================================================================== BUG: KASAN: use-after-free in constant_test_bit arch/x86/include/asm/bitops.h:317 [inline] BUG: KASAN: use-after-free in sock_flag include/net/sock.h:839 [inline] BUG: KASAN: use-after-free in l2cap_sock_kill net/bluetooth/l2cap_sock.c:1046 [inline] BUG: KASAN: use-after-free in l2cap_sock_close_cb+0xbd/0xd0 net/bluetooth/l2cap_sock.c:1311 Read of size 8 at addr ffff888084a7c5a0 by task syz-executor.1/22333 CPU: 1 PID: 22333 Comm: syz-executor.1 Not tainted 4.19.143-syzkaller #0 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+0x1fc/0x2fe lib/dump_stack.c:118 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256 kasan_report_error.cold+0x8a/0x1c7 mm/kasan/report.c:354 kasan_report mm/kasan/report.c:412 [inline] __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433 constant_test_bit arch/x86/include/asm/bitops.h:317 [inline] sock_flag include/net/sock.h:839 [inline] l2cap_sock_kill net/bluetooth/l2cap_sock.c:1046 [inline] l2cap_sock_close_cb+0xbd/0xd0 net/bluetooth/l2cap_sock.c:1311 l2cap_conn_del+0x3db/0x6b0 net/bluetooth/l2cap_core.c:1730 l2cap_disconn_cfm net/bluetooth/l2cap_core.c:7435 [inline] l2cap_disconn_cfm+0x85/0xa0 net/bluetooth/l2cap_core.c:7428 hci_disconn_cfm include/net/bluetooth/hci_core.h:1261 [inline] hci_conn_hash_flush+0x114/0x220 net/bluetooth/hci_conn.c:1495 hci_dev_do_close+0x624/0xe70 net/bluetooth/hci_core.c:1666 hci_rfkill_set_block net/bluetooth/hci_core.c:2100 [inline] hci_rfkill_set_block+0xd0/0x120 net/bluetooth/hci_core.c:2087 rfkill_set_block+0x1f9/0x540 net/rfkill/core.c:353 rfkill_fop_write+0x250/0x4a0 net/rfkill/core.c:1249 __vfs_write+0xf7/0x770 fs/read_write.c:485 vfs_write+0x1f3/0x540 fs/read_write.c:549 ksys_write+0x12b/0x2a0 fs/read_write.c:599 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45d5b9 Code: 5d b4 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 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f02545b1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000039200 RCX: 000000000045d5b9 RDX: 0000000000000008 RSI: 0000000020000200 RDI: 0000000000000003 RBP: 000000000118d020 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec R13: 00007fff6a7ff71f R14: 00007f02545b29c0 R15: 000000000118cfec Allocated by task 20774: __do_kmalloc mm/slab.c:3727 [inline] __kmalloc+0x15a/0x3c0 mm/slab.c:3736 kmalloc include/linux/slab.h:520 [inline] sk_prot_alloc+0x1e2/0x2d0 net/core/sock.c:1466 sk_alloc+0x36/0xec0 net/core/sock.c:1520 l2cap_sock_alloc.constprop.0+0x31/0x210 net/bluetooth/l2cap_sock.c:1590 l2cap_sock_create+0x110/0x1b0 net/bluetooth/l2cap_sock.c:1636 bt_sock_create+0x154/0x2a0 net/bluetooth/af_bluetooth.c:130 __sock_create+0x3d8/0x740 net/socket.c:1276 rfcomm_l2sock_create net/bluetooth/rfcomm/core.c:203 [inline] rfcomm_session_create net/bluetooth/rfcomm/core.c:738 [inline] __rfcomm_dlc_open net/bluetooth/rfcomm/core.c:388 [inline] rfcomm_dlc_open+0x6e2/0xcb0 net/bluetooth/rfcomm/core.c:431 rfcomm_sock_connect+0x317/0x420 net/bluetooth/rfcomm/sock.c:416 __sys_connect+0x265/0x2c0 net/socket.c:1663 __do_sys_connect net/socket.c:1674 [inline] __se_sys_connect net/socket.c:1671 [inline] __x64_sys_connect+0x6f/0xb0 net/socket.c:1671 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 3597: __cache_free mm/slab.c:3503 [inline] kfree+0xcc/0x210 mm/slab.c:3822 sk_prot_free net/core/sock.c:1503 [inline] __sk_destruct+0x5ff/0x810 net/core/sock.c:1584 sk_destruct net/core/sock.c:1599 [inline] __sk_free+0x165/0x3b0 net/core/sock.c:1610 sk_free+0x3b/0x50 net/core/sock.c:1621 sock_put include/net/sock.h:1711 [inline] l2cap_sock_kill.part.0+0x6b/0x80 net/bluetooth/l2cap_sock.c:1055 l2cap_sock_kill net/bluetooth/l2cap_sock.c:1206 [inline] l2cap_sock_release+0x158/0x190 net/bluetooth/l2cap_sock.c:1204 __sock_release net/socket.c:579 [inline] sock_release+0x87/0x1d0 net/socket.c:599 rfcomm_session_del+0x15a/0x1f0 net/bluetooth/rfcomm/core.c:684 rfcomm_session_close net/bluetooth/rfcomm/core.c:723 [inline] rfcomm_process_rx net/bluetooth/rfcomm/core.c:1916 [inline] rfcomm_process_sessions net/bluetooth/rfcomm/core.c:2000 [inline] rfcomm_run+0x12ed/0x4250 net/bluetooth/rfcomm/core.c:2087 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 The buggy address belongs to the object at ffff888084a7c540 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 96 bytes inside of 2048-byte region [ffff888084a7c540, ffff888084a7cd40) The buggy address belongs to the page: page:ffffea0002129f00 count:1 mapcount:0 mapping:ffff88812c39cc40 index:0xffff888084a7d640 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffffea00023c7288 ffffea00026c6188 ffff88812c39cc40 raw: ffff888084a7d640 ffff888084a7c540 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888084a7c480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888084a7c500: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb >ffff888084a7c580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888084a7c600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888084a7c680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== audit: type=1800 audit(1599537327.847:152): pid=22385 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.5" name="file0" dev="sda1" ino=16195 res=0 device batadv0 entered promiscuous mode