================================================================== BUG: KASAN: stack-out-of-bounds in profile_pc+0xa4/0xe0 arch/x86/kernel/time.c:42 Read of size 8 at addr ffff8881ec947720 by task udevd/162 CPU: 0 PID: 162 Comm: udevd Not tainted 5.4.274-syzkaller-00002-g6f97bd951d82 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d8/0x241 lib/dump_stack.c:118 print_address_description+0x8c/0x600 mm/kasan/report.c:384 __kasan_report+0xf3/0x120 mm/kasan/report.c:516 kasan_report+0x30/0x60 mm/kasan/common.c:653 profile_pc+0xa4/0xe0 arch/x86/kernel/time.c:42 profile_tick+0xb9/0x100 kernel/profile.c:416 tick_sched_handle kernel/time/tick-sched.c:206 [inline] tick_sched_timer+0x237/0x3c0 kernel/time/tick-sched.c:1342 __run_hrtimer kernel/time/hrtimer.c:1581 [inline] __hrtimer_run_queues+0x3e9/0xb90 kernel/time/hrtimer.c:1643 hrtimer_interrupt+0x38a/0x890 kernel/time/hrtimer.c:1705 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1122 [inline] smp_apic_timer_interrupt+0x110/0x460 arch/x86/kernel/apic/apic.c:1147 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834 RIP: 0010:arch_atomic_try_cmpxchg arch/x86/include/asm/atomic.h:200 [inline] RIP: 0010:atomic_try_cmpxchg include/asm-generic/atomic-instrumented.h:695 [inline] RIP: 0010:queued_spin_lock include/asm-generic/qspinlock.h:78 [inline] RIP: 0010:do_raw_spin_lock include/linux/spinlock.h:181 [inline] RIP: 0010:__raw_spin_lock include/linux/spinlock_api_smp.h:143 [inline] RIP: 0010:_raw_spin_lock+0xc0/0x1b0 kernel/locking/spinlock.c:151 Code: fd 4c 89 ff be 04 00 00 00 e8 6c ed 42 fd 43 0f b6 04 26 84 c0 0f 85 aa 00 00 00 8b 44 24 20 b9 01 00 00 00 f0 41 0f b1 4d 00 <75> 33 48 c7 04 24 0e 36 e0 45 49 c7 04 1c 00 00 00 00 65 48 8b 04 RSP: 0018:ffff8881ec947720 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: 1ffff1103d928ee4 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff8881ec947740 RBP: ffff8881ec9477a8 R08: dffffc0000000000 R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: dffffc0000000000 R13: ffff8881edf339e8 R14: 1ffff1103d928ee8 R15: ffff8881ec947740 spin_lock include/linux/spinlock.h:338 [inline] __d_lookup+0xe5/0x540 fs/dcache.c:2375 lookup_fast+0x119/0xa40 fs/namei.c:1694 walk_component+0x138/0x590 fs/namei.c:1881 link_path_walk+0x5c6/0x1040 fs/namei.c:2210 path_lookupat+0x53/0x3f0 fs/namei.c:2392 filename_lookup+0x253/0x6e0 fs/namei.c:2423 do_readlinkat+0x114/0x3a0 fs/stat.c:398 __do_sys_readlink fs/stat.c:431 [inline] __se_sys_readlink fs/stat.c:428 [inline] __x64_sys_readlink+0x7b/0x90 fs/stat.c:428 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f9e491ffd47 Code: 73 01 c3 48 8b 0d e1 90 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 59 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d b1 90 0d 00 f7 d8 64 89 01 48 RSP: 002b:00007ffe69f8ec18 EFLAGS: 00000202 ORIG_RAX: 0000000000000059 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9e491ffd47 RDX: 0000000000000400 RSI: 00007ffe69f8f028 RDI: 00007ffe69f8ec28 RBP: 00007ffe69f8f468 R08: 000055f7219141fd R09: 0000000000000000 R10: 0000000000000010 R11: 0000000000000202 R12: 0000000000000200 R13: 00007ffe69f8f028 R14: 00007ffe69f8ec28 R15: 0000000000000000 The buggy address belongs to the page: page:ffffea0007b251c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x8000000000000000() raw: 8000000000000000 ffffea0007b251c8 ffffea0007b251c8 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x400dc0(GFP_KERNEL_ACCOUNT|__GFP_ZERO) set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook mm/page_alloc.c:2165 [inline] prep_new_page+0x18f/0x370 mm/page_alloc.c:2171 get_page_from_freelist+0x2d13/0x2d90 mm/page_alloc.c:3794 __alloc_pages_nodemask+0x393/0x840 mm/page_alloc.c:4893 __alloc_pages include/linux/gfp.h:503 [inline] __alloc_pages_node include/linux/gfp.h:516 [inline] alloc_pages_node include/linux/gfp.h:530 [inline] alloc_thread_stack_node kernel/fork.c:259 [inline] dup_task_struct+0x85/0x600 kernel/fork.c:886 copy_process+0x56d/0x3230 kernel/fork.c:1889 _do_fork+0x197/0x900 kernel/fork.c:2399 __do_sys_clone kernel/fork.c:2557 [inline] __se_sys_clone kernel/fork.c:2538 [inline] __x64_sys_clone+0x26b/0x2c0 kernel/fork.c:2538 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 page_owner free stack trace missing addr ffff8881ec947720 is located in stack of task udevd/162 at offset 0 in frame: _raw_spin_lock+0x0/0x1b0 this frame has 1 object: [32, 36) 'val.i.i.i' Memory state around the buggy address: ffff8881ec947600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8881ec947680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8881ec947700: 00 00 00 00 f1 f1 f1 f1 04 f3 f3 f3 00 00 00 00 ^ ffff8881ec947780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8881ec947800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== ---------------- Code disassembly (best guess): 0: fd std 1: 4c 89 ff mov %r15,%rdi 4: be 04 00 00 00 mov $0x4,%esi 9: e8 6c ed 42 fd call 0xfd42ed7a e: 43 0f b6 04 26 movzbl (%r14,%r12,1),%eax 13: 84 c0 test %al,%al 15: 0f 85 aa 00 00 00 jne 0xc5 1b: 8b 44 24 20 mov 0x20(%rsp),%eax 1f: b9 01 00 00 00 mov $0x1,%ecx 24: f0 41 0f b1 4d 00 lock cmpxchg %ecx,0x0(%r13) * 2a: 75 33 jne 0x5f <-- trapping instruction 2c: 48 c7 04 24 0e 36 e0 movq $0x45e0360e,(%rsp) 33: 45 34: 49 c7 04 1c 00 00 00 movq $0x0,(%r12,%rbx,1) 3b: 00 3c: 65 gs 3d: 48 rex.W 3e: 8b .byte 0x8b 3f: 04 .byte 0x4