================================================================== BUG: KASAN: use-after-free in __read_once_size include/linux/compiler.h:182 [inline] BUG: KASAN: use-after-free in task_is_descendant.part.3+0x610/0x670 security/yama/yama_lsm.c:295 Read of size 8 at addr ffff8801ba2b89a0 by task syz-executor1/15037 CPU: 1 PID: 15037 Comm: syz-executor1 Not tainted 4.19.0+ #97 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+0x244/0x39d lib/dump_stack.c:113 print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 __read_once_size include/linux/compiler.h:182 [inline] task_is_descendant.part.3+0x610/0x670 security/yama/yama_lsm.c:295 task_is_descendant security/yama/yama_lsm.c:282 [inline] yama_ptrace_access_check+0x215/0x10fc security/yama/yama_lsm.c:371 security_ptrace_access_check+0x54/0xb0 security/security.c:271 __ptrace_may_access+0x5c8/0x980 kernel/ptrace.c:336 ptrace_attach+0x1fa/0x640 kernel/ptrace.c:389 __do_sys_ptrace kernel/ptrace.c:1139 [inline] __se_sys_ptrace kernel/ptrace.c:1119 [inline] __x64_sys_ptrace+0x229/0x260 kernel/ptrace.c:1119 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: fd b3 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 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f2bf4a27c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000065 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000457569 RDX: 0000000000000000 RSI: 0000000000000237 RDI: 0000000000000010 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2bf4a286d4 R13: 00000000004c3336 R14: 00000000004d4fc0 R15: 00000000ffffffff Allocated by task 12234: 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:158 [inline] dup_task_struct kernel/fork.c:843 [inline] copy_process+0x2026/0x87a0 kernel/fork.c:1751 _do_fork+0x1cb/0x11d0 kernel/fork.c:2216 __do_sys_clone kernel/fork.c:2323 [inline] __se_sys_clone kernel/fork.c:2317 [inline] __x64_sys_clone+0xbf/0x150 kernel/fork.c:2317 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 12234: 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:3760 free_task_struct kernel/fork.c:163 [inline] free_task+0x16e/0x1f0 kernel/fork.c:457 __put_task_struct+0x2e6/0x620 kernel/fork.c:730 put_task_struct include/linux/sched/task.h:96 [inline] finish_task_switch+0x628/0x910 kernel/sched/core.c:2715 context_switch kernel/sched/core.c:2834 [inline] __schedule+0x8d7/0x21d0 kernel/sched/core.c:3472 preempt_schedule_irq+0xb9/0x140 kernel/sched/core.c:3699 retint_kernel+0x1b/0x2d __sanitizer_cov_trace_pc+0x0/0x50 kernel/kcov.c:146 inet_release+0x104/0x1f0 net/ipv4/af_inet.c:428 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:458 __sock_release+0xd7/0x250 net/socket.c:579 sock_close+0x19/0x20 net/socket.c:1141 __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 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801ba2b84c0 which belongs to the cache task_struct(33:syz1) of size 6080 The buggy address is located 1248 bytes inside of 6080-byte region [ffff8801ba2b84c0, ffff8801ba2b9c80) The buggy address belongs to the page: page:ffffea0006e8ae00 count:1 mapcount:0 mapping:ffff8801cb5f3980 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000010200(slab|head) raw: 02fffc0000010200 ffffea0007490a08 ffffea000749e988 ffff8801cb5f3980 raw: 0000000000000000 ffff8801ba2b84c0 0000000100000001 ffff8801bbdda000 page dumped because: kasan: bad access detected page->mem_cgroup:ffff8801bbdda000 Memory state around the buggy address: ffff8801ba2b8880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801ba2b8900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801ba2b8980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801ba2b8a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801ba2b8a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================