================================================================== BUG: KASAN: use-after-free in rfcomm_dlc_get net/bluetooth/rfcomm/core.c:360 [inline] BUG: KASAN: use-after-free in rfcomm_dlc_exists+0x16f/0x190 net/bluetooth/rfcomm/core.c:550 Read of size 1 at addr ffff8880a2549144 by task syz-executor.1/1469 CPU: 0 PID: 1469 Comm: syz-executor.1 Not tainted 5.6.0-rc7-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+0x188/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:374 __kasan_report.cold+0x1a/0x32 mm/kasan/report.c:506 kasan_report+0xe/0x20 mm/kasan/common.c:641 rfcomm_dlc_get net/bluetooth/rfcomm/core.c:360 [inline] rfcomm_dlc_exists+0x16f/0x190 net/bluetooth/rfcomm/core.c:550 __rfcomm_create_dev net/bluetooth/rfcomm/tty.c:413 [inline] rfcomm_create_dev net/bluetooth/rfcomm/tty.c:486 [inline] rfcomm_dev_ioctl+0x9ea/0x1d70 net/bluetooth/rfcomm/tty.c:588 rfcomm_sock_ioctl+0x86/0xb0 net/bluetooth/rfcomm/sock.c:902 sock_do_ioctl+0xd8/0x2f0 net/socket.c:1053 sock_ioctl+0x3ed/0x790 net/socket.c:1204 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c849 Code: ad b6 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 b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f54e62cfc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f54e62d06d4 RCX: 000000000045c849 RDX: 0000000020000100 RSI: 00000000400452c8 RDI: 0000000000000004 RBP: 000000000076bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000316 R14: 00000000004c57dd R15: 000000000076bfac Allocated by task 18007: save_stack+0x1b/0x80 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:515 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:488 kmem_cache_alloc_trace+0x153/0x7d0 mm/slab.c:3551 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:669 [inline] rfcomm_dlc_alloc+0x7a/0x400 net/bluetooth/rfcomm/core.c:305 rfcomm_sock_alloc.constprop.0+0xad/0x370 net/bluetooth/rfcomm/sock.c:286 rfcomm_sock_create+0xe0/0x2a0 net/bluetooth/rfcomm/sock.c:329 bt_sock_create+0x154/0x2a0 net/bluetooth/af_bluetooth.c:130 __sock_create+0x3cb/0x730 net/socket.c:1433 sock_create net/socket.c:1484 [inline] __sys_socket+0xef/0x200 net/socket.c:1526 __do_sys_socket net/socket.c:1535 [inline] __se_sys_socket net/socket.c:1533 [inline] __x64_sys_socket+0x6f/0xb0 net/socket.c:1533 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 1466: save_stack+0x1b/0x80 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:337 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:476 __cache_free mm/slab.c:3426 [inline] kfree+0x109/0x2b0 mm/slab.c:3757 rfcomm_dlc_put include/net/bluetooth/rfcomm.h:258 [inline] __rfcomm_create_dev net/bluetooth/rfcomm/tty.c:417 [inline] rfcomm_create_dev net/bluetooth/rfcomm/tty.c:486 [inline] rfcomm_dev_ioctl+0x1a8c/0x1d70 net/bluetooth/rfcomm/tty.c:588 rfcomm_sock_ioctl+0x86/0xb0 net/bluetooth/rfcomm/sock.c:902 sock_do_ioctl+0xd8/0x2f0 net/socket.c:1053 sock_ioctl+0x3ed/0x790 net/socket.c:1204 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a2549000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 324 bytes inside of 512-byte region [ffff8880a2549000, ffff8880a2549200) The buggy address belongs to the page: page:ffffea0002895240 refcount:1 mapcount:0 mapping:ffff8880aa000a80 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002a10908 ffffea0002502d88 ffff8880aa000a80 raw: 0000000000000000 ffff8880a2549000 0000000100000004 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a2549000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a2549080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880a2549100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a2549180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a2549200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================