================================================================== 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:97 [inline] BUG: KASAN: use-after-free in _free_event+0x3dd/0x1220 kernel/events/core.c:4452 Write of size 4 at addr ffff888052a6c1a0 by task syz-executor.4/4673 CPU: 1 PID: 4673 Comm: syz-executor.4 Not tainted 5.0.0-rc8+ #3 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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x123/0x190 mm/kasan/generic.c:191 kasan_check_write+0x14/0x20 mm/kasan/common.c:106 atomic_dec_and_test include/asm-generic/atomic-instrumented.h:259 [inline] put_task_struct include/linux/sched/task.h:97 [inline] _free_event+0x3dd/0x1220 kernel/events/core.c:4452 free_event+0x5f/0xd0 kernel/events/core.c:4473 perf_event_release_kernel+0x5ae/0xbf0 kernel/events/core.c:4634 perf_release+0x37/0x50 kernel/events/core.c:4648 __fput+0x2df/0x8d0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x14a/0x1c0 kernel/task_work.c:113 get_signal+0x1961/0x1d50 kernel/signal.c:2388 do_signal+0x87/0x1940 arch/x86/kernel/signal.c:816 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457e29 Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 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 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f2f11a62c78 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffe6 RBX: 0000000000000003 RCX: 0000000000457e29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000040 kobject: 'ieee80211' (00000000bfa86a47): kobject_add_internal: parent: 'hwsim15', set: '(null)' RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2f11a636d4 R13: 00000000004be413 R14: 00000000004ced00 R15: 00000000ffffffff Allocated by task 4674: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:495 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:468 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:503 slab_post_alloc_hook mm/slab.h:440 [inline] slab_alloc_node mm/slab.c:3331 [inline] kmem_cache_alloc_node+0x131/0x710 mm/slab.c:3637 alloc_task_struct_node kernel/fork.c:158 [inline] dup_task_struct kernel/fork.c:845 [inline] copy_process.part.0+0x1d08/0x79a0 kernel/fork.c:1753 copy_process kernel/fork.c:1710 [inline] _do_fork+0x257/0xfe0 kernel/fork.c:2227 __do_sys_clone kernel/fork.c:2334 [inline] __se_sys_clone kernel/fork.c:2328 [inline] __x64_sys_clone+0xbf/0x150 kernel/fork.c:2328 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 4674: save_stack+0x45/0xd0 mm/kasan/common.c:73 kobject: 'phy16' (000000008b789133): kobject_add_internal: parent: 'ieee80211', set: 'devices' set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:457 kasan_slab_free+0xe/0x10 mm/kasan/common.c:465 __cache_free mm/slab.c:3494 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3754 free_task_struct kernel/fork.c:163 [inline] free_task+0xdd/0x120 kernel/fork.c:458 copy_process.part.0+0x1a3a/0x79a0 kernel/fork.c:2159 kobject: 'phy16' (000000008b789133): kobject_uevent_env copy_process kernel/fork.c:1710 [inline] _do_fork+0x257/0xfe0 kernel/fork.c:2227 __do_sys_clone kernel/fork.c:2334 [inline] __se_sys_clone kernel/fork.c:2328 [inline] __x64_sys_clone+0xbf/0x150 kernel/fork.c:2328 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888052a6c180 which belongs to the cache task_struct(81:syz4) of size 6080 The buggy address is located 32 bytes inside of 6080-byte region [ffff888052a6c180, ffff888052a6d940) The buggy address belongs to the page: page:ffffea00014a9b00 count:1 mapcount:0 mapping:ffff8880a3fd79c0 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea000210df08 ffffea0002a62008 ffff8880a3fd79c0 raw: 0000000000000000 ffff888052a6c180 0000000100000001 ffff88809bb2a6c0 kobject: 'phy16' (000000008b789133): fill_kobj_path: path = '/devices/virtual/mac80211_hwsim/hwsim15/ieee80211/phy16' page dumped because: kasan: bad access detected page->mem_cgroup:ffff88809bb2a6c0 Memory state around the buggy address: ffff888052a6c080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888052a6c100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888052a6c180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888052a6c200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888052a6c280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================