================================================================== BUG: KASAN: use-after-free in trace_event_raw_event_mm_filemap_op_page_cache+0x38a/0x3b0 include/trace/events/filemap.h:-1 Read of size 4 at addr ffff88811d4df010 by task syz.8.5219/20990 CPU: 1 PID: 20990 Comm: syz.8.5219 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0x100/0x140 mm/kasan/report.c:452 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 trace_event_raw_event_mm_filemap_op_page_cache+0x38a/0x3b0 include/trace/events/filemap.h:-1 trace_mm_filemap_delete_from_page_cache include/trace/events/filemap.h:47 [inline] __delete_from_page_cache+0x429/0x470 mm/filemap.c:241 __remove_mapping+0x581/0x6b0 mm/vmscan.c:985 shrink_page_list+0x21ee/0x4160 mm/vmscan.c:1498 shrink_inactive_list+0x90c/0xef0 mm/vmscan.c:2075 shrink_list mm/vmscan.c:2294 [inline] shrink_lruvec+0x281a/0x2ef0 mm/vmscan.c:5473 shrink_node_memcgs mm/vmscan.c:5660 [inline] shrink_node+0xee0/0x2690 mm/vmscan.c:5690 shrink_zones mm/vmscan.c:5896 [inline] do_try_to_free_pages+0x602/0x1590 mm/vmscan.c:5954 try_to_free_mem_cgroup_pages+0x261/0x610 mm/vmscan.c:6272 mem_cgroup_resize_max+0x309/0x3e0 mm/memcontrol.c:3387 mem_cgroup_write+0x1ed/0x230 mm/memcontrol.c:-1 cgroup_file_write+0x294/0x560 kernel/cgroup/cgroup.c:3902 kernfs_fop_write_iter+0x2bd/0x400 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2072 [inline] new_sync_write fs/read_write.c:518 [inline] vfs_write+0x770/0xd70 fs/read_write.c:605 ksys_write+0x14a/0x260 fs/read_write.c:658 __do_sys_write fs/read_write.c:670 [inline] __se_sys_write fs/read_write.c:667 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:667 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f0c70bb7159 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0c6f610028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f0c70e3efa0 RCX: 00007f0c70bb7159 RDX: 0000000000000001 RSI: 0000200000000080 RDI: 0000000000000003 RBP: 00007f0c70c4e06b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0c70e3f038 R14: 00007f0c70e3efa0 R15: 00007fff97a928b8 Allocated by task 20978: 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:430 [inline] ____kasan_kmalloc mm/kasan/common.c:509 [inline] __kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] kmem_cache_alloc_trace+0x179/0x2e0 mm/slub.c:2979 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:667 [inline] copy_verifier_state+0x711/0xc20 kernel/bpf/verifier.c:913 push_stack+0x19b/0x4f0 kernel/bpf/verifier.c:989 check_cond_jmp_op kernel/bpf/verifier.c:8305 [inline] do_check+0xbcd4/0xe3b0 kernel/bpf/verifier.c:10353 do_check_common+0x94e/0x1190 kernel/bpf/verifier.c:12087 do_check_main kernel/bpf/verifier.c:12150 [inline] bpf_check+0x97ea/0xdce0 kernel/bpf/verifier.c:12705 bpf_prog_load+0x1004/0x14e0 kernel/bpf/syscall.c:2234 __do_sys_bpf kernel/bpf/syscall.c:4435 [inline] __se_sys_bpf+0x49a/0x740 kernel/bpf/syscall.c:4391 __x64_sys_bpf+0x7b/0x90 kernel/bpf/syscall.c:4391 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 20978: 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:362 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370 kasan_slab_free include/linux/kasan.h:220 [inline] slab_free_hook mm/slub.c:1600 [inline] slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626 slab_free mm/slub.c:3208 [inline] kfree+0xc0/0x270 mm/slub.c:4196 free_func_state kernel/bpf/verifier.c:839 [inline] free_verifier_state+0xf1/0x250 kernel/bpf/verifier.c:855 pop_stack+0x393/0x510 kernel/bpf/verifier.c:964 do_check+0x87e5/0xe3b0 kernel/bpf/verifier.c:10342 do_check_common+0x94e/0x1190 kernel/bpf/verifier.c:12087 do_check_main kernel/bpf/verifier.c:12150 [inline] bpf_check+0x97ea/0xdce0 kernel/bpf/verifier.c:12705 bpf_prog_load+0x1004/0x14e0 kernel/bpf/syscall.c:2234 __do_sys_bpf kernel/bpf/syscall.c:4435 [inline] __se_sys_bpf+0x49a/0x740 kernel/bpf/syscall.c:4391 __x64_sys_bpf+0x7b/0x90 kernel/bpf/syscall.c:4391 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb 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+0x51/0x320 kernel/workqueue.c:1352 __queue_work+0x91f/0xca0 kernel/workqueue.c:1518 queue_work_on+0xe6/0x140 kernel/workqueue.c:1545 queue_work include/linux/workqueue.h:515 [inline] schedule_work include/linux/workqueue.h:576 [inline] destroy_super_rcu+0xd1/0xe0 fs/super.c:172 rcu_do_batch+0x488/0xaf0 kernel/rcu/tree.c:2494 rcu_core+0x50a/0xca0 kernel/rcu/tree.c:2735 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2748 __do_softirq+0x255/0x563 kernel/softirq.c:309 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 __call_rcu kernel/rcu/tree.c:2980 [inline] call_rcu+0x11a/0x1090 kernel/rcu/tree.c:3054 __put_super+0x254/0x2b0 fs/super.c:299 put_super fs/super.c:313 [inline] deactivate_locked_super+0xd4/0x100 fs/super.c:346 mount_bdev+0x288/0x380 fs/super.c:1455 f2fs_mount+0x34/0x40 fs/f2fs/super.c:4598 legacy_get_tree+0xed/0x190 fs/fs_context.c:593 vfs_get_tree+0x89/0x260 fs/super.c:1583 do_new_mount+0x25a/0xa30 fs/namespace.c:3006 path_mount+0x581/0xca0 fs/namespace.c:3336 do_mount fs/namespace.c:3349 [inline] __do_sys_mount fs/namespace.c:3557 [inline] __se_sys_mount+0x320/0x390 fs/namespace.c:3534 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3534 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff88811d4df000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 16 bytes inside of 2048-byte region [ffff88811d4df000, ffff88811d4df800) The buggy address belongs to the page: page:ffffea0004753600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11d4d8 head:ffffea0004753600 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 0000000000000000 0000000100000001 ffff888100042d80 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 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 12381, ts 970713908602, free_ts 970676920495 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x176/0x190 mm/page_alloc.c:2462 get_page_from_freelist+0x225f/0x23f0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x29a/0x640 mm/page_alloc.c:5384 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1813 [inline] new_slab+0x84/0x3f0 mm/slub.c:1874 new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc+0x2f8/0x4c0 mm/slub.c:2796 __slab_alloc+0x63/0xa0 mm/slub.c:2836 slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] __kmalloc_track_caller+0x1e4/0x310 mm/slub.c:4541 __kmalloc_reserve net/core/skbuff.c:144 [inline] __alloc_skb+0xdc/0x520 net/core/skbuff.c:212 alloc_skb include/linux/skbuff.h:1126 [inline] alloc_skb_with_frags+0xa3/0x560 net/core/skbuff.c:6048 sock_alloc_send_pskb+0x87f/0x9a0 net/core/sock.c:2392 sock_alloc_send_skb+0x32/0x40 net/core/sock.c:2409 mld_newpack+0x1a3/0x9c0 net/ipv6/mcast.c:1604 add_grhead net/ipv6/mcast.c:1707 [inline] add_grec+0xedf/0x1330 net/ipv6/mcast.c:1838 mld_send_cr net/ipv6/mcast.c:1964 [inline] mld_ifc_timer_expire+0x797/0xc60 net/ipv6/mcast.c:2471 call_timer_fn+0x38/0x290 kernel/time/timer.c:1450 expire_timers kernel/time/timer.c:1495 [inline] __run_timers+0x637/0x9a0 kernel/time/timer.c:1789 page last free stack trace: reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1349 [inline] __free_pages_ok+0x80b/0x830 mm/page_alloc.c:1629 free_the_page mm/page_alloc.c:5445 [inline] __free_pages+0xd8/0x390 mm/page_alloc.c:5454 __free_slab+0xcf/0x190 mm/slub.c:1899 free_slab mm/slub.c:1914 [inline] discard_slab mm/slub.c:1920 [inline] unfreeze_partials+0x150/0x180 mm/slub.c:2415 put_cpu_partial+0xc1/0x180 mm/slub.c:2451 __slab_free+0x2c9/0x3a0 mm/slub.c:3100 do_slab_free mm/slub.c:3196 [inline] ___cache_free+0x10e/0x130 mm/slub.c:3215 qlink_free+0x50/0x90 mm/kasan/quarantine.c:157 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x14a/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:440 kasan_slab_alloc include/linux/kasan.h:244 [inline] slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:580 slab_alloc_node mm/slub.c:2952 [inline] slab_alloc mm/slub.c:2960 [inline] kmem_cache_alloc+0x15a/0x2d0 mm/slub.c:2965 getname_flags+0xba/0x510 fs/namei.c:141 user_path_at_empty+0x2f/0x50 fs/namei.c:2790 user_path_at include/linux/namei.h:60 [inline] ksys_umount fs/namespace.c:1768 [inline] __do_sys_umount fs/namespace.c:1776 [inline] __se_sys_umount fs/namespace.c:1774 [inline] __x64_sys_umount+0xf9/0x170 fs/namespace.c:1774 Memory state around the buggy address: ffff88811d4def00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88811d4def80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88811d4df000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88811d4df080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811d4df100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================