"value":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: avoid deadlock between hci_dev->lock and socket lock\n\nCommit eab2404ba798 (\"Bluetooth: Add BT_PHY socket option\")addeda\ndependencybetweensocketlockandhci_dev->lockthatcouldleadto\ndeadlock.\n\nItturnsoutthathci_conn_get_phy()isnotinanywayrelyingonhdev\nbeingimmutableduringtheruntimeofthisfunction,neitherdoesiteven\nlookatanyofthemembersofhdev,andassuchthereisnoneedtohold\nthatlock.\n\nThisfixesthelockdepsplatbelow:\n\n======================================================\nWARNING:possiblecircularlockingdependencydetected\n5.12.0-rc1-00026-g73d464503354#10Nottainted\n------------------------------------------------------\nbluetoothd/1118istryingtoacquirelock:\nffff8f078383c078(&hdev->lock){+.+.}-{3:3},at:hci_conn_get_phy+0x1c/0x150[bluetooth]\n\nbuttaskisalreadyholdinglock:\nffff8f07e831d920(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0},at:l2cap_sock_getsockopt+0x8b/0x610\n\nwhichlockalreadydependsonthenewlock.\n\ntheexistingdependencychain(inreverseorder)is:\n\n->#3(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}:\nlock_sock_nested+0x72/0xa0\nl2cap_sock_ready_cb+0x18/0x70[bluetooth]\nl2cap_config_rsp+0x27a/0x520[bluetooth]\nl2cap_sig_channel+0x658/0x1330[bluetooth]\nl2cap_recv_frame+0x1ba/0x310[bluetooth]\nhci_rx_work+0x1cc/0x640[bluetooth]\nprocess_one_work+0x244/0x5f0\nworker_thread+0x3c/0x380\nkthread+0x13e/0x160\nret_from_fork+0x22/0x30\n\n->#2(&chan->lock#2/1){+.+.}-{3:3}:\n__mutex_lock+0xa3/0xa10\nl2cap_chan_connect+0x33a/0x940[bluetooth]\nl2cap_sock_connect+0x141/0x2a0[bluetooth]\n__sys_connect+0x9b/0xc0\n__x64_sys_connect+0x16/0x20\ndo_syscall_64+0x33/0x80\nentry_SYSCALL_64_after_hwframe+0x44/0xae\n\n->#1(&conn->chan_lock){+.+.}-{3:3}:\n__mutex_lock+0xa3/0xa10\nl2cap_chan_connect+0x322/0x940[bluetooth]\nl2cap_sock_connect+0x141/0x2a0[bluetooth]\n__sys_connect+0x9b/0xc0\n__x64_sys_connect+0x16/0x20\ndo_syscall_64+0x33/0x80\nentry_SYSCALL_64_after_hwframe+0x44/0xae\n\n->#0(&hdev->lock){+.+.}-{3:3}:\n__lock_acquire+0x147a/0x1a50\nlock_acquire+0x277/0x3d0\n__mutex_lock+0xa3/0xa10\nhci_conn_get_phy+0x1c/0x150[bluetooth]\nl2cap_sock_getsockopt+0x5a9/0x610[bluetooth]\n__sys_getsockopt+0xcc/0x200\n__x64_sys_getsockopt+0x20/0x30\ndo_syscall_64+0x33/0x80\nentry_SYSCALL_64_after_hwframe+0x44/0xae\n\notherinfothatmighthelpusdebugthis:\n\nChainexistsof:\n&hdev->lock-->&chan->lock#2/1-->sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP\n\nPossibleunsafelockingscenario:\n\nCPU0CPU1\n--------\nlock(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP);\nlock(&chan->lock#2/1);\nlock(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP);\nlock(&hdev->lock);\n\n***DEADLOCK***\n\n1lockheldbybluetoothd/1118:\n#0:ffff8f07e831d920(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0},at:l2cap_sock_getsockopt+0x8b/0x610[bluetooth]\n\nstackbacktrace:\nCPU:3PID:1118Comm:bluetoothdNottainted5.12.0-rc1-00026-g73d464503354#10\nHardwarename:LENOVO20K5S22R00/20K5S22R00,BIOSR0IET38W(1.16)05/31/2017\nCallTrace:\ndump_stack+0x7f/0xa1\ncheck_noncircular+0x105/0x120\n?__lock_acquire+0x147a/0x1a50\n__lock_acquire+0x147a/0x1a50\nlock_acquire+0x277/0x3d0\n?hci_conn_get_phy+0x1c/0x150[bluetooth]\n?__lock_acquire+0x2e1/0x1a50\n?lock_is_held_type+0xb4/0x120\n?hci_conn_get_phy+0x1c/0x150[bluetooth]\n__mutex_lock+0xa3/0xa10\n?hci_conn_get_phy+0x1c/0x150[bluetooth]\n?lock_acquire+0x277/0x3d0\n?mark_held_locks+0x49/0x70\n?mark_held_locks+0x49/0x70\n?hci_conn_get_phy+0x1c/0x150[bluetooth]\nhci_co
"value":"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: Bluetooth: evitar interbloqueo entre hci_dev->lock y socket lock. el commit eab2404ba798 (\"Bluetooth: Add BT_PHY socket option\") agreg\u00f3 una dependencia entre socket lock y hci_dev->lock que podr\u00eda provocar a un punto muerto. Resulta que hci_conn_get_phy() no depende de ninguna manera de que hdev sea inmutable durante el tiempo de ejecuci\u00f3n de esta funci\u00f3n, ni siquiera mira a ninguno de los miembros de hdev y, como tal, no es necesario mantener ese bloqueo. Esto soluciona el problema de bloqueo a continuaci\u00f3n: ============================================ =========== ADVERTENCIA: posible dependencia de bloqueo circular detectada 5.12.0-rc1-00026-g73d464503354 #10 No contaminado ------------------- ----------------------------------- bluetoothd/1118 est\u00e1 intentando adquirir el bloqueo: ffff8f078383c078 (&hdev->lock ){+.+.}-{3:3}, en: hci_conn_get_phy+0x1c/0x150 [bluetooth] pero la tarea ya est\u00e1 bloqueada: ffff8f07e831d920 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0 }, en: l2cap_sock_getsockopt+0x8b/0x610 cuyo bloqueo ya depende del nuevo bloqueo. la cadena de dependencia existente (en orden inverso) es: -> #3 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}: lock_sock_nested+0x72/0xa0 l2cap_sock_ready_cb+0x18/0x70 [bluetooth] l2cap_config_rsp+ 0x27a/0x520 [bluetooth] l2cap_sig_channel+0x658/0x1330 [bluetooth] l2cap_recv_frame+0x1ba/0x310 [bluetooth] hci_rx_work+0x1cc/0x640 [bluetooth] Process_one_work+0x244/0x5f0 trabajador_thread+0x3c/0x380 kthread+0 x13e/0x160 ret_from_fork+0x22/0x30 -> #2 (&chan->lock#2/1){+.+.}-{3:3}: __mutex_lock+0xa3/0xa10 l2cap_chan_connect+0x33a/0x940 [bluetooth] l2cap_sock_connect+0x141/0x2a0 [bluetooth] __sys_connect+ 0x9b/0xc0 __x64_sys_connect+0x16/0x20 do_syscall_64+0x33/0x80 Entry_SYSCALL_64_after_hwframe+0x44/0xae -> #1 (&conn->chan_lock){+.+.}-{3:3}: __mutex_lock+0xa3/0xa10 l2cap_chan_connect+0 x322/ 0x940 [bluetooth] l2cap_sock_connect+0x141/0x2a0 [bluetooth] __sys_connect+0x9b/0xc0 __x64_sys_connect+0x16/0x20 do_syscall_64+0x33/0x80 Entry_SYSCALL_64_after_hwframe+0x44/0xae -> #0 (&hdev- >bloquear){+.+.}-{ 3:3}: __lock_acquire+0x147a/0x1a50 lock_acquire+0x277/0x3d0 __mutex_lock+0xa3/0xa10 hci_conn_get_phy+0x1c/0x150 [bluetooth] l2cap_sock_getsockopt+0x5a9/0x610 [bluetooth] __sys_getsockopt+0xcc /0x200 __x64_sys_getsockopt+0x20/0x30 do_syscall_64+0x33/ 0x80 Entry_SYSCALL_64_after_hwframe+0x44/0xae otra informaci\u00f3n que podr\u00eda ayudarnos a depurar esto: Existe cadena de: &hdev->lock --> &chan->lock#2/1 --> sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP Posible escenario de bloqueo inseguro: CPU0 CPU1 - --- ---- bloqueo(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP); bloquear(&chan->bloquear#2/1); bloquear(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP); bloquear(&hdev->bloquear); *** DEADLOCK *** 1 bloqueo retenido por bluetoothd/1118: #0: ffff8f07e831d920 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}, en: l2cap_sock_getsockopt+0x8b/0x610 pila [bluetooth] backtrace: CPU: 3 PID: 1118 Comm: bluetoothd No contaminado 5.12.0-rc1-00026-g73d464503354 #10 Nombre de hardware: LENOVO 20K5S22R00/20K5S22R00, BIOS R0IET38W (1.16) 31/05/2017 Seguimiento de llamadas: dump_stack+0x7 f/0xa1 check_noncircular+0x105/0x120? __lock_acquire+0x147a/0x1a50 __lock_acquire+0x147a/0x1a50 lock_acquire+0x277/0x3d0 ? hci_conn_get_phy+0x1c/0x150 [bluetooth] ? __lock_acquire+0x2e1/0x1a50? lock_is_held_type+0xb4/0x120? hci_conn_get_phy+0x1c/0x150 [bluetooth] __mutex_lock+0xa3/0xa10 ? hci_conn_get_phy+0x1c/0x150 [bluetooth] ? lock_acquire+0x277/0x3d0? mark_held_locks+0x49/0x70? mark_held_locks+0x49/0x70? hci_conn_get_phy+0x1c/0x150 [bluetooth] hci_conn_get_phy+0x ---truncado---"