This is a note to let you know that I've just added the patch titled iommu/omap: Check for failure of a call to omap_iommu_dump_ctx to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: iommu-omap-check-for-failure-of-a-call-to-omap_iommu.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit f69fdc720455fed3408c77227d7f156c52ce19d5 Author: Colin Ian King <colin.king@xxxxxxxxxxxxx> Date: Tue Jul 14 20:22:11 2020 +0100 iommu/omap: Check for failure of a call to omap_iommu_dump_ctx [ Upstream commit dee9d154f40c58d02f69acdaa5cfd1eae6ebc28b ] It is possible for the call to omap_iommu_dump_ctx to return a negative error number, so check for the failure and return the error number rather than pass the negative value to simple_read_from_buffer. Fixes: 14e0e6796a0d ("OMAP: iommu: add initial debugfs support") Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20200714192211.744776-1-colin.king@xxxxxxxxxxxxx Addresses-Coverity: ("Improper use of negative value") Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/iommu/omap-iommu-debug.c b/drivers/iommu/omap-iommu-debug.c index 9bc20e2119a35..82bf208295f4b 100644 --- a/drivers/iommu/omap-iommu-debug.c +++ b/drivers/iommu/omap-iommu-debug.c @@ -101,8 +101,11 @@ static ssize_t debug_read_regs(struct file *file, char __user *userbuf, mutex_lock(&iommu_debug_lock); bytes = omap_iommu_dump_ctx(obj, p, count); + if (bytes < 0) + goto err; bytes = simple_read_from_buffer(userbuf, count, ppos, buf, bytes); +err: mutex_unlock(&iommu_debug_lock); kfree(buf);