In the Linux kernel, the following vulnerability has been resolved: tracing: Restructure trace_clock_global() to never block It was reported that a fix to the ring buffer recursion detection would cause a hung machine when performing suspend / resume testing. The following backtrace was extracted from debugging that case: Call Trace: trace_clock_global+0x91/0xa0 __rb_reserve_next+0x237/0x460 ring_buffer_lock_reserve+0x12a/0x3f0 trace_buffer_lock_reserve+0x10/0x50 __trace_graph_return+0x1f/0x80 trace_graph_return+0xb7/0xf0 ? trace_clock_global+0x91/0xa0 ftrace_return_to_handler+0x8b/0xf0 ? pv_hash+0xa0/0xa0 return_to_handler+0x15/0x30 ? ftrace_graph_caller+0xa0/0xa0 ? trace_clock_global+0x91/0xa0 ? __rb_reserve_next+0x237/0x460 ? ring_buffer_lock_reserve+0x12a/0x3f0 ? trace_event_buffer_lock_reserve+0x3c/0x120 ? trace_event_buffer_reserve+0x6b/0xc0 ? trace_event_raw_event_device_pm_callback_start+0x125/0x2d0 ? dpm_run_callback+0x3b/0xc0 ? pm_ops_is_empty+0x50/0x50 ? platform_get_irq_byname_optional+0x90/0x90 ? trace_device_pm_callback_start+0x82/0xd0 ? dpm_run_callback+0x49/0xc0 With the following RIP: RIP: 0010:native_queued_spin_lock_slowpath+0x69/0x200 Since the fix to the recursion detection would allow a single recursion to happen while tracing, this lead to the trace_clock_global() taking a spin lock and then trying to take it again: ring_buffer_lock_reserve() { trace_clock_global() { arch_spin_lock() { queued_spin_lock_slowpath() { /* lock taken */ (something else gets traced by function graph tracer) ring_buffer_lock_reserve() { trace_clock_global() { arch_spin_lock() { queued_spin_lock_slowpath() { /* DEAD LOCK! */ Tracing should *never* block, as it can lead to strange lockups like the above. Restructure the trace_clock_global() code to instead of simply taking a lock to update the recorded "prev_time" simply use it, as two events happening on two different CPUs that calls this at the same time, really doesn't matter which one goes first. Use a trylock to grab the lock for updating the prev_time, and if it fails, simply try again the next time. If it failed to be taken, that means something else is already updating it. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212761

In the Linux kernel, the following vulnerability has been resolved: net: fix use-after-free in tw_timer_handler A real world panic issue was found as follow in Linux 5.4. BUG: unable to handle page fault for address: ffffde49a863de28 PGD 7e6fe62067 P4D 7e6fe62067 PUD 7e6fe63067 PMD f51e064067 PTE 0 RIP: 0010:tw_timer_handler+0x20/0x40 Call Trace: <IRQ> call_timer_fn+0x2b/0x120 run_timer_softirq+0x1ef/0x450 __do_softirq+0x10d/0x2b8 irq_exit+0xc7/0xd0 smp_apic_timer_interrupt+0x68/0x120 apic_timer_interrupt+0xf/0x20 This issue was also reported since 2017 in the thread [1], unfortunately, the issue was still can be reproduced after fixing DCCP. The ipv4_mib_exit_net is called before tcp_sk_exit_batch when a net namespace is destroyed since tcp_sk_ops is registered befrore ipv4_mib_ops, which means tcp_sk_ops is in the front of ipv4_mib_ops in the list of pernet_list. There will be a use-after-free on net->mib.net_statistics in tw_timer_handler after ipv4_mib_exit_net if there are some inflight time-wait timers. This bug is not introduced by commit f2bf415cfed7 ("mib: add net to NET_ADD_STATS_BH") since the net_statistics is a global variable instead of dynamic allocation and freeing. Actually, commit 61a7e26028b9 ("mib: put net statistics on struct net") introduces the bug since it put net statistics on struct net and free it when net namespace is destroyed. Moving init_ipv4_mibs() to the front of tcp_init() to fix this bug and replace pr_crit() with panic() since continuing is meaningless when init_ipv4_mibs() fails. [1] https://groups.google.com/g/syzkaller/c/p1tn-_Kc6l4/m/smuL_FMAAgAJ?pli=1

In the Linux kernel, the following vulnerability has been resolved: Input: appletouch - initialize work before device registration Syzbot has reported warning in __flush_work(). This warning is caused by work->func == NULL, which means missing work initialization. This may happen, since input_dev->close() calls cancel_work_sync(&dev->work), but dev->work initalization happens _after_ input_register_device() call. So this patch moves dev->work initialization before registering input device

In the Linux kernel, the following vulnerability has been resolved: parisc: Clear stale IIR value on instruction access rights trap When a trap 7 (Instruction access rights) occurs, this means the CPU couldn't execute an instruction due to missing execute permissions on the memory region. In this case it seems the CPU didn't even fetched the instruction from memory and thus did not store it in the cr19 (IIR) register before calling the trap handler. So, the trap handler will find some random old stale value in cr19. This patch simply overwrites the stale IIR value with a constant magic "bad food" value (0xbaadf00d), in the hope people don't start to try to understand the various random IIR values in trap 7 dumps.

In the Linux kernel, the following vulnerability has been resolved: ALSA: hda: intel-sdw-acpi: harden detection of controller The existing code currently sets a pointer to an ACPI handle before checking that it's actually a SoundWire controller. This can lead to issues where the graph walk continues and eventually fails, but the pointer was set already. This patch changes the logic so that the information provided to the caller is set when a controller is found.

In the Linux kernel, the following vulnerability has been resolved: HID: usbhid: fix info leak in hid_submit_ctrl In hid_submit_ctrl(), the way of calculating the report length doesn't take into account that report->size can be zero. When running the syzkaller reproducer, a report of size 0 causes hid_submit_ctrl) to calculate transfer_buffer_length as 16384. When this urb is passed to the usb core layer, KMSAN reports an info leak of 16384 bytes. To fix this, first modify hid_report_len() to account for the zero report size case by using DIV_ROUND_UP for the division. Then, call it from hid_submit_ctrl().

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid potential deadlock Using f2fs_trylock_op() in f2fs_write_compressed_pages() to avoid potential deadlock like we did in f2fs_write_single_data_page().

In the Linux kernel, the following vulnerability has been resolved: netlabel: fix out-of-bounds memory accesses There are two array out-of-bounds memory accesses, one in cipso_v4_map_lvl_valid(), the other in netlbl_bitmap_walk(). Both errors are embarassingly simple, and the fixes are straightforward. As a FYI for anyone backporting this patch to kernels prior to v4.8, you'll want to apply the netlbl_bitmap_walk() patch to cipso_v4_bitmap_walk() as netlbl_bitmap_walk() doesn't exist before Linux v4.8.

In the Linux kernel, the following vulnerability has been resolved: binder: signal epoll threads of self-work In (e)poll mode, threads often depend on I/O events to determine when data is ready for consumption. Within binder, a thread may initiate a command via BINDER_WRITE_READ without a read buffer and then make use of epoll_wait() or similar to consume any responses afterwards. It is then crucial that epoll threads are signaled via wakeup when they queue their own work. Otherwise, they risk waiting indefinitely for an event leaving their work unhandled. What is worse, subsequent commands won't trigger a wakeup either as the thread has pending work.

In the Linux kernel, the following vulnerability has been resolved: ext4: regenerate buddy after block freeing failed if under fc replay This mostly reverts commit 6bd97bf273bd ("ext4: remove redundant mb_regenerate_buddy()") and reintroduces mb_regenerate_buddy(). Based on code in mb_free_blocks(), fast commit replay can end up marking as free blocks that are already marked as such. This causes corruption of the buddy bitmap so we need to regenerate it in that case.

In the Linux kernel, the following vulnerability has been resolved: phy: ti: phy-omap-usb2: Fix NULL pointer dereference for SRP If the external phy working together with phy-omap-usb2 does not implement send_srp(), we may still attempt to call it. This can happen on an idle Ethernet gadget triggering a wakeup for example: configfs-gadget.g1 gadget.0: ECM Suspend configfs-gadget.g1 gadget.0: Port suspended. Triggering wakeup ... Unable to handle kernel NULL pointer dereference at virtual address 00000000 when execute ... PC is at 0x0 LR is at musb_gadget_wakeup+0x1d4/0x254 [musb_hdrc] ... musb_gadget_wakeup [musb_hdrc] from usb_gadget_wakeup+0x1c/0x3c [udc_core] usb_gadget_wakeup [udc_core] from eth_start_xmit+0x3b0/0x3d4 [u_ether] eth_start_xmit [u_ether] from dev_hard_start_xmit+0x94/0x24c dev_hard_start_xmit from sch_direct_xmit+0x104/0x2e4 sch_direct_xmit from __dev_queue_xmit+0x334/0xd88 __dev_queue_xmit from arp_solicit+0xf0/0x268 arp_solicit from neigh_probe+0x54/0x7c neigh_probe from __neigh_event_send+0x22c/0x47c __neigh_event_send from neigh_resolve_output+0x14c/0x1c0 neigh_resolve_output from ip_finish_output2+0x1c8/0x628 ip_finish_output2 from ip_send_skb+0x40/0xd8 ip_send_skb from udp_send_skb+0x124/0x340 udp_send_skb from udp_sendmsg+0x780/0x984 udp_sendmsg from __sys_sendto+0xd8/0x158 __sys_sendto from ret_fast_syscall+0x0/0x58 Let's fix the issue by checking for send_srp() and set_vbus() before calling them. For USB peripheral only cases these both could be NULL.

In the Linux kernel, the following vulnerability has been resolved: moxart: fix potential use-after-free on remove path It was reported that the mmc host structure could be accessed after it was freed in moxart_remove(), so fix this by saving the base register of the device and using it instead of the pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: net: hso: fix NULL-deref on disconnect regression Commit 8a12f8836145 ("net: hso: fix null-ptr-deref during tty device unregistration") fixed the racy minor allocation reported by syzbot, but introduced an unconditional NULL-pointer dereference on every disconnect instead. Specifically, the serial device table must no longer be accessed after the minor has been released by hso_serial_tty_unregister().

In the Linux kernel, the following vulnerability has been resolved: net: hso: fix null-ptr-deref during tty device unregistration Multiple ttys try to claim the same the minor number causing a double unregistration of the same device. The first unregistration succeeds but the next one results in a null-ptr-deref. The get_free_serial_index() function returns an available minor number but doesn't assign it immediately. The assignment is done by the caller later. But before this assignment, calls to get_free_serial_index() would return the same minor number. Fix this by modifying get_free_serial_index to assign the minor number immediately after one is found to be and rename it to obtain_minor() to better reflect what it does. Similary, rename set_serial_by_index() to release_minor() and modify it to free up the minor number of the given hso_serial. Every obtain_minor() should have corresponding release_minor() call.

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: vgic-its: Avoid potential UAF in LPI translation cache There is a potential UAF scenario in the case of an LPI translation cache hit racing with an operation that invalidates the cache, such as a DISCARD ITS command. The root of the problem is that vgic_its_check_cache() does not elevate the refcount on the vgic_irq before dropping the lock that serializes refcount changes. Have vgic_its_check_cache() raise the refcount on the returned vgic_irq and add the corresponding decrement after queueing the interrupt.

In the Linux kernel, the following vulnerability has been resolved: bpf: fix check for attempt to corrupt spilled pointer When register is spilled onto a stack as a 1/2/4-byte register, we set slot_type[BPF_REG_SIZE - 1] (plus potentially few more below it, depending on actual spill size). So to check if some stack slot has spilled register we need to consult slot_type[7], not slot_type[0]. To avoid the need to remember and double-check this in the future, just use is_spilled_reg() helper.

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix re-attachment branch in bpf_tracing_prog_attach The following case can cause a crash due to missing attach_btf: 1) load rawtp program 2) load fentry program with rawtp as target_fd 3) create tracing link for fentry program with target_fd = 0 4) repeat 3 In the end we have: - prog->aux->dst_trampoline == NULL - tgt_prog == NULL (because we did not provide target_fd to link_create) - prog->aux->attach_btf == NULL (the program was loaded with attach_prog_fd=X) - the program was loaded for tgt_prog but we have no way to find out which one BUG: kernel NULL pointer dereference, address: 0000000000000058 Call Trace: <TASK> ? __die+0x20/0x70 ? page_fault_oops+0x15b/0x430 ? fixup_exception+0x22/0x330 ? exc_page_fault+0x6f/0x170 ? asm_exc_page_fault+0x22/0x30 ? bpf_tracing_prog_attach+0x279/0x560 ? btf_obj_id+0x5/0x10 bpf_tracing_prog_attach+0x439/0x560 __sys_bpf+0x1cf4/0x2de0 __x64_sys_bpf+0x1c/0x30 do_syscall_64+0x41/0xf0 entry_SYSCALL_64_after_hwframe+0x6e/0x76 Return -EINVAL in this situation.

In the Linux kernel, the following vulnerability has been resolved: LoongArch: BPF: Prevent out-of-bounds memory access The test_tag test triggers an unhandled page fault: # ./test_tag [ 130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70 [ 130.640501] Oops[#3]: [ 130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G D O 6.7.0-rc4-loong-devel-gb62ab1a397cf #47 61985c1d94084daa2432f771daa45b56b10d8d2a [ 130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022 [ 130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40 [ 130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000 [ 130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000 [ 130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70 [ 130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0 [ 130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0 [ 130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000 [ 130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000 [ 130.641900] ra: 9000000003139e70 build_body+0x1fcc/0x4988 [ 130.642007] ERA: 9000000003137f7c build_body+0xd8/0x4988 [ 130.642112] CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE) [ 130.642261] PRMD: 00000004 (PPLV0 +PIE -PWE) [ 130.642353] EUEN: 00000003 (+FPE +SXE -ASXE -BTE) [ 130.642458] ECFG: 00071c1c (LIE=2-4,10-12 VS=7) [ 130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0) [ 130.642658] BADV: ffff80001b898004 [ 130.642719] PRID: 0014c010 (Loongson-64bit, Loongson-3A5000) [ 130.642815] Modules linked in: [last unloaded: bpf_testmod(O)] [ 130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd) [ 130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8 [ 130.643213] 0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0 [ 130.643378] 0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000 [ 130.643538] 0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000 [ 130.643685] 00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000 [ 130.643831] ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000 [ 130.643983] 0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558 [ 130.644131] 0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000 [ 130.644276] 9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc [ 130.644423] ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0 [ 130.644572] ... [ 130.644629] Call Trace: [ 130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988 [ 130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec [ 130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0 [ 130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44 [ 130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588 [ 130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c [ 130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94 [ 130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158 [ 130.645507] [ 130.645539] Code: 380839f6 380831f9 28412bae <24000ca6> 004081ad 0014cb50 004083e8 02bff34c 58008e91 [ 130.645729] [ 130.646418] ---[ end trace 0000000000000000 ]--- On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at loading a BPF prog with 2039 instructions: prog = (struct bpf_prog *)ffff80001b894000 insn = (struct bpf_insn *)(prog->insnsi)fff ---truncated---

In the Linux kernel, the following vulnerability has been resolved: net: netdevsim: don't try to destroy PHC on VFs PHC gets initialized in nsim_init_netdevsim(), which is only called if (nsim_dev_port_is_pf()). Create a counterpart of nsim_init_netdevsim() and move the mock_phc_destroy() there. This fixes a crash trying to destroy netdevsim with VFs instantiated, as caught by running the devlink.sh test: BUG: kernel NULL pointer dereference, address: 00000000000000b8 RIP: 0010:mock_phc_destroy+0xd/0x30 Call Trace: <TASK> nsim_destroy+0x4a/0x70 [netdevsim] __nsim_dev_port_del+0x47/0x70 [netdevsim] nsim_dev_reload_destroy+0x105/0x120 [netdevsim] nsim_drv_remove+0x2f/0xb0 [netdevsim] device_release_driver_internal+0x1a1/0x210 bus_remove_device+0xd5/0x120 device_del+0x159/0x490 device_unregister+0x12/0x30 del_device_store+0x11a/0x1a0 [netdevsim] kernfs_fop_write_iter+0x130/0x1d0 vfs_write+0x30b/0x4b0 ksys_write+0x69/0xf0 do_syscall_64+0xcc/0x1e0 entry_SYSCALL_64_after_hwframe+0x6f/0x77

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.