5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Titouan Ameline de Cadeville [ Upstream commit 7b1a1af4556a4f95ef273e91435fe804cbfcd223 ] coreboot_table_populate() iterates over firmware-provided table entries with no validation that the entries stay within the mapped memory region. A corrupt table with a large `entry->size` advances `ptr_entry` past the mapped region, causing an out-of-bounds read on the next iteration. Add a check before dereferencing `ptr_entry` to ensure the entry header is readable, and a second check after reading `entry->size` to ensure the full entry stays within the mapped region. Pass `len` from coreboot_table_probe() into coreboot_table_populate() to make the mapped region size available for validation. Signed-off-by: Titouan Ameline de Cadeville Reviewed-by: Julius Werner Link: https://lore.kernel.org/r/20260426214739.117131-1-titouan.ameline@gmail.com Signed-off-by: Tzung-Bi Shih Stable-dep-of: a58a57a1076f ("firmware: coreboot: Validate table bounds") Signed-off-by: Sasha Levin --- drivers/firmware/google/coreboot_table.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/firmware/google/coreboot_table.c b/drivers/firmware/google/coreboot_table.c index 1f52d8b82ef8d..32657b6bb316b 100644 --- a/drivers/firmware/google/coreboot_table.c +++ b/drivers/firmware/google/coreboot_table.c @@ -84,16 +84,20 @@ void coreboot_driver_unregister(struct coreboot_driver *driver) } EXPORT_SYMBOL(coreboot_driver_unregister); -static int coreboot_table_populate(struct device *dev, void *ptr) +static int coreboot_table_populate(struct device *dev, void *ptr, resource_size_t len) { int i, ret; void *ptr_entry; struct coreboot_device *device; struct coreboot_table_entry *entry; struct coreboot_table_header *header = ptr; + void *ptr_end; + ptr_end = ptr + len; ptr_entry = ptr + header->header_bytes; for (i = 0; i < header->table_entries; i++) { + if (ptr_entry + sizeof(*entry) > ptr_end) + return -EINVAL; entry = ptr_entry; if (entry->size < sizeof(*entry)) { @@ -101,6 +105,9 @@ static int coreboot_table_populate(struct device *dev, void *ptr) return -EINVAL; } + if (ptr_entry + entry->size > ptr_end) + return -EINVAL; + device = kzalloc(sizeof(device->dev) + entry->size, GFP_KERNEL); if (!device) return -ENOMEM; @@ -157,7 +164,7 @@ static int coreboot_table_probe(struct platform_device *pdev) if (!ptr) return -ENOMEM; - ret = coreboot_table_populate(dev, ptr); + ret = coreboot_table_populate(dev, ptr, len); memunmap(ptr); -- 2.53.0