In the Linux kernel, the following vulnerability has been resolved: net, sunrpc: Remap EPERM in case of connection failure in xs_tcp_setup_socket When using a BPF program on kernel_connect(), the call can return -EPERM. This causes xs_tcp_setup_socket() to loop forever, filling up the syslog and causing the kernel to potentially freeze up. Neil suggested: This will propagate -EPERM up into other layers which might not be ready to handle it. It might be safer to map EPERM to an error we would be more likely to expect from the network system - such as ECONNREFUSED or ENETDOWN. ECONNREFUSED as error seems reasonable. For programs setting a different error can be out of reach (see handling in 4fbac77d2d09) in particular on kernels which do not have f10d05966196 ("bpf: Make BPF_PROG_RUN_ARRAY return -err instead of allow boolean"), thus given that it is better to simply remap for consistent behavior. UDP does handle EPERM in xs_udp_send_request().

An Ubuntu-specific modification to AccountsService in versions before 0.6.55-0ubuntu13.2, among other earlier versions, would perform unbounded read operations on user-controlled ~/.pam_environment files, allowing an infinite loop if /dev/zero is symlinked to this location.

In the Linux kernel, the following vulnerability has been resolved: net/sched: act_api: fix possible infinite loop in tcf_idr_check_alloc() syzbot found hanging tasks waiting on rtnl_lock [1] A reproducer is available in the syzbot bug. When a request to add multiple actions with the same index is sent, the second request will block forever on the first request. This holds rtnl_lock, and causes tasks to hang. Return -EAGAIN to prevent infinite looping, while keeping documented behavior. [1] INFO: task kworker/1:0:5088 blocked for more than 143 seconds. Not tainted 6.9.0-rc4-syzkaller-00173-g3cdb45594619 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:0 state:D stack:23744 pid:5088 tgid:5088 ppid:2 flags:0x00004000 Workqueue: events_power_efficient reg_check_chans_work Call Trace: <TASK> context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6838 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6895 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752 wiphy_lock include/net/cfg80211.h:5953 [inline] reg_leave_invalid_chans net/wireless/reg.c:2466 [inline] reg_check_chans_work+0x10a/0x10e0 net/wireless/reg.c:2481

The arch_timer_reg_read_stable macro in arch/arm64/include/asm/arch_timer.h in the Linux kernel before 4.13 allows local users to cause a denial of service (infinite recursion) by writing to a file under /sys/kernel/debug in certain circumstances, as demonstrated by a scenario involving debugfs, ftrace, PREEMPT_TRACER, and FUNCTION_GRAPH_TRACER.

A flaw was found in avahi in versions 0.6 up to 0.8. The event used to signal the termination of the client connection on the avahi Unix socket is not correctly handled in the client_work function, allowing a local attacker to trigger an infinite loop. The highest threat from this vulnerability is to the availability of the avahi service, which becomes unresponsive after this flaw is triggered.

In the Linux kernel, the following vulnerability has been resolved: kprobes: don't call disarm_kprobe() for disabled kprobes The assumption in __disable_kprobe() is wrong, and it could try to disarm an already disarmed kprobe and fire the WARN_ONCE() below. [0] We can easily reproduce this issue. 1. Write 0 to /sys/kernel/debug/kprobes/enabled. # echo 0 > /sys/kernel/debug/kprobes/enabled 2. Run execsnoop. At this time, one kprobe is disabled. # /usr/share/bcc/tools/execsnoop & [1] 2460 PCOMM PID PPID RET ARGS # cat /sys/kernel/debug/kprobes/list ffffffff91345650 r __x64_sys_execve+0x0 [FTRACE] ffffffff91345650 k __x64_sys_execve+0x0 [DISABLED][FTRACE] 3. Write 1 to /sys/kernel/debug/kprobes/enabled, which changes kprobes_all_disarmed to false but does not arm the disabled kprobe. # echo 1 > /sys/kernel/debug/kprobes/enabled # cat /sys/kernel/debug/kprobes/list ffffffff91345650 r __x64_sys_execve+0x0 [FTRACE] ffffffff91345650 k __x64_sys_execve+0x0 [DISABLED][FTRACE] 4. Kill execsnoop, when __disable_kprobe() calls disarm_kprobe() for the disabled kprobe and hits the WARN_ONCE() in __disarm_kprobe_ftrace(). # fg /usr/share/bcc/tools/execsnoop ^C Actually, WARN_ONCE() is fired twice, and __unregister_kprobe_top() misses some cleanups and leaves the aggregated kprobe in the hash table. Then, __unregister_trace_kprobe() initialises tk->rp.kp.list and creates an infinite loop like this. aggregated kprobe.list -> kprobe.list -. ^ | '.__.' In this situation, these commands fall into the infinite loop and result in RCU stall or soft lockup. cat /sys/kernel/debug/kprobes/list : show_kprobe_addr() enters into the infinite loop with RCU. /usr/share/bcc/tools/execsnoop : warn_kprobe_rereg() holds kprobe_mutex, and __get_valid_kprobe() is stuck in the loop. To avoid the issue, make sure we don't call disarm_kprobe() for disabled kprobes. [0] Failed to disarm kprobe-ftrace at __x64_sys_execve+0x0/0x40 (error -2) WARNING: CPU: 6 PID: 2460 at kernel/kprobes.c:1130 __disarm_kprobe_ftrace.isra.19 (kernel/kprobes.c:1129) Modules linked in: ena CPU: 6 PID: 2460 Comm: execsnoop Not tainted 5.19.0+ #28 Hardware name: Amazon EC2 c5.2xlarge/, BIOS 1.0 10/16/2017 RIP: 0010:__disarm_kprobe_ftrace.isra.19 (kernel/kprobes.c:1129) Code: 24 8b 02 eb c1 80 3d c4 83 f2 01 00 75 d4 48 8b 75 00 89 c2 48 c7 c7 90 fa 0f 92 89 04 24 c6 05 ab 83 01 e8 e4 94 f0 ff <0f> 0b 8b 04 24 eb b1 89 c6 48 c7 c7 60 fa 0f 92 89 04 24 e8 cc 94 RSP: 0018:ffff9e6ec154bd98 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffffffff930f7b00 RCX: 0000000000000001 RDX: 0000000080000001 RSI: ffffffff921461c5 RDI: 00000000ffffffff RBP: ffff89c504286da8 R08: 0000000000000000 R09: c0000000fffeffff R10: 0000000000000000 R11: ffff9e6ec154bc28 R12: ffff89c502394e40 R13: ffff89c502394c00 R14: ffff9e6ec154bc00 R15: 0000000000000000 FS: 00007fe800398740(0000) GS:ffff89c812d80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c00057f010 CR3: 0000000103b54006 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> __disable_kprobe (kernel/kprobes.c:1716) disable_kprobe (kernel/kprobes.c:2392) __disable_trace_kprobe (kernel/trace/trace_kprobe.c:340) disable_trace_kprobe (kernel/trace/trace_kprobe.c:429) perf_trace_event_unreg.isra.2 (./include/linux/tracepoint.h:93 kernel/trace/trace_event_perf.c:168) perf_kprobe_destroy (kernel/trace/trace_event_perf.c:295) _free_event (kernel/events/core.c:4971) perf_event_release_kernel (kernel/events/core.c:5176) perf_release (kernel/events/core.c:5186) __fput (fs/file_table.c:321) task_work_run (./include/linux/ ---truncated---

In multiple locations, there is a possible way to trigger a persistent reboot loop due to improper input validation. This could lead to local denial of service with User execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-13Android ID: A-246750467

In multiple locations, there is a possible way to trigger a persistent reboot loop due to improper input validation. This could lead to local denial of service with User execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-13Android ID: A-246749702

In multiple locations, there is a possible way to trigger a persistent reboot loop due to improper input validation. This could lead to local denial of service with User execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-13Android ID: A-246749936

Remote Denial of Service in LwM2M do_write_op_tlv. Zephyr versions >= 1.14.2, >= 2.2.0 contain Improper Input Validation (CWE-20), Loop with Unreachable Exit Condition ('Infinite Loop') (CWE-835). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-g9mg-fj58-6fqh

When dynamic memory allocation fails, currently the process sleeps for one second and continues with infinite loop without retrying for memory allocation in Snapdragon Automobile, Snapdragon Mobile, Snapdragon Wear in version MDM9206, MDM9607, MDM9640, MDM9650, MSM8909W, QCN5502, SD 210/SD 212/SD 205, SD 425, SD 430, SD 450, SD 600, SD 615/16/SD 415, SD 625, SD 650/52, SD 810, SD 820, SD 820A, SD 835.

The madvise_willneed function in mm/madvise.c in the Linux kernel before 4.14.4 allows local users to cause a denial of service (infinite loop) by triggering use of MADVISE_WILLNEED for a DAX mapping.

In the Linux kernel, the following vulnerability has been resolved: f2fs: avoid infinite loop to flush node pages xfstests/generic/475 can give EIO all the time which give an infinite loop to flush node page like below. Let's avoid it. [16418.518551] Call Trace: [16418.518553] ? dm_submit_bio+0x48/0x400 [16418.518574] ? submit_bio_checks+0x1ac/0x5a0 [16418.525207] __submit_bio+0x1a9/0x230 [16418.525210] ? kmem_cache_alloc+0x29e/0x3c0 [16418.525223] submit_bio_noacct+0xa8/0x2b0 [16418.525226] submit_bio+0x4d/0x130 [16418.525238] __submit_bio+0x49/0x310 [f2fs] [16418.525339] ? bio_add_page+0x6a/0x90 [16418.525344] f2fs_submit_page_bio+0x134/0x1f0 [f2fs] [16418.525365] read_node_page+0x125/0x1b0 [f2fs] [16418.525388] __get_node_page.part.0+0x58/0x3f0 [f2fs] [16418.525409] __get_node_page+0x2f/0x60 [f2fs] [16418.525431] f2fs_get_dnode_of_data+0x423/0x860 [f2fs] [16418.525452] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [16418.525458] ? __mod_memcg_state.part.0+0x2a/0x30 [16418.525465] ? __mod_memcg_lruvec_state+0x27/0x40 [16418.525467] ? __xa_set_mark+0x57/0x70 [16418.525472] f2fs_do_write_data_page+0x10e/0x7b0 [f2fs] [16418.525493] f2fs_write_single_data_page+0x555/0x830 [f2fs] [16418.525514] ? sysvec_apic_timer_interrupt+0x4e/0x90 [16418.525518] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [16418.525523] f2fs_write_cache_pages+0x303/0x880 [f2fs] [16418.525545] ? blk_flush_plug_list+0x47/0x100 [16418.525548] f2fs_write_data_pages+0xfd/0x320 [f2fs] [16418.525569] do_writepages+0xd5/0x210 [16418.525648] filemap_fdatawrite_wbc+0x7d/0xc0 [16418.525655] filemap_fdatawrite+0x50/0x70 [16418.525658] f2fs_sync_dirty_inodes+0xa4/0x230 [f2fs] [16418.525679] f2fs_write_checkpoint+0x16d/0x1720 [f2fs] [16418.525699] ? ttwu_do_wakeup+0x1c/0x160 [16418.525709] ? ttwu_do_activate+0x6d/0xd0 [16418.525711] ? __wait_for_common+0x11d/0x150 [16418.525715] kill_f2fs_super+0xca/0x100 [f2fs] [16418.525733] deactivate_locked_super+0x3b/0xb0 [16418.525739] deactivate_super+0x40/0x50 [16418.525741] cleanup_mnt+0x139/0x190 [16418.525747] __cleanup_mnt+0x12/0x20 [16418.525749] task_work_run+0x6d/0xa0 [16418.525765] exit_to_user_mode_prepare+0x1ad/0x1b0 [16418.525771] syscall_exit_to_user_mode+0x27/0x50 [16418.525774] do_syscall_64+0x48/0xc0 [16418.525776] entry_SYSCALL_64_after_hwframe+0x44/0xae

In the Linux kernel, the following vulnerability has been resolved: crypto: qcom-rng - fix infinite loop on requests not multiple of WORD_SZ The commit referenced in the Fixes tag removed the 'break' from the else branch in qcom_rng_read(), causing an infinite loop whenever 'max' is not a multiple of WORD_SZ. This can be reproduced e.g. by running: kcapi-rng -b 67 >/dev/null There are many ways to fix this without adding back the 'break', but they all seem more awkward than simply adding it back, so do just that. Tested on a machine with Qualcomm Amberwing processor.

long running loops in grant table handling In order to properly monitor resource use, Xen maintains information on the grant mappings a domain may create to map grants offered by other domains. In the process of carrying out certain actions, Xen would iterate over all such entries, including ones which aren't in use anymore and some which may have been created but never used. If the number of entries for a given domain is large enough, this iterating of the entire table may tie up a CPU for too long, starving other domains or causing issues in the hypervisor itself. Note that a domain may map its own grants, i.e. there is no need for multiple domains to be involved here. A pair of "cooperating" guests may, however, cause the effects to be more severe.

In the Linux kernel, the following vulnerability has been resolved: NFS: Avoid writeback threads getting stuck in mempool_alloc() In a low memory situation, allow the NFS writeback code to fail without getting stuck in infinite loops in mempool_alloc().

In the Linux kernel, the following vulnerability has been resolved: iavf: Fix hang during reboot/shutdown Recent commit 974578017fc1 ("iavf: Add waiting so the port is initialized in remove") adds a wait-loop at the beginning of iavf_remove() to ensure that port initialization is finished prior unregistering net device. This causes a regression in reboot/shutdown scenario because in this case callback iavf_shutdown() is called and this callback detaches the device, makes it down if it is running and sets its state to __IAVF_REMOVE. Later shutdown callback of associated PF driver (e.g. ice_shutdown) is called. That callback calls among other things sriov_disable() that calls indirectly iavf_remove() (see stack trace below). As the adapter state is already __IAVF_REMOVE then the mentioned loop is end-less and shutdown process hangs. The patch fixes this by checking adapter's state at the beginning of iavf_remove() and skips the rest of the function if the adapter is already in remove state (shutdown is in progress). Reproducer: 1. Create VF on PF driven by ice or i40e driver 2. Ensure that the VF is bound to iavf driver 3. Reboot [52625.981294] sysrq: SysRq : Show Blocked State [52625.988377] task:reboot state:D stack: 0 pid:17359 ppid: 1 f2 [52625.996732] Call Trace: [52625.999187] __schedule+0x2d1/0x830 [52626.007400] schedule+0x35/0xa0 [52626.010545] schedule_hrtimeout_range_clock+0x83/0x100 [52626.020046] usleep_range+0x5b/0x80 [52626.023540] iavf_remove+0x63/0x5b0 [iavf] [52626.027645] pci_device_remove+0x3b/0xc0 [52626.031572] device_release_driver_internal+0x103/0x1f0 [52626.036805] pci_stop_bus_device+0x72/0xa0 [52626.040904] pci_stop_and_remove_bus_device+0xe/0x20 [52626.045870] pci_iov_remove_virtfn+0xba/0x120 [52626.050232] sriov_disable+0x2f/0xe0 [52626.053813] ice_free_vfs+0x7c/0x340 [ice] [52626.057946] ice_remove+0x220/0x240 [ice] [52626.061967] ice_shutdown+0x16/0x50 [ice] [52626.065987] pci_device_shutdown+0x34/0x60 [52626.070086] device_shutdown+0x165/0x1c5 [52626.074011] kernel_restart+0xe/0x30 [52626.077593] __do_sys_reboot+0x1d2/0x210 [52626.093815] do_syscall_64+0x5b/0x1a0 [52626.097483] entry_SYSCALL_64_after_hwframe+0x65/0xca

In the Linux kernel, the following vulnerability has been resolved: net/smc: Avoid overwriting the copies of clcsock callback functions The callback functions of clcsock will be saved and replaced during the fallback. But if the fallback happens more than once, then the copies of these callback functions will be overwritten incorrectly, resulting in a loop call issue: clcsk->sk_error_report |- smc_fback_error_report() <------------------------------| |- smc_fback_forward_wakeup() | (loop) |- clcsock_callback() (incorrectly overwritten) | |- smc->clcsk_error_report() ------------------| So this patch fixes the issue by saving these function pointers only once in the fallback and avoiding overwriting.

A list management bug in BSS handling in the mac80211 stack in the Linux kernel 5.1 through 5.19.x before 5.19.16 could be used by local attackers (able to inject WLAN frames) to corrupt a linked list and, in turn, potentially execute code.

An issue was discovered in Xen through 4.9.x allowing HVM guest OS users to cause a denial of service (infinite loop and host OS hang) by leveraging the mishandling of Populate on Demand (PoD) errors.

In Threshold::getHistogram of ImageProcessHelper.java, there is a possible crash loop due to an uncaught exception. This could lead to local denial of service with User execution privileges needed. User interaction is needed for exploitation.Product: AndroidVersions: Android-10 Android-8.0 Android-8.1Android ID: A-156087409

In the Linux kernel, the following vulnerability has been resolved: netlink: avoid infinite retry looping in netlink_unicast() netlink_attachskb() checks for the socket's read memory allocation constraints. Firstly, it has: rmem < READ_ONCE(sk->sk_rcvbuf) to check if the just increased rmem value fits into the socket's receive buffer. If not, it proceeds and tries to wait for the memory under: rmem + skb->truesize > READ_ONCE(sk->sk_rcvbuf) The checks don't cover the case when skb->truesize + sk->sk_rmem_alloc is equal to sk->sk_rcvbuf. Thus the function neither successfully accepts these conditions, nor manages to reschedule the task - and is called in retry loop for indefinite time which is caught as: rcu: INFO: rcu_sched self-detected stall on CPU rcu: 0-....: (25999 ticks this GP) idle=ef2/1/0x4000000000000000 softirq=262269/262269 fqs=6212 (t=26000 jiffies g=230833 q=259957) NMI backtrace for cpu 0 CPU: 0 PID: 22 Comm: kauditd Not tainted 5.10.240 #68 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc42 04/01/2014 Call Trace: <IRQ> dump_stack lib/dump_stack.c:120 nmi_cpu_backtrace.cold lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace lib/nmi_backtrace.c:62 rcu_dump_cpu_stacks kernel/rcu/tree_stall.h:335 rcu_sched_clock_irq.cold kernel/rcu/tree.c:2590 update_process_times kernel/time/timer.c:1953 tick_sched_handle kernel/time/tick-sched.c:227 tick_sched_timer kernel/time/tick-sched.c:1399 __hrtimer_run_queues kernel/time/hrtimer.c:1652 hrtimer_interrupt kernel/time/hrtimer.c:1717 __sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1113 asm_call_irq_on_stack arch/x86/entry/entry_64.S:808 </IRQ> netlink_attachskb net/netlink/af_netlink.c:1234 netlink_unicast net/netlink/af_netlink.c:1349 kauditd_send_queue kernel/audit.c:776 kauditd_thread kernel/audit.c:897 kthread kernel/kthread.c:328 ret_from_fork arch/x86/entry/entry_64.S:304 Restore the original behavior of the check which commit in Fixes accidentally missed when restructuring the code. Found by Linux Verification Center (linuxtesting.org).

A flaw was found in the Linux kernel in the function hid_debug_events_read() in drivers/hid/hid-debug.c file which may enter an infinite loop with certain parameters passed from a userspace. A local privileged user ("root") can cause a system lock up and a denial of service. Versions from v4.18 and newer are vulnerable.

In the Linux kernel, the following vulnerability has been resolved: ipv6: prevent infinite loop in rt6_nlmsg_size() While testing prior patch, I was able to trigger an infinite loop in rt6_nlmsg_size() in the following place: list_for_each_entry_rcu(sibling, &f6i->fib6_siblings, fib6_siblings) { rt6_nh_nlmsg_size(sibling->fib6_nh, &nexthop_len); } This is because fib6_del_route() and fib6_add_rt2node() uses list_del_rcu(), which can confuse rcu readers, because they might no longer see the head of the list. Restart the loop if f6i->fib6_nsiblings is zero.

In the Linux kernel, the following vulnerability has been resolved: net_sched: hfsc: Address reentrant enqueue adding class to eltree twice Savino says: "We are writing to report that this recent patch (141d34391abbb315d68556b7c67ad97885407547) [1] can be bypassed, and a UAF can still occur when HFSC is utilized with NETEM. The patch only checks the cl->cl_nactive field to determine whether it is the first insertion or not [2], but this field is only incremented by init_vf [3]. By using HFSC_RSC (which uses init_ed) [4], it is possible to bypass the check and insert the class twice in the eltree. Under normal conditions, this would lead to an infinite loop in hfsc_dequeue for the reasons we already explained in this report [5]. However, if TBF is added as root qdisc and it is configured with a very low rate, it can be utilized to prevent packets from being dequeued. This behavior can be exploited to perform subsequent insertions in the HFSC eltree and cause a UAF." To fix both the UAF and the infinite loop, with netem as an hfsc child, check explicitly in hfsc_enqueue whether the class is already in the eltree whenever the HFSC_RSC flag is set. [1] https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=141d34391abbb315d68556b7c67ad97885407547 [2] https://elixir.bootlin.com/linux/v6.15-rc5/source/net/sched/sch_hfsc.c#L1572 [3] https://elixir.bootlin.com/linux/v6.15-rc5/source/net/sched/sch_hfsc.c#L677 [4] https://elixir.bootlin.com/linux/v6.15-rc5/source/net/sched/sch_hfsc.c#L1574 [5] https://lore.kernel.org/netdev/8DuRWwfqjoRDLDmBMlIfbrsZg9Gx50DHJc1ilxsEBNe2D6NMoigR_eIRIG0LOjMc3r10nUUZtArXx4oZBIdUfZQrwjcQhdinnMis_0G7VEk=@willsroot.io/T/#u

In the Linux kernel, the following vulnerability has been resolved: ipv6: fix possible infinite loop in fib6_info_uses_dev() fib6_info_uses_dev() seems to rely on RCU without an explicit protection. Like the prior fix in rt6_nlmsg_size(), we need to make sure fib6_del_route() or fib6_add_rt2node() have not removed the anchor from the list, or we risk an infinite loop.

When GNOME Dia before 2019-11-27 is launched with a filename argument that is not a valid codepoint in the current encoding, it enters an endless loop, thus endlessly writing text to stdout. If this launch is from a thumbnailer service, this output will usually be written to disk via the system's logging facility (potentially with elevated privileges), thus filling up the disk and eventually rendering the system unusable. (The filename can be for a nonexistent file.) NOTE: this does not affect an upstream release, but affects certain Linux distribution packages with version numbers such as 0.97.3.

An issue was discovered in Xen through 4.12.x allowing Arm domU attackers to cause a denial of service (infinite loop) involving a LoadExcl or StoreExcl operation.

An issue was discovered in Xen through 4.12.x allowing Arm domU attackers to cause a denial of service (infinite loop) involving a compare-and-exchange operation.

In the Linux kernel, the following vulnerability has been resolved: tee: optee: Fix supplicant wait loop OP-TEE supplicant is a user-space daemon and it's possible for it be hung or crashed or killed in the middle of processing an OP-TEE RPC call. It becomes more complicated when there is incorrect shutdown ordering of the supplicant process vs the OP-TEE client application which can eventually lead to system hang-up waiting for the closure of the client application. Allow the client process waiting in kernel for supplicant response to be killed rather than indefinitely waiting in an unkillable state. Also, a normal uninterruptible wait should not have resulted in the hung-task watchdog getting triggered, but the endless loop would. This fixes issues observed during system reboot/shutdown when supplicant got hung for some reason or gets crashed/killed which lead to client getting hung in an unkillable state. It in turn lead to system being in hung up state requiring hard power off/on to recover.

In the Linux kernel, the following vulnerability has been resolved: iomap: avoid avoid truncating 64-bit offset to 32 bits on 32-bit kernels, iomap_write_delalloc_scan() was inadvertently using a 32-bit position due to folio_next_index() returning an unsigned long. This could lead to an infinite loop when writing to an xfs filesystem.

QEMU (aka Quick Emulator) built with the e1000 NIC emulation support is vulnerable to an infinite loop issue. It could occur while processing data via transmit or receive descriptors, provided the initial receive/transmit descriptor head (TDH/RDH) is set outside the allocated descriptor buffer. A privileged user inside guest could use this flaw to crash the QEMU instance resulting in DoS.

QEMU (aka Quick Emulator) built with the ColdFire Fast Ethernet Controller emulator support is vulnerable to an infinite loop issue. It could occur while receiving packets in 'mcf_fec_receive'. A privileged user/process inside guest could use this issue to crash the QEMU process on the host leading to DoS.

In the Linux kernel, the following vulnerability has been resolved: af_unix: Fix task hung while purging oob_skb in GC. syzbot reported a task hung; at the same time, GC was looping infinitely in list_for_each_entry_safe() for OOB skb. [0] syzbot demonstrated that the list_for_each_entry_safe() was not actually safe in this case. A single skb could have references for multiple sockets. If we free such a skb in the list_for_each_entry_safe(), the current and next sockets could be unlinked in a single iteration. unix_notinflight() uses list_del_init() to unlink the socket, so the prefetched next socket forms a loop itself and list_for_each_entry_safe() never stops. Here, we must use while() and make sure we always fetch the first socket. [0]: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5065 Comm: syz-executor236 Not tainted 6.8.0-rc3-syzkaller-00136-g1f719a2f3fa6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0xd/0x60 kernel/kcov.c:207 Code: cc cc cc cc 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 48 8b 14 25 40 c2 03 00 <65> 8b 05 b4 7c 78 7e a9 00 01 ff 00 48 8b 34 24 74 0f f6 c4 01 74 RSP: 0018:ffffc900033efa58 EFLAGS: 00000283 RAX: ffff88807b077800 RBX: ffff88807b077800 RCX: 1ffffffff27b1189 RDX: ffff88802a5a3b80 RSI: ffffffff8968488d RDI: ffff88807b077f70 RBP: ffffc900033efbb0 R08: 0000000000000001 R09: fffffbfff27a900c R10: ffffffff93d48067 R11: ffffffff8ae000eb R12: ffff88807b077800 R13: dffffc0000000000 R14: ffff88807b077e40 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564f4fc1e3a8 CR3: 000000000d57a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <TASK> unix_gc+0x563/0x13b0 net/unix/garbage.c:319 unix_release_sock+0xa93/0xf80 net/unix/af_unix.c:683 unix_release+0x91/0xf0 net/unix/af_unix.c:1064 __sock_release+0xb0/0x270 net/socket.c:659 sock_close+0x1c/0x30 net/socket.c:1421 __fput+0x270/0xb80 fs/file_table.c:376 task_work_run+0x14f/0x250 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xa8a/0x2ad0 kernel/exit.c:871 do_group_exit+0xd4/0x2a0 kernel/exit.c:1020 __do_sys_exit_group kernel/exit.c:1031 [inline] __se_sys_exit_group kernel/exit.c:1029 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1029 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd5/0x270 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7f9d6cbdac09 Code: Unable to access opcode bytes at 0x7f9d6cbdabdf. RSP: 002b:00007fff5952feb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9d6cbdac09 RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 RBP: 00007f9d6cc552b0 R08: ffffffffffffffb8 R09: 0000000000000006 R10: 0000000000000006 R11: 0000000000000246 R12: 00007f9d6cc552b0 R13: 0000000000000000 R14: 00007f9d6cc55d00 R15: 00007f9d6cbabe70 </TASK>

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: fixed integer types and null check locations [why]: issues fixed: - comparison with wider integer type in loop condition which can cause infinite loops - pointer dereference before null check

In the Linux kernel, the following vulnerability has been resolved: x86/fpu: Stop relying on userspace for info to fault in xsave buffer Before this change, the expected size of the user space buffer was taken from fx_sw->xstate_size. fx_sw->xstate_size can be changed from user-space, so it is possible construct a sigreturn frame where: * fx_sw->xstate_size is smaller than the size required by valid bits in fx_sw->xfeatures. * user-space unmaps parts of the sigrame fpu buffer so that not all of the buffer required by xrstor is accessible. In this case, xrstor tries to restore and accesses the unmapped area which results in a fault. But fault_in_readable succeeds because buf + fx_sw->xstate_size is within the still mapped area, so it goes back and tries xrstor again. It will spin in this loop forever. Instead, fault in the maximum size which can be touched by XRSTOR (taken from fpstate->user_size). [ dhansen: tweak subject / changelog ]

The pcnet_rdra_addr function in hw/net/pcnet.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) by setting the (1) receive or (2) transmit descriptor ring length to 0.

In the Linux kernel, the following vulnerability has been resolved: netdevsim: avoid potential loop in nsim_dev_trap_report_work() Many syzbot reports include the following trace [1] If nsim_dev_trap_report_work() can not grab the mutex, it should rearm itself at least one jiffie later. [1] Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 32383 Comm: kworker/0:2 Not tainted 6.8.0-rc2-syzkaller-00031-g861c0981648f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Workqueue: events nsim_dev_trap_report_work RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:89 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x101/0x190 mm/kasan/generic.c:189 Code: 07 49 39 d1 75 0a 45 3a 11 b8 01 00 00 00 7c 0b 44 89 c2 e8 21 ed ff ff 83 f0 01 5b 5d 41 5c c3 48 85 d2 74 4f 48 01 ea eb 09 <48> 83 c0 01 48 39 d0 74 41 80 38 00 74 f2 eb b6 41 bc 08 00 00 00 RSP: 0018:ffffc90012dcf998 EFLAGS: 00000046 RAX: fffffbfff258af1e RBX: fffffbfff258af1f RCX: ffffffff8168eda3 RDX: fffffbfff258af1f RSI: 0000000000000004 RDI: ffffffff92c578f0 RBP: fffffbfff258af1e R08: 0000000000000000 R09: fffffbfff258af1e R10: ffffffff92c578f3 R11: ffffffff8acbcbc0 R12: 0000000000000002 R13: ffff88806db38400 R14: 1ffff920025b9f42 R15: ffffffff92c578e8 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c00994e078 CR3: 000000002c250000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <TASK> instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] queued_spin_is_locked include/asm-generic/qspinlock.h:57 [inline] debug_spin_unlock kernel/locking/spinlock_debug.c:101 [inline] do_raw_spin_unlock+0x53/0x230 kernel/locking/spinlock_debug.c:141 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:150 [inline] _raw_spin_unlock_irqrestore+0x22/0x70 kernel/locking/spinlock.c:194 debug_object_activate+0x349/0x540 lib/debugobjects.c:726 debug_work_activate kernel/workqueue.c:578 [inline] insert_work+0x30/0x230 kernel/workqueue.c:1650 __queue_work+0x62e/0x11d0 kernel/workqueue.c:1802 __queue_delayed_work+0x1bf/0x270 kernel/workqueue.c:1953 queue_delayed_work_on+0x106/0x130 kernel/workqueue.c:1989 queue_delayed_work include/linux/workqueue.h:563 [inline] schedule_delayed_work include/linux/workqueue.h:677 [inline] nsim_dev_trap_report_work+0x9c0/0xc80 drivers/net/netdevsim/dev.c:842 process_one_work+0x886/0x15d0 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2787 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 </TASK>

Windows Hyper-V Denial of Service Vulnerability

The vmsvga_fifo_run function in hw/display/vmware_vga.c in QEMU allows local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) via a VGA command.

In the Linux kernel, the following vulnerability has been resolved: exfat: add cluster chain loop check for dir An infinite loop may occur if the following conditions occur due to file system corruption. (1) Condition for exfat_count_dir_entries() to loop infinitely. - The cluster chain includes a loop. - There is no UNUSED entry in the cluster chain. (2) Condition for exfat_create_upcase_table() to loop infinitely. - The cluster chain of the root directory includes a loop. - There are no UNUSED entry and up-case table entry in the cluster chain of the root directory. (3) Condition for exfat_load_bitmap() to loop infinitely. - The cluster chain of the root directory includes a loop. - There are no UNUSED entry and bitmap entry in the cluster chain of the root directory. (4) Condition for exfat_find_dir_entry() to loop infinitely. - The cluster chain includes a loop. - The unused directory entries were exhausted by some operation. (5) Condition for exfat_check_dir_empty() to loop infinitely. - The cluster chain includes a loop. - The unused directory entries were exhausted by some operation. - All files and sub-directories under the directory are deleted. This commit adds checks to break the above infinite loop.

In the Linux kernel, the following vulnerability has been resolved: arm64: dts: qcom: qcs615: fix a crash issue caused by infinite loop for Coresight An infinite loop has been created by the Coresight devices. When only a source device is enabled, the coresight_find_activated_sysfs_sink function is recursively invoked in an attempt to locate an active sink device, ultimately leading to a stack overflow and system crash. Therefore, disable the replicator1 to break the infinite loop and prevent a potential stack overflow. replicator1_out -> funnel_swao_in6 -> tmc_etf_swao_in -> tmc_etf_swao_out | | replicator1_in replicator_swao_in | | replicator0_out1 replicator_swao_out0 | | replicator0_in funnel_in1_in3 | | tmc_etf_out <- tmc_etf_in <- funnel_merg_out <- funnel_merg_in1 <- funnel_in1_out [call trace] dump_backtrace+0x9c/0x128 show_stack+0x20/0x38 dump_stack_lvl+0x48/0x60 dump_stack+0x18/0x28 panic+0x340/0x3b0 nmi_panic+0x94/0xa0 panic_bad_stack+0x114/0x138 handle_bad_stack+0x34/0xb8 __bad_stack+0x78/0x80 coresight_find_activated_sysfs_sink+0x28/0xa0 [coresight] coresight_find_activated_sysfs_sink+0x5c/0xa0 [coresight] coresight_find_activated_sysfs_sink+0x5c/0xa0 [coresight] coresight_find_activated_sysfs_sink+0x5c/0xa0 [coresight] coresight_find_activated_sysfs_sink+0x5c/0xa0 [coresight] ... coresight_find_activated_sysfs_sink+0x5c/0xa0 [coresight] coresight_enable_sysfs+0x80/0x2a0 [coresight] side effect after the change: Only trace data originating from AOSS can reach the ETF_SWAO and EUD sinks.

In the Linux kernel, the following vulnerability has been resolved: ubi: ubi_wl_put_peb: Fix infinite loop when wear-leveling work failed Following process will trigger an infinite loop in ubi_wl_put_peb(): ubifs_bgt ubi_bgt ubifs_leb_unmap ubi_leb_unmap ubi_eba_unmap_leb ubi_wl_put_peb wear_leveling_worker e1 = rb_entry(rb_first(&ubi->used) e2 = get_peb_for_wl(ubi) ubi_io_read_vid_hdr // return err (flash fault) out_error: ubi->move_from = ubi->move_to = NULL wl_entry_destroy(ubi, e1) ubi->lookuptbl[e->pnum] = NULL retry: e = ubi->lookuptbl[pnum]; // return NULL if (e == ubi->move_from) { // NULL == NULL gets true goto retry; // infinite loop !!! $ top PID USER PR NI VIRT RES SHR S %CPU %MEM COMMAND 7676 root 20 0 0 0 0 R 100.0 0.0 ubifs_bgt0_0 Fix it by: 1) Letting ubi_wl_put_peb() returns directly if wearl leveling entry has been removed from 'ubi->lookuptbl'. 2) Using 'ubi->wl_lock' protecting wl entry deletion to preventing an use-after-free problem for wl entry in ubi_wl_put_peb(). Fetch a reproducer in [Link].

In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: Fix an infinite loop error when len is 0 in tcp_bpf_recvmsg_parser() When the buffer length of the recvmsg system call is 0, we got the flollowing soft lockup problem: watchdog: BUG: soft lockup - CPU#3 stuck for 27s! [a.out:6149] CPU: 3 PID: 6149 Comm: a.out Kdump: loaded Not tainted 6.2.0+ #30 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 RIP: 0010:remove_wait_queue+0xb/0xc0 Code: 5e 41 5f c3 cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 41 57 <41> 56 41 55 41 54 55 48 89 fd 53 48 89 f3 4c 8d 6b 18 4c 8d 73 20 RSP: 0018:ffff88811b5978b8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff88811a7d3780 RCX: ffffffffb7a4d768 RDX: dffffc0000000000 RSI: ffff88811b597908 RDI: ffff888115408040 RBP: 1ffff110236b2f1b R08: 0000000000000000 R09: ffff88811a7d37e7 R10: ffffed10234fa6fc R11: 0000000000000001 R12: ffff88811179b800 R13: 0000000000000001 R14: ffff88811a7d38a8 R15: ffff88811a7d37e0 FS: 00007f6fb5398740(0000) GS:ffff888237180000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000000 CR3: 000000010b6ba002 CR4: 0000000000370ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> tcp_msg_wait_data+0x279/0x2f0 tcp_bpf_recvmsg_parser+0x3c6/0x490 inet_recvmsg+0x280/0x290 sock_recvmsg+0xfc/0x120 ____sys_recvmsg+0x160/0x3d0 ___sys_recvmsg+0xf0/0x180 __sys_recvmsg+0xea/0x1a0 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc The logic in tcp_bpf_recvmsg_parser is as follows: msg_bytes_ready: copied = sk_msg_recvmsg(sk, psock, msg, len, flags); if (!copied) { wait data; goto msg_bytes_ready; } In this case, "copied" always is 0, the infinite loop occurs. According to the Linux system call man page, 0 should be returned in this case. Therefore, in tcp_bpf_recvmsg_parser(), if the length is 0, directly return. Also modify several other functions with the same problem.

In the Linux kernel, the following vulnerability has been resolved: ext4: fix task hung in ext4_xattr_delete_inode Syzbot reported a hung task problem: ================================================================== INFO: task syz-executor232:5073 blocked for more than 143 seconds. Not tainted 6.2.0-rc2-syzkaller-00024-g512dee0c00ad #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-exec232 state:D stack:21024 pid:5073 ppid:5072 flags:0x00004004 Call Trace: <TASK> context_switch kernel/sched/core.c:5244 [inline] __schedule+0x995/0xe20 kernel/sched/core.c:6555 schedule+0xcb/0x190 kernel/sched/core.c:6631 __wait_on_freeing_inode fs/inode.c:2196 [inline] find_inode_fast+0x35a/0x4c0 fs/inode.c:950 iget_locked+0xb1/0x830 fs/inode.c:1273 __ext4_iget+0x22e/0x3ed0 fs/ext4/inode.c:4861 ext4_xattr_inode_iget+0x68/0x4e0 fs/ext4/xattr.c:389 ext4_xattr_inode_dec_ref_all+0x1a7/0xe50 fs/ext4/xattr.c:1148 ext4_xattr_delete_inode+0xb04/0xcd0 fs/ext4/xattr.c:2880 ext4_evict_inode+0xd7c/0x10b0 fs/ext4/inode.c:296 evict+0x2a4/0x620 fs/inode.c:664 ext4_orphan_cleanup+0xb60/0x1340 fs/ext4/orphan.c:474 __ext4_fill_super fs/ext4/super.c:5516 [inline] ext4_fill_super+0x81cd/0x8700 fs/ext4/super.c:5644 get_tree_bdev+0x400/0x620 fs/super.c:1282 vfs_get_tree+0x88/0x270 fs/super.c:1489 do_new_mount+0x289/0xad0 fs/namespace.c:3145 do_mount fs/namespace.c:3488 [inline] __do_sys_mount fs/namespace.c:3697 [inline] __se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3674 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fa5406fd5ea RSP: 002b:00007ffc7232f968 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fa5406fd5ea RDX: 0000000020000440 RSI: 0000000020000000 RDI: 00007ffc7232f970 RBP: 00007ffc7232f970 R08: 00007ffc7232f9b0 R09: 0000000000000432 R10: 0000000000804a03 R11: 0000000000000202 R12: 0000000000000004 R13: 0000555556a7a2c0 R14: 00007ffc7232f9b0 R15: 0000000000000000 </TASK> ================================================================== The problem is that the inode contains an xattr entry with ea_inum of 15 when cleaning up an orphan inode <15>. When evict inode <15>, the reference counting of the corresponding EA inode is decreased. When EA inode <15> is found by find_inode_fast() in __ext4_iget(), it is found that the EA inode holds the I_FREEING flag and waits for the EA inode to complete deletion. As a result, when inode <15> is being deleted, we wait for inode <15> to complete the deletion, resulting in an infinite loop and triggering Hung Task. To solve this problem, we only need to check whether the ino of EA inode and parent is the same before getting EA inode.

In the Linux kernel, the following vulnerability has been resolved: dm crypt: add cond_resched() to dmcrypt_write() The loop in dmcrypt_write may be running for unbounded amount of time, thus we need cond_resched() in it. This commit fixes the following warning: [ 3391.153255][ C12] watchdog: BUG: soft lockup - CPU#12 stuck for 23s! [dmcrypt_write/2:2897] ... [ 3391.387210][ C12] Call trace: [ 3391.390338][ C12] blk_attempt_bio_merge.part.6+0x38/0x158 [ 3391.395970][ C12] blk_attempt_plug_merge+0xc0/0x1b0 [ 3391.401085][ C12] blk_mq_submit_bio+0x398/0x550 [ 3391.405856][ C12] submit_bio_noacct+0x308/0x380 [ 3391.410630][ C12] dmcrypt_write+0x1e4/0x208 [dm_crypt] [ 3391.416005][ C12] kthread+0x130/0x138 [ 3391.419911][ C12] ret_from_fork+0x10/0x18

The fuse_fill_write_pages function in fs/fuse/file.c in the Linux kernel before 4.4 allows local users to cause a denial of service (infinite loop) via a writev system call that triggers a zero length for the first segment of an iov.

A vulnerability was found in libX11 due to an infinite loop within the PutSubImage() function. This flaw allows a local user to consume all available system resources and cause a denial of service condition.

In the Linux kernel, the following vulnerability has been resolved: filemap: avoid truncating 64-bit offset to 32 bits On 32-bit kernels, folio_seek_hole_data() was inadvertently truncating a 64-bit value to 32 bits, leading to a possible infinite loop when writing to an xfs filesystem.

The ehci_process_itd function in hw/usb/hcd-ehci.c in QEMU allows local guest OS administrators to cause a denial of service (infinite loop and CPU consumption) via a circular isochronous transfer descriptor (iTD) list.