================================================================== BUG: KASAN: use-after-free in kill_fasync+0x45e/0x470 fs/fcntl.c:1014 Read of size 8 at addr ffff888075f88568 by task kworker/1:4/3687 CPU: 1 PID: 3687 Comm: kworker/1:4 Not tainted 5.19.0-rc5-syzkaller-00233-gb1c428b6c368 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Workqueue: events key_garbage_collector Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0xeb/0x467 mm/kasan/report.c:313 print_report mm/kasan/report.c:429 [inline] kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491 kill_fasync+0x45e/0x470 fs/fcntl.c:1014 post_one_notification.isra.0+0x6e4/0x990 kernel/watch_queue.c:128 remove_watch_from_object+0x35a/0x9d0 kernel/watch_queue.c:527 remove_watch_list include/linux/watch_queue.h:115 [inline] key_gc_unused_keys.constprop.0+0x2e5/0x600 security/keys/gc.c:135 key_garbage_collector+0x3d7/0x920 security/keys/gc.c:297 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 Allocated by task 10728: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:436 [inline] ____kasan_kmalloc mm/kasan/common.c:515 [inline] ____kasan_kmalloc mm/kasan/common.c:474 [inline] __kasan_kmalloc+0xa6/0xd0 mm/kasan/common.c:524 kasan_kmalloc include/linux/kasan.h:234 [inline] kmem_cache_alloc_trace+0x1ea/0x4a0 mm/slab.c:3569 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] alloc_pipe_info+0x10e/0x590 fs/pipe.c:790 get_pipe_inode fs/pipe.c:881 [inline] create_pipe_files+0x8d/0x880 fs/pipe.c:913 __do_pipe_flags fs/pipe.c:962 [inline] do_pipe2+0x96/0x1b0 fs/pipe.c:1010 __do_sys_pipe2 fs/pipe.c:1028 [inline] __se_sys_pipe2 fs/pipe.c:1026 [inline] __x64_sys_pipe2+0x50/0x70 fs/pipe.c:1026 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Freed by task 10727: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free+0x13d/0x180 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:200 [inline] __cache_free mm/slab.c:3425 [inline] kfree+0x113/0x310 mm/slab.c:3796 put_pipe_info fs/pipe.c:711 [inline] pipe_release+0x2b6/0x310 fs/pipe.c:734 __fput+0x277/0x9d0 fs/file_table.c:317 task_work_run+0xdd/0x1a0 kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:169 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x46/0xb0 The buggy address belongs to the object at ffff888075f88400 which belongs to the cache kmalloc-cg-512 of size 512 The buggy address is located 360 bytes inside of 512-byte region [ffff888075f88400, ffff888075f88600) The buggy address belongs to the physical page: page:ffffea0001d7e200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x75f88 memcg:ffff88807a6cde41 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea0001eeb388 ffffea000083e488 ffff888011843a00 raw: 0000000000000000 ffff888075f88000 0000000100000004 ffff88807a6cde41 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x3c20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_THISNODE), pid 10109, tgid 10108 (syz-executor.5), ts 677019861081, free_ts 674680256493 prep_new_page mm/page_alloc.c:2456 [inline] get_page_from_freelist+0x1290/0x3b70 mm/page_alloc.c:4198 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5426 __alloc_pages_node include/linux/gfp.h:587 [inline] kmem_getpages mm/slab.c:1363 [inline] cache_grow_begin+0x75/0x350 mm/slab.c:2569 cache_alloc_refill+0x27f/0x380 mm/slab.c:2942 ____cache_alloc mm/slab.c:3024 [inline] ____cache_alloc mm/slab.c:3007 [inline] slab_alloc_node mm/slab.c:3227 [inline] kmem_cache_alloc_node_trace+0x518/0x5b0 mm/slab.c:3611 __do_kmalloc_node mm/slab.c:3633 [inline] __kmalloc_node_track_caller+0x38/0x60 mm/slab.c:3648 kmalloc_reserve net/core/skbuff.c:354 [inline] __alloc_skb+0xde/0x340 net/core/skbuff.c:426 alloc_skb include/linux/skbuff.h:1426 [inline] alloc_skb_with_frags+0x93/0x730 net/core/skbuff.c:5992 sock_alloc_send_pskb+0x793/0x920 net/core/sock.c:2662 unix_dgram_sendmsg+0x425/0x1ad0 net/unix/af_unix.c:1895 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 ____sys_sendmsg+0x334/0x810 net/socket.c:2488 ___sys_sendmsg+0xf3/0x170 net/socket.c:2542 __sys_sendmmsg+0x195/0x470 net/socket.c:2628 __do_sys_sendmmsg net/socket.c:2657 [inline] __se_sys_sendmmsg net/socket.c:2654 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2654 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1371 [inline] free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1421 free_unref_page_prepare mm/page_alloc.c:3343 [inline] free_unref_page_list+0x16f/0xf80 mm/page_alloc.c:3475 release_pages+0xff1/0x2290 mm/swap.c:980 __pagevec_release+0x77/0x100 mm/swap.c:1000 pagevec_release include/linux/pagevec.h:82 [inline] folio_batch_release include/linux/pagevec.h:146 [inline] truncate_inode_pages_range+0x319/0x1530 mm/truncate.c:373 kill_bdev block/bdev.c:77 [inline] blkdev_flush_mapping+0x18f/0x3c0 block/bdev.c:663 blkdev_put_whole+0xd1/0xf0 block/bdev.c:694 blkdev_put+0x226/0x770 block/bdev.c:954 deactivate_locked_super+0x94/0x160 fs/super.c:332 deactivate_super+0xad/0xd0 fs/super.c:363 cleanup_mnt+0x3a2/0x540 fs/namespace.c:1186 task_work_run+0xdd/0x1a0 kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:169 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Memory state around the buggy address: ffff888075f88400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888075f88480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888075f88500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888075f88580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888075f88600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================