From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Logan Gunthorpe <logang@deltatee.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Bjorn Helgaas <bhelgaas@google.com>,
Sasha Levin <sashal@kernel.org>,
linux-pci@vger.kernel.org
Subject: [PATCH AUTOSEL 4.14 09/22] PCI/switchtec: Fix init_completion race condition with poll_wait()
Date: Thu, 9 Apr 2020 23:50:31 -0400 [thread overview]
Message-ID: <20200410035044.9698-9-sashal@kernel.org> (raw)
In-Reply-To: <20200410035044.9698-1-sashal@kernel.org>
From: Logan Gunthorpe <logang@deltatee.com>
[ Upstream commit efbdc769601f4d50018bf7ca50fc9f7c67392ece ]
The call to init_completion() in mrpc_queue_cmd() can theoretically
race with the call to poll_wait() in switchtec_dev_poll().
poll() write()
switchtec_dev_poll() switchtec_dev_write()
poll_wait(&s->comp.wait); mrpc_queue_cmd()
init_completion(&s->comp)
init_waitqueue_head(&s->comp.wait)
To my knowledge, no one has hit this bug.
Fix this by using reinit_completion() instead of init_completion() in
mrpc_queue_cmd().
Fixes: 080b47def5e5 ("MicroSemi Switchtec management interface driver")
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lkml.kernel.org/r/20200313183608.2646-1-logang@deltatee.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/pci/switch/switchtec.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/pci/switch/switchtec.c b/drivers/pci/switch/switchtec.c
index bf229b442e723..6ef0d4b756f09 100644
--- a/drivers/pci/switch/switchtec.c
+++ b/drivers/pci/switch/switchtec.c
@@ -412,7 +412,7 @@ static int mrpc_queue_cmd(struct switchtec_user *stuser)
kref_get(&stuser->kref);
stuser->read_len = sizeof(stuser->data);
stuser_set_state(stuser, MRPC_QUEUED);
- init_completion(&stuser->comp);
+ reinit_completion(&stuser->comp);
list_add_tail(&stuser->list, &stdev->mrpc_queue);
mrpc_cmd_submit(stdev);
--
2.20.1
next prev parent reply other threads:[~2020-04-10 3:53 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-10 3:50 [PATCH AUTOSEL 4.14 01/22] null_blk: Fix the null_add_dev() error path Sasha Levin
2020-04-10 3:50 ` [PATCH AUTOSEL 4.14 02/22] null_blk: Handle null_add_dev() failures properly Sasha Levin
2020-04-10 3:50 ` [PATCH AUTOSEL 4.14 03/22] null_blk: fix spurious IO errors after failed past-wp access Sasha Levin
2020-04-10 3:50 ` [PATCH AUTOSEL 4.14 04/22] x86: Don't let pgprot_modify() change the page encryption bit Sasha Levin
2020-04-10 3:50 ` [PATCH AUTOSEL 4.14 05/22] block: keep bdi->io_pages in sync with max_sectors_kb for stacked devices Sasha Levin
2020-04-10 3:50 ` [PATCH AUTOSEL 4.14 06/22] irqchip/versatile-fpga: Handle chained IRQs properly Sasha Levin
2020-04-10 3:50 ` [PATCH AUTOSEL 4.14 07/22] sched: Avoid scale real weight down to zero Sasha Levin
2020-04-10 3:50 ` [PATCH AUTOSEL 4.14 08/22] selftests/x86/ptrace_syscall_32: Fix no-vDSO segfault Sasha Levin
2020-04-10 3:50 ` Sasha Levin [this message]
2020-04-10 3:50 ` [PATCH AUTOSEL 4.14 10/22] libata: Remove extra scsi_host_put() in ata_scsi_add_hosts() Sasha Levin
2020-04-10 3:50 ` [PATCH AUTOSEL 4.14 11/22] gfs2: Don't demote a glock until its revokes are written Sasha Levin
2020-04-10 3:50 ` [PATCH AUTOSEL 4.14 12/22] x86/boot: Use unsigned comparison for addresses Sasha Levin
2020-04-10 3:50 ` [PATCH AUTOSEL 4.14 13/22] efi/x86: Ignore the memory attributes table on i386 Sasha Levin
2020-04-10 3:50 ` [PATCH AUTOSEL 4.14 14/22] genirq/irqdomain: Check pointer in irq_domain_alloc_irqs_hierarchy() Sasha Levin
2020-04-10 3:50 ` [PATCH AUTOSEL 4.14 15/22] block: Fix use-after-free issue accessing struct io_cq Sasha Levin
2020-04-10 3:50 ` [PATCH AUTOSEL 4.14 16/22] usb: dwc3: core: add support for disabling SS instances in park mode Sasha Levin
2020-04-10 3:50 ` [PATCH AUTOSEL 4.14 17/22] irqchip/gic-v4: Provide irq_retrigger to avoid circular locking dependency Sasha Levin
2020-04-10 3:50 ` [PATCH AUTOSEL 4.14 18/22] locking/lockdep: Avoid recursion in lockdep_count_{for,back}ward_deps() Sasha Levin
2020-04-10 3:50 ` [PATCH AUTOSEL 4.14 19/22] block, bfq: fix use-after-free in bfq_idle_slice_timer_body Sasha Levin
2020-04-10 3:50 ` [PATCH AUTOSEL 4.14 20/22] btrfs: hold a ref on the root in btrfs_recover_relocation Sasha Levin
2020-04-10 3:50 ` [PATCH AUTOSEL 4.14 21/22] btrfs: remove a BUG_ON() from merge_reloc_roots() Sasha Levin
2020-04-10 3:50 ` [PATCH AUTOSEL 4.14 22/22] btrfs: track reloc roots based on their commit root bytenr Sasha Levin
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