtd_read_oob mtd_read_oob_std gluebi_read mtd->read() gluebi->desc - NULL Detailed reproduction information available at the Link [1], In the normal case, obtain gluebi->desc in the gluebi_get_device(), and access gluebi->desc in the gluebi_read(). However, gluebi_get_device() is not executed in advance in the ftl_add_mtd() process, which leads to NULL pointer dereference. The solution for the gluebi module is to run jffs2 on the UBI volume without considering working with ftl or mtdblock [2]. Therefore, this problem can be avoided by preventing gluebi from creating the mtdblock device after creating mtd partition of the type MTD_UBIVOLUME.

In the Linux kernel, the following vulnerability has been resolved: i915/perf: Fix NULL deref bugs with drm_dbg() calls When i915 perf interface is not available dereferencing it will lead to NULL dereferences. As returning -ENOTSUPP is pretty clear return when perf interface is not available. [tursulin: added stable tag] (cherry picked from commit 36f27350ff745bd228ab04d7845dfbffc177a889)