CVE-2024-46788: In the Linux kernel, the following vulnerability has been resolved:  tracing/osnoise: Use a cpumask to know what threads are kthreads  The start_kthread() and stop_thread() code was not always called with the interface_lock held. This means that the kthread variable could be unexpectedly changed causing the kthread_stop() to be called on it when it should not have been, leading to:   while true; do    rtla timerlat top -u -q & PID=$!;    sleep 5;    kill -INT $PID;    sleep 0.001;    kill -TERM $PID;    wait $PID;   done  Causing the following OOPS:   Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN PTI  KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]  CPU: 5 UID: 0 PID: 885 Comm: timerlatu/5 Not tainted 6.11.0-rc4-test-00002-gbc754cc76d1b-dirty #125 a533010b71dab205ad2f507188ce8c82203b0254  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014  RIP: 0010:hrtimer_active+0x58/0x300  Code: 48 c1 ee 03 41 54 48 01 d1 48 01 d6 55 53 48 83 ec 20 80 39 00 0f 85 30 02 00 00 49 8b 6f 30 4c 8d 75 10 4c 89 f0 48 c1 e8 03 <0f> b6 3c 10 4c 89 f0 83 e0 07 83 c0 03 40 38 f8 7c 09 40 84 ff 0f  RSP: 0018:ffff88811d97f940 EFLAGS: 00010202  RAX: 0000000000000002 RBX: ffff88823c6b5b28 RCX: ffffed10478d6b6b  RDX: dffffc0000000000 RSI: ffffed10478d6b6c RDI: ffff88823c6b5b28  RBP: 0000000000000000 R08: ffff88823c6b5b58 R09: ffff88823c6b5b60  R10: ffff88811d97f957 R11: 0000000000000010 R12: 00000000000a801d  R13: ffff88810d8b35d8 R14: 0000000000000010 R15: ffff88823c6b5b28  FS:  0000000000000000(0000) GS:ffff88823c680000(0000) knlGS:0000000000000000  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033  CR2: 0000561858ad7258 CR3: 000000007729e001 CR4: 0000000000170ef0  Call Trace:   <TASK>   ? die_addr+0x40/0xa0   ? exc_general_protection+0x154/0x230   ? asm_exc_general_protection+0x26/0x30   ? hrtimer_active+0x58/0x300   ? __pfx_mutex_lock+0x10/0x10   ? __pfx_locks_remove_file+0x10/0x10   hrtimer_cancel+0x15/0x40   timerlat_fd_release+0x8e/0x1f0   ? security_file_release+0x43/0x80   __fput+0x372/0xb10   task_work_run+0x11e/0x1f0   ? _raw_spin_lock+0x85/0xe0   ? __pfx_task_work_run+0x10/0x10   ? poison_slab_object+0x109/0x170   ? do_exit+0x7a0/0x24b0   do_exit+0x7bd/0x24b0   ? __pfx_migrate_enable+0x10/0x10   ? __pfx_do_exit+0x10/0x10   ? __pfx_read_tsc+0x10/0x10   ? ktime_get+0x64/0x140   ? _raw_spin_lock_irq+0x86/0xe0   do_group_exit+0xb0/0x220   get_signal+0x17ba/0x1b50   ? vfs_read+0x179/0xa40   ? timerlat_fd_read+0x30b/0x9d0   ? __pfx_get_signal+0x10/0x10   ? __pfx_timerlat_fd_read+0x10/0x10   arch_do_signal_or_restart+0x8c/0x570   ? __pfx_arch_do_signal_or_restart+0x10/0x10   ? vfs_read+0x179/0xa40   ? ksys_read+0xfe/0x1d0   ? __pfx_ksys_read+0x10/0x10   syscall_exit_to_user_mode+0xbc/0x130   do_syscall_64+0x74/0x110   ? __pfx___rseq_handle_notify_resume+0x10/0x10   ? __pfx_ksys_read+0x10/0x10   ? fpregs_restore_userregs+0xdb/0x1e0   ? fpregs_restore_userregs+0xdb/0x1e0   ? syscall_exit_to_user_mode+0x116/0x130   ? do_syscall_64+0x74/0x110   ? do_syscall_64+0x74/0x110   ? do_syscall_64+0x74/0x110   entry_SYSCALL_64_after_hwframe+0x71/0x79  RIP: 0033:0x7ff0070eca9c  Code: Unable to access opcode bytes at 0x7ff0070eca72.  RSP: 002b:00007ff006dff8c0 EFLAGS: 00000246 ORIG_RAX: 0000000000000000  RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00007ff0070eca9c  RDX: 0000000000000400 RSI: 00007ff006dff9a0 RDI: 0000000000000003  RBP: 00007ff006dffde0 R08: 0000000000000000 R09: 00007ff000000ba0  R10: 00007ff007004b08 R11: 0000000000000246 R12: 0000000000000003  R13: 00007ff006dff9a0 R14: 0000000000000007 R15: 0000000000000008   </TASK>  Modules linked in: snd_hda_intel snd_intel_dspcfg snd_intel_sdw_acpi snd_hda_codec snd_hwdep snd_hda_core  ---[ end trace 0000000000000000 ]---  This is because it would mistakenly call kthread_stop() on a user space thread making it "exit" before it actually exits.  Since kthread ---truncated---