[5.7,55/79] ipv4: Silence suspicious RCU usage warning

Message ID	20200810151814.967879403@linuxfoundation.org
State	New
Headers	show Return-Path: <SRS0=uOiG=BU=vger.kernel.org=stable-owner@kernel.org> From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, stable@vger.kernel.org, Ido Schimmel <idosch@mellanox.com>, Jiri Pirko <jiri@mellanox.com>, "David S. Miller" <davem@davemloft.net> Subject: [PATCH 5.7 55/79] ipv4: Silence suspicious RCU usage warning Date: Mon, 10 Aug 2020 17:21:14 +0200 Message-Id: <20200810151814.967879403@linuxfoundation.org> In-Reply-To: <20200810151812.114485777@linuxfoundation.org> References: <20200810151812.114485777@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk
Series	None \| expand [5.7,02/79] USB: serial: qcserial: add EM7305 QDL product ID [5.7,05/79] usb: xhci: Fix ASMedia ASM1142 DMA addressing [5.7,09/79] ALSA: hda/ca0132 - Fix ZxR Headphone gain control get value. [5.7,10/79] ALSA: hda/ca0132 - Fix AE-5 microphone selection commands. [5.7,12/79] staging: android: ashmem: Fix lockdep warning for write operation [5.7,15/79] Bluetooth: Fix slab-out-of-bounds read in hci_extended_inquiry_result_evt() [5.7,16/79] Bluetooth: Prevent out-of-bounds read in hci_inquiry_result_evt() [5.7,18/79] omapfb: dss: Fix max fclk divider for omap36xx [5.7,20/79] Smack: fix use-after-free in smk_write_relabel_self() [5.7,22/79] lkdtm/heap: Avoid edge and middle of slabs [5.7,24/79] mtd: properly check all write ioctls for permissions [5.7,26/79] leds: lm36274: fix use-after-free on unbind [5.7,27/79] leds: da903x: fix use-after-free on unbind [5.7,31/79] bpf: Fix NULL pointer dereference in __btf_resolve_helper_id() [5.7,32/79] net/9p: validate fds in p9_fd_open [5.7,34/79] drm/nouveau/fbcon: fix module unload when fbcon init has failed for some reason [5.7,35/79] drm/nouveau/fbcon: zero-initialise the mode_cmd2 structure [5.7,36/79] io_uring: fix lockup in io_fail_links() [5.7,39/79] drm/panel: Fix auo, kd101n80-45na horizontal noise on edges of panel [5.7,42/79] i2c: slave: improve sanity check when registering [5.7,43/79] i2c: slave: add sanity check when unregistering [5.7,46/79] ALSA: hda: fix NULL pointer dereference during suspend [5.7,48/79] cfg80211: check vendor command doit pointer before use [5.7,50/79] atm: fix atm_dev refcnt leaks in atmtcp_remove_persistent [5.7,53/79] Revert "powerpc/kasan: Fix shadow pages allocation failure" [5.7,55/79] ipv4: Silence suspicious RCU usage warning [5.7,57/79] ipv6: Fix nexthop refcnt leak when creating ipv6 route info [5.7,58/79] rxrpc: Fix race between recvmsg and sendmsg on immediate call failure [5.7,59/79] vxlan: Ensure FDB dump is performed under RCU [5.7,62/79] devlink: ignore -EOPNOTSUPP errors on dumpit [5.7,63/79] appletalk: Fix atalk_proc_init() return path [5.7,65/79] hv_netvsc: do not use VF device if link is down [5.7,67/79] net: gre: recompute gre csum for sctp over gre tunnels [5.7,71/79] net: thunderx: use spin_lock_bh in nicvf_set_rx_mode_task() [5.7,72/79] openvswitch: Prevent kernel-infoleak in ovs_ct_put_key() [5.7,75/79] tcp: apply a floor of 1 for RTT samples from TCP timestamps [5.7,76/79] mptcp: be careful on subflow creation [5.7,77/79] mptcp: fix bogus sendmsg() return code under pressure [5.7,79/79] arm64: kaslr: Use standard early random function

Message ID

20200810151814.967879403@linuxfoundation.org

State

New

Headers

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Ido Schimmel <idosch@mellanox.com>,
	Jiri Pirko <jiri@mellanox.com>, "David S. Miller" <davem@davemloft.net>
Subject: [PATCH 5.7 55/79] ipv4: Silence suspicious RCU usage warning
Date: Mon, 10 Aug 2020 17:21:14 +0200
Message-Id: <20200810151814.967879403@linuxfoundation.org>
In-Reply-To: <20200810151812.114485777@linuxfoundation.org>
References: <20200810151812.114485777@linuxfoundation.org>
User-Agent: quilt/0.66
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Sender: stable-owner@vger.kernel.org
Precedence: bulk

Series

None | expand

Commit Message

Greg KH Aug. 10, 2020, 3:21 p.m. UTC

From: Ido Schimmel <idosch@mellanox.com>

[ Upstream commit 83f3522860f702748143e022f1a546547314c715 ]

fib_trie_unmerge() is called with RTNL held, but not from an RCU
read-side critical section. This leads to the following warning [1] when
the FIB alias list in a leaf is traversed with
hlist_for_each_entry_rcu().

Since the function is always called with RTNL held and since
modification of the list is protected by RTNL, simply use
hlist_for_each_entry() and silence the warning.

[1]
WARNING: suspicious RCU usage
5.8.0-rc4-custom-01520-gc1f937f3f83b #30 Not tainted
-----------------------------
net/ipv4/fib_trie.c:1867 RCU-list traversed in non-reader section!!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
1 lock held by ip/164:
 #0: ffffffff85a27850 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x49a/0xbd0

stack backtrace:
CPU: 0 PID: 164 Comm: ip Not tainted 5.8.0-rc4-custom-01520-gc1f937f3f83b #30
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
 dump_stack+0x100/0x184
 lockdep_rcu_suspicious+0x153/0x15d
 fib_trie_unmerge+0x608/0xdb0
 fib_unmerge+0x44/0x360
 fib4_rule_configure+0xc8/0xad0
 fib_nl_newrule+0x37a/0x1dd0
 rtnetlink_rcv_msg+0x4f7/0xbd0
 netlink_rcv_skb+0x17a/0x480
 rtnetlink_rcv+0x22/0x30
 netlink_unicast+0x5ae/0x890
 netlink_sendmsg+0x98a/0xf40
 ____sys_sendmsg+0x879/0xa00
 ___sys_sendmsg+0x122/0x190
 __sys_sendmsg+0x103/0x1d0
 __x64_sys_sendmsg+0x7d/0xb0
 do_syscall_64+0x54/0xa0
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fc80a234e97
Code: Bad RIP value.
RSP: 002b:00007ffef8b66798 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc80a234e97
RDX: 0000000000000000 RSI: 00007ffef8b66800 RDI: 0000000000000003
RBP: 000000005f141b1c R08: 0000000000000001 R09: 0000000000000000
R10: 00007fc80a2a8ac0 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 00007ffef8b67008 R15: 0000556fccb10020

Fixes: 0ddcf43d5d4a ("ipv4: FIB Local/MAIN table collapse")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/ipv4/fib_trie.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1864,7 +1864,7 @@  struct fib_table *fib_trie_unmerge(struc
 	while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
 		struct key_vector *local_l = NULL, *local_tp;
 
-		hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
+		hlist_for_each_entry(fa, &l->leaf, fa_list) {
 			struct fib_alias *new_fa;
 
 			if (local_tb->tb_id != fa->tb_id)

[5.7,55/79] ipv4: Silence suspicious RCU usage warning

Commit Message

Patch