From ce9ff21ea89d191e477a02ad7eabf4f996b80a69 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Wed, 22 Jan 2025 10:38:30 -0700 Subject: [PATCH] vfio/platform: check the bounds of read/write syscalls MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit count and offset are passed from user space and not checked, only offset is capped to 40 bits, which can be used to read/write out of bounds of the device. Fixes: 6e3f26456009 (“vfio/platform: read and write support for the device fd”) Cc: stable@vger.kernel.org Reported-by: Mostafa Saleh Reviewed-by: Eric Auger Reviewed-by: Mostafa Saleh Tested-by: Mostafa Saleh Signed-off-by: Alex Williamson --- drivers/vfio/platform/vfio_platform_common.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c index e53757d1d095..3bf1043cd795 100644 --- a/drivers/vfio/platform/vfio_platform_common.c +++ b/drivers/vfio/platform/vfio_platform_common.c @@ -388,6 +388,11 @@ static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg, { unsigned int done = 0; + if (off >= reg->size) + return -EINVAL; + + count = min_t(size_t, count, reg->size - off); + if (!reg->ioaddr) { reg->ioaddr = ioremap(reg->addr, reg->size); @@ -467,6 +472,11 @@ static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg, { unsigned int done = 0; + if (off >= reg->size) + return -EINVAL; + + count = min_t(size_t, count, reg->size - off); + if (!reg->ioaddr) { reg->ioaddr = ioremap(reg->addr, reg->size); -- 2.50.1