================================================================== BUG: KASAN: use-after-free in x25_kill_by_device net/x25/af_x25.c:217 [inline] BUG: KASAN: use-after-free in x25_device_event+0x296/0x2b0 net/x25/af_x25.c:252 Read of size 8 at addr ffff8880a5ae9d50 by task syz-executor.4/30760 CPU: 1 PID: 30760 Comm: syz-executor.4 Not tainted 5.0.0+ #110 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 x25_kill_by_device net/x25/af_x25.c:217 [inline] x25_device_event+0x296/0x2b0 net/x25/af_x25.c:252 notifier_call_chain+0xc7/0x240 kernel/notifier.c:93 __raw_notifier_call_chain kernel/notifier.c:394 [inline] raw_notifier_call_chain+0x2e/0x40 kernel/notifier.c:401 call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1739 call_netdevice_notifiers_extack net/core/dev.c:1751 [inline] call_netdevice_notifiers net/core/dev.c:1765 [inline] __dev_notify_flags+0x1e9/0x2c0 net/core/dev.c:7607 dev_change_flags+0x10d/0x170 net/core/dev.c:7643 dev_ifsioc+0x2b0/0x940 net/core/dev_ioctl.c:237 dev_ioctl+0x1b8/0xc70 net/core/dev_ioctl.c:488 sock_do_ioctl+0x1bd/0x300 net/socket.c:995 sock_ioctl+0x32b/0x610 net/socket.c:1096 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xd6e/0x1390 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457f29 Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fb39f738c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457f29 RDX: 0000000020000080 RSI: 0000000000008914 RDI: 0000000000000005 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb39f7396d4 R13: 00000000004c35d0 R14: 00000000004d6408 R15: 00000000ffffffff Allocated by task 30147: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:495 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:468 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:509 __do_kmalloc mm/slab.c:3716 [inline] __kmalloc+0x15c/0x740 mm/slab.c:3725 kmalloc include/linux/slab.h:550 [inline] kzalloc include/linux/slab.h:740 [inline] crypto_create_tfm+0x88/0x310 crypto/api.c:464 crypto_alloc_tfm+0x104/0x2f0 crypto/api.c:543 crypto_alloc_shash+0x2d/0x40 crypto/shash.c:460 sctp_listen_start net/sctp/socket.c:8183 [inline] sctp_inet_listen+0x6bd/0x880 net/sctp/socket.c:8270 __sys_listen+0x19b/0x270 net/socket.c:1538 __do_sys_listen net/socket.c:1547 [inline] __se_sys_listen net/socket.c:1545 [inline] __x64_sys_listen+0x54/0x80 net/socket.c:1545 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 30137: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:457 kasan_slab_free+0xe/0x10 mm/kasan/common.c:465 __cache_free mm/slab.c:3494 [inline] kfree+0xcf/0x230 mm/slab.c:3811 kzfree+0x29/0x30 mm/slab_common.c:1590 crypto_destroy_tfm+0x158/0x300 crypto/api.c:584 crypto_free_shash include/crypto/hash.h:710 [inline] sctp_destruct_sock+0x3e/0x60 net/sctp/socket.c:5129 __sk_destruct+0x55/0x6d0 net/core/sock.c:1699 sk_destruct+0x7b/0x90 net/core/sock.c:1734 __sk_free+0xce/0x300 net/core/sock.c:1745 sk_free+0x42/0x50 net/core/sock.c:1756 sock_put include/net/sock.h:1708 [inline] sctp_close+0x70f/0x860 net/sctp/socket.c:1569 inet_release+0x105/0x1f0 net/ipv4/af_inet.c:428 inet6_release+0x53/0x80 net/ipv6/af_inet6.c:473 __sock_release+0xd3/0x2b0 net/socket.c:579 sock_close+0x1b/0x30 net/socket.c:1162 __fput+0x2df/0x8d0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x14a/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a5ae9d40 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 16 bytes inside of 256-byte region [ffff8880a5ae9d40, ffff8880a5ae9e40) The buggy address belongs to the page: page:ffffea000296ba40 count:1 mapcount:0 mapping:ffff88812c3f07c0 index:0xffff8880a5ae95c0 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea0002368548 ffffea00024791c8 ffff88812c3f07c0 raw: ffff8880a5ae95c0 ffff8880a5ae90c0 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a5ae9c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880a5ae9c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc >ffff8880a5ae9d00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff8880a5ae9d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a5ae9e00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================