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 4.14-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-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Wed Feb 7 11:29:20 PST 2018
From: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Fri, 2 Feb 2018 10:27:27 -0800
Subject: soreuseport: fix mem leak in reuseport_add_sock()
From: Eric Dumazet <edumazet@xxxxxxxxxx>
[ 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 <edumazet@xxxxxxxxxx>
Reported-by: syzbot+c0ea2226f77a42936bf7@xxxxxxxxxxxxxxxxxxxxxxxxx
Acked-by: Craig Gallek <kraig@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -94,6 +94,16 @@ 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.
@@ -102,7 +112,7 @@ 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);
@@ -113,10 +123,13 @@ 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);
@@ -134,19 +147,11 @@ 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@xxxxxxxxxx are
queue-4.14/tcp-release-sk_frag.page-in-tcp_disconnect.patch
queue-4.14/net-igmp-add-a-missing-rcu-locking-section.patch
queue-4.14/soreuseport-fix-mem-leak-in-reuseport_add_sock.patch
queue-4.14/revert-defer-call-to-mem_cgroup_sk_alloc.patch