Add patch from Will Woods to fix fanotify EOVERFLOW issue (rhbz 696821)

1 files changed, 39 insertions, 0 deletions

diff --git a/fanotify-fix-EOVERFLOW-on-64-bit.patch b/fanotify-fix-EOVERFLOW-on-64-bit.patch
new file mode 100644
index 000000000..cd6260c2c
--- /dev/null
+++ b/fanotify-fix-EOVERFLOW-on-64-bit.patch
@@ -0,0 +1,39 @@
+Bugzilla: 696821
+Upstream-status: Sent http://marc.info/?l=linux-kernel&m=139835974112096&w=2
+
+On 64-bit systems, O_LARGEFILE is automatically added to flags inside
+the open() syscall (also openat(), blkdev_open(), etc).
+Userspace therefore defines O_LARGEFILE to be 0 - you can use it,
+but it's a no-op. Everything should be O_LARGEFILE by default.
+
+But: when fanotify does create_fd() it uses dentry_open(), which skips
+all that. And userspace can't set O_LARGEFILE in fanotify_init() because
+it's defined to 0. So if fanotify gets an event regarding a large file,
+the read() will just fail with -EOVERFLOW.
+
+This patch adds O_LARGEFILE to fanotify_init()'s event_f_flags on 64-bit
+systems, using the same test as open()/openat()/etc.
+
+Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=696821
+
+Acked-by: Eric Paris <eparis@redhat.com>
+Signed-off-by: Will Woods <wwoods@redhat.com>
+---
+ fs/notify/fanotify/fanotify_user.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
+index 4e565c8..732648b 100644
+--- a/fs/notify/fanotify/fanotify_user.c
++++ b/fs/notify/fanotify/fanotify_user.c
+@@ -698,6 +698,8 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
+ 	}
+ 	group->overflow_event = &oevent->fse;
+ 
++	if (force_o_largefile())
++		event_f_flags |= O_LARGEFILE;
+ 	group->fanotify_data.f_flags = event_f_flags;
+ #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+ 	spin_lock_init(&group->fanotify_data.access_lock);
+-- 
+1.9.0