From: Audra Mitchell <audra@redhat.com>
To: viro@zeniv.linux.org.uk
Cc: brauner@kernel.org, jack@suse.cz, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
shuah@kernel.org, linux-kselftest@vger.kernel.org,
linux-mm@kvack.org, raquini@redhat.com
Subject: [PATCH 1/2] Fix userfaultfd_api to return EINVAL as expected
Date: Tue, 7 May 2024 15:55:09 -0400 [thread overview]
Message-ID: <20240507195510.283744-1-audra@redhat.com> (raw)
Currently if we request a feature that is not set in the Kernel
config we fail silently and return the available features. However, the
documentation indicates we should return an EINVAL.
We need to fix this issue since we can end up with a Kernel warning
should a program request the feature UFFD_FEATURE_WP_UNPOPULATED on
a kernel with the config not set with this feature.
Signed-off-by: Audra Mitchell <audra@redhat.com>
---
fs/userfaultfd.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 60dcfafdc11a..17210558de79 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -2073,6 +2073,11 @@ static int userfaultfd_api(struct userfaultfd_ctx *ctx,
uffdio_api.features &= ~UFFD_FEATURE_WP_UNPOPULATED;
uffdio_api.features &= ~UFFD_FEATURE_WP_ASYNC;
#endif
+
+ ret = -EINVAL;
+ if (features & ~uffdio_api.features)
+ goto err_out;
+
uffdio_api.ioctls = UFFD_API_IOCTLS;
ret = -EFAULT;
if (copy_to_user(buf, &uffdio_api, sizeof(uffdio_api)))
--
2.44.0
next reply other threads:[~2024-05-07 20:05 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-07 19:55 Audra Mitchell [this message]
2024-05-07 19:55 ` [PATCH 2/2] Update uffd-stress to handle EINVAL for unset config features Audra Mitchell
2024-05-08 7:39 ` [PATCH 1/2] Fix userfaultfd_api to return EINVAL as expected David Hildenbrand
2024-05-08 12:58 ` Audra Mitchell
2024-05-08 14:11 ` Peter Xu
2024-05-30 15:59 ` Audra Mitchell
2024-05-08 16:43 ` David Hildenbrand
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