From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 80DEDC47088 for ; Sat, 3 Dec 2022 19:24:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229848AbiLCTYb (ORCPT ); Sat, 3 Dec 2022 14:24:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33042 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229730AbiLCTYa (ORCPT ); Sat, 3 Dec 2022 14:24:30 -0500 Received: from mail-pj1-x102a.google.com (mail-pj1-x102a.google.com [IPv6:2607:f8b0:4864:20::102a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7C662186EC for ; Sat, 3 Dec 2022 11:24:29 -0800 (PST) Received: by mail-pj1-x102a.google.com with SMTP id hd14-20020a17090b458e00b0021909875bccso8493920pjb.1 for ; Sat, 03 Dec 2022 11:24:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:subject:references :in-reply-to:message-id:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=55rmkUMZEa9+PRhwz9T505wsEW1RMyFqZE0ZJ8UMoG8=; b=qG/KBen62vQd1EavFV59J5+YAnnTJJdmghGdmKyjOirRG6MAfRFJMkPHThCqphFyue gxmjFinAyagyFy2KmINW3sevfD56fTyKZv+hg5R09z2uxi1hdOzFZQn/yBw2JN4MWp0z Uod9O2wMuydjZhw+AUszHuxhddLCrs/u0SznTgkG8aw04qNE16WZsLVV1KUrxPy/FSpX 5WK/I1O32vRH3dvoWP+5cRuiTKmq56E9oF66ceSu/tIhjq8dsP8uX+geNNHR2ZWlqJGY zBSHRZ1VXlnXHhG4lR7Ocme1O32okXKsdNeXVYEto8levbCld7dIkw/QnsG+Gj1iWuee UhPA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:subject:references :in-reply-to:message-id:cc:to:from:date:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=55rmkUMZEa9+PRhwz9T505wsEW1RMyFqZE0ZJ8UMoG8=; b=1UkIrzZUJWUMrW1wgTboWa8dBh6ho7Zkq2KZyCF4llKHmoYpPaHTh22aZFvReeWX0L 6NFdGqoJgzmGXcd7SjJX4RCbkC2az9VJk1vGpYfduPUV5nknmn8L9Stht0lLdH13Gn28 03tgPmEUAJPivTGdMy53Kws0SL9g1gYj4FG/SWlFEIzJfD+902V+8rY9Q3ZGxe6Yy4lm 7VI5wHGNKWhhJvONbA+TgJ4Fj/dMJuxzdaKHUd1Q/Whq7eO11NgKG7liXiL1co0lOBJS ZPjSWAB/QeqK1hoQfqfXT1uA0VM3MusooCZb4Iulaf3gWHUw28QBpH9oaiFtFoiWsV42 Rr0w== X-Gm-Message-State: ANoB5plDHmL8j3Ce1GTCTUTFhDpFjJ9309T+ehd7r5a6P2q8lEFjd1jx BFWcGO7MrrHIc/r7oA3wGPY= X-Google-Smtp-Source: AA0mqf4uzzqfiJp7lhdxRIKBS2kjOZZrYPYTkVd4tVyrJrMaIuDpWnSc5sMmbhniK+phybau4Y/fbg== X-Received: by 2002:a17:902:e949:b0:189:7a15:1336 with SMTP id b9-20020a170902e94900b001897a151336mr36562272pll.122.1670095468901; Sat, 03 Dec 2022 11:24:28 -0800 (PST) Received: from localhost ([129.95.228.55]) by smtp.gmail.com with ESMTPSA id f139-20020a623891000000b005746c3b2445sm7047285pfa.151.2022.12.03.11.24.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 03 Dec 2022 11:24:28 -0800 (PST) Date: Sat, 03 Dec 2022 11:24:27 -0800 From: John Fastabend To: Eric Dumazet , "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet , syzbot , Jakub Sitnicki , John Fastabend , Alexei Starovoitov , Daniel Borkmann , Song Liu Message-ID: <638ba26b634d8_16f04208a2@john.notmuch> In-Reply-To: <20221202111640.2745533-1-edumazet@google.com> References: <20221202111640.2745533-1-edumazet@google.com> Subject: RE: [PATCH net] bpf, sockmap: fix race in sock_map_free() Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Eric Dumazet wrote: > sock_map_free() calls release_sock(sk) without owning a reference > on the socket. This can cause use-after-free as syzbot found [1] > > Jakub Sitnicki already took care of a similar issue > in sock_hash_free() in commit 75e68e5bf2c7 ("bpf, sockhash: > Synchronize delete from bucket list on map free") > > [1] > refcount_t: decrement hit 0; leaking memory. > WARNING: CPU: 0 PID: 3785 at lib/refcount.c:31 refcount_warn_saturate+0x17c/0x1a0 lib/refcount.c:31 > Modules linked in: > CPU: 0 PID: 3785 Comm: kworker/u4:6 Not tainted 6.1.0-rc7-syzkaller-00103-gef4d3ea40565 #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 > Workqueue: events_unbound bpf_map_free_deferred > RIP: 0010:refcount_warn_saturate+0x17c/0x1a0 lib/refcount.c:31 > Code: 68 8b 31 c0 e8 75 71 15 fd 0f 0b e9 64 ff ff ff e8 d9 6e 4e fd c6 05 62 9c 3d 0a 01 48 c7 c7 80 bb 68 8b 31 c0 e8 54 71 15 fd <0f> 0b e9 43 ff ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c a2 fe ff > RSP: 0018:ffffc9000456fb60 EFLAGS: 00010246 > RAX: eae59bab72dcd700 RBX: 0000000000000004 RCX: ffff8880207057c0 > RDX: 0000000000000000 RSI: 0000000000000201 RDI: 0000000000000000 > RBP: 0000000000000004 R08: ffffffff816fdabd R09: fffff520008adee5 > R10: fffff520008adee5 R11: 1ffff920008adee4 R12: 0000000000000004 > R13: dffffc0000000000 R14: ffff88807b1c6c00 R15: 1ffff1100f638dcf > FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000001b30c30000 CR3: 000000000d08e000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > > __refcount_dec include/linux/refcount.h:344 [inline] > refcount_dec include/linux/refcount.h:359 [inline] > __sock_put include/net/sock.h:779 [inline] > tcp_release_cb+0x2d0/0x360 net/ipv4/tcp_output.c:1092 > release_sock+0xaf/0x1c0 net/core/sock.c:3468 > sock_map_free+0x219/0x2c0 net/core/sock_map.c:356 > process_one_work+0x81c/0xd10 kernel/workqueue.c:2289 > worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 > kthread+0x266/0x300 kernel/kthread.c:376 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 > > > Fixes: 7e81a3530206 ("bpf: Sockmap, ensure sock lock held during tear down") > Signed-off-by: Eric Dumazet > Reported-by: syzbot > Cc: Jakub Sitnicki > Cc: John Fastabend > Cc: Alexei Starovoitov > Cc: Daniel Borkmann > Cc: Song Liu Thanks. Acked-by: John Fastabend