From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out162-62-58-216.mail.qq.com (out162-62-58-216.mail.qq.com [162.62.58.216]) (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 24A001E897 for ; Fri, 29 Mar 2024 21:48:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=162.62.58.216 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711748930; cv=none; b=sZ6d/1wdn1CNbitAJNBMn7fsC9tbsWdPigLV88XTAp7AQ3DIJ3LXWH9hiQ0T9bXbRGWNueHDtxKZ5QXXakookV0To6HBTzPJJU3bHmAOpO/Fc1BxJ3UqeVjCRsHKMi+x+sUKl/9PMEyemPS2KSNMXwi9iZOd0oNOSfosswHTA4w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711748930; c=relaxed/simple; bh=BUffWdP8GQDH3Y4el9iZGb0ZPbexiibWEVvVLXO/DAU=; h=Message-ID:From:To:Cc:Subject:Date:In-Reply-To:References: MIME-Version; b=TcKJ49O29rJe6JqI8YKKJJIfqiK7tD9h4xKamETjhw0+cODNQ+qCf9OKkV19ksQwJ5EE8zndt6XOUNrUcjFp4aU0V4d8+22GUM+OPc6Ci38CaLbHSQ74AUtGNiD7UH/0ioZxu6Huegj9sYDznz235fBS8NEWMaknDQSWsn43oEE= ARC-Authentication-Results:i=1; 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Sat, 30 Mar 2024 05:43:35 +0800 X-QQ-mid: xmsmtpt1711748615thj57ysf5 Message-ID: X-QQ-XMAILINFO: MFWpArBVhhGTGTXc2JWhf4QcXUSb63YXMuI8I9N5/x06LWxcYpgoTdIV2zpXfE xPl5fn6dyADxKWBTmLzUR76rFYoZ/mHixqdKoh8t6DUlYh3oMgCIr/QtsRx00XZLeskTCe1AB7UC wF/6nh3xS/VRda+efupXS/ux4I4weQlZFCxbwyfxsfauGmDYnwiw9nRuInlcUM3Riry+AEclim0v Kq8mIYV1Q8LZrAYX9laGdeZvQxcNiwBu6qLhYKkNYricJk0N0nzu/RjTXwisQQXy/J/f2UTbmohx bE0uhXFOvqh5RwrJURm+SCM4SwwgyU8CNvGtPCjZZNk75Akfpy/B2JV0uigdIzlrtLgesjVdCPjD Pr7HkWr4AAJLq9iFfyGhTOhk3r/pCBYxNx3yTziCYKlk2Kahb+n4CZJkUnrkWfL3+8QYt8lb6e5k w7TIXKTX5lKjfYDcF2IUPiVizTmFnjGIW0uXGAmqA+uH5ugXyDtEhuY6tRc9QdX2DM+fvqrABO4Q lmpliKjCguIz6eb5Nwpt3p2xK3a2TCiBT8EPhgJr3HuncHisTaAXeZeJnloapFrvCdBCNrgYuc/U FkBcUtmQeSFqs4LtUDvpBH+1GQPvYj2cPmjJGdGN1BRDS4yNsRmjKdSBJhS2qgEqXo8+oFv9KUOX JRCWd0bKXoyTukZocTV6JydPvo31TDJdORLGHf20vA1Nbsk7vTBdxGZEAZMNvSoW+c07GmxZBCt2 e/nxbxP8YxwMHppGXXusyhlofSPejynVoVO86ulTZOMWkFOaOICPhpBavGUit+lOCOSFz0lNuQgn px4mzGz5IaVU3raKfhlUx8n9xX4LVGtESQCodUt31wHjknXQAa0AFp9yjCEVVP4VxEGXGNEkJaln XPYg/zd9PYSLwiEgHDaYGSj6a9C5kO+fk4cekZG44wXotI61AuAHd6/AV30WLVCw== X-QQ-XMRINFO: Nq+8W0+stu50PRdwbJxPCL0= From: Edward Adam Davis To: syzbot+e4374f6c021d422de3d1@syzkaller.appspotmail.com Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [bpf?] [net?] possible deadlock in tick_setup_sched_timer Date: Sat, 30 Mar 2024 05:43:34 +0800 X-OQ-MSGID: <20240329214333.3537719-2-eadavis@qq.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <0000000000004fbc7a0614cc4eb9@google.com> References: <0000000000004fbc7a0614cc4eb9@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit please test dl in tick_setup_sched_timer #syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master diff --git a/net/core/sock_map.c b/net/core/sock_map.c index 27d733c0f65e..ae8f81b26e16 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -932,11 +932,12 @@ static long sock_hash_delete_elem(struct bpf_map *map, void *key) struct bpf_shtab_bucket *bucket; struct bpf_shtab_elem *elem; int ret = -ENOENT; + unsigned long flags; hash = sock_hash_bucket_hash(key, key_size); bucket = sock_hash_select_bucket(htab, hash); - spin_lock_bh(&bucket->lock); + spin_lock_irqsave(&bucket->lock, flags); elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); if (elem) { hlist_del_rcu(&elem->node); @@ -944,7 +945,7 @@ static long sock_hash_delete_elem(struct bpf_map *map, void *key) sock_hash_free_elem(htab, elem); ret = 0; } - spin_unlock_bh(&bucket->lock); + spin_unlock_irqrestore(&bucket->lock, flags); return ret; } @@ -1136,6 +1137,7 @@ static void sock_hash_free(struct bpf_map *map) struct bpf_shtab_elem *elem; struct hlist_node *node; int i; + unsigned long flags; /* After the sync no updates or deletes will be in-flight so it * is safe to walk map and remove entries without risking a race @@ -1151,11 +1153,11 @@ static void sock_hash_free(struct bpf_map *map) * exists, psock exists and holds a ref to socket. That * lets us to grab a socket ref too. */ - spin_lock_bh(&bucket->lock); + spin_lock_irqsave(&bucket->lock, flags); hlist_for_each_entry(elem, &bucket->head, node) sock_hold(elem->sk); hlist_move_list(&bucket->head, &unlink_list); - spin_unlock_bh(&bucket->lock); + spin_unlock_irqrestore(&bucket->lock, flags); /* Process removed entries out of atomic context to * block for socket lock before deleting the psock's