hulk inclusion category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9RBZI CVE: CVE-2021-47469
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Move struct mutex add_lock from struct spi_controller to struct device in case of kabi breakage in struct spi_controller.
Fixes: 6098475d4cb4 ("spi: Fix deadlock when adding SPI controllers on SPI buses") Signed-off-by: Zeng Heng zengheng4@huawei.com --- drivers/spi/spi.c | 37 ++++++++++++++++++++++++++----------- include/linux/device.h | 8 ++++++++ include/linux/spi/spi.h | 3 --- 3 files changed, 34 insertions(+), 14 deletions(-)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index d510b9ca798f..49ff49d97745 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -575,7 +575,7 @@ int spi_add_device(struct spi_device *spi) * chipselect **BEFORE** we call setup(), else we'll trash * its configuration. Lock against concurrent add() calls. */ - mutex_lock(&ctlr->add_lock); + mutex_lock(ctlr->dev.add_lock);
status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check); if (status) { @@ -619,7 +619,7 @@ int spi_add_device(struct spi_device *spi) }
done: - mutex_unlock(&ctlr->add_lock); + mutex_unlock(ctlr->dev.add_lock); return status; } EXPORT_SYMBOL_GPL(spi_add_device); @@ -2682,14 +2682,20 @@ int spi_register_controller(struct spi_controller *ctlr) if (status) return status;
+ ctlr->dev.add_lock = kmalloc(sizeof(struct mutex), GFP_KERNEL); + if (!ctlr->dev.add_lock) + return -ENOMEM; + if (ctlr->bus_num >= 0) { /* devices with a fixed bus num must check-in with the num */ mutex_lock(&board_lock); id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num, ctlr->bus_num + 1, GFP_KERNEL); mutex_unlock(&board_lock); - if (WARN(id < 0, "couldn't get idr")) - return id == -ENOSPC ? -EBUSY : id; + if (WARN(id < 0, "couldn't get idr")) { + status = (id == -ENOSPC) ? -EBUSY : id; + goto free_add_lock; + } ctlr->bus_num = id; } else if (ctlr->dev.of_node) { /* allocate dynamic bus number using Linux idr */ @@ -2700,8 +2706,10 @@ int spi_register_controller(struct spi_controller *ctlr) id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num, ctlr->bus_num + 1, GFP_KERNEL); mutex_unlock(&board_lock); - if (WARN(id < 0, "couldn't get idr")) - return id == -ENOSPC ? -EBUSY : id; + if (WARN(id < 0, "couldn't get idr")) { + status = (id == -ENOSPC) ? -EBUSY : id; + goto free_add_lock; + } } } if (ctlr->bus_num < 0) { @@ -2715,8 +2723,11 @@ int spi_register_controller(struct spi_controller *ctlr) id = idr_alloc(&spi_master_idr, ctlr, first_dynamic, 0, GFP_KERNEL); mutex_unlock(&board_lock); - if (WARN(id < 0, "couldn't get idr")) - return id; + if (WARN(id < 0, "couldn't get idr")) { + status = id; + goto free_add_lock; + } + ctlr->bus_num = id; } INIT_LIST_HEAD(&ctlr->queue); @@ -2724,7 +2735,7 @@ int spi_register_controller(struct spi_controller *ctlr) spin_lock_init(&ctlr->bus_lock_spinlock); mutex_init(&ctlr->bus_lock_mutex); mutex_init(&ctlr->io_mutex); - mutex_init(&ctlr->add_lock); + mutex_init(ctlr->dev.add_lock); ctlr->bus_lock_flag = 0; init_completion(&ctlr->xfer_completion); if (!ctlr->max_dma_len) @@ -2801,6 +2812,8 @@ int spi_register_controller(struct spi_controller *ctlr) mutex_lock(&board_lock); idr_remove(&spi_master_idr, ctlr->bus_num); mutex_unlock(&board_lock); +free_add_lock: + kfree(ctlr->dev.add_lock); return status; } EXPORT_SYMBOL_GPL(spi_register_controller); @@ -2870,7 +2883,7 @@ void spi_unregister_controller(struct spi_controller *ctlr)
/* Prevent addition of new devices, unregister existing ones */ if (IS_ENABLED(CONFIG_SPI_DYNAMIC)) - mutex_lock(&ctlr->add_lock); + mutex_lock(ctlr->dev.add_lock);
device_for_each_child(&ctlr->dev, NULL, __unregister);
@@ -2895,7 +2908,9 @@ void spi_unregister_controller(struct spi_controller *ctlr) mutex_unlock(&board_lock);
if (IS_ENABLED(CONFIG_SPI_DYNAMIC)) - mutex_unlock(&ctlr->add_lock); + mutex_unlock(ctlr->dev.add_lock); + + kfree(ctlr->dev.add_lock);
/* Release the last reference on the controller if its driver * has not yet been converted to devm_spi_alloc_master/slave(). diff --git a/include/linux/device.h b/include/linux/device.h index 929b66dc5ea9..8b54f2bcca46 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -567,7 +567,15 @@ struct device { bool dma_ops_bypass : 1; #endif /* Use device_extended after all RESERVE fields used */ +#ifdef CONFIG_SPI_MASTER + /* + * Reserved for struct spi_controller. + * Used to avoid adding the same CS twice. + */ + KABI_USE(1, struct mutex *add_lock) +#else KABI_RESERVE(1) +#endif KABI_RESERVE(2) KABI_RESERVE(3) KABI_RESERVE(4) diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 8f5ed0beeea4..e1d88630ff24 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -527,9 +527,6 @@ struct spi_controller { /* I/O mutex */ struct mutex io_mutex;
- /* Used to avoid adding the same CS twice */ - struct mutex add_lock; - /* lock and mutex for SPI bus locking */ spinlock_t bus_lock_spinlock; struct mutex bus_lock_mutex;