From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:49700 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753433AbeBFUs7 (ORCPT ); Tue, 6 Feb 2018 15:48:59 -0500 Subject: Patch "soreuseport: fix mem leak in reuseport_add_sock()" has been added to the 4.9-stable tree To: edumazet@google.com Cc: , From: Date: Tue, 06 Feb 2018 12:48:56 -0800 Message-ID: <151795013685248@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled soreuseport: fix mem leak in reuseport_add_sock() to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: soreuseport-fix-mem-leak-in-reuseport_add_sock.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Tue Feb 6 12:42:23 PST 2018 From: Eric Dumazet Date: Fri, 2 Feb 2018 10:27:27 -0800 Subject: soreuseport: fix mem leak in reuseport_add_sock() From: Eric Dumazet [ Upstream commit 4db428a7c9ab07e08783e0fcdc4ca0f555da0567 ] reuseport_add_sock() needs to deal with attaching a socket having its own sk_reuseport_cb, after a prior setsockopt(SO_ATTACH_REUSEPORT_?BPF) Without this fix, not only a WARN_ONCE() was issued, but we were also leaking memory. Thanks to sysbot and Eric Biggers for providing us nice C repros. ------------[ cut here ]------------ socket already in reuseport group WARNING: CPU: 0 PID: 3496 at net/core/sock_reuseport.c:119   reuseport_add_sock+0x742/0x9b0 net/core/sock_reuseport.c:117 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 3496 Comm: syzkaller869503 Not tainted 4.15.0-rc6+ #245 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS   Google 01/01/2011 Call Trace:   __dump_stack lib/dump_stack.c:17 [inline]   dump_stack+0x194/0x257 lib/dump_stack.c:53   panic+0x1e4/0x41c kernel/panic.c:183   __warn+0x1dc/0x200 kernel/panic.c:547   report_bug+0x211/0x2d0 lib/bug.c:184   fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178   fixup_bug arch/x86/kernel/traps.c:247 [inline]   do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296   do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315   invalid_op+0x22/0x40 arch/x86/entry/entry_64.S:1079 Fixes: ef456144da8e ("soreuseport: define reuseport groups") Signed-off-by: Eric Dumazet Reported-by: syzbot+c0ea2226f77a42936bf7@syzkaller.appspotmail.com Acked-by: Craig Gallek Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/sock_reuseport.c | 35 ++++++++++++++++++++--------------- 1 file changed, 20 insertions(+), 15 deletions(-) --- a/net/core/sock_reuseport.c +++ b/net/core/sock_reuseport.c @@ -93,6 +93,16 @@ static struct sock_reuseport *reuseport_ return more_reuse; } +static void reuseport_free_rcu(struct rcu_head *head) +{ + struct sock_reuseport *reuse; + + reuse = container_of(head, struct sock_reuseport, rcu); + if (reuse->prog) + bpf_prog_destroy(reuse->prog); + kfree(reuse); +} + /** * reuseport_add_sock - Add a socket to the reuseport group of another. * @sk: New socket to add to the group. @@ -101,7 +111,7 @@ static struct sock_reuseport *reuseport_ */ int reuseport_add_sock(struct sock *sk, struct sock *sk2) { - struct sock_reuseport *reuse; + struct sock_reuseport *old_reuse, *reuse; if (!rcu_access_pointer(sk2->sk_reuseport_cb)) { int err = reuseport_alloc(sk2); @@ -112,10 +122,13 @@ int reuseport_add_sock(struct sock *sk, spin_lock_bh(&reuseport_lock); reuse = rcu_dereference_protected(sk2->sk_reuseport_cb, - lockdep_is_held(&reuseport_lock)), - WARN_ONCE(rcu_dereference_protected(sk->sk_reuseport_cb, - lockdep_is_held(&reuseport_lock)), - "socket already in reuseport group"); + lockdep_is_held(&reuseport_lock)); + old_reuse = rcu_dereference_protected(sk->sk_reuseport_cb, + lockdep_is_held(&reuseport_lock)); + if (old_reuse && old_reuse->num_socks != 1) { + spin_unlock_bh(&reuseport_lock); + return -EBUSY; + } if (reuse->num_socks == reuse->max_socks) { reuse = reuseport_grow(reuse); @@ -133,19 +146,11 @@ int reuseport_add_sock(struct sock *sk, spin_unlock_bh(&reuseport_lock); + if (old_reuse) + call_rcu(&old_reuse->rcu, reuseport_free_rcu); return 0; } -static void reuseport_free_rcu(struct rcu_head *head) -{ - struct sock_reuseport *reuse; - - reuse = container_of(head, struct sock_reuseport, rcu); - if (reuse->prog) - bpf_prog_destroy(reuse->prog); - kfree(reuse); -} - void reuseport_detach_sock(struct sock *sk) { struct sock_reuseport *reuse; Patches currently in stable-queue which might be from edumazet@google.com are queue-4.9/tcp-release-sk_frag.page-in-tcp_disconnect.patch queue-4.9/net-igmp-add-a-missing-rcu-locking-section.patch queue-4.9/soreuseport-fix-mem-leak-in-reuseport_add_sock.patch