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path: root/fs/notify/fanotify/fanotify_user.c
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Diffstat (limited to 'fs/notify/fanotify/fanotify_user.c')
-rw-r--r--fs/notify/fanotify/fanotify_user.c840
1 files changed, 556 insertions, 284 deletions
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index f69c451018e3..d0b9b984002f 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -1,7 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/fanotify.h>
#include <linux/fcntl.h>
-#include <linux/fdtable.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/anon_inodes.h>
@@ -23,7 +22,7 @@
#include <asm/ioctls.h>
-#include "../../mount.h"
+#include "../fsnotify.h"
#include "../fdinfo.h"
#include "fanotify.h"
@@ -51,6 +50,7 @@
/* configurable via /proc/sys/fs/fanotify/ */
static int fanotify_max_queued_events __read_mostly;
+static int perm_group_timeout __read_mostly;
#ifdef CONFIG_SYSCTL
@@ -59,7 +59,7 @@ static int fanotify_max_queued_events __read_mostly;
static long ft_zero = 0;
static long ft_int_max = INT_MAX;
-static struct ctl_table fanotify_table[] = {
+static const struct ctl_table fanotify_table[] = {
{
.procname = "max_user_groups",
.data = &init_user_ns.ucount_max[UCOUNT_FANOTIFY_GROUPS],
@@ -86,7 +86,14 @@ static struct ctl_table fanotify_table[] = {
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO
},
- { }
+ {
+ .procname = "watchdog_timeout",
+ .data = &perm_group_timeout,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ },
};
static void __init fanotify_sysctls_init(void)
@@ -97,13 +104,97 @@ static void __init fanotify_sysctls_init(void)
#define fanotify_sysctls_init() do { } while (0)
#endif /* CONFIG_SYSCTL */
+static LIST_HEAD(perm_group_list);
+static DEFINE_SPINLOCK(perm_group_lock);
+static void perm_group_watchdog(struct work_struct *work);
+static DECLARE_DELAYED_WORK(perm_group_work, perm_group_watchdog);
+
+static void perm_group_watchdog_schedule(void)
+{
+ schedule_delayed_work(&perm_group_work, secs_to_jiffies(perm_group_timeout));
+}
+
+static void perm_group_watchdog(struct work_struct *work)
+{
+ struct fsnotify_group *group;
+ struct fanotify_perm_event *event;
+ struct task_struct *task;
+ pid_t failed_pid = 0;
+
+ guard(spinlock)(&perm_group_lock);
+ if (list_empty(&perm_group_list))
+ return;
+
+ list_for_each_entry(group, &perm_group_list,
+ fanotify_data.perm_grp_list) {
+ /*
+ * Ok to test without lock, racing with an addition is
+ * fine, will deal with it next round
+ */
+ if (list_empty(&group->fanotify_data.access_list))
+ continue;
+
+ spin_lock(&group->notification_lock);
+ list_for_each_entry(event, &group->fanotify_data.access_list,
+ fae.fse.list) {
+ if (likely(event->watchdog_cnt == 0)) {
+ event->watchdog_cnt = 1;
+ } else if (event->watchdog_cnt == 1) {
+ /* Report on event only once */
+ event->watchdog_cnt = 2;
+
+ /* Do not report same pid repeatedly */
+ if (event->recv_pid == failed_pid)
+ continue;
+
+ failed_pid = event->recv_pid;
+ rcu_read_lock();
+ task = find_task_by_pid_ns(event->recv_pid,
+ &init_pid_ns);
+ pr_warn_ratelimited(
+ "PID %u (%s) failed to respond to fanotify queue for more than %d seconds\n",
+ event->recv_pid,
+ task ? task->comm : NULL,
+ perm_group_timeout);
+ rcu_read_unlock();
+ }
+ }
+ spin_unlock(&group->notification_lock);
+ }
+ perm_group_watchdog_schedule();
+}
+
+static void fanotify_perm_watchdog_group_remove(struct fsnotify_group *group)
+{
+ if (!list_empty(&group->fanotify_data.perm_grp_list)) {
+ /* Perm event watchdog can no longer scan this group. */
+ spin_lock(&perm_group_lock);
+ list_del_init(&group->fanotify_data.perm_grp_list);
+ spin_unlock(&perm_group_lock);
+ }
+}
+
+static void fanotify_perm_watchdog_group_add(struct fsnotify_group *group)
+{
+ if (!perm_group_timeout)
+ return;
+
+ spin_lock(&perm_group_lock);
+ if (list_empty(&group->fanotify_data.perm_grp_list)) {
+ /* Add to perm_group_list for monitoring by watchdog. */
+ if (list_empty(&perm_group_list))
+ perm_group_watchdog_schedule();
+ list_add_tail(&group->fanotify_data.perm_grp_list, &perm_group_list);
+ }
+ spin_unlock(&perm_group_lock);
+}
+
/*
* All flags that may be specified in parameter event_f_flags of fanotify_init.
*
* Internal and external open flags are stored together in field f_flags of
* struct file. Only external open flags shall be allowed in event_f_flags.
- * Internal flags like FMODE_NONOTIFY, FMODE_EXEC, FMODE_NOCMTIME shall be
- * excluded.
+ * Internal flags like FMODE_EXEC shall be excluded.
*/
#define FANOTIFY_INIT_ALL_EVENT_F_BITS ( \
O_ACCMODE | O_APPEND | O_NONBLOCK | \
@@ -112,18 +203,23 @@ static void __init fanotify_sysctls_init(void)
extern const struct fsnotify_ops fanotify_fsnotify_ops;
-struct kmem_cache *fanotify_mark_cache __read_mostly;
-struct kmem_cache *fanotify_fid_event_cachep __read_mostly;
-struct kmem_cache *fanotify_path_event_cachep __read_mostly;
-struct kmem_cache *fanotify_perm_event_cachep __read_mostly;
+struct kmem_cache *fanotify_mark_cache __ro_after_init;
+struct kmem_cache *fanotify_fid_event_cachep __ro_after_init;
+struct kmem_cache *fanotify_path_event_cachep __ro_after_init;
+struct kmem_cache *fanotify_perm_event_cachep __ro_after_init;
+struct kmem_cache *fanotify_mnt_event_cachep __ro_after_init;
#define FANOTIFY_EVENT_ALIGN 4
#define FANOTIFY_FID_INFO_HDR_LEN \
(sizeof(struct fanotify_event_info_fid) + sizeof(struct file_handle))
-#define FANOTIFY_PIDFD_INFO_HDR_LEN \
+#define FANOTIFY_PIDFD_INFO_LEN \
sizeof(struct fanotify_event_info_pidfd)
#define FANOTIFY_ERROR_INFO_LEN \
(sizeof(struct fanotify_event_info_error))
+#define FANOTIFY_RANGE_INFO_LEN \
+ (sizeof(struct fanotify_event_info_range))
+#define FANOTIFY_MNT_INFO_LEN \
+ (sizeof(struct fanotify_event_info_mnt))
static int fanotify_fid_info_len(int fh_len, int name_len)
{
@@ -161,9 +257,6 @@ static size_t fanotify_event_len(unsigned int info_mode,
int fh_len;
int dot_len = 0;
- if (!info_mode)
- return event_len;
-
if (fanotify_is_error_event(event->mask))
event_len += FANOTIFY_ERROR_INFO_LEN;
@@ -178,13 +271,18 @@ static size_t fanotify_event_len(unsigned int info_mode,
dot_len = 1;
}
- if (info_mode & FAN_REPORT_PIDFD)
- event_len += FANOTIFY_PIDFD_INFO_HDR_LEN;
-
if (fanotify_event_has_object_fh(event)) {
fh_len = fanotify_event_object_fh_len(event);
event_len += fanotify_fid_info_len(fh_len, dot_len);
}
+ if (fanotify_is_mnt_event(event->mask))
+ event_len += FANOTIFY_MNT_INFO_LEN;
+
+ if (info_mode & FAN_REPORT_PIDFD)
+ event_len += FANOTIFY_PIDFD_INFO_LEN;
+
+ if (fanotify_event_has_access_range(event))
+ event_len += FANOTIFY_RANGE_INFO_LEN;
return event_len;
}
@@ -260,20 +358,12 @@ static int create_fd(struct fsnotify_group *group, const struct path *path,
return client_fd;
/*
- * we need a new file handle for the userspace program so it can read even if it was
- * originally opened O_WRONLY.
+ * We provide an fd for the userspace program, so it could access the
+ * file without generating fanotify events itself.
*/
- new_file = dentry_open(path,
- group->fanotify_data.f_flags | __FMODE_NONOTIFY,
- current_cred());
+ new_file = dentry_open_nonotify(path, group->fanotify_data.f_flags,
+ current_cred());
if (IS_ERR(new_file)) {
- /*
- * we still send an event even if we can't open the file. this
- * can happen when say tasks are gone and we try to open their
- * /proc files or we try to open a WRONLY file like in sysfs
- * we just send the errno to userspace since there isn't much
- * else we can do.
- */
put_unused_fd(client_fd);
client_fd = PTR_ERR(new_file);
} else {
@@ -336,11 +426,12 @@ static int process_access_response(struct fsnotify_group *group,
struct fanotify_perm_event *event;
int fd = response_struct->fd;
u32 response = response_struct->response;
+ int errno = fanotify_get_response_errno(response);
int ret = info_len;
struct fanotify_response_info_audit_rule friar;
- pr_debug("%s: group=%p fd=%d response=%u buf=%p size=%zu\n", __func__,
- group, fd, response, info, info_len);
+ pr_debug("%s: group=%p fd=%d response=%x errno=%d buf=%p size=%zu\n",
+ __func__, group, fd, response, errno, info, info_len);
/*
* make sure the response is valid, if invalid we do nothing and either
* userspace can send a valid response or we will clean it up after the
@@ -351,7 +442,31 @@ static int process_access_response(struct fsnotify_group *group,
switch (response & FANOTIFY_RESPONSE_ACCESS) {
case FAN_ALLOW:
+ if (errno)
+ return -EINVAL;
+ break;
case FAN_DENY:
+ /* Custom errno is supported only for pre-content groups */
+ if (errno && group->priority != FSNOTIFY_PRIO_PRE_CONTENT)
+ return -EINVAL;
+
+ /*
+ * Limit errno to values expected on open(2)/read(2)/write(2)
+ * of regular files.
+ */
+ switch (errno) {
+ case 0:
+ case EIO:
+ case EPERM:
+ case EBUSY:
+ case ETXTBSY:
+ case EAGAIN:
+ case ENOSPC:
+ case EDQUOT:
+ break;
+ default:
+ return -EINVAL;
+ }
break;
default:
return -EINVAL;
@@ -389,6 +504,25 @@ static int process_access_response(struct fsnotify_group *group,
return -ENOENT;
}
+static size_t copy_mnt_info_to_user(struct fanotify_event *event,
+ char __user *buf, int count)
+{
+ struct fanotify_event_info_mnt info = { };
+
+ info.hdr.info_type = FAN_EVENT_INFO_TYPE_MNT;
+ info.hdr.len = FANOTIFY_MNT_INFO_LEN;
+
+ if (WARN_ON(count < info.hdr.len))
+ return -EFAULT;
+
+ info.mnt_id = FANOTIFY_ME(event)->mnt_id;
+
+ if (copy_to_user(buf, &info, sizeof(info)))
+ return -EFAULT;
+
+ return info.hdr.len;
+}
+
static size_t copy_error_info_to_user(struct fanotify_event *event,
char __user *buf, int count)
{
@@ -515,7 +649,7 @@ static int copy_pidfd_info_to_user(int pidfd,
size_t count)
{
struct fanotify_event_info_pidfd info = { };
- size_t info_len = FANOTIFY_PIDFD_INFO_HDR_LEN;
+ size_t info_len = FANOTIFY_PIDFD_INFO_LEN;
if (WARN_ON_ONCE(info_len > count))
return -EFAULT;
@@ -530,6 +664,30 @@ static int copy_pidfd_info_to_user(int pidfd,
return info_len;
}
+static size_t copy_range_info_to_user(struct fanotify_event *event,
+ char __user *buf, int count)
+{
+ struct fanotify_perm_event *pevent = FANOTIFY_PERM(event);
+ struct fanotify_event_info_range info = { };
+ size_t info_len = FANOTIFY_RANGE_INFO_LEN;
+
+ if (WARN_ON_ONCE(info_len > count))
+ return -EFAULT;
+
+ if (WARN_ON_ONCE(!pevent->ppos))
+ return -EINVAL;
+
+ info.hdr.info_type = FAN_EVENT_INFO_TYPE_RANGE;
+ info.hdr.len = info_len;
+ info.offset = *(pevent->ppos);
+ info.count = pevent->count;
+
+ if (copy_to_user(buf, &info, info_len))
+ return -EFAULT;
+
+ return info_len;
+}
+
static int copy_info_records_to_user(struct fanotify_event *event,
struct fanotify_info *info,
unsigned int info_mode, int pidfd,
@@ -651,6 +809,24 @@ static int copy_info_records_to_user(struct fanotify_event *event,
total_bytes += ret;
}
+ if (fanotify_event_has_access_range(event)) {
+ ret = copy_range_info_to_user(event, buf, count);
+ if (ret < 0)
+ return ret;
+ buf += ret;
+ count -= ret;
+ total_bytes += ret;
+ }
+
+ if (fanotify_is_mnt_event(event->mask)) {
+ ret = copy_mnt_info_to_user(event, buf, count);
+ if (ret < 0)
+ return ret;
+ buf += ret;
+ count -= ret;
+ total_bytes += ret;
+ }
+
return total_bytes;
}
@@ -664,7 +840,7 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
unsigned int info_mode = FAN_GROUP_FLAG(group, FANOTIFY_INFO_MODES);
unsigned int pidfd_mode = info_mode & FAN_REPORT_PIDFD;
struct file *f = NULL, *pidfd_file = NULL;
- int ret, pidfd = FAN_NOPIDFD, fd = FAN_NOFD;
+ int ret, pidfd = -ESRCH, fd = -EBADF;
pr_debug("%s: group=%p event=%p\n", __func__, group, event);
@@ -692,10 +868,39 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
if (!FAN_GROUP_FLAG(group, FANOTIFY_UNPRIV) &&
path && path->mnt && path->dentry) {
fd = create_fd(group, path, &f);
- if (fd < 0)
- return fd;
+ /*
+ * Opening an fd from dentry can fail for several reasons.
+ * For example, when tasks are gone and we try to open their
+ * /proc files or we try to open a WRONLY file like in sysfs
+ * or when trying to open a file that was deleted on the
+ * remote network server.
+ *
+ * For a group with FAN_REPORT_FD_ERROR, we will send the
+ * event with the error instead of the open fd, otherwise
+ * Userspace may not get the error at all.
+ * In any case, userspace will not know which file failed to
+ * open, so add a debug print for further investigation.
+ */
+ if (fd < 0) {
+ pr_debug("fanotify: create_fd(%pd2) failed err=%d\n",
+ path->dentry, fd);
+ if (!FAN_GROUP_FLAG(group, FAN_REPORT_FD_ERROR)) {
+ /*
+ * Historically, we've handled EOPENSTALE in a
+ * special way and silently dropped such
+ * events. Now we have to keep it to maintain
+ * backward compatibility...
+ */
+ if (fd == -EOPENSTALE)
+ fd = 0;
+ return fd;
+ }
+ }
}
- metadata.fd = fd;
+ if (FAN_GROUP_FLAG(group, FAN_REPORT_FD_ERROR))
+ metadata.fd = fd;
+ else
+ metadata.fd = fd >= 0 ? fd : FAN_NOFD;
if (pidfd_mode) {
/*
@@ -710,18 +915,16 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
* The PIDTYPE_TGID check for an event->pid is performed
* preemptively in an attempt to catch out cases where the event
* listener reads events after the event generating process has
- * already terminated. Report FAN_NOPIDFD to the event listener
- * in those cases, with all other pidfd creation errors being
- * reported as FAN_EPIDFD.
+ * already terminated. Depending on flag FAN_REPORT_FD_ERROR,
+ * report either -ESRCH or FAN_NOPIDFD to the event listener in
+ * those cases with all other pidfd creation errors reported as
+ * the error code itself or as FAN_EPIDFD.
*/
- if (metadata.pid == 0 ||
- !pid_has_task(event->pid, PIDTYPE_TGID)) {
- pidfd = FAN_NOPIDFD;
- } else {
+ if (metadata.pid && pid_has_task(event->pid, PIDTYPE_TGID))
pidfd = pidfd_prepare(event->pid, 0, &pidfd_file);
- if (pidfd < 0)
- pidfd = FAN_EPIDFD;
- }
+
+ if (!FAN_GROUP_FLAG(group, FAN_REPORT_FD_ERROR) && pidfd < 0)
+ pidfd = pidfd == -ESRCH ? FAN_NOPIDFD : FAN_EPIDFD;
}
ret = -EFAULT;
@@ -738,15 +941,10 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
buf += FAN_EVENT_METADATA_LEN;
count -= FAN_EVENT_METADATA_LEN;
- if (fanotify_is_perm_event(event->mask))
- FANOTIFY_PERM(event)->fd = fd;
-
- if (info_mode) {
- ret = copy_info_records_to_user(event, info, info_mode, pidfd,
- buf, count);
- if (ret < 0)
- goto out_close_fd;
- }
+ ret = copy_info_records_to_user(event, info, info_mode, pidfd,
+ buf, count);
+ if (ret < 0)
+ goto out_close_fd;
if (f)
fd_install(fd, f);
@@ -754,15 +952,18 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
if (pidfd_file)
fd_install(pidfd, pidfd_file);
+ if (fanotify_is_perm_event(event->mask))
+ FANOTIFY_PERM(event)->fd = fd;
+
return metadata.event_len;
out_close_fd:
- if (fd != FAN_NOFD) {
+ if (f) {
put_unused_fd(fd);
fput(f);
}
- if (pidfd >= 0) {
+ if (pidfd_file) {
put_unused_fd(pidfd);
fput(pidfd_file);
}
@@ -829,15 +1030,6 @@ static ssize_t fanotify_read(struct file *file, char __user *buf,
}
ret = copy_event_to_user(group, event, buf, count);
- if (unlikely(ret == -EOPENSTALE)) {
- /*
- * We cannot report events with stale fd so drop it.
- * Setting ret to 0 will continue the event loop and
- * do the right thing if there are no more events to
- * read (i.e. return bytes read, -EAGAIN or wait).
- */
- ret = 0;
- }
/*
* Permission events get queued to wait for response. Other
@@ -846,7 +1038,7 @@ static ssize_t fanotify_read(struct file *file, char __user *buf,
if (!fanotify_is_perm_event(event->mask)) {
fsnotify_destroy_event(group, &event->fse);
} else {
- if (ret <= 0) {
+ if (ret <= 0 || FANOTIFY_PERM(event)->fd < 0) {
spin_lock(&group->notification_lock);
finish_permission_event(group,
FANOTIFY_PERM(event), FAN_DENY, NULL);
@@ -855,6 +1047,7 @@ static ssize_t fanotify_read(struct file *file, char __user *buf,
spin_lock(&group->notification_lock);
list_add_tail(&event->fse.list,
&group->fanotify_data.access_list);
+ FANOTIFY_PERM(event)->recv_pid = current->pid;
spin_unlock(&group->notification_lock);
}
}
@@ -914,6 +1107,8 @@ static int fanotify_release(struct inode *ignored, struct file *file)
*/
fsnotify_group_stop_queueing(group);
+ fanotify_perm_watchdog_group_remove(group);
+
/*
* Process all permission events on access_list and notification queue
* and simulate reply from userspace.
@@ -1004,22 +1199,17 @@ static int fanotify_find_path(int dfd, const char __user *filename,
dfd, filename, flags);
if (filename == NULL) {
- struct fd f = fdget(dfd);
+ CLASS(fd, f)(dfd);
- ret = -EBADF;
- if (!f.file)
- goto out;
+ if (fd_empty(f))
+ return -EBADF;
- ret = -ENOTDIR;
if ((flags & FAN_MARK_ONLYDIR) &&
- !(S_ISDIR(file_inode(f.file)->i_mode))) {
- fdput(f);
- goto out;
- }
+ !(S_ISDIR(file_inode(fd_file(f))->i_mode)))
+ return -ENOTDIR;
- *path = f.file->f_path;
+ *path = fd_file(f)->f_path;
path_get(path);
- fdput(f);
} else {
unsigned int lookup_flags = 0;
@@ -1077,7 +1267,7 @@ static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark,
}
static int fanotify_remove_mark(struct fsnotify_group *group,
- fsnotify_connp_t *connp, __u32 mask,
+ void *obj, unsigned int obj_type, __u32 mask,
unsigned int flags, __u32 umask)
{
struct fsnotify_mark *fsn_mark = NULL;
@@ -1085,7 +1275,7 @@ static int fanotify_remove_mark(struct fsnotify_group *group,
int destroy_mark;
fsnotify_group_lock(group);
- fsn_mark = fsnotify_find_mark(connp, group);
+ fsn_mark = fsnotify_find_mark(obj, obj_type, group);
if (!fsn_mark) {
fsnotify_group_unlock(group);
return -ENOENT;
@@ -1106,30 +1296,6 @@ static int fanotify_remove_mark(struct fsnotify_group *group,
return 0;
}
-static int fanotify_remove_vfsmount_mark(struct fsnotify_group *group,
- struct vfsmount *mnt, __u32 mask,
- unsigned int flags, __u32 umask)
-{
- return fanotify_remove_mark(group, &real_mount(mnt)->mnt_fsnotify_marks,
- mask, flags, umask);
-}
-
-static int fanotify_remove_sb_mark(struct fsnotify_group *group,
- struct super_block *sb, __u32 mask,
- unsigned int flags, __u32 umask)
-{
- return fanotify_remove_mark(group, &sb->s_fsnotify_marks, mask,
- flags, umask);
-}
-
-static int fanotify_remove_inode_mark(struct fsnotify_group *group,
- struct inode *inode, __u32 mask,
- unsigned int flags, __u32 umask)
-{
- return fanotify_remove_mark(group, &inode->i_fsnotify_marks, mask,
- flags, umask);
-}
-
static bool fanotify_mark_update_flags(struct fsnotify_mark *fsn_mark,
unsigned int fan_flags)
{
@@ -1192,13 +1358,71 @@ static bool fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark,
return recalc;
}
+struct fan_fsid {
+ struct super_block *sb;
+ __kernel_fsid_t id;
+ bool weak;
+};
+
+static int fanotify_set_mark_fsid(struct fsnotify_group *group,
+ struct fsnotify_mark *mark,
+ struct fan_fsid *fsid)
+{
+ struct fsnotify_mark_connector *conn;
+ struct fsnotify_mark *old;
+ struct super_block *old_sb = NULL;
+
+ FANOTIFY_MARK(mark)->fsid = fsid->id;
+ mark->flags |= FSNOTIFY_MARK_FLAG_HAS_FSID;
+ if (fsid->weak)
+ mark->flags |= FSNOTIFY_MARK_FLAG_WEAK_FSID;
+
+ /* First mark added will determine if group is single or multi fsid */
+ if (list_empty(&group->marks_list))
+ return 0;
+
+ /* Find sb of an existing mark */
+ list_for_each_entry(old, &group->marks_list, g_list) {
+ conn = READ_ONCE(old->connector);
+ if (!conn)
+ continue;
+ old_sb = fsnotify_connector_sb(conn);
+ if (old_sb)
+ break;
+ }
+
+ /* Only detached marks left? */
+ if (!old_sb)
+ return 0;
+
+ /* Do not allow mixing of marks with weak and strong fsid */
+ if ((mark->flags ^ old->flags) & FSNOTIFY_MARK_FLAG_WEAK_FSID)
+ return -EXDEV;
+
+ /* Allow mixing of marks with strong fsid from different fs */
+ if (!fsid->weak)
+ return 0;
+
+ /* Do not allow mixing marks with weak fsid from different fs */
+ if (old_sb != fsid->sb)
+ return -EXDEV;
+
+ /* Do not allow mixing marks from different btrfs sub-volumes */
+ if (!fanotify_fsid_equal(&FANOTIFY_MARK(old)->fsid,
+ &FANOTIFY_MARK(mark)->fsid))
+ return -EXDEV;
+
+ return 0;
+}
+
static struct fsnotify_mark *fanotify_add_new_mark(struct fsnotify_group *group,
- fsnotify_connp_t *connp,
+ void *obj,
unsigned int obj_type,
unsigned int fan_flags,
- __kernel_fsid_t *fsid)
+ struct fan_fsid *fsid)
{
struct ucounts *ucounts = group->fanotify_data.ucounts;
+ struct fanotify_mark *fan_mark;
struct fsnotify_mark *mark;
int ret;
@@ -1207,28 +1431,39 @@ static struct fsnotify_mark *fanotify_add_new_mark(struct fsnotify_group *group,
* A group with FAN_UNLIMITED_MARKS does not contribute to mark count
* in the limited groups account.
*/
+ BUILD_BUG_ON(!(FANOTIFY_ADMIN_INIT_FLAGS & FAN_UNLIMITED_MARKS));
if (!FAN_GROUP_FLAG(group, FAN_UNLIMITED_MARKS) &&
!inc_ucount(ucounts->ns, ucounts->uid, UCOUNT_FANOTIFY_MARKS))
return ERR_PTR(-ENOSPC);
- mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
- if (!mark) {
+ fan_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
+ if (!fan_mark) {
ret = -ENOMEM;
goto out_dec_ucounts;
}
+ mark = &fan_mark->fsn_mark;
fsnotify_init_mark(mark, group);
if (fan_flags & FAN_MARK_EVICTABLE)
mark->flags |= FSNOTIFY_MARK_FLAG_NO_IREF;
- ret = fsnotify_add_mark_locked(mark, connp, obj_type, 0, fsid);
- if (ret) {
- fsnotify_put_mark(mark);
- goto out_dec_ucounts;
+ /* Cache fsid of filesystem containing the marked object */
+ if (fsid) {
+ ret = fanotify_set_mark_fsid(group, mark, fsid);
+ if (ret)
+ goto out_put_mark;
+ } else {
+ fan_mark->fsid.val[0] = fan_mark->fsid.val[1] = 0;
}
+ ret = fsnotify_add_mark_locked(mark, obj, obj_type, 0);
+ if (ret)
+ goto out_put_mark;
+
return mark;
+out_put_mark:
+ fsnotify_put_mark(mark);
out_dec_ucounts:
if (!FAN_GROUP_FLAG(group, FAN_UNLIMITED_MARKS))
dec_ucount(ucounts, UCOUNT_FANOTIFY_MARKS);
@@ -1246,7 +1481,7 @@ static int fanotify_group_init_error_pool(struct fsnotify_group *group)
}
static int fanotify_may_update_existing_mark(struct fsnotify_mark *fsn_mark,
- unsigned int fan_flags)
+ __u32 mask, unsigned int fan_flags)
{
/*
* Non evictable mark cannot be downgraded to evictable mark.
@@ -1273,22 +1508,27 @@ static int fanotify_may_update_existing_mark(struct fsnotify_mark *fsn_mark,
fsn_mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY)
return -EEXIST;
+ /* For now pre-content events are not generated for directories */
+ mask |= fsn_mark->mask;
+ if (mask & FANOTIFY_PRE_CONTENT_EVENTS && mask & FAN_ONDIR)
+ return -EEXIST;
+
return 0;
}
static int fanotify_add_mark(struct fsnotify_group *group,
- fsnotify_connp_t *connp, unsigned int obj_type,
+ void *obj, unsigned int obj_type,
__u32 mask, unsigned int fan_flags,
- __kernel_fsid_t *fsid)
+ struct fan_fsid *fsid)
{
struct fsnotify_mark *fsn_mark;
bool recalc;
int ret = 0;
fsnotify_group_lock(group);
- fsn_mark = fsnotify_find_mark(connp, group);
+ fsn_mark = fsnotify_find_mark(obj, obj_type, group);
if (!fsn_mark) {
- fsn_mark = fanotify_add_new_mark(group, connp, obj_type,
+ fsn_mark = fanotify_add_new_mark(group, obj, obj_type,
fan_flags, fsid);
if (IS_ERR(fsn_mark)) {
fsnotify_group_unlock(group);
@@ -1299,7 +1539,7 @@ static int fanotify_add_mark(struct fsnotify_group *group,
/*
* Check if requested mark flags conflict with an existing mark flags.
*/
- ret = fanotify_may_update_existing_mark(fsn_mark, fan_flags);
+ ret = fanotify_may_update_existing_mark(fsn_mark, mask, fan_flags);
if (ret)
goto out;
@@ -1322,43 +1562,11 @@ out:
fsnotify_group_unlock(group);
fsnotify_put_mark(fsn_mark);
- return ret;
-}
-
-static int fanotify_add_vfsmount_mark(struct fsnotify_group *group,
- struct vfsmount *mnt, __u32 mask,
- unsigned int flags, __kernel_fsid_t *fsid)
-{
- return fanotify_add_mark(group, &real_mount(mnt)->mnt_fsnotify_marks,
- FSNOTIFY_OBJ_TYPE_VFSMOUNT, mask, flags, fsid);
-}
-
-static int fanotify_add_sb_mark(struct fsnotify_group *group,
- struct super_block *sb, __u32 mask,
- unsigned int flags, __kernel_fsid_t *fsid)
-{
- return fanotify_add_mark(group, &sb->s_fsnotify_marks,
- FSNOTIFY_OBJ_TYPE_SB, mask, flags, fsid);
-}
-
-static int fanotify_add_inode_mark(struct fsnotify_group *group,
- struct inode *inode, __u32 mask,
- unsigned int flags, __kernel_fsid_t *fsid)
-{
- pr_debug("%s: group=%p inode=%p\n", __func__, group, inode);
- /*
- * If some other task has this inode open for write we should not add
- * an ignore mask, unless that ignore mask is supposed to survive
- * modification changes anyway.
- */
- if ((flags & FANOTIFY_MARK_IGNORE_BITS) &&
- !(flags & FAN_MARK_IGNORED_SURV_MODIFY) &&
- inode_is_open_for_write(inode))
- return 0;
+ if (!ret && (mask & FANOTIFY_PERM_EVENTS))
+ fanotify_perm_watchdog_group_add(group);
- return fanotify_add_mark(group, &inode->i_fsnotify_marks,
- FSNOTIFY_OBJ_TYPE_INODE, mask, flags, fsid);
+ return ret;
}
static struct fsnotify_event *fanotify_alloc_overflow_event(void)
@@ -1389,10 +1597,16 @@ static struct hlist_head *fanotify_alloc_merge_hash(void)
return hash;
}
+DEFINE_CLASS(fsnotify_group,
+ struct fsnotify_group *,
+ if (!IS_ERR_OR_NULL(_T)) fsnotify_destroy_group(_T),
+ fsnotify_alloc_group(ops, flags),
+ const struct fsnotify_ops *ops, int flags)
+
/* fanotify syscalls */
SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
{
- struct fsnotify_group *group;
+ struct user_namespace *user_ns = current_user_ns();
int f_flags, fd;
unsigned int fid_mode = flags & FANOTIFY_FID_BITS;
unsigned int class = flags & FANOTIFY_CLASS_BITS;
@@ -1405,10 +1619,11 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
/*
* An unprivileged user can setup an fanotify group with
* limited functionality - an unprivileged group is limited to
- * notification events with file handles and it cannot use
- * unlimited queue/marks.
+ * notification events with file handles or mount ids and it
+ * cannot use unlimited queue/marks.
*/
- if ((flags & FANOTIFY_ADMIN_INIT_FLAGS) || !fid_mode)
+ if ((flags & FANOTIFY_ADMIN_INIT_FLAGS) ||
+ !(flags & (FANOTIFY_FID_BITS | FAN_REPORT_MNT)))
return -EPERM;
/*
@@ -1434,6 +1649,14 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
if ((flags & FAN_REPORT_PIDFD) && (flags & FAN_REPORT_TID))
return -EINVAL;
+ /* Don't allow mixing mnt events with inode events for now */
+ if (flags & FAN_REPORT_MNT) {
+ if (class != FAN_CLASS_NOTIF)
+ return -EINVAL;
+ if (flags & (FANOTIFY_FID_BITS | FAN_REPORT_FD_ERROR))
+ return -EINVAL;
+ }
+
if (event_f_flags & ~FANOTIFY_INIT_ALL_EVENT_F_BITS)
return -EINVAL;
@@ -1465,109 +1688,95 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
(!(fid_mode & FAN_REPORT_NAME) || !(fid_mode & FAN_REPORT_FID)))
return -EINVAL;
- f_flags = O_RDWR | __FMODE_NONOTIFY;
+ f_flags = O_RDWR;
if (flags & FAN_CLOEXEC)
f_flags |= O_CLOEXEC;
if (flags & FAN_NONBLOCK)
f_flags |= O_NONBLOCK;
+ CLASS(fsnotify_group, group)(&fanotify_fsnotify_ops,
+ FSNOTIFY_GROUP_USER);
/* fsnotify_alloc_group takes a ref. Dropped in fanotify_release */
- group = fsnotify_alloc_group(&fanotify_fsnotify_ops,
- FSNOTIFY_GROUP_USER | FSNOTIFY_GROUP_NOFS);
- if (IS_ERR(group)) {
+ if (IS_ERR(group))
return PTR_ERR(group);
- }
/* Enforce groups limits per user in all containing user ns */
- group->fanotify_data.ucounts = inc_ucount(current_user_ns(),
- current_euid(),
+ group->fanotify_data.ucounts = inc_ucount(user_ns, current_euid(),
UCOUNT_FANOTIFY_GROUPS);
- if (!group->fanotify_data.ucounts) {
- fd = -EMFILE;
- goto out_destroy_group;
- }
+ if (!group->fanotify_data.ucounts)
+ return -EMFILE;
group->fanotify_data.flags = flags | internal_flags;
group->memcg = get_mem_cgroup_from_mm(current->mm);
+ group->user_ns = get_user_ns(user_ns);
group->fanotify_data.merge_hash = fanotify_alloc_merge_hash();
- if (!group->fanotify_data.merge_hash) {
- fd = -ENOMEM;
- goto out_destroy_group;
- }
+ if (!group->fanotify_data.merge_hash)
+ return -ENOMEM;
group->overflow_event = fanotify_alloc_overflow_event();
- if (unlikely(!group->overflow_event)) {
- fd = -ENOMEM;
- goto out_destroy_group;
- }
+ if (unlikely(!group->overflow_event))
+ return -ENOMEM;
if (force_o_largefile())
event_f_flags |= O_LARGEFILE;
group->fanotify_data.f_flags = event_f_flags;
init_waitqueue_head(&group->fanotify_data.access_waitq);
INIT_LIST_HEAD(&group->fanotify_data.access_list);
+ INIT_LIST_HEAD(&group->fanotify_data.perm_grp_list);
switch (class) {
case FAN_CLASS_NOTIF:
- group->priority = FS_PRIO_0;
+ group->priority = FSNOTIFY_PRIO_NORMAL;
break;
case FAN_CLASS_CONTENT:
- group->priority = FS_PRIO_1;
+ group->priority = FSNOTIFY_PRIO_CONTENT;
break;
case FAN_CLASS_PRE_CONTENT:
- group->priority = FS_PRIO_2;
+ group->priority = FSNOTIFY_PRIO_PRE_CONTENT;
break;
default:
- fd = -EINVAL;
- goto out_destroy_group;
+ return -EINVAL;
}
+ BUILD_BUG_ON(!(FANOTIFY_ADMIN_INIT_FLAGS & FAN_UNLIMITED_QUEUE));
if (flags & FAN_UNLIMITED_QUEUE) {
- fd = -EPERM;
- if (!capable(CAP_SYS_ADMIN))
- goto out_destroy_group;
group->max_events = UINT_MAX;
} else {
group->max_events = fanotify_max_queued_events;
}
- if (flags & FAN_UNLIMITED_MARKS) {
- fd = -EPERM;
- if (!capable(CAP_SYS_ADMIN))
- goto out_destroy_group;
- }
-
if (flags & FAN_ENABLE_AUDIT) {
- fd = -EPERM;
if (!capable(CAP_AUDIT_WRITE))
- goto out_destroy_group;
+ return -EPERM;
}
- fd = anon_inode_getfd("[fanotify]", &fanotify_fops, group, f_flags);
- if (fd < 0)
- goto out_destroy_group;
-
- return fd;
-
-out_destroy_group:
- fsnotify_destroy_group(group);
+ fd = FD_ADD(f_flags,
+ anon_inode_getfile_fmode("[fanotify]", &fanotify_fops,
+ group, f_flags, FMODE_NONOTIFY));
+ if (fd >= 0)
+ retain_and_null_ptr(group);
return fd;
}
-static int fanotify_test_fsid(struct dentry *dentry, __kernel_fsid_t *fsid)
+static int fanotify_test_fsid(struct dentry *dentry, unsigned int flags,
+ struct fan_fsid *fsid)
{
+ unsigned int mark_type = flags & FANOTIFY_MARK_TYPE_BITS;
__kernel_fsid_t root_fsid;
int err;
/*
* Make sure dentry is not of a filesystem with zero fsid (e.g. fuse).
*/
- err = vfs_get_fsid(dentry, fsid);
+ err = vfs_get_fsid(dentry, &fsid->id);
if (err)
return err;
- if (!fsid->val[0] && !fsid->val[1])
- return -ENODEV;
+ fsid->sb = dentry->d_sb;
+ if (!fsid->id.val[0] && !fsid->id.val[1]) {
+ err = -ENODEV;
+ goto weak;
+ }
/*
* Make sure dentry is not of a filesystem subvolume (e.g. btrfs)
@@ -1577,24 +1786,40 @@ static int fanotify_test_fsid(struct dentry *dentry, __kernel_fsid_t *fsid)
if (err)
return err;
- if (root_fsid.val[0] != fsid->val[0] ||
- root_fsid.val[1] != fsid->val[1])
- return -EXDEV;
+ if (!fanotify_fsid_equal(&root_fsid, &fsid->id)) {
+ err = -EXDEV;
+ goto weak;
+ }
+ fsid->weak = false;
return 0;
+
+weak:
+ /* Allow weak fsid when marking inodes */
+ fsid->weak = true;
+ return (mark_type == FAN_MARK_INODE) ? 0 : err;
}
/* Check if filesystem can encode a unique fid */
-static int fanotify_test_fid(struct dentry *dentry)
+static int fanotify_test_fid(struct dentry *dentry, unsigned int flags)
{
+ unsigned int mark_type = flags & FANOTIFY_MARK_TYPE_BITS;
+ const struct export_operations *nop = dentry->d_sb->s_export_op;
+
+ /*
+ * We need to make sure that the filesystem supports encoding of
+ * file handles so user can use name_to_handle_at() to compare fids
+ * reported with events to the file handle of watched objects.
+ */
+ if (!exportfs_can_encode_fid(nop))
+ return -EOPNOTSUPP;
+
/*
- * We need to make sure that the file system supports at least
- * encoding a file handle so user can use name_to_handle_at() to
- * compare fid returned with event to the file handle of watched
- * objects. However, even the relaxed AT_HANDLE_FID flag requires
- * at least empty export_operations for ecoding unique file ids.
+ * For sb/mount mark, we also need to make sure that the filesystem
+ * supports decoding file handles, so user has a way to map back the
+ * reported fids to filesystem objects.
*/
- if (!dentry->d_sb->s_export_op)
+ if (mark_type != FAN_MARK_INODE && !exportfs_can_decode_fh(nop))
return -EOPNOTSUPP;
return 0;
@@ -1605,12 +1830,24 @@ static int fanotify_events_supported(struct fsnotify_group *group,
unsigned int flags)
{
unsigned int mark_type = flags & FANOTIFY_MARK_TYPE_BITS;
+ bool is_dir = d_is_dir(path->dentry);
/* Strict validation of events in non-dir inode mask with v5.17+ APIs */
bool strict_dir_events = FAN_GROUP_FLAG(group, FAN_REPORT_TARGET_FID) ||
(mask & FAN_RENAME) ||
(flags & FAN_MARK_IGNORE);
/*
+ * Filesystems need to opt-into pre-content evnets (a.k.a HSM)
+ * and they are only supported on regular files and directories.
+ */
+ if (mask & FANOTIFY_PRE_CONTENT_EVENTS) {
+ if (!(path->mnt->mnt_sb->s_iflags & SB_I_ALLOW_HSM))
+ return -EOPNOTSUPP;
+ if (!is_dir && !d_is_reg(path->dentry))
+ return -EINVAL;
+ }
+
+ /*
* 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
@@ -1642,7 +1879,7 @@ static int fanotify_events_supported(struct fsnotify_group *group,
* but because we always allowed it, error only when using new APIs.
*/
if (strict_dir_events && mark_type == FAN_MARK_INODE &&
- !d_is_dir(path->dentry) && (mask & FANOTIFY_DIRONLY_EVENT_BITS))
+ !is_dir && (mask & FANOTIFY_DIRONLY_EVENT_BITS))
return -ENOTDIR;
return 0;
@@ -1652,16 +1889,17 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
int dfd, const char __user *pathname)
{
struct inode *inode = NULL;
- struct vfsmount *mnt = NULL;
struct fsnotify_group *group;
- struct fd f;
struct path path;
- __kernel_fsid_t __fsid, *fsid = NULL;
+ struct fan_fsid __fsid, *fsid = NULL;
+ struct user_namespace *user_ns = NULL;
+ struct mnt_namespace *mntns;
u32 valid_mask = FANOTIFY_EVENTS | FANOTIFY_EVENT_FLAGS;
unsigned int mark_type = flags & FANOTIFY_MARK_TYPE_BITS;
unsigned int mark_cmd = flags & FANOTIFY_MARK_CMD_BITS;
unsigned int ignore = flags & FANOTIFY_MARK_IGNORE_BITS;
unsigned int obj_type, fid_mode;
+ void *obj = NULL;
u32 umask = 0;
int ret;
@@ -1685,6 +1923,9 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
case FAN_MARK_FILESYSTEM:
obj_type = FSNOTIFY_OBJ_TYPE_SB;
break;
+ case FAN_MARK_MNTNS:
+ obj_type = FSNOTIFY_OBJ_TYPE_MNTNS;
+ break;
default:
return -EINVAL;
}
@@ -1723,39 +1964,50 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
umask = FANOTIFY_EVENT_FLAGS;
}
- f = fdget(fanotify_fd);
- if (unlikely(!f.file))
+ CLASS(fd, f)(fanotify_fd);
+ if (fd_empty(f))
return -EBADF;
/* verify that this is indeed an fanotify instance */
- ret = -EINVAL;
- if (unlikely(f.file->f_op != &fanotify_fops))
- goto fput_and_out;
- group = f.file->private_data;
+ if (unlikely(fd_file(f)->f_op != &fanotify_fops))
+ return -EINVAL;
+ group = fd_file(f)->private_data;
+
+ /* Only report mount events on mnt namespace */
+ if (FAN_GROUP_FLAG(group, FAN_REPORT_MNT)) {
+ if (mask & ~FANOTIFY_MOUNT_EVENTS)
+ return -EINVAL;
+ if (mark_type != FAN_MARK_MNTNS)
+ return -EINVAL;
+ } else {
+ if (mask & FANOTIFY_MOUNT_EVENTS)
+ return -EINVAL;
+ if (mark_type == FAN_MARK_MNTNS)
+ return -EINVAL;
+ }
/*
- * An unprivileged user is not allowed to setup mount nor filesystem
- * marks. This also includes setting up such marks by a group that
- * was initialized by an unprivileged user.
+ * A user is allowed to setup sb/mount/mntns marks only if it is
+ * capable in the user ns where the group was created.
*/
- ret = -EPERM;
- if ((!capable(CAP_SYS_ADMIN) ||
- FAN_GROUP_FLAG(group, FANOTIFY_UNPRIV)) &&
+ if (!ns_capable(group->user_ns, CAP_SYS_ADMIN) &&
mark_type != FAN_MARK_INODE)
- goto fput_and_out;
+ return -EPERM;
/*
- * group->priority == FS_PRIO_0 == FAN_CLASS_NOTIF. These are not
- * allowed to set permissions events.
+ * Permission events are not allowed for FAN_CLASS_NOTIF.
+ * Pre-content permission events are not allowed for FAN_CLASS_CONTENT.
*/
- ret = -EINVAL;
if (mask & FANOTIFY_PERM_EVENTS &&
- group->priority == FS_PRIO_0)
- goto fput_and_out;
+ group->priority == FSNOTIFY_PRIO_NORMAL)
+ return -EINVAL;
+ else if (mask & FANOTIFY_PRE_CONTENT_EVENTS &&
+ group->priority == FSNOTIFY_PRIO_CONTENT)
+ return -EINVAL;
if (mask & FAN_FS_ERROR &&
mark_type != FAN_MARK_FILESYSTEM)
- goto fput_and_out;
+ return -EINVAL;
/*
* Evictable is only relevant for inode marks, because only inode object
@@ -1763,7 +2015,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
*/
if (flags & FAN_MARK_EVICTABLE &&
mark_type != FAN_MARK_INODE)
- goto fput_and_out;
+ return -EINVAL;
/*
* Events that do not carry enough information to report
@@ -1773,9 +2025,9 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
* point.
*/
fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS);
- if (mask & ~(FANOTIFY_FD_EVENTS|FANOTIFY_EVENT_FLAGS) &&
+ if (mask & ~(FANOTIFY_FD_EVENTS|FANOTIFY_MOUNT_EVENTS|FANOTIFY_EVENT_FLAGS) &&
(!fid_mode || mark_type == FAN_MARK_MOUNT))
- goto fput_and_out;
+ return -EINVAL;
/*
* FAN_RENAME uses special info type records to report the old and
@@ -1783,23 +2035,21 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
* useful and was not implemented.
*/
if (mask & FAN_RENAME && !(fid_mode & FAN_REPORT_NAME))
- goto fput_and_out;
+ return -EINVAL;
+
+ /* Pre-content events are not currently generated for directories. */
+ if (mask & FANOTIFY_PRE_CONTENT_EVENTS && mask & FAN_ONDIR)
+ return -EINVAL;
if (mark_cmd == FAN_MARK_FLUSH) {
- ret = 0;
- if (mark_type == FAN_MARK_MOUNT)
- fsnotify_clear_vfsmount_marks_by_group(group);
- else if (mark_type == FAN_MARK_FILESYSTEM)
- fsnotify_clear_sb_marks_by_group(group);
- else
- fsnotify_clear_inode_marks_by_group(group);
- goto fput_and_out;
+ fsnotify_clear_marks_by_group(group, obj_type);
+ return 0;
}
ret = fanotify_find_path(dfd, pathname, &path, flags,
(mask & ALL_FSNOTIFY_EVENTS), obj_type);
if (ret)
- goto fput_and_out;
+ return ret;
if (mark_cmd == FAN_MARK_ADD) {
ret = fanotify_events_supported(group, &path, mask, flags);
@@ -1808,32 +2058,69 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
}
if (fid_mode) {
- ret = fanotify_test_fsid(path.dentry, &__fsid);
+ ret = fanotify_test_fsid(path.dentry, flags, &__fsid);
if (ret)
goto path_put_and_out;
- ret = fanotify_test_fid(path.dentry);
+ ret = fanotify_test_fid(path.dentry, flags);
if (ret)
goto path_put_and_out;
fsid = &__fsid;
}
- /* inode held in place by reference to path; group by fget on fd */
- if (mark_type == FAN_MARK_INODE)
+ /*
+ * In addition to being capable in the user ns where group was created,
+ * the user also needs to be capable in the user ns associated with
+ * the filesystem or in the user ns associated with the mntns
+ * (when marking mntns).
+ */
+ if (obj_type == FSNOTIFY_OBJ_TYPE_INODE) {
inode = path.dentry->d_inode;
- else
- mnt = path.mnt;
+ obj = inode;
+ } else if (obj_type == FSNOTIFY_OBJ_TYPE_VFSMOUNT) {
+ user_ns = path.mnt->mnt_sb->s_user_ns;
+ obj = path.mnt;
+ } else if (obj_type == FSNOTIFY_OBJ_TYPE_SB) {
+ user_ns = path.mnt->mnt_sb->s_user_ns;
+ obj = path.mnt->mnt_sb;
+ } else if (obj_type == FSNOTIFY_OBJ_TYPE_MNTNS) {
+ ret = -EINVAL;
+ mntns = mnt_ns_from_dentry(path.dentry);
+ if (!mntns)
+ goto path_put_and_out;
+ user_ns = mntns->user_ns;
+ obj = mntns;
+ }
+
+ ret = -EPERM;
+ if (user_ns && !ns_capable(user_ns, CAP_SYS_ADMIN))
+ goto path_put_and_out;
- ret = mnt ? -EINVAL : -EISDIR;
- /* FAN_MARK_IGNORE requires SURV_MODIFY for sb/mount/dir marks */
- if (mark_cmd == FAN_MARK_ADD && ignore == FAN_MARK_IGNORE &&
- (mnt || S_ISDIR(inode->i_mode)) &&
- !(flags & FAN_MARK_IGNORED_SURV_MODIFY))
+ ret = -EINVAL;
+ if (!obj)
goto path_put_and_out;
+ /*
+ * If some other task has this inode open for write we should not add
+ * an ignore mask, unless that ignore mask is supposed to survive
+ * modification changes anyway.
+ */
+ if (mark_cmd == FAN_MARK_ADD && (flags & FANOTIFY_MARK_IGNORE_BITS) &&
+ !(flags & FAN_MARK_IGNORED_SURV_MODIFY)) {
+ ret = !inode ? -EINVAL : -EISDIR;
+ /* FAN_MARK_IGNORE requires SURV_MODIFY for sb/mount/dir marks */
+ if (ignore == FAN_MARK_IGNORE &&
+ (!inode || S_ISDIR(inode->i_mode)))
+ goto path_put_and_out;
+
+ ret = 0;
+ if (inode && inode_is_open_for_write(inode))
+ goto path_put_and_out;
+ }
+
/* Mask out FAN_EVENT_ON_CHILD flag for sb/mount/non-dir marks */
- if (mnt || !S_ISDIR(inode->i_mode)) {
+ if (!inode || !S_ISDIR(inode->i_mode)) {
mask &= ~FAN_EVENT_ON_CHILD;
umask = FAN_EVENT_ON_CHILD;
/*
@@ -1848,26 +2135,12 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
/* create/update an inode mark */
switch (mark_cmd) {
case FAN_MARK_ADD:
- if (mark_type == FAN_MARK_MOUNT)
- ret = fanotify_add_vfsmount_mark(group, mnt, mask,
- flags, fsid);
- else if (mark_type == FAN_MARK_FILESYSTEM)
- ret = fanotify_add_sb_mark(group, mnt->mnt_sb, mask,
- flags, fsid);
- else
- ret = fanotify_add_inode_mark(group, inode, mask,
- flags, fsid);
+ ret = fanotify_add_mark(group, obj, obj_type, mask, flags,
+ fsid);
break;
case FAN_MARK_REMOVE:
- if (mark_type == FAN_MARK_MOUNT)
- ret = fanotify_remove_vfsmount_mark(group, mnt, mask,
- flags, umask);
- else if (mark_type == FAN_MARK_FILESYSTEM)
- ret = fanotify_remove_sb_mark(group, mnt->mnt_sb, mask,
- flags, umask);
- else
- ret = fanotify_remove_inode_mark(group, inode, mask,
- flags, umask);
+ ret = fanotify_remove_mark(group, obj, obj_type, mask, flags,
+ umask);
break;
default:
ret = -EINVAL;
@@ -1875,8 +2148,6 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
path_put_and_out:
path_put(&path);
-fput_and_out:
- fdput(f);
return ret;
}
@@ -1923,10 +2194,10 @@ static int __init fanotify_user_setup(void)
FANOTIFY_DEFAULT_MAX_USER_MARKS);
BUILD_BUG_ON(FANOTIFY_INIT_FLAGS & FANOTIFY_INTERNAL_GROUP_FLAGS);
- BUILD_BUG_ON(HWEIGHT32(FANOTIFY_INIT_FLAGS) != 12);
+ BUILD_BUG_ON(HWEIGHT32(FANOTIFY_INIT_FLAGS) != 14);
BUILD_BUG_ON(HWEIGHT32(FANOTIFY_MARK_FLAGS) != 11);
- fanotify_mark_cache = KMEM_CACHE(fsnotify_mark,
+ fanotify_mark_cache = KMEM_CACHE(fanotify_mark,
SLAB_PANIC|SLAB_ACCOUNT);
fanotify_fid_event_cachep = KMEM_CACHE(fanotify_fid_event,
SLAB_PANIC);
@@ -1936,6 +2207,7 @@ static int __init fanotify_user_setup(void)
fanotify_perm_event_cachep =
KMEM_CACHE(fanotify_perm_event, SLAB_PANIC);
}
+ fanotify_mnt_event_cachep = KMEM_CACHE(fanotify_mnt_event, SLAB_PANIC);
fanotify_max_queued_events = FANOTIFY_DEFAULT_MAX_EVENTS;
init_user_ns.ucount_max[UCOUNT_FANOTIFY_GROUPS] =
generated by cgit (git 2.34.1) at 2025-12-26 00:43:28 +0000