================================================================== BUG: KASAN: use-after-free in kill_fasync+0x45e/0x470 fs/fcntl.c:1014 Read of size 8 at addr ffff88807abbe968 by task syz-executor339/3606 CPU: 1 PID: 3606 Comm: syz-executor339 Not tainted 5.19.0-rc6-syzkaller-00418-g972a278fe60c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 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/0x495 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 __post_watch_notification kernel/watch_queue.c:206 [inline] __post_watch_notification+0x561/0x840 kernel/watch_queue.c:176 post_watch_notification include/linux/watch_queue.h:109 [inline] notify_key security/keys/internal.h:199 [inline] __key_update security/keys/key.c:775 [inline] key_create_or_update+0xdbf/0xde0 security/keys/key.c:979 __do_sys_add_key+0x215/0x430 security/keys/keyctl.c:134 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+0x63/0xcd RIP: 0033:0x7fb1a43aaf49 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 90 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc4dcbdb48 EFLAGS: 00000246 ORIG_RAX: 00000000000000f8 RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007fb1a43aaf49 RDX: 0000000020000280 RSI: 0000000020000100 RDI: 00000000200000c0 RBP: 0000000000000000 R08: 00000000fffffffc R09: 0000000000000001 R10: 0000000000000048 R11: 0000000000000246 R12: 00007fb1a436e720 R13: 0000000000000000 R14: 00007ffc4dcbdb70 R15: 00007ffc4dcbdb60 Allocated by task 3600: 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+0xa9/0xd0 mm/kasan/common.c:524 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] alloc_pipe_info+0x105/0x590 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+0x63/0xcd Freed by task 3600: 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+0x166/0x1a0 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1754 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1780 slab_free mm/slub.c:3536 [inline] kfree+0xd6/0x4d0 mm/slub.c:4584 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 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xade/0x29d0 kernel/exit.c:795 do_group_exit+0xd2/0x2f0 kernel/exit.c:925 __do_sys_exit_group kernel/exit.c:936 [inline] __se_sys_exit_group kernel/exit.c:934 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:934 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+0x63/0xcd The buggy address belongs to the object at ffff88807abbe800 which belongs to the cache kmalloc-cg-512 of size 512 The buggy address is located 360 bytes inside of 512-byte region [ffff88807abbe800, ffff88807abbea00) The buggy address belongs to the physical page: page:ffffea0001eaef00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7abbc head:ffffea0001eaef00 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888011842dc0 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3185, tgid 3185 (dhcpcd), ts 21830558237, free_ts 18232364269 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+0x1aa/0x310 mm/mempolicy.c:2272 alloc_slab_page mm/slub.c:1824 [inline] allocate_slab+0x26c/0x3c0 mm/slub.c:1969 new_slab mm/slub.c:2029 [inline] ___slab_alloc+0x9c4/0xe20 mm/slub.c:3031 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3118 slab_alloc_node mm/slub.c:3209 [inline] __kmalloc_node_track_caller+0x2cb/0x360 mm/slub.c:4979 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 sock_write_iter+0x284/0x3c0 net/socket.c:1108 call_write_iter include/linux/fs.h:2058 [inline] do_iter_readv_writev+0x3d1/0x640 fs/read_write.c:742 do_iter_write+0x182/0x700 fs/read_write.c:868 vfs_writev+0x1aa/0x630 fs/read_write.c:941 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+0x19/0x6a0 mm/page_alloc.c:3438 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:446 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:750 [inline] slab_alloc_node mm/slub.c:3243 [inline] slab_alloc mm/slub.c:3251 [inline] __kmem_cache_alloc_lru mm/slub.c:3258 [inline] kmem_cache_alloc+0x204/0x3b0 mm/slub.c:3268 getname_flags.part.0+0x50/0x4f0 fs/namei.c:139 getname_flags+0x9a/0xe0 include/linux/audit.h:323 vfs_fstatat+0x73/0xb0 fs/stat.c:254 __do_sys_newfstatat+0x91/0x110 fs/stat.c:425 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+0x63/0xcd Memory state around the buggy address: ffff88807abbe800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807abbe880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807abbe900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807abbe980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807abbea00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================