================================================================== 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+0x17d/0x1a0 net/bluetooth/rfcomm/core.c:549 Read of size 1 at addr ffff88808058f6c4 by task syz-executor.0/31032 CPU: 1 PID: 31032 Comm: syz-executor.0 Not tainted 4.19.96-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+0x197/0x210 lib/dump_stack.c:118 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report mm/kasan/report.c:412 [inline] kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430 rfcomm_dlc_get net/bluetooth/rfcomm/core.c:360 [inline] rfcomm_dlc_exists+0x17d/0x1a0 net/bluetooth/rfcomm/core.c:549 __rfcomm_create_dev net/bluetooth/rfcomm/tty.c:413 [inline] rfcomm_create_dev net/bluetooth/rfcomm/tty.c:486 [inline] rfcomm_dev_ioctl+0x9c8/0x1c90 net/bluetooth/rfcomm/tty.c:588 rfcomm_sock_ioctl+0x90/0xb0 net/bluetooth/rfcomm/sock.c:902 sock_do_ioctl+0xd8/0x2f0 net/socket.c:950 sock_ioctl+0x325/0x610 net/socket.c:1074 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45aff9 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:00007f9817250c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f98172516d4 RCX: 000000000045aff9 RDX: 0000000020000100 RSI: 00000000400452c8 RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002f5 R14: 00000000004c3d0a R15: 000000000075bf2c Allocated by task 8600: save_stack+0x45/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc mm/kasan/kasan.c:553 [inline] kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531 kmem_cache_alloc_trace+0x152/0x760 mm/slab.c:3625 kmalloc include/linux/slab.h:515 [inline] kzalloc include/linux/slab.h:709 [inline] rfcomm_dlc_alloc+0x66/0x3f0 net/bluetooth/rfcomm/core.c:305 rfcomm_sock_alloc.constprop.0+0xb3/0x360 net/bluetooth/rfcomm/sock.c:286 rfcomm_sock_create+0xf3/0x2b0 net/bluetooth/rfcomm/sock.c:329 bt_sock_create+0x16a/0x2d0 net/bluetooth/af_bluetooth.c:130 __sock_create+0x3d8/0x730 net/socket.c:1276 sock_create net/socket.c:1316 [inline] __sys_socket+0x103/0x220 net/socket.c:1346 __do_sys_socket net/socket.c:1355 [inline] __se_sys_socket net/socket.c:1353 [inline] __x64_sys_socket+0x73/0xb0 net/socket.c:1353 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 31032: save_stack+0x45/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3503 [inline] kfree+0xcf/0x220 mm/slab.c:3822 rfcomm_dlc_free+0x20/0x30 net/bluetooth/rfcomm/core.c:328 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+0x1988/0x1c90 net/bluetooth/rfcomm/tty.c:588 rfcomm_sock_ioctl+0x90/0xb0 net/bluetooth/rfcomm/sock.c:902 sock_do_ioctl+0xd8/0x2f0 net/socket.c:950 sock_ioctl+0x325/0x610 net/socket.c:1074 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88808058f580 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 324 bytes inside of 512-byte region [ffff88808058f580, ffff88808058f780) The buggy address belongs to the page: page:ffffea00020163c0 count:1 mapcount:0 mapping:ffff88812c31c940 index:0x0 flags: 0xfffe0000000100(slab) raw: 00fffe0000000100 ffffea000256fc08 ffffea0002a59a48 ffff88812c31c940 raw: 0000000000000000 ffff88808058f080 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808058f580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808058f600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88808058f680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88808058f700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808058f780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready