================================================================== BUG: KASAN: slab-use-after-free in bpf_link_free+0x234/0x2d0 kernel/bpf/syscall.c:3078 Read of size 8 at addr ffff88801bbc0d10 by task syz-executor.0/7549 CPU: 0 PID: 7549 Comm: syz-executor.0 Not tainted 6.9.0-syzkaller-g6f130e4d4a5f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 bpf_link_free+0x234/0x2d0 kernel/bpf/syscall.c:3078 bpf_link_put_direct kernel/bpf/syscall.c:3106 [inline] bpf_link_release+0x7b/0x90 kernel/bpf/syscall.c:3113 __fput+0x429/0x8a0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xa1b/0x27e0 kernel/exit.c:877 do_group_exit+0x207/0x2c0 kernel/exit.c:1026 get_signal+0x16a1/0x1740 kernel/signal.c:2911 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x102/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb8e487cee9 Code: Unable to access opcode bytes at 0x7fb8e487cebf. RSP: 002b:00007fb8e560a178 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fb8e49ac058 RCX: 00007fb8e487cee9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb8e49ac058 RBP: 00007fb8e49ac050 R08: 00007fb8e560a6c0 R09: 00007fb8e560a6c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb8e49ac05c R13: 000000000000004d R14: 00007ffc581852c0 R15: 00007ffc581853a8 Allocated by task 7549: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] kmalloc_trace+0x1db/0x370 mm/slub.c:4070 kmalloc include/linux/slab.h:628 [inline] kzalloc include/linux/slab.h:749 [inline] bpf_raw_tp_link_attach+0x2a0/0x6e0 kernel/bpf/syscall.c:3858 bpf_raw_tracepoint_open+0x1c2/0x240 kernel/bpf/syscall.c:3905 __sys_bpf+0x3c0/0x810 kernel/bpf/syscall.c:5729 __do_sys_bpf kernel/bpf/syscall.c:5794 [inline] __se_sys_bpf kernel/bpf/syscall.c:5792 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5792 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 16: 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:579 poison_slab_object+0xa6/0xe0 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2121 [inline] slab_free mm/slub.c:4353 [inline] kfree+0x153/0x3b0 mm/slub.c:4463 rcu_do_batch kernel/rcu/tree.c:2535 [inline] rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2809 handle_softirqs+0x2d6/0x990 kernel/softirq.c:554 run_ksoftirqd+0xca/0x130 kernel/softirq.c:928 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 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+0xac/0xc0 mm/kasan/generic.c:541 __call_rcu_common kernel/rcu/tree.c:3072 [inline] call_rcu+0x167/0xa70 kernel/rcu/tree.c:3176 bpf_link_free+0x1f8/0x2d0 kernel/bpf/syscall.c:3076 bpf_link_put_direct kernel/bpf/syscall.c:3106 [inline] bpf_link_release+0x7b/0x90 kernel/bpf/syscall.c:3113 __fput+0x429/0x8a0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xa1b/0x27e0 kernel/exit.c:877 do_group_exit+0x207/0x2c0 kernel/exit.c:1026 get_signal+0x16a1/0x1740 kernel/signal.c:2911 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x102/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88801bbc0d00 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 16 bytes inside of freed 128-byte region [ffff88801bbc0d00, ffff88801bbc0d80) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1bbc0 ksm flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000800 ffff888015041a00 ffffea00007cb8c0 dead000000000003 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x152cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 4545, tgid 4545 (udevd), ts 73102535857, free_ts 73056699634 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1534 prep_new_page mm/page_alloc.c:1541 [inline] get_page_from_freelist+0x3410/0x35b0 mm/page_alloc.c:3317 __alloc_pages+0x256/0x6c0 mm/page_alloc.c:4575 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page+0x5f/0x160 mm/slub.c:2190 allocate_slab mm/slub.c:2353 [inline] new_slab+0x84/0x2f0 mm/slub.c:2406 ___slab_alloc+0xb07/0x12e0 mm/slub.c:3592 __slab_alloc mm/slub.c:3682 [inline] __slab_alloc_node mm/slub.c:3735 [inline] slab_alloc_node mm/slub.c:3908 [inline] kmalloc_trace+0x269/0x370 mm/slub.c:4065 kmalloc include/linux/slab.h:628 [inline] kzalloc include/linux/slab.h:749 [inline] kernfs_get_open_node fs/kernfs/file.c:525 [inline] kernfs_fop_open+0x829/0xd10 fs/kernfs/file.c:700 do_dentry_open+0x907/0x15a0 fs/open.c:955 do_open fs/namei.c:3650 [inline] path_openat+0x2860/0x3240 fs/namei.c:3807 do_filp_open+0x235/0x490 fs/namei.c:3834 do_sys_openat2+0x13e/0x1d0 fs/open.c:1406 do_sys_open fs/open.c:1421 [inline] __do_sys_openat fs/open.c:1437 [inline] __se_sys_openat fs/open.c:1432 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1432 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 5576 tgid 5574 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1141 [inline] free_unref_page_prepare+0x986/0xab0 mm/page_alloc.c:2347 free_unref_folios+0x1f2/0xc10 mm/page_alloc.c:2536 folios_put_refs+0x93a/0xa60 mm/swap.c:1034 free_pages_and_swap_cache+0x5c8/0x690 mm/swap_state.c:332 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline] tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:366 [inline] tlb_flush_mmu+0x3a3/0x680 mm/mmu_gather.c:373 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:465 exit_mmap+0x4bb/0xd60 mm/mmap.c:3282 __mmput+0x115/0x3c0 kernel/fork.c:1346 exit_mm+0x220/0x310 kernel/exit.c:568 do_exit+0x99e/0x27e0 kernel/exit.c:864 do_group_exit+0x207/0x2c0 kernel/exit.c:1026 get_signal+0x16a1/0x1740 kernel/signal.c:2911 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x102/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88801bbc0c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801bbc0c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88801bbc0d00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801bbc0d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801bbc0e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc ==================================================================