Many functions in PCI use accessor macros such as pci_resource_len(), which take a BAR index. That index, however, is never checked for validity, potentially resulting in undefined behavior by overflowing the array pci_dev.resource in the macro pci_resource_n(). Since many users of those macros directly assign the accessed value to an unsigned integer, the macros cannot be changed easily anymore to return -EINVAL for invalid indexes. Consequently, the problem has to be mitigated in higher layers. Add pci_bar_index_valid(). Use it where appropriate. Reported-by: Bingbu Cao <bingbu.cao@xxxxxxxxxxxxxxx> Closes: https://lore.kernel.org/all/adb53b1f-29e1-3d14-0e61-351fd2d3ff0d@xxxxxxxxxxxxxxx/ Signed-off-by: Philipp Stanner <phasta@xxxxxxxxxx> --- drivers/pci/devres.c | 16 ++++++++++++++-- drivers/pci/iomap.c | 30 +++++++++++++++++++++--------- drivers/pci/pci.c | 6 ++++++ drivers/pci/pci.h | 8 ++++++++ 4 files changed, 49 insertions(+), 11 deletions(-) diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c index 3431a7df3e0d..d2c09589c537 100644 --- a/drivers/pci/devres.c +++ b/drivers/pci/devres.c @@ -577,7 +577,7 @@ static int pcim_add_mapping_to_legacy_table(struct pci_dev *pdev, { void __iomem **legacy_iomap_table; - if (bar >= PCI_STD_NUM_BARS) + if (!pci_bar_index_is_valid(bar)) return -EINVAL; legacy_iomap_table = (void __iomem **)pcim_iomap_table(pdev); @@ -622,7 +622,7 @@ static void pcim_remove_bar_from_legacy_table(struct pci_dev *pdev, int bar) { void __iomem **legacy_iomap_table; - if (bar >= PCI_STD_NUM_BARS) + if (!pci_bar_index_is_valid(bar)) return; legacy_iomap_table = (void __iomem **)pcim_iomap_table(pdev); @@ -655,6 +655,9 @@ void __iomem *pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen) void __iomem *mapping; struct pcim_addr_devres *res; + if (!pci_bar_index_is_valid(bar)) + return NULL; + res = pcim_addr_devres_alloc(pdev); if (!res) return NULL; @@ -722,6 +725,9 @@ void __iomem *pcim_iomap_region(struct pci_dev *pdev, int bar, int ret; struct pcim_addr_devres *res; + if (!pci_bar_index_is_valid(bar)) + return IOMEM_ERR_PTR(-EINVAL); + res = pcim_addr_devres_alloc(pdev); if (!res) return IOMEM_ERR_PTR(-ENOMEM); @@ -823,6 +829,9 @@ static int _pcim_request_region(struct pci_dev *pdev, int bar, const char *name, int ret; struct pcim_addr_devres *res; + if (!pci_bar_index_is_valid(bar)) + return -EINVAL; + res = pcim_addr_devres_alloc(pdev); if (!res) return -ENOMEM; @@ -991,6 +1000,9 @@ void __iomem *pcim_iomap_range(struct pci_dev *pdev, int bar, void __iomem *mapping; struct pcim_addr_devres *res; + if (!pci_bar_index_is_valid(bar)) + return IOMEM_ERR_PTR(-EINVAL); + res = pcim_addr_devres_alloc(pdev); if (!res) return IOMEM_ERR_PTR(-ENOMEM); diff --git a/drivers/pci/iomap.c b/drivers/pci/iomap.c index 9fb7cacc15cd..0cab82cbcc99 100644 --- a/drivers/pci/iomap.c +++ b/drivers/pci/iomap.c @@ -9,6 +9,8 @@ #include <linux/export.h> +#include "pci.h" /* for pci_bar_index_is_valid() */ + /** * pci_iomap_range - create a virtual mapping cookie for a PCI BAR * @dev: PCI device that owns the BAR @@ -33,12 +35,18 @@ void __iomem *pci_iomap_range(struct pci_dev *dev, unsigned long offset, unsigned long maxlen) { - resource_size_t start = pci_resource_start(dev, bar); - resource_size_t len = pci_resource_len(dev, bar); - unsigned long flags = pci_resource_flags(dev, bar); + resource_size_t start, len; + unsigned long flags; + if (!pci_bar_index_is_valid(bar)) + return NULL; if (len <= offset || !start) return NULL; + + start = pci_resource_start(dev, bar); + len = pci_resource_len(dev, bar); + flags = pci_resource_flags(dev, bar); + len -= offset; start += offset; if (maxlen && len > maxlen) @@ -77,17 +85,21 @@ void __iomem *pci_iomap_wc_range(struct pci_dev *dev, unsigned long offset, unsigned long maxlen) { - resource_size_t start = pci_resource_start(dev, bar); - resource_size_t len = pci_resource_len(dev, bar); - unsigned long flags = pci_resource_flags(dev, bar); - + resource_size_t start, len; + unsigned long flags; - if (flags & IORESOURCE_IO) + if (!pci_bar_index_is_valid(bar)) return NULL; - if (len <= offset || !start) return NULL; + start = pci_resource_start(dev, bar); + len = pci_resource_len(dev, bar); + flags = pci_resource_flags(dev, bar); + + if (flags & IORESOURCE_IO) + return NULL; + len -= offset; start += offset; if (maxlen && len > maxlen) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 869d204a70a3..da82d734d09c 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3921,6 +3921,9 @@ EXPORT_SYMBOL(pci_enable_atomic_ops_to_root); */ void pci_release_region(struct pci_dev *pdev, int bar) { + if (!pci_bar_index_is_valid(bar)) + return; + /* * This is done for backwards compatibility, because the old PCI devres * API had a mode in which the function became managed if it had been @@ -3965,6 +3968,9 @@ EXPORT_SYMBOL(pci_release_region); static int __pci_request_region(struct pci_dev *pdev, int bar, const char *name, int exclusive) { + if (!pci_bar_index_is_valid(bar)) + return -EINVAL; + if (pci_is_managed(pdev)) { if (exclusive == IORESOURCE_EXCLUSIVE) return pcim_request_region_exclusive(pdev, bar, name); diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 01e51db8d285..ae8b2f5c118b 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -167,6 +167,14 @@ static inline void pci_wakeup_event(struct pci_dev *dev) pm_wakeup_event(&dev->dev, 100); } +static inline bool pci_bar_index_is_valid(int bar) +{ + if (bar < 0 || bar >= PCI_NUM_RESOURCES) + return false; + + return true; +} + static inline bool pci_has_subordinate(struct pci_dev *pci_dev) { return !!(pci_dev->subordinate); -- 2.48.1
