diff options
Diffstat (limited to 'fs/notify/fanotify')
| -rw-r--r-- | fs/notify/fanotify/fanotify.c | 58 | ||||
| -rw-r--r-- | fs/notify/fanotify/fanotify.h | 9 | ||||
| -rw-r--r-- | fs/notify/fanotify/fanotify_user.c | 60 |
3 files changed, 67 insertions, 60 deletions
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 2fa99aeaa095..6702a6a0bbb5 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include <linux/fanotify.h> #include <linux/fdtable.h> #include <linux/fsnotify_backend.h> @@ -9,6 +10,7 @@ #include <linux/sched/user.h> #include <linux/types.h> #include <linux/wait.h> +#include <linux/audit.h> #include "fanotify.h" @@ -35,15 +37,13 @@ static int fanotify_merge(struct list_head *list, struct fsnotify_event *event) pr_debug("%s: list=%p event=%p\n", __func__, list, event); -#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS /* * Don't merge a permission event with any other event so that we know * the event structure we have created in fanotify_handle_event() is the * one we should check for permission response. */ - if (event->mask & FAN_ALL_PERM_EVENTS) + if (fanotify_is_perm_event(event->mask)) return 0; -#endif list_for_each_entry_reverse(test_event, list, list) { if (should_merge(test_event, event)) { @@ -55,7 +55,6 @@ static int fanotify_merge(struct list_head *list, struct fsnotify_event *event) return 0; } -#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS static int fanotify_get_response(struct fsnotify_group *group, struct fanotify_perm_event_info *event, struct fsnotify_iter_info *iter_info) @@ -64,21 +63,10 @@ static int fanotify_get_response(struct fsnotify_group *group, pr_debug("%s: group=%p event=%p\n", __func__, group, event); - /* - * fsnotify_prepare_user_wait() fails if we race with mark deletion. - * Just let the operation pass in that case. - */ - if (!fsnotify_prepare_user_wait(iter_info)) { - event->response = FAN_ALLOW; - goto out; - } - wait_event(group->fanotify_data.access_waitq, event->response); - fsnotify_finish_user_wait(iter_info); -out: /* userspace responded, convert to something usable */ - switch (event->response) { + switch (event->response & ~FAN_AUDIT) { case FAN_ALLOW: ret = 0; break; @@ -86,6 +74,11 @@ out: default: ret = -EPERM; } + + /* Check if the response should be audited */ + if (event->response & FAN_AUDIT) + audit_fanotify(event->response & ~FAN_AUDIT); + event->response = 0; pr_debug("%s: group=%p event=%p about to return ret=%d\n", __func__, @@ -93,7 +86,6 @@ out: return ret; } -#endif static bool fanotify_should_send_event(struct fsnotify_mark *inode_mark, struct fsnotify_mark *vfsmnt_mark, @@ -152,8 +144,7 @@ struct fanotify_event_info *fanotify_alloc_event(struct inode *inode, u32 mask, { struct fanotify_event_info *event; -#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS - if (mask & FAN_ALL_PERM_EVENTS) { + if (fanotify_is_perm_event(mask)) { struct fanotify_perm_event_info *pevent; pevent = kmem_cache_alloc(fanotify_perm_event_cachep, @@ -164,7 +155,6 @@ struct fanotify_event_info *fanotify_alloc_event(struct inode *inode, u32 mask, pevent->response = 0; goto init; } -#endif event = kmem_cache_alloc(fanotify_event_cachep, GFP_KERNEL); if (!event) return NULL; @@ -211,9 +201,19 @@ static int fanotify_handle_event(struct fsnotify_group *group, pr_debug("%s: group=%p inode=%p mask=%x\n", __func__, group, inode, mask); + if (fanotify_is_perm_event(mask)) { + /* + * fsnotify_prepare_user_wait() fails if we race with mark + * deletion. Just let the operation pass in that case. + */ + if (!fsnotify_prepare_user_wait(iter_info)) + return 0; + } + event = fanotify_alloc_event(inode, mask, data); + ret = -ENOMEM; if (unlikely(!event)) - return -ENOMEM; + goto finish; fsn_event = &event->fse; ret = fsnotify_add_event(group, fsn_event, fanotify_merge); @@ -223,16 +223,16 @@ static int fanotify_handle_event(struct fsnotify_group *group, /* Our event wasn't used in the end. Free it. */ fsnotify_destroy_event(group, fsn_event); - return 0; - } - -#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS - if (mask & FAN_ALL_PERM_EVENTS) { + ret = 0; + } else if (fanotify_is_perm_event(mask)) { ret = fanotify_get_response(group, FANOTIFY_PE(fsn_event), iter_info); fsnotify_destroy_event(group, fsn_event); } -#endif +finish: + if (fanotify_is_perm_event(mask)) + fsnotify_finish_user_wait(iter_info); + return ret; } @@ -252,13 +252,11 @@ static void fanotify_free_event(struct fsnotify_event *fsn_event) event = FANOTIFY_E(fsn_event); path_put(&event->path); put_pid(event->tgid); -#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS - if (fsn_event->mask & FAN_ALL_PERM_EVENTS) { + if (fanotify_is_perm_event(fsn_event->mask)) { kmem_cache_free(fanotify_perm_event_cachep, FANOTIFY_PE(fsn_event)); return; } -#endif kmem_cache_free(fanotify_event_cachep, event); } diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h index 4eb6f5efa282..256d9d1ddea9 100644 --- a/fs/notify/fanotify/fanotify.h +++ b/fs/notify/fanotify/fanotify.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #include <linux/fsnotify_backend.h> #include <linux/path.h> #include <linux/slab.h> @@ -21,7 +22,6 @@ struct fanotify_event_info { struct pid *tgid; }; -#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS /* * Structure for permission fanotify events. It gets allocated and freed in * fanotify_handle_event() since we wait there for user response. When the @@ -40,7 +40,12 @@ FANOTIFY_PE(struct fsnotify_event *fse) { return container_of(fse, struct fanotify_perm_event_info, fae.fse); } -#endif + +static inline bool fanotify_is_perm_event(u32 mask) +{ + return IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS) && + mask & FAN_ALL_PERM_EVENTS; +} static inline struct fanotify_event_info *FANOTIFY_E(struct fsnotify_event *fse) { diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 907a481ac781..d0d4bc4c4b70 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include <linux/fanotify.h> #include <linux/fcntl.h> #include <linux/file.h> @@ -142,7 +143,6 @@ static int fill_event_metadata(struct fsnotify_group *group, return ret; } -#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS static struct fanotify_perm_event_info *dequeue_event( struct fsnotify_group *group, int fd) { @@ -179,7 +179,7 @@ static int process_access_response(struct fsnotify_group *group, * userspace can send a valid response or we will clean it up after the * timeout */ - switch (response) { + switch (response & ~FAN_AUDIT) { case FAN_ALLOW: case FAN_DENY: break; @@ -190,6 +190,9 @@ static int process_access_response(struct fsnotify_group *group, if (fd < 0) return -EINVAL; + if ((response & FAN_AUDIT) && !group->fanotify_data.audit) + return -EINVAL; + event = dequeue_event(group, fd); if (!event) return -ENOENT; @@ -199,7 +202,6 @@ static int process_access_response(struct fsnotify_group *group, return 0; } -#endif static ssize_t copy_event_to_user(struct fsnotify_group *group, struct fsnotify_event *event, @@ -221,10 +223,8 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, fanotify_event_metadata.event_len)) goto out_close_fd; -#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS - if (event->mask & FAN_ALL_PERM_EVENTS) + if (fanotify_is_perm_event(event->mask)) FANOTIFY_PE(event)->fd = fd; -#endif if (fd != FAN_NOFD) fd_install(fd, f); @@ -309,10 +309,9 @@ static ssize_t fanotify_read(struct file *file, char __user *buf, * Permission events get queued to wait for response. Other * events can be destroyed now. */ - if (!(kevent->mask & FAN_ALL_PERM_EVENTS)) { + if (!fanotify_is_perm_event(kevent->mask)) { fsnotify_destroy_event(group, kevent); } else { -#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS if (ret <= 0) { FANOTIFY_PE(kevent)->response = FAN_DENY; wake_up(&group->fanotify_data.access_waitq); @@ -322,7 +321,6 @@ static ssize_t fanotify_read(struct file *file, char __user *buf, &group->fanotify_data.access_list); spin_unlock(&group->notification_lock); } -#endif } if (ret < 0) break; @@ -338,11 +336,13 @@ static ssize_t fanotify_read(struct file *file, char __user *buf, static ssize_t fanotify_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) { -#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS struct fanotify_response response = { .fd = -1, .response = -1 }; struct fsnotify_group *group; int ret; + if (!IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS)) + return -EINVAL; + group = file->private_data; if (count > sizeof(response)) @@ -358,16 +358,11 @@ static ssize_t fanotify_write(struct file *file, const char __user *buf, size_t count = ret; return count; -#else - return -EINVAL; -#endif } static int fanotify_release(struct inode *ignored, struct file *file) { struct fsnotify_group *group = file->private_data; - -#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS struct fanotify_perm_event_info *event, *next; struct fsnotify_event *fsn_event; @@ -403,14 +398,14 @@ static int fanotify_release(struct inode *ignored, struct file *file) spin_unlock(&group->notification_lock); fsnotify_destroy_event(group, fsn_event); spin_lock(&group->notification_lock); - } else + } else { FANOTIFY_PE(fsn_event)->response = FAN_ALLOW; + } } spin_unlock(&group->notification_lock); /* Response for all permission events it set, wakeup waiters */ wake_up(&group->fanotify_data.access_waitq); -#endif /* matches the fanotify_init->fsnotify_alloc_group */ fsnotify_destroy_group(group); @@ -721,7 +716,11 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) if (!capable(CAP_SYS_ADMIN)) return -EPERM; +#ifdef CONFIG_AUDITSYSCALL + if (flags & ~(FAN_ALL_INIT_FLAGS | FAN_ENABLE_AUDIT)) +#else if (flags & ~FAN_ALL_INIT_FLAGS) +#endif return -EINVAL; if (event_f_flags & ~FANOTIFY_INIT_ALL_EVENT_F_BITS) @@ -768,10 +767,8 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) if (force_o_largefile()) event_f_flags |= O_LARGEFILE; group->fanotify_data.f_flags = event_f_flags; -#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS init_waitqueue_head(&group->fanotify_data.access_waitq); INIT_LIST_HEAD(&group->fanotify_data.access_list); -#endif switch (flags & FAN_ALL_CLASS_BITS) { case FAN_CLASS_NOTIF: group->priority = FS_PRIO_0; @@ -805,6 +802,13 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) group->fanotify_data.max_marks = FANOTIFY_DEFAULT_MAX_MARKS; } + if (flags & FAN_ENABLE_AUDIT) { + fd = -EPERM; + if (!capable(CAP_AUDIT_WRITE)) + goto out_destroy_group; + group->fanotify_data.audit = true; + } + fd = anon_inode_getfd("[fanotify]", &fanotify_fops, group, f_flags); if (fd < 0) goto out_destroy_group; @@ -825,6 +829,7 @@ SYSCALL_DEFINE5(fanotify_mark, int, fanotify_fd, unsigned int, flags, struct fsnotify_group *group; struct fd f; struct path path; + u32 valid_mask = FAN_ALL_EVENTS | FAN_EVENT_ON_CHILD; int ret; pr_debug("%s: fanotify_fd=%d flags=%x dfd=%d pathname=%p mask=%llx\n", @@ -855,11 +860,10 @@ SYSCALL_DEFINE5(fanotify_mark, int, fanotify_fd, unsigned int, flags, mask &= ~FAN_ONDIR; } -#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS - if (mask & ~(FAN_ALL_EVENTS | FAN_ALL_PERM_EVENTS | FAN_EVENT_ON_CHILD)) -#else - if (mask & ~(FAN_ALL_EVENTS | FAN_EVENT_ON_CHILD)) -#endif + if (IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS)) + valid_mask |= FAN_ALL_PERM_EVENTS; + + if (mask & ~valid_mask) return -EINVAL; f = fdget(fanotify_fd); @@ -949,10 +953,10 @@ static int __init fanotify_user_setup(void) { fanotify_mark_cache = KMEM_CACHE(fsnotify_mark, SLAB_PANIC); fanotify_event_cachep = KMEM_CACHE(fanotify_event_info, SLAB_PANIC); -#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS - fanotify_perm_event_cachep = KMEM_CACHE(fanotify_perm_event_info, - SLAB_PANIC); -#endif + if (IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS)) { + fanotify_perm_event_cachep = + KMEM_CACHE(fanotify_perm_event_info, SLAB_PANIC); + } return 0; } |
