RBP: dffffc0000000000 R08: ffffffff8a2d136b R09: 1ffffffff25fc8e8 R10: dffffc0000000000 R11: fffffbfff25fc8e9 R12: ffffc900041576a0 R13: ffff8880291b0700 R14: ffff8880291b0700 R15: 1ffff110052360e0 ================================================================== BUG: KASAN: stack-out-of-bounds in user_mode arch/x86/include/asm/ptrace.h:214 [inline] BUG: KASAN: stack-out-of-bounds in unwind_next_frame+0x2177/0x2a00 arch/x86/kernel/unwind_orc.c:482 Read of size 2 at addr ffffc900041575d0 by task syz-executor.2/7607 CPU: 1 UID: 0 PID: 7607 Comm: syz-executor.2 Not tainted 6.10.0-rc4-next-20240621-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 user_mode arch/x86/include/asm/ptrace.h:214 [inline] unwind_next_frame+0x2177/0x2a00 arch/x86/kernel/unwind_orc.c:482 show_trace_log_lvl+0x381/0x520 arch/x86/kernel/dumpstack.c:296 sched_show_task+0x578/0x740 kernel/sched/core.c:7503 report_rtnl_holders+0x1ba/0x2d0 net/core/rtnetlink.c:104 call_timer_fn+0x18e/0x650 kernel/time/timer.c:1792 expire_timers kernel/time/timer.c:1843 [inline] __run_timers kernel/time/timer.c:2417 [inline] __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2428 run_timer_base kernel/time/timer.c:2437 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2447 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:finish_task_switch+0x1ea/0x870 kernel/sched/core.c:5123 Code: c9 50 e8 69 b8 0b 00 48 83 c4 08 4c 89 f7 e8 dd 38 00 00 e9 de 04 00 00 4c 89 f7 e8 30 a6 34 0a e8 ab 84 37 00 fb 48 8b 5d c0 <48> 8d bb f8 15 00 00 48 89 f8 48 c1 e8 03 49 be 00 00 00 00 00 fc RSP: 0018:ffffc90003c57288 EFLAGS: 00000282 RAX: 9195a65d1261f900 RBX: ffff888024c8da00 RCX: ffffffff816fd09a RDX: dffffc0000000000 RSI: ffffffff8bcac8a0 RDI: ffffffff8c206c80 RBP: ffffc90003c572d0 R08: ffffffff92fe47ef R09: 1ffffffff25fc8fd R10: dffffc0000000000 R11: fffffbfff25fc8fe R12: 1ffff110172a7ec7 R13: dffffc0000000000 R14: ffff8880b943e8c0 R15: ffff8880b953f638 context_switch kernel/sched/core.c:5252 [inline] __schedule+0x17f0/0x4a20 kernel/sched/core.c:6594 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6773 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6797 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x130/0x140 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] __wake_up_common_lock+0x18c/0x1e0 kernel/sched/wait.c:108 __unix_dgram_recvmsg+0x5f4/0x12f0 net/unix/af_unix.c:2415 sock_recvmsg_nosec+0x18e/0x1d0 net/socket.c:1046 ____sys_recvmsg+0x3c0/0x470 net/socket.c:2814 ___sys_recvmsg net/socket.c:2858 [inline] do_recvmmsg+0x474/0xae0 net/socket.c:2952 __sys_recvmmsg net/socket.c:3031 [inline] __do_sys_recvmmsg net/socket.c:3054 [inline] __se_sys_recvmmsg net/socket.c:3047 [inline] __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3047 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc27d67d0a9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc27e3920c8 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007fc27d7b4050 RCX: 00007fc27d67d0a9 RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00007fc27d6ec074 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007fc27d7b4050 R15: 00007fff5b81d208 The buggy address belongs to the virtual mapping at [ffffc90004150000, ffffc90004159000) created by: copy_process+0x5d1/0x3d90 kernel/fork.c:2206 The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2226b flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2dc2(GFP_KERNEL|__GFP_HIGHMEM|__GFP_NOWARN|__GFP_ZERO), pid 2, tgid 2 (kthreadd), ts 7469715658, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1500 prep_new_page mm/page_alloc.c:1508 [inline] get_page_from_freelist+0x2ccb/0x2d80 mm/page_alloc.c:3487 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4745 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2263 vm_area_alloc_pages mm/vmalloc.c:3576 [inline] __vmalloc_area_node mm/vmalloc.c:3652 [inline] __vmalloc_node_range_noprof+0x971/0x1460 mm/vmalloc.c:3833 alloc_thread_stack_node kernel/fork.c:313 [inline] dup_task_struct+0x444/0x8c0 kernel/fork.c:1114 copy_process+0x5d1/0x3d90 kernel/fork.c:2206 kernel_clone+0x226/0x8f0 kernel/fork.c:2788 kernel_thread+0x1bc/0x240 kernel/fork.c:2850 create_kthread kernel/kthread.c:412 [inline] kthreadd+0x60d/0x810 kernel/kthread.c:765 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:144 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 page_owner free stack trace missing Memory state around the buggy address: ffffc90004157480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffc90004157500: 00 00 00 00 f1 f1 f1 f1 00 00 00 f2 f2 f2 f2 f2 >ffffc90004157580: 04 f2 00 f2 f2 f2 00 00 f3 f3 f3 f3 00 00 00 00 ^ ffffc90004157600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffc90004157680: 00 00 00 00 f1 f1 f1 f1 00 00 00 00 00 f2 f2 f2 ================================================================== ---------------- Code disassembly (best guess): 0: c9 leave 1: 50 push %rax 2: e8 69 b8 0b 00 call 0xbb870 7: 48 83 c4 08 add $0x8,%rsp b: 4c 89 f7 mov %r14,%rdi e: e8 dd 38 00 00 call 0x38f0 13: e9 de 04 00 00 jmp 0x4f6 18: 4c 89 f7 mov %r14,%rdi 1b: e8 30 a6 34 0a call 0xa34a650 20: e8 ab 84 37 00 call 0x3784d0 25: fb sti 26: 48 8b 5d c0 mov -0x40(%rbp),%rbx * 2a: 48 8d bb f8 15 00 00 lea 0x15f8(%rbx),%rdi <-- trapping instruction 31: 48 89 f8 mov %rdi,%rax 34: 48 c1 e8 03 shr $0x3,%rax 38: 49 rex.WB 39: be 00 00 00 00 mov $0x0,%esi 3e: 00 fc add %bh,%ah