================================================================== BUG: KASAN: slab-use-after-free in task_work_run+0x22b/0x310 kernel/task_work.c:226 Read of size 8 at addr ffff888079ef0ab8 by task syz.3.2287/15394 CPU: 0 UID: 0 PID: 15394 Comm: syz.3.2287 Not tainted 6.14.0-rc3-syzkaller-g63817c771194 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0x16e/0x5b0 mm/kasan/report.c:521 kasan_report+0x143/0x180 mm/kasan/report.c:634 task_work_run+0x22b/0x310 kernel/task_work.c:226 get_signal+0x15d1/0x1720 kernel/signal.c:2809 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb11818d169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb11902c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffff2 RBX: 00007fb1183a5fa0 RCX: 00007fb11818d169 RDX: 000000110e22fff6 RSI: 00000000c004743e RDI: 0000000000000003 RBP: 00007fb11820e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb1183a5fa0 R15: 00007ffc7b30db58 Allocated by task 15394: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4115 [inline] slab_alloc_node mm/slub.c:4164 [inline] kmem_cache_alloc_node_noprof+0x1d9/0x380 mm/slub.c:4216 perf_event_alloc+0x157/0x1e40 kernel/events/core.c:12240 __do_sys_perf_event_open kernel/events/core.c:12875 [inline] __se_sys_perf_event_open+0xa5d/0x34b0 kernel/events/core.c:12765 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 24: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4609 [inline] kmem_cache_free+0x195/0x410 mm/slub.c:4711 rcu_do_batch kernel/rcu/tree.c:2546 [inline] rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2802 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561 run_ksoftirqd+0xca/0x130 kernel/softirq.c:950 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xaa/0xc0 mm/kasan/generic.c:548 __call_rcu_common kernel/rcu/tree.c:3065 [inline] call_rcu+0x168/0xac0 kernel/rcu/tree.c:3172 put_event kernel/events/core.c:5447 [inline] perf_event_release_kernel+0x7c1/0x850 kernel/events/core.c:5572 perf_release+0x38/0x40 kernel/events/core.c:5582 __fput+0x3e9/0x9f0 fs/file_table.c:464 task_work_run+0x24f/0x310 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f Second to last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xaa/0xc0 mm/kasan/generic.c:548 task_work_add+0xb8/0x450 kernel/task_work.c:65 __perf_event_overflow+0x78d/0xdc0 kernel/events/core.c:9945 perf_swevent_event+0x317/0x680 do_perf_sw_event kernel/events/core.c:10185 [inline] ___perf_sw_event+0x4f3/0x730 kernel/events/core.c:10212 __perf_sw_event+0xff/0x1b0 kernel/events/core.c:10224 perf_sw_event include/linux/perf_event.h:1503 [inline] do_user_addr_fault arch/x86/mm/fault.c:1284 [inline] handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x710/0x8b0 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 The buggy address belongs to the object at ffff888079ef0630 which belongs to the cache perf_event of size 1456 The buggy address is located 1160 bytes inside of freed 1456-byte region [ffff888079ef0630, ffff888079ef0be0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888079ef1ef0 pfn:0x79ef0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b091500 0000000000000000 0000000000000001 raw: ffff888079ef1ef0 0000000000140013 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b091500 0000000000000000 0000000000000001 head: ffff888079ef1ef0 0000000000140013 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001e7bc01 ffffffffffffffff 0000000000000000 head: 0000000000000008 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 13262, tgid 13261 (syz.3.1737), ts 351837880525, free_ts 351826740193 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551 prep_new_page mm/page_alloc.c:1559 [inline] get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4739 alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:2423 [inline] allocate_slab+0x8f/0x3a0 mm/slub.c:2587 new_slab mm/slub.c:2640 [inline] ___slab_alloc+0xc27/0x14a0 mm/slub.c:3826 __slab_alloc+0x58/0xa0 mm/slub.c:3916 __slab_alloc_node mm/slub.c:3991 [inline] slab_alloc_node mm/slub.c:4152 [inline] kmem_cache_alloc_node_noprof+0x269/0x380 mm/slub.c:4216 perf_event_alloc+0x157/0x1e40 kernel/events/core.c:12240 __do_sys_perf_event_open kernel/events/core.c:12875 [inline] __se_sys_perf_event_open+0xa5d/0x34b0 kernel/events/core.c:12765 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 13263 tgid 13263 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660 discard_slab mm/slub.c:2684 [inline] __put_partials+0x160/0x1c0 mm/slub.c:3153 put_cpu_partial+0x17c/0x250 mm/slub.c:3228 __slab_free+0x290/0x380 mm/slub.c:4479 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4115 [inline] slab_alloc_node mm/slub.c:4164 [inline] __do_kmalloc_node mm/slub.c:4293 [inline] __kmalloc_noprof+0x236/0x4c0 mm/slub.c:4306 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x26f/0x540 security/tomoyo/realpath.c:80 tomoyo_path_perm+0x3e8/0x610 security/tomoyo/file.c:831 tomoyo_path_symlink+0xde/0x120 security/tomoyo/tomoyo.c:212 security_path_symlink+0x16f/0x370 security/security.c:1984 do_symlinkat+0x136/0x3a0 fs/namei.c:4695 __do_sys_symlinkat fs/namei.c:4713 [inline] __se_sys_symlinkat fs/namei.c:4710 [inline] __x64_sys_symlinkat+0x95/0xb0 fs/namei.c:4710 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888079ef0980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888079ef0a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888079ef0a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888079ef0b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888079ef0b80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================