================================================================== BUG: KASAN: use-after-free in atomic_dec_and_test include/asm-generic/atomic-instrumented.h:259 [inline] BUG: KASAN: use-after-free in put_task_struct include/linux/sched/task.h:95 [inline] BUG: KASAN: use-after-free in _free_event+0x49a/0x1610 kernel/events/core.c:4451 Write of size 4 at addr ffff8800bb2cc220 by task syz-executor4/2878 CPU: 0 PID: 2878 Comm: syz-executor4 Not tainted 4.19.0-rc2+ #228 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412 check_memory_region_inline mm/kasan/kasan.c:260 [inline] check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267 kasan_check_write+0x14/0x20 mm/kasan/kasan.c:278 atomic_dec_and_test include/asm-generic/atomic-instrumented.h:259 [inline] put_task_struct include/linux/sched/task.h:95 [inline] _free_event+0x49a/0x1610 kernel/events/core.c:4451 free_event+0xb4/0x180 kernel/events/core.c:4472 perf_event_release_kernel+0x7d8/0xfa0 kernel/events/core.c:4633 perf_release+0x37/0x50 kernel/events/core.c:4647 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x1ad7/0x2610 kernel/exit.c:867 do_group_exit+0x177/0x440 kernel/exit.c:970 get_signal+0x8b0/0x1980 kernel/signal.c:2513 do_signal+0x9c/0x21e0 arch/x86/kernel/signal.c:816 exit_to_usermode_loop+0x2e5/0x380 arch/x86/entry/common.c:162 prepare_exit_to_usermode+0x342/0x3b0 arch/x86/entry/common.c:197 retint_user+0x8/0x18 RIP: 0033:0x4570a5 Code: 00 00 00 66 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 0f 83 cb b4 fb ff 66 2e 0f 1f 84 00 00 00 00 00 48 85 ff 41 57 4d 89 cf 41 56 41 RSP: 002b:0000000020000040 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f44ccbb56d4 RCX: 0000000000457099 RDX: 0000000020000100 RSI: 0000000020000040 RDI: 0000000000000000 RBP: 00000000009300a0 R08: 0000000020000080 R09: 0000000000000000 R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004cbae8 R14: 00000000004c33c7 R15: 0000000000000000 Allocated by task 2868: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc_node+0x144/0x730 mm/slab.c:3644 alloc_task_struct_node kernel/fork.c:157 [inline] dup_task_struct kernel/fork.c:802 [inline] copy_process+0x1ff4/0x8780 kernel/fork.c:1707 _do_fork+0x1cb/0x11d0 kernel/fork.c:2166 __do_sys_clone kernel/fork.c:2273 [inline] __se_sys_clone kernel/fork.c:2267 [inline] __x64_sys_clone+0xbf/0x150 kernel/fork.c:2267 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 2868: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x83/0x290 mm/slab.c:3756 free_task_struct kernel/fork.c:162 [inline] free_task+0x16e/0x1f0 kernel/fork.c:416 copy_process+0x1d9a/0x8780 kernel/fork.c:2098 _do_fork+0x1cb/0x11d0 kernel/fork.c:2166 __do_sys_clone kernel/fork.c:2273 [inline] __se_sys_clone kernel/fork.c:2267 [inline] __x64_sys_clone+0xbf/0x150 kernel/fork.c:2267 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8800bb2cc200 which belongs to the cache task_struct(129:syz4) of size 6080 The buggy address is located 32 bytes inside of 6080-byte region [ffff8800bb2cc200, ffff8800bb2cd9c0) The buggy address belongs to the page: page:ffffea0002ecb300 count:1 mapcount:0 mapping:ffff8801ce0c2a80 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000008100(slab|head) raw: 01fffc0000008100 ffffea000765e788 ffffea0006401988 ffff8801ce0c2a80 raw: 0000000000000000 ffff8800bb2cc200 0000000100000001 ffff8801c811c9c0 page dumped because: kasan: bad access detected page->mem_cgroup:ffff8801c811c9c0 Memory state around the buggy address: ffff8800bb2cc100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8800bb2cc180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8800bb2cc200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8800bb2cc280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8800bb2cc300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================