================================================================== BUG: KASAN: slab-use-after-free in bpf_link_free+0x234/0x2d0 kernel/bpf/syscall.c:3078 Read of size 8 at addr ffff888024325c10 by task syz-executor.1/23893 CPU: 0 PID: 23893 Comm: syz-executor.1 Not tainted 6.9.0-syzkaller-12123-g531876c80004 #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+0x406/0x8b0 fs/file_table.c:422 __do_sys_close fs/open.c:1555 [inline] __se_sys_close fs/open.c:1540 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1540 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 RIP: 0033:0x7fe8a8c7bdda Code: 48 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c 24 0c e8 03 7f 02 00 8b 7c 24 0c 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 36 89 d7 89 44 24 0c e8 63 7f 02 00 8b 44 24 RSP: 002b:00007ffed1ed1c50 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007fe8a8c7bdda RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007 RBP: ffffffffffffffff R08: 00007fe8a8c00000 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000293 R12: 00007fe8a8db3fa0 R13: 00007fe8a8db3fac R14: 0000000000000226 R15: 00007fe8a8db59a0 Allocated by task 23895: 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_noprof+0x19c/0x2c0 mm/slub.c:4152 kmalloc_noprof include/linux/slab.h:660 [inline] kzalloc_noprof include/linux/slab.h:778 [inline] bpf_raw_tp_link_attach+0x2a0/0x6e0 kernel/bpf/syscall.c:3879 bpf_raw_tracepoint_open+0x1c2/0x240 kernel/bpf/syscall.c:3926 __sys_bpf+0x3c0/0x810 kernel/bpf/syscall.c:5751 __do_sys_bpf kernel/bpf/syscall.c:5816 [inline] __se_sys_bpf kernel/bpf/syscall.c:5814 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5814 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 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+0xe0/0x150 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:2195 [inline] slab_free mm/slub.c:4436 [inline] kfree+0x149/0x360 mm/slub.c:4557 rcu_do_batch kernel/rcu/tree.c:2535 [inline] rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2809 handle_softirqs+0x2c4/0x970 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+0x406/0x8b0 fs/file_table.c:422 __do_sys_close fs/open.c:1555 [inline] __se_sys_close fs/open.c:1540 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1540 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 The buggy address belongs to the object at ffff888024325c00 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 16 bytes inside of freed 128-byte region [ffff888024325c00, ffff888024325c80) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x24325 anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffefff(slab) raw: 00fff00000000000 ffff888015041a00 0000000000000000 dead000000000001 raw: 0000000000000000 0000000080100010 00000001ffffefff 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 4547, tgid 4547 (udevd), ts 1115413069030, free_ts 1115402087282 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1468 prep_new_page mm/page_alloc.c:1476 [inline] get_page_from_freelist+0x2e2d/0x2ee0 mm/page_alloc.c:3402 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4660 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] alloc_slab_page+0x5f/0x120 mm/slub.c:2264 allocate_slab+0x5a/0x2e0 mm/slub.c:2427 new_slab mm/slub.c:2480 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3666 __slab_alloc+0x58/0xa0 mm/slub.c:3756 __slab_alloc_node mm/slub.c:3809 [inline] slab_alloc_node mm/slub.c:3988 [inline] kmalloc_trace_noprof+0x1d5/0x2c0 mm/slub.c:4147 kmalloc_noprof include/linux/slab.h:660 [inline] kzalloc_noprof include/linux/slab.h:778 [inline] kernfs_get_open_node fs/kernfs/file.c:525 [inline] kernfs_fop_open+0x829/0xd10 fs/kernfs/file.c:700 do_dentry_open+0x95a/0x1720 fs/open.c:955 do_open fs/namei.c:3650 [inline] path_openat+0x289f/0x3280 fs/namei.c:3807 do_filp_open+0x235/0x490 fs/namei.c:3834 do_sys_openat2+0x13e/0x1d0 fs/open.c:1405 do_sys_open fs/open.c:1420 [inline] __do_sys_openat fs/open.c:1436 [inline] __se_sys_openat fs/open.c:1431 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1431 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 9081 tgid 9076 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1088 [inline] free_unref_folios+0xf23/0x19e0 mm/page_alloc.c:2614 folios_put_refs+0x93a/0xa60 mm/swap.c:1024 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+0x44f/0xc80 mm/mmap.c:3325 __mmput+0x115/0x3c0 kernel/fork.c:1346 exit_mm+0x220/0x310 kernel/exit.c:565 do_exit+0x9aa/0x27e0 kernel/exit.c:861 do_group_exit+0x207/0x2c0 kernel/exit.c:1023 get_signal+0x16a1/0x1740 kernel/signal.c:2909 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+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888024325b00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888024325b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888024325c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888024325c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888024325d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc ==================================================================