From patchwork Thu Jul 20 11:44:38 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Dumazet X-Patchwork-Id: 13320387 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 73F5E174E6 for ; Thu, 20 Jul 2023 11:44:45 +0000 (UTC) Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DD5C3197 for ; Thu, 20 Jul 2023 04:44:43 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id 3f1490d57ef6-cca32102e3cso608676276.1 for ; Thu, 20 Jul 2023 04:44:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1689853483; x=1690458283; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=DuXvykG6hdNeayWwL/tNxVS8PZdAVcLPAGOTgBK6Q4g=; b=tjTPN7s9epPx68xvpLymIPVUs5sKW/57acYN6zkCykbYRXXcNuBcYkxXyut0KmMk7r Sd91i3rbokSPMKv4KtE61krl4tqMb322aAtO1Zn3I+8+TRh60cyrxZvpOJS8TosX3g8J N3XjnSroDPTHVvZ4XOOD8I1Rj5dQpnkiyt9vk6lH/eJuKXwMx45MrFy2sQjem8vYjIxI k/wwqLer3CMSERVdrxSYKgXlOBBoQqC9p9ejnA+uQYiw1Hrd3Xvcr/oIQpkTYhyjTD7U nRb47kYBpMqTwF1oiSkz68B/aymmZwQLWgjP5kLFpAWMhrZ2B7Qc57izVsf6L7NYHeT2 +Csg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689853483; x=1690458283; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=DuXvykG6hdNeayWwL/tNxVS8PZdAVcLPAGOTgBK6Q4g=; b=Qfm4UdU2TFWegQFDxY7dcNkJoHMs2ZJLny7m4c3fRaEd66sPtwDkd+KC1tQugN5Ggq 7mesBAqAYs9gKrNLypajbZKXnyb92QGNKqXfwraXQ39BVPHgbpXqtBf5n3BQoAuMDsUo ct+rC2LX1bxpe81afTbvJgVMi72IPrs/8pZjl896eg+/c8++3dg/rr8fqodFyS4b7zGk HVIC9blXdgFnKdGTq7yUR2AmiE7LlpaZ7OHvgqnGatx5QLH6OCRMQjSvT72V5xTyhoWT EnYxTzhEPSnFhFtQeCsjwwljQaQ9BmxPtUH17oUuEiZYGdcPs8d7Ox8meOhIxlpvXOEk PS/Q== X-Gm-Message-State: ABy/qLa57COLB5BkkwGfSIA7ZKz/9mnn7nlAtaOlx2r3Yki70PJaQ+o5 s2nyMI8QXuc5G8ro7PRpRMC7bqSZbsv0qA== X-Google-Smtp-Source: APBJJlGilmpMxlKLdzyWk7evEnfDWhYpi0O2OMBNDT79id0tR7viT0yXJjdLNZbbibmxfa8faMXX6i6gFpcaOg== X-Received: from edumazet1.c.googlers.com ([fda3:e722:ac3:cc00:2b:7d90:c0a8:395a]) (user=edumazet job=sendgmr) by 2002:a05:6902:1024:b0:c67:975c:74ab with SMTP id x4-20020a056902102400b00c67975c74abmr50332ybt.4.1689853483088; Thu, 20 Jul 2023 04:44:43 -0700 (PDT) Date: Thu, 20 Jul 2023 11:44:38 +0000 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.41.0.255.g8b1d071c50-goog Message-ID: <20230720114438.172434-1-edumazet@google.com> Subject: [PATCH net] can: raw: fix lockdep issue in raw_release() From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, linux-can@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet , syzbot , Ziyang Xuan , Oliver Hartkopp , stable@vger.kernel.org, Marc Kleine-Budde X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE, USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: kuba@kernel.org syzbot complained about a lockdep issue [1] Since raw_bind() and raw_setsockopt() first get RTNL before locking the socket, we must adopt the same order in raw_release() [1] WARNING: possible circular locking dependency detected 6.5.0-rc1-syzkaller-00192-g78adb4bcf99e #0 Not tainted ------------------------------------------------------ syz-executor.0/14110 is trying to acquire lock: ffff88804e4b6130 (sk_lock-AF_CAN){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1708 [inline] ffff88804e4b6130 (sk_lock-AF_CAN){+.+.}-{0:0}, at: raw_bind+0xb1/0xab0 net/can/raw.c:435 but task is already holding lock: ffffffff8e3df368 (rtnl_mutex){+.+.}-{3:3}, at: raw_bind+0xa7/0xab0 net/can/raw.c:434 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (rtnl_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x181/0x1340 kernel/locking/mutex.c:747 raw_release+0x1c6/0x9b0 net/can/raw.c:391 __sock_release+0xcd/0x290 net/socket.c:654 sock_close+0x1c/0x20 net/socket.c:1386 __fput+0x3fd/0xac0 fs/file_table.c:384 task_work_run+0x14d/0x240 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x210/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297 do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (sk_lock-AF_CAN){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3142 [inline] check_prevs_add kernel/locking/lockdep.c:3261 [inline] validate_chain kernel/locking/lockdep.c:3876 [inline] __lock_acquire+0x2e3d/0x5de0 kernel/locking/lockdep.c:5144 lock_acquire kernel/locking/lockdep.c:5761 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5726 lock_sock_nested+0x3a/0xf0 net/core/sock.c:3492 lock_sock include/net/sock.h:1708 [inline] raw_bind+0xb1/0xab0 net/can/raw.c:435 __sys_bind+0x1ec/0x220 net/socket.c:1792 __do_sys_bind net/socket.c:1803 [inline] __se_sys_bind net/socket.c:1801 [inline] __x64_sys_bind+0x72/0xb0 net/socket.c:1801 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(rtnl_mutex); lock(sk_lock-AF_CAN); lock(rtnl_mutex); lock(sk_lock-AF_CAN); *** DEADLOCK *** 1 lock held by syz-executor.0/14110: stack backtrace: CPU: 0 PID: 14110 Comm: syz-executor.0 Not tainted 6.5.0-rc1-syzkaller-00192-g78adb4bcf99e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 check_noncircular+0x311/0x3f0 kernel/locking/lockdep.c:2195 check_prev_add kernel/locking/lockdep.c:3142 [inline] check_prevs_add kernel/locking/lockdep.c:3261 [inline] validate_chain kernel/locking/lockdep.c:3876 [inline] __lock_acquire+0x2e3d/0x5de0 kernel/locking/lockdep.c:5144 lock_acquire kernel/locking/lockdep.c:5761 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5726 lock_sock_nested+0x3a/0xf0 net/core/sock.c:3492 lock_sock include/net/sock.h:1708 [inline] raw_bind+0xb1/0xab0 net/can/raw.c:435 __sys_bind+0x1ec/0x220 net/socket.c:1792 __do_sys_bind net/socket.c:1803 [inline] __se_sys_bind net/socket.c:1801 [inline] __x64_sys_bind+0x72/0xb0 net/socket.c:1801 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fd89007cb29 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 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 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd890d2a0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000031 RAX: ffffffffffffffda RBX: 00007fd89019bf80 RCX: 00007fd89007cb29 RDX: 0000000000000010 RSI: 0000000020000040 RDI: 0000000000000003 RBP: 00007fd8900c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fd89019bf80 R15: 00007ffebf8124f8 Fixes: ee8b94c8510c ("can: raw: fix receiver memory leak") Reported-by: syzbot Signed-off-by: Eric Dumazet Cc: Ziyang Xuan Cc: Oliver Hartkopp Cc: stable@vger.kernel.org Cc: Marc Kleine-Budde --- net/can/raw.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/can/raw.c b/net/can/raw.c index 2302e48829677334f8b2d74a479e5a9cbb5ce03c..ba6b52b1d7767fdd7b57d1b8e5519495340c572c 100644 --- a/net/can/raw.c +++ b/net/can/raw.c @@ -386,9 +386,9 @@ static int raw_release(struct socket *sock) list_del(&ro->notifier); spin_unlock(&raw_notifier_lock); + rtnl_lock(); lock_sock(sk); - rtnl_lock(); /* remove current filters & unregister */ if (ro->bound) { if (ro->dev) @@ -405,12 +405,13 @@ static int raw_release(struct socket *sock) ro->dev = NULL; ro->count = 0; free_percpu(ro->uniq); - rtnl_unlock(); sock_orphan(sk); sock->sk = NULL; release_sock(sk); + rtnl_unlock(); + sock_put(sk); return 0;