================================================================== BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:71 [inline] BUG: KASAN: use-after-free in atomic_long_read include/linux/atomic/atomic-instrumented.h:1183 [inline] BUG: KASAN: use-after-free in __down_read_trylock kernel/locking/rwsem.c:1348 [inline] BUG: KASAN: use-after-free in down_read_trylock+0x91/0x660 kernel/locking/rwsem.c:1624 Read of size 8 at addr ffff88810eb7b070 by task kworker/u4:80/11858 CPU: 1 PID: 11858 Comm: kworker/u4:80 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: writeback wb_workfn (flush-7:2) Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report+0xf1/0x140 mm/kasan/report.c:444 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x280/0x290 mm/kasan/generic.c:189 __kasan_check_read+0x11/0x20 mm/kasan/shadow.c:31 instrument_atomic_read include/linux/instrumented.h:71 [inline] atomic_long_read include/linux/atomic/atomic-instrumented.h:1183 [inline] __down_read_trylock kernel/locking/rwsem.c:1348 [inline] down_read_trylock+0x91/0x660 kernel/locking/rwsem.c:1624 trylock_super+0x1f/0xf0 fs/super.c:418 __writeback_inodes_wb+0x119/0x400 fs/fs-writeback.c:2002 wb_writeback+0x403/0x980 fs/fs-writeback.c:2118 wb_check_old_data_flush fs/fs-writeback.c:2222 [inline] wb_do_writeback fs/fs-writeback.c:2275 [inline] wb_workfn+0x9ae/0xe20 fs/fs-writeback.c:2304 process_one_work+0x6be/0xba0 kernel/workqueue.c:2325 worker_thread+0xa59/0x1200 kernel/workqueue.c:2472 kthread+0x411/0x500 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Allocated by task 25022: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:433 [inline] ____kasan_kmalloc mm/kasan/common.c:512 [inline] __kasan_kmalloc+0xda/0x110 mm/kasan/common.c:521 kasan_kmalloc include/linux/kasan.h:227 [inline] __kmalloc+0x13d/0x2c0 mm/slub.c:4436 kmalloc include/linux/slab.h:624 [inline] sk_prot_alloc+0xed/0x320 net/core/sock.c:1868 sk_alloc+0x38/0x430 net/core/sock.c:1928 __netlink_create net/netlink/af_netlink.c:629 [inline] __netlink_kernel_create+0x186/0x940 net/netlink/af_netlink.c:2048 netlink_kernel_create include/linux/netlink.h:62 [inline] uevent_net_init+0xe1/0x2b0 lib/kobject_uevent.c:785 ops_init+0x1ba/0x4a0 net/core/net_namespace.c:138 setup_net+0x344/0xa90 net/core/net_namespace.c:332 copy_net_ns+0x355/0x5c0 net/core/net_namespace.c:476 create_new_namespaces+0x3a2/0x660 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x120/0x170 kernel/nsproxy.c:226 ksys_unshare+0x4ac/0x7b0 kernel/fork.c:3242 __do_sys_unshare kernel/fork.c:3316 [inline] __se_sys_unshare kernel/fork.c:3314 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3314 x64_sys_call+0x442/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:273 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 25: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4a/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:365 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373 kasan_slab_free include/linux/kasan.h:193 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1754 slab_free mm/slub.c:3526 [inline] kfree+0xc4/0x270 mm/slub.c:4588 sk_prot_free net/core/sock.c:1911 [inline] __sk_destruct+0x4c0/0x5e0 net/core/sock.c:1997 sk_destruct net/core/sock.c:2012 [inline] __sk_free+0x313/0x410 net/core/sock.c:2023 sk_free+0x54/0x90 net/core/sock.c:2034 deferred_put_nlk_sk+0xa6/0xe0 net/netlink/af_netlink.c:723 rcu_do_batch+0x51d/0xba0 kernel/rcu/tree.c:2523 rcu_core+0x5e4/0xf80 kernel/rcu/tree.c:2763 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2776 handle_softirqs+0x250/0x560 kernel/softirq.c:583 run_ksoftirqd+0x28/0x40 kernel/softirq.c:959 smpboot_thread_fn+0x45a/0x8c0 kernel/smpboot.c:164 kthread+0x411/0x500 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 __call_rcu_common kernel/rcu/tree.c:3011 [inline] call_rcu+0x105/0xfe0 kernel/rcu/tree.c:3129 netlink_release+0x1288/0x1690 net/netlink/af_netlink.c:803 __sock_release net/socket.c:649 [inline] sock_release+0x7f/0x140 net/socket.c:677 netlink_kernel_release+0x4d/0x60 net/netlink/af_netlink.c:2110 uevent_net_exit+0xbe/0x1f0 lib/kobject_uevent.c:814 ops_exit_list net/core/net_namespace.c:172 [inline] cleanup_net+0x58b/0xad0 net/core/net_namespace.c:599 process_one_work+0x6be/0xba0 kernel/workqueue.c:2325 worker_thread+0xa59/0x1200 kernel/workqueue.c:2472 kthread+0x411/0x500 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Second to last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 insert_work+0x51/0x310 kernel/workqueue.c:1373 __queue_work+0x8e5/0xc60 kernel/workqueue.c:1539 queue_work_on+0xd2/0x140 kernel/workqueue.c:1566 queue_work include/linux/workqueue.h:510 [inline] schedule_work include/linux/workqueue.h:571 [inline] destroy_super_rcu+0xd1/0xe0 fs/super.c:172 rcu_do_batch+0x51d/0xba0 kernel/rcu/tree.c:2523 rcu_core+0x5e4/0xf80 kernel/rcu/tree.c:2763 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2776 handle_softirqs+0x250/0x560 kernel/softirq.c:583 run_ksoftirqd+0x28/0x40 kernel/softirq.c:959 smpboot_thread_fn+0x45a/0x8c0 kernel/smpboot.c:164 kthread+0x411/0x500 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 The buggy address belongs to the object at ffff88810eb7b000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 112 bytes inside of 2048-byte region [ffff88810eb7b000, ffff88810eb7b800) The buggy address belongs to the page: page:ffffea00043ade00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10eb78 head:ffffea00043ade00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100043200 raw: 0000000000000000 0000000000080008 00000001ffffffff 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 42, ts 22856054030, free_ts 22843177254 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2605 prep_new_page+0x1c/0x110 mm/page_alloc.c:2611 get_page_from_freelist+0x2cc5/0x2d50 mm/page_alloc.c:4485 __alloc_pages+0x18f/0x440 mm/page_alloc.c:5808 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1937 [inline] new_slab+0xa1/0x4d0 mm/slub.c:2000 ___slab_alloc+0x381/0x810 mm/slub.c:3033 __slab_alloc+0x49/0x90 mm/slub.c:3120 slab_alloc_node mm/slub.c:3211 [inline] slab_alloc mm/slub.c:3255 [inline] __kmalloc_track_caller+0x169/0x2c0 mm/slub.c:4954 kmalloc_reserve net/core/skbuff.c:357 [inline] __alloc_skb+0x21a/0x740 net/core/skbuff.c:428 alloc_skb include/linux/skbuff.h:1183 [inline] mld_newpack+0x13a/0x9d0 net/ipv6/mcast.c:1745 add_grhead+0x5e/0x290 net/ipv6/mcast.c:1856 add_grec+0xd41/0x1100 net/ipv6/mcast.c:1994 mld_send_cr net/ipv6/mcast.c:2120 [inline] mld_ifc_work+0x75d/0xbe0 net/ipv6/mcast.c:2658 process_one_work+0x6be/0xba0 kernel/workqueue.c:2325 worker_thread+0xa59/0x1200 kernel/workqueue.c:2472 kthread+0x411/0x500 kernel/kthread.c:337 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1472 [inline] free_pcp_prepare mm/page_alloc.c:1544 [inline] free_unref_page_prepare+0x542/0x550 mm/page_alloc.c:3534 free_unref_page+0xa2/0x550 mm/page_alloc.c:3616 free_the_page mm/page_alloc.c:805 [inline] __free_pages+0x6c/0x100 mm/page_alloc.c:5884 free_nonslab_page+0x86/0xc0 mm/slub.c:3564 kfree+0x19a/0x270 mm/slub.c:4585 kvfree+0x35/0x40 mm/util.c:661 btf_add_type kernel/bpf/btf.c:1476 [inline] btf_check_all_metas+0x5f1/0xa70 kernel/bpf/btf.c:4017 btf_parse_vmlinux+0x3f4/0xdf0 kernel/bpf/btf.c:4598 bpf_get_btf_vmlinux kernel/bpf/verifier.c:13991 [inline] bpf_check+0x63f/0xf280 kernel/bpf/verifier.c:14030 bpf_prog_load+0x1042/0x1550 kernel/bpf/syscall.c:2328 __sys_bpf+0x4c3/0x730 kernel/bpf/syscall.c:4633 __do_sys_bpf kernel/bpf/syscall.c:4737 [inline] __se_sys_bpf kernel/bpf/syscall.c:4735 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:4735 x64_sys_call+0x4b9/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:322 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Memory state around the buggy address: ffff88810eb7af00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88810eb7af80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88810eb7b000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88810eb7b080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88810eb7b100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================