RDX: 0000000020000380 RSI: 0000000000005423 RDI: 0000000000000004 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb13120c6d4 R13: 00000000004c207b R14: 00000000004d4450 R15: 0000000000000005 ================================================================== BUG: KASAN: double-free or invalid-free in x25_asy_free+0x37/0x140 drivers/net/wan/x25_asy.c:111 CPU: 1 PID: 1780 Comm: syz-executor1 Not tainted 4.20.0+ #8 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+0x1db/0x2d0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report_invalid_free+0x65/0xa0 mm/kasan/report.c:278 __kasan_slab_free+0x13a/0x150 mm/kasan/common.c:423 kasan_slab_free+0xe/0x10 mm/kasan/common.c:452 __cache_free mm/slab.c:3485 [inline] kfree+0xcf/0x230 mm/slab.c:3804 x25_asy_free+0x37/0x140 drivers/net/wan/x25_asy.c:111 x25_asy_open_tty+0x67b/0x80b drivers/net/wan/x25_asy.c:572 kobject: 'tx-0' (000000006777c2d3): kobject_add_internal: parent: 'queues', set: 'queues' tty_ldisc_open.isra.0+0x8b/0xe0 drivers/tty/tty_ldisc.c:460 kobject: 'tx-0' (000000006777c2d3): kobject_uevent_env tty_set_ldisc+0x2d7/0x690 drivers/tty/tty_ldisc.c:587 tiocsetd drivers/tty/tty_io.c:2323 [inline] tty_ioctl+0xffa/0x16c0 drivers/tty/tty_io.c:2583 kobject: 'tx-0' (000000006777c2d3): fill_kobj_path: path = '/devices/virtual/net/tunl0/queues/tx-0' kobject: 'ip6gretap0' (0000000072a468ce): kobject_cleanup, parent (null) kobject: 'gre0' (00000000e588173e): kobject_add_internal: parent: 'net', set: 'devices' kobject: 'ip6gretap0' (0000000072a468ce): auto cleanup 'remove' event vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696 kobject: 'gre0' (00000000e588173e): kobject_uevent_env kobject: 'ip6gretap0' (0000000072a468ce): kobject_uevent_env kobject: 'ip6gretap0' (0000000072a468ce): kobject_uevent_env: uevent_suppress caused the event to drop! 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+0x1a3/0x800 arch/x86/entry/common.c:290 kobject: 'gre0' (00000000e588173e): fill_kobj_path: path = '/devices/virtual/net/gre0' entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: 6d b7 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 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fb13120bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 kobject: 'ip6gretap0' (0000000072a468ce): calling ktype release RAX: ffffffffffffffda RBX: 00007fb13120bc90 RCX: 0000000000457ec9 RDX: 0000000020000380 RSI: 0000000000005423 RDI: 0000000000000004 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb13120c6d4 R13: 00000000004c207b R14: 00000000004d4450 R15: 0000000000000005 Allocated by task 1780: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] kasan_kmalloc mm/kasan/common.c:482 [inline] kasan_kmalloc+0xcf/0xe0 mm/kasan/common.c:455 kobject: 'queues' (000000006e3df3ef): kobject_add_internal: parent: 'gre0', set: '' __do_kmalloc mm/slab.c:3709 [inline] __kmalloc+0x15c/0x740 mm/slab.c:3718 kmalloc include/linux/slab.h:550 [inline] x25_asy_open drivers/net/wan/x25_asy.c:465 [inline] x25_asy_open_tty+0x470/0x80b drivers/net/wan/x25_asy.c:570 tty_ldisc_open.isra.0+0x8b/0xe0 drivers/tty/tty_ldisc.c:460 tty_set_ldisc+0x2d7/0x690 drivers/tty/tty_ldisc.c:587 tiocsetd drivers/tty/tty_io.c:2323 [inline] tty_ioctl+0xffa/0x16c0 drivers/tty/tty_io.c:2583 kobject: 'ip6gretap0': free name vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 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+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe kobject: 'queues' (000000006e3df3ef): kobject_uevent_env Freed by task 1780: 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:444 kasan_slab_free+0xe/0x10 mm/kasan/common.c:452 __cache_free mm/slab.c:3485 [inline] kfree+0xcf/0x230 mm/slab.c:3804 kobject: 'queues' (000000006e3df3ef): kobject_uevent_env: filter function caused the event to drop! x25_asy_open drivers/net/wan/x25_asy.c:489 [inline] x25_asy_open_tty+0x66e/0x80b drivers/net/wan/x25_asy.c:570 tty_ldisc_open.isra.0+0x8b/0xe0 drivers/tty/tty_ldisc.c:460 tty_set_ldisc+0x2d7/0x690 drivers/tty/tty_ldisc.c:587 tiocsetd drivers/tty/tty_io.c:2323 [inline] tty_ioctl+0xffa/0x16c0 drivers/tty/tty_io.c:2583 kobject: 'rx-0' (00000000e1ed907b): kobject_add_internal: parent: 'queues', set: 'queues' vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 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+0x1a3/0x800 arch/x86/entry/common.c:290 kobject: 'rx-0' (00000000e1ed907b): kobject_uevent_env entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888085143b40 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 0 bytes inside of 1024-byte region [ffff888085143b40, ffff888085143f40) The buggy address belongs to the page: kobject: 'rx-0' (00000000e1ed907b): fill_kobj_path: path = '/devices/virtual/net/gre0/queues/rx-0' page:ffffea0002145080 count:1 mapcount:0 mapping:ffff88812c3f0ac0 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0002261888 ffffea00023cff88 ffff88812c3f0ac0 raw: 0000000000000000 ffff888085142040 0000000100000007 0000000000000000 page dumped because: kasan: bad access detected kobject: 'tx-0' (000000001d4944da): kobject_add_internal: parent: 'queues', set: 'queues' Memory state around the buggy address: ffff888085143a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888085143a80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff888085143b00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ kobject: 'tx-0' (000000001d4944da): kobject_uevent_env ffff888085143b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888085143c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================