From: Colin Ian King colin.king@canonical.com
[ 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@canonical.com Link: https://lore.kernel.org/r/20200714192211.744776-1-colin.king@canonical.com Addresses-Coverity: ("Improper use of negative value") Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iommu/omap-iommu-debug.c | 3 +++ 1 file changed, 3 insertions(+)
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);