Stable Archive on lore.kernel.org
 help / color / Atom feed
From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: David Howells <dhowells@redhat.com>,
	syzbot+72af434e4b3417318f84@syzkaller.appspotmail.com,
	Marc Dionne <marc.dionne@auristor.com>,
	Jeffrey Altman <jaltman@auristor.com>,
	Sasha Levin <sashal@kernel.org>,
	linux-afs@lists.infradead.org, netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 4.19 29/68] rxrpc: Fix potential deadlock
Date: Tue, 13 Aug 2019 22:15:07 -0400
Message-ID: <20190814021548.16001-29-sashal@kernel.org> (raw)
In-Reply-To: <20190814021548.16001-1-sashal@kernel.org>

From: David Howells <dhowells@redhat.com>

[ Upstream commit 60034d3d146b11922ab1db613bce062dddc0327a ]

There is a potential deadlock in rxrpc_peer_keepalive_dispatch() whereby
rxrpc_put_peer() is called with the peer_hash_lock held, but if it reduces
the peer's refcount to 0, rxrpc_put_peer() calls __rxrpc_put_peer() - which
the tries to take the already held lock.

Fix this by providing a version of rxrpc_put_peer() that can be called in
situations where the lock is already held.

The bug may produce the following lockdep report:

============================================
WARNING: possible recursive locking detected
5.2.0-next-20190718 #41 Not tainted
--------------------------------------------
kworker/0:3/21678 is trying to acquire lock:
00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at: spin_lock_bh
/./include/linux/spinlock.h:343 [inline]
00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at:
__rxrpc_put_peer /net/rxrpc/peer_object.c:415 [inline]
00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at:
rxrpc_put_peer+0x2d3/0x6a0 /net/rxrpc/peer_object.c:435

but task is already holding lock:
00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at: spin_lock_bh
/./include/linux/spinlock.h:343 [inline]
00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at:
rxrpc_peer_keepalive_dispatch /net/rxrpc/peer_event.c:378 [inline]
00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at:
rxrpc_peer_keepalive_worker+0x6b3/0xd02 /net/rxrpc/peer_event.c:430

Fixes: 330bdcfadcee ("rxrpc: Fix the keepalive generator [ver #2]")
Reported-by: syzbot+72af434e4b3417318f84@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/rxrpc/ar-internal.h |  1 +
 net/rxrpc/peer_event.c  |  2 +-
 net/rxrpc/peer_object.c | 18 ++++++++++++++++++
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 03e0fc8c183f0..a4c341828b72f 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -1057,6 +1057,7 @@ void rxrpc_destroy_all_peers(struct rxrpc_net *);
 struct rxrpc_peer *rxrpc_get_peer(struct rxrpc_peer *);
 struct rxrpc_peer *rxrpc_get_peer_maybe(struct rxrpc_peer *);
 void rxrpc_put_peer(struct rxrpc_peer *);
+void rxrpc_put_peer_locked(struct rxrpc_peer *);
 
 /*
  * proc.c
diff --git a/net/rxrpc/peer_event.c b/net/rxrpc/peer_event.c
index bd2fa3b7caa7e..dc7fdaf20445b 100644
--- a/net/rxrpc/peer_event.c
+++ b/net/rxrpc/peer_event.c
@@ -375,7 +375,7 @@ static void rxrpc_peer_keepalive_dispatch(struct rxrpc_net *rxnet,
 		spin_lock_bh(&rxnet->peer_hash_lock);
 		list_add_tail(&peer->keepalive_link,
 			      &rxnet->peer_keepalive[slot & mask]);
-		rxrpc_put_peer(peer);
+		rxrpc_put_peer_locked(peer);
 	}
 
 	spin_unlock_bh(&rxnet->peer_hash_lock);
diff --git a/net/rxrpc/peer_object.c b/net/rxrpc/peer_object.c
index 5691b7d266ca0..71547e8673b99 100644
--- a/net/rxrpc/peer_object.c
+++ b/net/rxrpc/peer_object.c
@@ -440,6 +440,24 @@ void rxrpc_put_peer(struct rxrpc_peer *peer)
 	}
 }
 
+/*
+ * Drop a ref on a peer record where the caller already holds the
+ * peer_hash_lock.
+ */
+void rxrpc_put_peer_locked(struct rxrpc_peer *peer)
+{
+	const void *here = __builtin_return_address(0);
+	int n;
+
+	n = atomic_dec_return(&peer->usage);
+	trace_rxrpc_peer(peer, rxrpc_peer_put, n, here);
+	if (n == 0) {
+		hash_del_rcu(&peer->hash_link);
+		list_del_init(&peer->keepalive_link);
+		kfree_rcu(peer, rcu);
+	}
+}
+
 /*
  * Make sure all peer records have been discarded.
  */
-- 
2.20.1


  parent reply index

Thread overview: 69+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-14  2:14 [PATCH AUTOSEL 4.19 01/68] iio: adc: max9611: Fix misuse of GENMASK macro Sasha Levin
2019-08-14  2:14 ` [PATCH AUTOSEL 4.19 02/68] iio: cros_ec_accel_legacy: Fix incorrect channel setting Sasha Levin
2019-08-14  2:14 ` [PATCH AUTOSEL 4.19 03/68] HID: Add 044f:b320 ThrustMaster, Inc. 2 in 1 DT Sasha Levin
2019-08-14  2:14 ` [PATCH AUTOSEL 4.19 04/68] MIPS: kernel: only use i8253 clocksource with periodic clockevent Sasha Levin
2019-08-14  2:14 ` [PATCH AUTOSEL 4.19 05/68] mips: fix cacheinfo Sasha Levin
2019-08-14  2:14 ` [PATCH AUTOSEL 4.19 06/68] netfilter: ebtables: fix a memory leak bug in compat Sasha Levin
2019-08-14  2:14 ` [PATCH AUTOSEL 4.19 07/68] ASoC: dapm: Fix handling of custom_stop_condition on DAPM graph walks Sasha Levin
2019-08-14  2:14 ` [PATCH AUTOSEL 4.19 08/68] selftests/bpf: fix sendmsg6_prog on s390 Sasha Levin
2019-08-14  2:14 ` [PATCH AUTOSEL 4.19 09/68] bonding: Force slave speed check after link state recovery for 802.3ad Sasha Levin
2019-08-14  2:14 ` [PATCH AUTOSEL 4.19 10/68] net: mvpp2: Don't check for 3 consecutive Idle frames for 10G links Sasha Levin
2019-08-14  2:14 ` [PATCH AUTOSEL 4.19 11/68] selftests: forwarding: gre_multipath: Enable IPv4 forwarding Sasha Levin
2019-08-14  2:14 ` [PATCH AUTOSEL 4.19 12/68] selftests: forwarding: gre_multipath: Fix flower filters Sasha Levin
2019-08-14  2:14 ` [PATCH AUTOSEL 4.19 13/68] can: dev: call netif_carrier_off() in register_candev() Sasha Levin
2019-08-14  2:14 ` [PATCH AUTOSEL 4.19 14/68] can: mcp251x: add error check when wq alloc failed Sasha Levin
2019-08-14  2:14 ` [PATCH AUTOSEL 4.19 15/68] can: gw: Fix error path of cgw_module_init Sasha Levin
2019-08-14  2:14 ` [PATCH AUTOSEL 4.19 16/68] ASoC: Fail card instantiation if DAI format setup fails Sasha Levin
2019-08-14  2:14 ` [PATCH AUTOSEL 4.19 17/68] st21nfca_connectivity_event_received: null check the allocation Sasha Levin
2019-08-14  2:14 ` [PATCH AUTOSEL 4.19 18/68] st_nci_hci_connectivity_event_received: " Sasha Levin
2019-08-14  2:14 ` [PATCH AUTOSEL 4.19 19/68] ASoC: rockchip: Fix mono capture Sasha Levin
2019-08-14  2:14 ` [PATCH AUTOSEL 4.19 20/68] ASoC: ti: davinci-mcasp: Correct slot_width posed constraint Sasha Levin
2019-08-14  2:14 ` [PATCH AUTOSEL 4.19 21/68] net: usb: qmi_wwan: Add the BroadMobi BM818 card Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 22/68] qed: RDMA - Fix the hw_ver returned in device attributes Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 23/68] isdn: mISDN: hfcsusb: Fix possible null-pointer dereferences in start_isoc_chain() Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 24/68] mac80211_hwsim: Fix possible null-pointer dereferences in hwsim_dump_radio_nl() Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 25/68] netfilter: ipset: Actually allow destination MAC address for hash:ip,mac sets too Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 26/68] netfilter: ipset: Copy the right MAC address in bitmap:ip,mac and hash:ip,mac sets Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 27/68] netfilter: ipset: Fix rename concurrency with listing Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 28/68] netfilter: ebtables: also count base chain policies Sasha Levin
2019-08-14  2:15 ` Sasha Levin [this message]
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 30/68] rxrpc: Fix the lack of notification when sendmsg() fails on a DATA packet Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 31/68] driver core: Fix use-after-free and double free on glue directory Sasha Levin
2019-08-14  7:36   ` Greg Kroah-Hartman
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 32/68] isdn: hfcsusb: Fix mISDN driver crash caused by transfer buffer on the stack Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 33/68] net: phy: phy_led_triggers: Fix a possible null-pointer dereference in phy_led_trigger_change_speed() Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 34/68] perf bench numa: Fix cpu0 binding Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 35/68] Input: kbtab - sanity check for endpoint type Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 36/68] net: usb: pegasus: fix improper read if get_registers() fail Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 37/68] can: sja1000: force the string buffer NULL-terminated Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 38/68] can: peak_usb: " Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 39/68] net/ethernet/qlogic/qed: " Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 40/68] NFSv4: Fix a potential sleep while atomic in nfs4_do_reclaim() Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 41/68] NFS: Fix regression whereby fscache errors are appearing on 'nofsc' mounts Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 42/68] HID: quirks: Set the INCREMENT_USAGE_ON_DUPLICATE quirk on Saitek X52 Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 43/68] HID: holtek: test for sanity of intfdata Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 44/68] HID: input: fix a4tech horizontal wheel custom usage Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 45/68] drm/rockchip: Suspend DP late Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 46/68] SMB3: Fix potential memory leak when processing compound chain Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 47/68] SMB3: Kernel oops mounting a encryptData share with CONFIG_DEBUG_VIRTUAL Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 48/68] HID: hiddev: avoid opening a disconnected device Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 49/68] HID: hiddev: do cleanup in failure of opening a device Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 50/68] s390: put _stext and _etext into .text section Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 51/68] Input: iforce - add sanity checks Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 52/68] net: cxgb3_main: Fix a resource leak in a error path in 'init_one()' Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 53/68] net: stmmac: Fix issues when number of Queues >= 4 Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 54/68] net: stmmac: tc: Do not return a fragment entry Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 55/68] net: hisilicon: make hip04_tx_reclaim non-reentrant Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 56/68] net: hisilicon: fix hip04-xmit never return TX_BUSY Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 57/68] net: hisilicon: Fix dma_map_single failed on arm64 Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 58/68] libata: have ata_scsi_rw_xlat() fail invalid passthrough requests Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 59/68] libata: add SG safety checks in SFF pio transfers Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 60/68] x86/lib/cpu: Address missing prototypes warning Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 61/68] drm/vmwgfx: fix memory leak when too many retries have occurred Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 62/68] block, bfq: handle NULL return value by bfq_init_rq() Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 63/68] perf ftrace: Fix failure to set cpumask when only one cpu is present Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 64/68] perf cpumap: Fix writing to illegal memory in handling cpumap mask Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 65/68] perf pmu-events: Fix missing "cpu_clk_unhalted.core" event Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 66/68] KVM: arm64: Don't write junk to sysregs on reset Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 67/68] KVM: arm: Don't write junk to CP15 registers " Sasha Levin
2019-08-14  2:15 ` [PATCH AUTOSEL 4.19 68/68] selftests: kvm: Adding config fragments Sasha Levin

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190814021548.16001-29-sashal@kernel.org \
    --to=sashal@kernel.org \
    --cc=dhowells@redhat.com \
    --cc=jaltman@auristor.com \
    --cc=linux-afs@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=marc.dionne@auristor.com \
    --cc=netdev@vger.kernel.org \
    --cc=stable@vger.kernel.org \
    --cc=syzbot+72af434e4b3417318f84@syzkaller.appspotmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Stable Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/stable/0 stable/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 stable stable/ https://lore.kernel.org/stable \
		stable@vger.kernel.org stable@archiver.kernel.org
	public-inbox-index stable


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.stable


AGPL code for this site: git clone https://public-inbox.org/ public-inbox