path: root/fs/notify/fanotify/fanotify_user.c
diff options
authorEric Paris <eparis@redhat.com>2010-10-28 17:21:58 -0400
committerEric Paris <eparis@redhat.com>2010-10-28 17:22:15 -0400
commitac7e22dcfafd04c842a02057afd6541c1d613ef9 (patch)
tree54e84b0596d9915f29e56e6b6a8d8370771202c5 /fs/notify/fanotify/fanotify_user.c
parente7099d8a5a34d2876908a9fab4952dabdcfc5909 (diff)
fanotify: allow userspace to override max marks
Some fanotify groups, especially those like AV scanners, will need to place lots of marks, particularly ignore marks. Since ignore marks do not pin inodes in cache and are cleared if the inode is removed from core (usually under memory pressure) we expose an interface for listeners, with CAP_SYS_ADMIN, to override the maximum number of marks and be allowed to set and 'unlimited' number of marks. Programs which make use of this feature will be able to OOM a machine. Signed-off-by: Eric Paris <eparis@redhat.com>
Diffstat (limited to 'fs/notify/fanotify/fanotify_user.c')
1 files changed, 8 insertions, 1 deletions
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 1d33d7db277..f9216102b42 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -707,7 +707,14 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
group->max_events = FANOTIFY_DEFAULT_MAX_EVENTS;
- group->fanotify_data.max_marks = FANOTIFY_DEFAULT_MAX_MARKS;
+ if (flags & FAN_UNLIMITED_MARKS) {
+ fd = -EPERM;
+ if (!capable(CAP_SYS_ADMIN))
+ goto out_put_group;
+ group->fanotify_data.max_marks = UINT_MAX;
+ } else {
+ group->fanotify_data.max_marks = FANOTIFY_DEFAULT_MAX_MARKS;
+ }
fd = anon_inode_getfd("[fanotify]", &fanotify_fops, group, f_flags);
if (fd < 0)