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Filename Latest commit message Latest commit date
Chengfeng Ye d2bf25674c scsi: fcoe: Fix potential deadlock on &fip->ctlr_lock
[ Upstream commit 1a1975551943f681772720f639ff42fbaa746212 ]

There is a long call chain that &fip->ctlr_lock is acquired by isr
fnic_isr_msix_wq_copy() under hard IRQ context. Thus other process context
code acquiring the lock should disable IRQ, otherwise deadlock could happen
if the IRQ preempts the execution while the lock is held in process context
on the same CPU.

[ISR]
fnic_isr_msix_wq_copy()
 -> fnic_wq_copy_cmpl_handler()
 -> fnic_fcpio_cmpl_handler()
 -> fnic_fcpio_flogi_reg_cmpl_handler()
 -> fnic_flush_tx()
 -> fnic_send_frame()
 -> fcoe_ctlr_els_send()
 -> spin_lock_bh(&fip->ctlr_lock)

[Process Context]
1. fcoe_ctlr_timer_work()
 -> fcoe_ctlr_flogi_send()
 -> spin_lock_bh(&fip->ctlr_lock)

2. fcoe_ctlr_recv_work()
 -> fcoe_ctlr_recv_handler()
 -> fcoe_ctlr_recv_els()
 -> fcoe_ctlr_announce()
 -> spin_lock_bh(&fip->ctlr_lock)

3. fcoe_ctlr_recv_work()
 -> fcoe_ctlr_recv_handler()
 -> fcoe_ctlr_recv_els()
 -> fcoe_ctlr_flogi_retry()
 -> spin_lock_bh(&fip->ctlr_lock)

4. -> fcoe_xmit()
 -> fcoe_ctlr_els_send()
 -> spin_lock_bh(&fip->ctlr_lock)

spin_lock_bh() is not enough since fnic_isr_msix_wq_copy() is a
hardirq.

These flaws were found by an experimental static analysis tool I am
developing for irq-related deadlock.

The patch fix the potential deadlocks by spin_lock_irqsave() to disable
hard irq.

Fixes: 794d98e77f ("[SCSI] libfcoe: retry rejected FLOGI to another FCF if possible")
Signed-off-by: Chengfeng Ye <dg573847474@gmail.com>
Link: https://lore.kernel.org/r/20230817074708.7509-1-dg573847474@gmail.com
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-23 10:59:52 +02:00
arch x86/APM: drop the duplicate APM_MINOR_DEV macro 2023-09-23 10:59:50 +02:00
block
certs
crypto
Documentation Documentation/sysctl: document page_lock_unfairness 2023-08-30 16:27:27 +02:00
drivers scsi: fcoe: Fix potential deadlock on &fip->ctlr_lock 2023-09-23 10:59:52 +02:00
fs NFS: Guard against READDIR loop when entry names exceed MAXNAMELEN 2023-09-23 10:59:48 +02:00
include scsi: core: Use 32-bit hostnum in scsi_host_lookup() 2023-09-23 10:59:51 +02:00
init x86/mm: Initialize text poking earlier 2023-08-08 19:56:36 +02:00
ipc
kernel audit: fix possible soft lockup in __audit_inode_child() 2023-09-23 10:59:46 +02:00
lib radix tree: remove unused variable 2023-08-30 16:27:26 +02:00
LICENSES
mm tmpfs: verify {g,u}id mount options correctly 2023-09-23 10:59:40 +02:00
net netrom: Deny concurrent connect(). 2023-09-23 10:59:43 +02:00
samples
scripts
security smackfs: Prevent underflow in smk_set_cipso() 2023-09-23 10:59:46 +02:00
sound ALSA: ac97: Fix possible error value of *rac97 2023-09-23 10:59:46 +02:00
tools selftests: mirror_gre_changes: Tighten up the TTL test match 2023-08-30 16:27:16 +02:00
usr
virt
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS iio: stx104: Move to addac subdirectory 2023-08-30 16:27:12 +02:00
Makefile Linux 5.4.256 2023-09-02 09:19:19 +02:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.