================================================================== BUG: KASAN: slab-use-after-free in set_next_task kernel/sched/sched.h:2331 [inline] BUG: KASAN: slab-use-after-free in pick_next_task kernel/sched/core.c:6143 [inline] BUG: KASAN: slab-use-after-free in __schedule+0x5478/0x5c60 kernel/sched/core.c:6691 Read of size 8 at addr ffff8880242ba6b0 by task syz-executor.0/7291 CPU: 0 PID: 7291 Comm: syz-executor.0 Not tainted 6.8.0-rc2-syzkaller-g41b9fb381a48 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc4/0x620 mm/kasan/report.c:488 kasan_report+0xda/0x110 mm/kasan/report.c:601 set_next_task kernel/sched/sched.h:2331 [inline] pick_next_task kernel/sched/core.c:6143 [inline] __schedule+0x5478/0x5c60 kernel/sched/core.c:6691 preempt_schedule_irq+0x52/0x90 kernel/sched/core.c:7047 irqentry_exit+0x36/0x90 kernel/entry/common.c:348 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:rcu_preempt_read_enter kernel/rcu/tree_plugin.h:379 [inline] RIP: 0010:__rcu_read_lock+0x27/0x100 kernel/rcu/tree_plugin.h:402 Code: 90 90 90 f3 0f 1e fa 48 b8 00 00 00 00 00 fc ff df 55 53 65 48 8b 1c 25 40 c2 03 00 48 8d bb 3c 04 00 00 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 a8 RSP: 0018:ffffc9002150f3f0 EFLAGS: 00000a07 RAX: dffffc0000000000 RBX: ffff888046ef0000 RCX: ffffffff81ef6e03 RDX: 1ffff11008dde087 RSI: ffffffff81ef3712 RDI: ffff888046ef043c RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffffea00011579c0 R13: 0000000000000000 R14: 0000000000000000 R15: ffffea00011579c0 rcu_read_lock include/linux/rcupdate.h:748 [inline] page_ext_get+0x17/0x310 mm/page_ext.c:508 __page_table_check_zero+0x139/0x5e0 mm/page_table_check.c:140 page_table_check_free include/linux/page_table_check.h:41 [inline] free_pages_prepare mm/page_alloc.c:1141 [inline] free_unref_page_prepare+0x517/0xb10 mm/page_alloc.c:2346 free_unref_page_list+0xe6/0xb40 mm/page_alloc.c:2532 release_pages+0x32a/0x14f0 mm/swap.c:1042 tlb_batch_pages_flush+0x9a/0x190 mm/mmu_gather.c:98 zap_pte_range mm/memory.c:1558 [inline] zap_pmd_range mm/memory.c:1597 [inline] zap_pud_range mm/memory.c:1626 [inline] zap_p4d_range mm/memory.c:1647 [inline] unmap_page_range+0x18d6/0x2af0 mm/memory.c:1668 unmap_single_vma+0x194/0x2b0 mm/memory.c:1714 unmap_vmas+0x22f/0x490 mm/memory.c:1758 exit_mmap+0x1c1/0xb50 mm/mmap.c:3279 __mmput+0x12a/0x4d0 kernel/fork.c:1343 mmput+0x62/0x70 kernel/fork.c:1365 exit_mm kernel/exit.c:569 [inline] do_exit+0x9a5/0x2ad0 kernel/exit.c:858 do_group_exit+0xd4/0x2a0 kernel/exit.c:1020 get_signal+0x23b9/0x2790 kernel/signal.c:2893 arch_do_signal_or_restart+0x90/0x7f0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:105 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline] syscall_exit_to_user_mode+0x156/0x2b0 kernel/entry/common.c:212 do_syscall_64+0xe5/0x270 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7f85a747cae9 Code: Unable to access opcode bytes at 0x7f85a747cabf. RSP: 002b:00007f85a8134178 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f85a759c058 RCX: 00007f85a747cae9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f85a759c058 RBP: 00007f85a759c050 R08: 00007f85a81346c0 R09: 00007f85a81346c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f85a759c05c R13: 000000000000006e R14: 00007ffd974822a0 R15: 00007ffd97482388 Allocated by task 7287: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:314 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:340 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3813 [inline] slab_alloc_node mm/slub.c:3860 [inline] kmem_cache_alloc_node+0x177/0x350 mm/slub.c:3903 alloc_task_struct_node kernel/fork.c:174 [inline] dup_task_struct kernel/fork.c:1104 [inline] copy_process+0x44f/0x97b0 kernel/fork.c:2327 kernel_clone+0xfd/0x930 kernel/fork.c:2902 __do_sys_clone3+0x1f5/0x270 kernel/fork.c:3203 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 Freed by task 7291: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3f/0x60 mm/kasan/generic.c:640 poison_slab_object mm/kasan/common.c:241 [inline] __kasan_slab_free+0x121/0x1c0 mm/kasan/common.c:257 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2121 [inline] slab_free mm/slub.c:4299 [inline] kmem_cache_free+0x129/0x360 mm/slub.c:4363 put_task_struct include/linux/sched/task.h:138 [inline] put_task_struct include/linux/sched/task.h:125 [inline] delayed_put_task_struct+0x21b/0x2c0 kernel/exit.c:229 rcu_do_batch kernel/rcu/tree.c:2190 [inline] rcu_core+0x819/0x1680 kernel/rcu/tree.c:2465 __do_softirq+0x21c/0x8e7 kernel/softirq.c:553 Last potentially related work creation: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 __kasan_record_aux_stack+0xba/0x110 mm/kasan/generic.c:586 __call_rcu_common.constprop.0+0x9a/0x7c0 kernel/rcu/tree.c:2715 put_task_struct_rcu_user kernel/exit.c:235 [inline] put_task_struct_rcu_user+0x87/0xd0 kernel/exit.c:232 context_switch kernel/sched/core.c:5403 [inline] __schedule+0xf1a/0x5c60 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6802 [inline] schedule+0xe9/0x280 kernel/sched/core.c:6817 futex_wait_queue+0xfe/0x1f0 kernel/futex/waitwake.c:370 __futex_wait+0x292/0x3c0 kernel/futex/waitwake.c:669 futex_wait+0xea/0x390 kernel/futex/waitwake.c:697 do_futex+0x22b/0x350 kernel/futex/syscalls.c:102 __do_sys_futex kernel/futex/syscalls.c:179 [inline] __se_sys_futex kernel/futex/syscalls.c:160 [inline] __x64_sys_futex+0x1e1/0x4c0 kernel/futex/syscalls.c:160 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 Second to last potentially related work creation: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 __kasan_record_aux_stack+0xba/0x110 mm/kasan/generic.c:586 task_work_add+0x88/0x2a0 kernel/task_work.c:48 scheduler_tick+0x22e/0x650 kernel/sched/core.c:5680 update_process_times+0x19f/0x220 kernel/time/timer.c:2092 tick_sched_handle+0x8e/0x170 kernel/time/tick-sched.c:255 tick_nohz_highres_handler+0xed/0x120 kernel/time/tick-sched.c:1519 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x64a/0xc30 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1065 [inline] __sysvec_apic_timer_interrupt+0x108/0x400 arch/x86/kernel/apic/apic.c:1082 sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649 The buggy address belongs to the object at ffff8880242ba400 which belongs to the cache task_struct of size 8960 The buggy address is located 688 bytes inside of freed 8960-byte region [ffff8880242ba400, ffff8880242bc700) The buggy address belongs to the physical page: page:ffffea000090ae00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880242bc800 pfn:0x242b8 head:ffffea000090ae00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888024f50b81 flags: 0xfff00000000a40(workingset|slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000a40 ffff8880162e6140 ffffea0001145010 ffffea00006f7210 raw: ffff8880242bc800 0000000000030002 00000001ffffffff ffff888024f50b81 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 6848, tgid 6848 (syz-executor.3), ts 125499547479, free_ts 125489600776 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2d4/0x350 mm/page_alloc.c:1533 prep_new_page mm/page_alloc.c:1540 [inline] get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3311 __alloc_pages+0x22f/0x2440 mm/page_alloc.c:4567 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page mm/slub.c:2190 [inline] allocate_slab mm/slub.c:2354 [inline] new_slab+0xcc/0x3a0 mm/slub.c:2407 ___slab_alloc+0x4af/0x19a0 mm/slub.c:3540 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3625 __slab_alloc_node mm/slub.c:3678 [inline] slab_alloc_node mm/slub.c:3850 [inline] kmem_cache_alloc_node+0x10a/0x350 mm/slub.c:3903 alloc_task_struct_node kernel/fork.c:174 [inline] dup_task_struct kernel/fork.c:1104 [inline] copy_process+0x44f/0x97b0 kernel/fork.c:2327 kernel_clone+0xfd/0x930 kernel/fork.c:2902 __do_sys_clone3+0x1f5/0x270 kernel/fork.c:3203 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 page last free pid 4669 tgid 4669 stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1140 [inline] free_unref_page_prepare+0x527/0xb10 mm/page_alloc.c:2346 free_unref_page+0x33/0x3c0 mm/page_alloc.c:2486 __put_partials+0x14c/0x170 mm/slub.c:2922 qlink_free mm/kasan/quarantine.c:160 [inline] qlist_free_all+0x58/0x150 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:324 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3813 [inline] slab_alloc_node mm/slub.c:3860 [inline] kmem_cache_alloc+0x136/0x320 mm/slub.c:3867 getname_flags.part.0+0x50/0x4f0 fs/namei.c:140 getname_flags+0x9c/0xf0 include/linux/audit.h:322 vfs_fstatat+0x9a/0x150 fs/stat.c:303 __do_sys_newfstatat+0x98/0x120 fs/stat.c:468 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 Memory state around the buggy address: ffff8880242ba580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880242ba600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880242ba680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880242ba700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880242ba780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 90 nop 1: 90 nop 2: 90 nop 3: f3 0f 1e fa endbr64 7: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax e: fc ff df 11: 55 push %rbp 12: 53 push %rbx 13: 65 48 8b 1c 25 40 c2 mov %gs:0x3c240,%rbx 1a: 03 00 1c: 48 8d bb 3c 04 00 00 lea 0x43c(%rbx),%rdi 23: 48 89 fa mov %rdi,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx <-- trapping instruction 2e: 48 89 f8 mov %rdi,%rax 31: 83 e0 07 and $0x7,%eax 34: 83 c0 03 add $0x3,%eax 37: 38 d0 cmp %dl,%al 39: 7c 08 jl 0x43 3b: 84 d2 test %dl,%dl 3d: 0f .byte 0xf 3e: 85 .byte 0x85 3f: a8 .byte 0xa8