diff options
Diffstat (limited to 'fs/notify')
| -rw-r--r-- | fs/notify/fanotify/fanotify.c | 5 | ||||
| -rw-r--r-- | fs/notify/fanotify/fanotify_user.c | 22 | ||||
| -rw-r--r-- | fs/notify/fsnotify.c | 41 | ||||
| -rw-r--r-- | fs/notify/inotify/inotify_fsnotify.c | 8 |
4 files changed, 32 insertions, 44 deletions
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index b428c295d13f..5778d1347b35 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -288,10 +288,13 @@ struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group, /* * For queues with unlimited length lost events are not expected and * can possibly have security implications. Avoid losing events when - * memory is short. + * memory is short. For the limited size queues, avoid OOM killer in the + * target monitoring memcg as it may have security repercussion. */ if (group->max_events == UINT_MAX) gfp |= __GFP_NOFAIL; + else + gfp |= __GFP_RETRY_MAYFAIL; /* Whoever is interested in the event, pays for the allocation. */ memalloc_use_memcg(group->memcg); diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index a90bb19dcfa2..91006f47e420 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -920,6 +920,22 @@ static int fanotify_test_fid(struct path *path, __kernel_fsid_t *fsid) return 0; } +static int fanotify_events_supported(struct path *path, __u64 mask) +{ + /* + * Some filesystems such as 'proc' acquire unusual locks when opening + * files. For them fanotify permission events have high chances of + * deadlocking the system - open done when reporting fanotify event + * blocks on this "unusual" lock while another process holding the lock + * waits for fanotify permission event to be answered. Just disallow + * permission events for such filesystems. + */ + if (mask & FANOTIFY_PERM_EVENTS && + path->mnt->mnt_sb->s_type->fs_flags & FS_DISALLOW_NOTIFY_PERM) + return -EINVAL; + return 0; +} + static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask, int dfd, const char __user *pathname) { @@ -1018,6 +1034,12 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask, if (ret) goto fput_and_out; + if (flags & FAN_MARK_ADD) { + ret = fanotify_events_supported(&path, mask); + if (ret) + goto path_put_and_out; + } + if (FAN_GROUP_FLAG(group, FAN_REPORT_FID)) { ret = fanotify_test_fid(&path, &__fsid); if (ret) diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index 4eb2ebfac468..2ecef6155fc0 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -95,47 +95,6 @@ void fsnotify_sb_delete(struct super_block *sb) } /* - * fsnotify_nameremove - a filename was removed from a directory - * - * This is mostly called under parent vfs inode lock so name and - * dentry->d_parent should be stable. However there are some corner cases where - * inode lock is not held. So to be on the safe side and be reselient to future - * callers and out of tree users of d_delete(), we do not assume that d_parent - * and d_name are stable and we use dget_parent() and - * take_dentry_name_snapshot() to grab stable references. - */ -void fsnotify_nameremove(struct dentry *dentry, int isdir) -{ - struct dentry *parent; - struct name_snapshot name; - __u32 mask = FS_DELETE; - - /* d_delete() of pseudo inode? (e.g. __ns_get_path() playing tricks) */ - if (IS_ROOT(dentry)) - return; - - if (isdir) - mask |= FS_ISDIR; - - parent = dget_parent(dentry); - /* Avoid unneeded take_dentry_name_snapshot() */ - if (!(d_inode(parent)->i_fsnotify_mask & FS_DELETE) && - !(dentry->d_sb->s_fsnotify_mask & FS_DELETE)) - goto out_dput; - - take_dentry_name_snapshot(&name, dentry); - - fsnotify(d_inode(parent), mask, d_inode(dentry), FSNOTIFY_EVENT_INODE, - &name.name, 0); - - release_dentry_name_snapshot(&name); - -out_dput: - dput(parent); -} -EXPORT_SYMBOL(fsnotify_nameremove); - -/* * Given an inode, first check if we care what happens to our children. Inotify * and dnotify both tell their parents about events. If we care about any event * on a child we run all of our children and set a dentry flag saying that the diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c index 2fda08b2b885..d510223d302c 100644 --- a/fs/notify/inotify/inotify_fsnotify.c +++ b/fs/notify/inotify/inotify_fsnotify.c @@ -90,9 +90,13 @@ int inotify_handle_event(struct fsnotify_group *group, i_mark = container_of(inode_mark, struct inotify_inode_mark, fsn_mark); - /* Whoever is interested in the event, pays for the allocation. */ + /* + * Whoever is interested in the event, pays for the allocation. Do not + * trigger OOM killer in the target monitoring memcg as it may have + * security repercussion. + */ memalloc_use_memcg(group->memcg); - event = kmalloc(alloc_len, GFP_KERNEL_ACCOUNT); + event = kmalloc(alloc_len, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL); memalloc_unuse_memcg(); if (unlikely(!event)) { |
