From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Florian Westphal <fw@strlen.de>,
Thomas Jarosch <thomas.jarosch@intra2net.com>,
Juliana Rodrigueiro <juliana.rodrigueiro@intra2net.com>,
Pablo Neira Ayuso <pablo@netfilter.org>,
Sasha Levin <sashal@kernel.org>,
netfilter-devel@vger.kernel.org, coreteam@netfilter.org,
netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 5.2 02/76] netfilter: nfnetlink: avoid deadlock due to synchronous request_module
Date: Fri, 2 Aug 2019 09:18:36 -0400 [thread overview]
Message-ID: <20190802131951.11600-2-sashal@kernel.org> (raw)
In-Reply-To: <20190802131951.11600-1-sashal@kernel.org>
From: Florian Westphal <fw@strlen.de>
[ Upstream commit 1b0890cd60829bd51455dc5ad689ed58c4408227 ]
Thomas and Juliana report a deadlock when running:
(rmmod nf_conntrack_netlink/xfrm_user)
conntrack -e NEW -E &
modprobe -v xfrm_user
They provided following analysis:
conntrack -e NEW -E
netlink_bind()
netlink_lock_table() -> increases "nl_table_users"
nfnetlink_bind()
# does not unlock the table as it's locked by netlink_bind()
__request_module()
call_usermodehelper_exec()
This triggers "modprobe nf_conntrack_netlink" from kernel, netlink_bind()
won't return until modprobe process is done.
"modprobe xfrm_user":
xfrm_user_init()
register_pernet_subsys()
-> grab pernet_ops_rwsem
..
netlink_table_grab()
calls schedule() as "nl_table_users" is non-zero
so modprobe is blocked because netlink_bind() increased
nl_table_users while also holding pernet_ops_rwsem.
"modprobe nf_conntrack_netlink" runs and inits nf_conntrack_netlink:
ctnetlink_init()
register_pernet_subsys()
-> blocks on "pernet_ops_rwsem" thanks to xfrm_user module
both modprobe processes wait on one another -- neither can make
progress.
Switch netlink_bind() to "nowait" modprobe -- this releases the netlink
table lock, which then allows both modprobe instances to complete.
Reported-by: Thomas Jarosch <thomas.jarosch@intra2net.com>
Reported-by: Juliana Rodrigueiro <juliana.rodrigueiro@intra2net.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/netfilter/nfnetlink.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c
index 92077d4591090..4abbb452cf6c6 100644
--- a/net/netfilter/nfnetlink.c
+++ b/net/netfilter/nfnetlink.c
@@ -578,7 +578,7 @@ static int nfnetlink_bind(struct net *net, int group)
ss = nfnetlink_get_subsys(type << 8);
rcu_read_unlock();
if (!ss)
- request_module("nfnetlink-subsys-%d", type);
+ request_module_nowait("nfnetlink-subsys-%d", type);
return 0;
}
#endif
--
2.20.1
next prev parent reply other threads:[~2019-08-02 13:20 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-02 13:18 [PATCH AUTOSEL 5.2 01/76] powerpc: fix off by one in max_zone_pfn initialization for ZONE_DMA Sasha Levin
2019-08-02 13:18 ` Sasha Levin [this message]
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 03/76] vfio-ccw: Set pa_nr to 0 if memory allocation fails for pa_iova_pfn Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 04/76] vfio-ccw: Don't call cp_free if we are processing a channel program Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 05/76] netfilter: Fix rpfilter dropping vrf packets by mistake Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 06/76] netfilter: nf_tables: fix module autoload for redir Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 07/76] netfilter: conntrack: always store window size un-scaled Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 08/76] netfilter: nft_hash: fix symhash with modulus one Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 09/76] scripts/sphinx-pre-install: fix script for RHEL/CentOS Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 10/76] scripts/sphinx-pre-install: don't use LaTeX with CentOS 7 Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 11/76] scripts/sphinx-pre-install: fix latexmk dependencies Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 12/76] rq-qos: don't reset has_sleepers on spurious wakeups Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 13/76] rq-qos: set ourself TASK_UNINTERRUPTIBLE after we schedule Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 14/76] rq-qos: use a mb for got_token Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 15/76] netfilter: nf_tables: Support auto-loading for inet nat Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 16/76] drm/amd/display: No audio endpoint for Dell MST display Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 17/76] drm/amd/display: Clock does not lower in Updateplanes Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 18/76] drm/amd/display: Wait for backlight programming completion in set backlight level Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 19/76] drm/amd/display: fix DMCU hang when going into Modern Standby Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 20/76] drm/amd/display: use encoder's engine id to find matched free audio device Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 21/76] drm/amd/display: put back front end initialization sequence Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 22/76] drm/amd/display: allocate 4 ddc engines for RV2 Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 23/76] drm/amd/display: Fix dc_create failure handling and 666 color depths Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 24/76] drm/amd/display: Only enable audio if speaker allocation exists Sasha Levin
2019-08-02 13:18 ` [PATCH AUTOSEL 5.2 25/76] drm/amd/display: Increase size of audios array Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 26/76] iscsi_ibft: make ISCSI_IBFT dependson ACPI instead of ISCSI_IBFT_FIND Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 27/76] nl80211: fix NL80211_HE_MAX_CAPABILITY_LEN Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 28/76] mac80211: fix possible memory leak in ieee80211_assign_beacon Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 29/76] mac80211: don't warn about CW params when not using them Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 30/76] allocate_flower_entry: should check for null deref Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 31/76] hwmon: (occ) Fix division by zero issue Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 32/76] hwmon: (nct6775) Fix register address and added missed tolerance for nct6106 Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 33/76] ARM: dts: imx6ul: fix clock frequency property name of I2C buses Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 34/76] x86/mm: Check for pfn instead of page in vmalloc_sync_one() Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 35/76] x86/mm: Sync also unmappings in vmalloc_sync_all() Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 36/76] mm/vmalloc: Sync unmappings in __purge_vmap_area_lazy() Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 37/76] powerpc/papr_scm: Force a scm-unbind if initial scm-bind fails Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 38/76] arm64: Force SSBS on context switch Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 39/76] arm64: entry: SP Alignment Fault doesn't write to FAR_EL1 Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 40/76] iommu/vt-d: Check if domain->pgd was allocated Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 41/76] drm/msm/dpu: Correct dpu encoder spinlock initialization Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 42/76] drm/msm: stop abusing dma_map/unmap for cache Sasha Levin
2019-08-03 0:14 ` Rob Clark
2019-08-14 2:03 ` Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 43/76] drm: silence variable 'conn' set but not used Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 44/76] arm64: dts: imx8mm: Correct SAI3 RXC/TXFS pin's mux option #1 Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 45/76] arm64: dts: imx8mq: fix SAI compatible Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 46/76] cpufreq/pasemi: fix use-after-free in pas_cpufreq_cpu_init() Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 47/76] s390/qdio: add sanity checks to the fast-requeue path Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 48/76] ALSA: compress: Fix regression on compressed capture streams Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 49/76] ALSA: compress: Prevent bypasses of set_params Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 50/76] ALSA: compress: Don't allow paritial drain operations on capture streams Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 51/76] ALSA: compress: Be more restrictive about when a drain is allowed Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 52/76] perf script: Fix off by one in brstackinsn IPC computation Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 53/76] perf tools: Fix proper buffer size for feature processing Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 54/76] perf stat: Fix segfault for event group in repeat mode Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 55/76] perf session: Fix loading of compressed data split across adjacent records Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 56/76] perf probe: Avoid calling freeing routine multiple times for same pointer Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 57/76] drbd: dynamically allocate shash descriptor Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 58/76] ACPI/IORT: Fix off-by-one check in iort_dev_find_its_id() Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 59/76] nvme: ignore subnqn for ADATA SX6000LNP Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 60/76] nvme: fix memory leak caused by incorrect subsystem free Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 61/76] nvme: fix multipath crash when ANA is deactivated Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 62/76] ARM: davinci: fix sleep.S build error on ARMv4 Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 63/76] ARM: dts: bcm: bcm47094: add missing #cells for mdio-bus-mux Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 64/76] scsi: megaraid_sas: fix panic on loading firmware crashdump Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 65/76] scsi: ibmvfc: fix WARN_ON during event pool release Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 66/76] scsi: scsi_dh_alua: always use a 2 second delay before retrying RTPG Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 67/76] test_firmware: fix a memory leak bug Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 68/76] sched/fair: Don't free p->numa_faults with concurrent readers Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 69/76] sched/fair: Use RCU accessors consistently for ->numa_group Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 70/76] tty/ldsem, locking/rwsem: Add missing ACQUIRE to read_failed sleep loop Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 71/76] perf/x86/intel: Fix SLOTS PEBS event constraint Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 72/76] perf/x86/intel: Fix invalid Bit 13 for Icelake MSR_OFFCORE_RSP_x register Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 73/76] perf/x86: Apply more accurate check on hypervisor platform Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 74/76] perf/core: Fix creating kernel counters for PMUs that override event->cpu Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 75/76] s390/dma: provide proper ARCH_ZONE_DMA_BITS value Sasha Levin
2019-08-02 13:19 ` [PATCH AUTOSEL 5.2 76/76] gen_compile_commands: lower the entry count threshold Sasha Levin
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