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-rw-r--r--fs/notify/fanotify/fanotify.c15
-rw-r--r--fs/notify/fanotify/fanotify.h6
-rw-r--r--fs/notify/fanotify/fanotify_user.c112
-rw-r--r--include/linux/fsnotify_backend.h1
4 files changed, 101 insertions, 33 deletions
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index aff1ab3c32aa..1e4def21811e 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -29,12 +29,6 @@ static unsigned int fanotify_hash_path(const struct path *path)
hash_ptr(path->mnt, FANOTIFY_EVENT_HASH_BITS);
}
-static inline bool fanotify_fsid_equal(__kernel_fsid_t *fsid1,
- __kernel_fsid_t *fsid2)
-{
- return fsid1->val[0] == fsid2->val[0] && fsid1->val[1] == fsid2->val[1];
-}
-
static unsigned int fanotify_hash_fsid(__kernel_fsid_t *fsid)
{
return hash_32(fsid->val[0], FANOTIFY_EVENT_HASH_BITS) ^
@@ -851,7 +845,8 @@ static __kernel_fsid_t fanotify_get_fsid(struct fsnotify_iter_info *iter_info)
if (!(mark->flags & FSNOTIFY_MARK_FLAG_HAS_FSID))
continue;
fsid = FANOTIFY_MARK(mark)->fsid;
- if (WARN_ON_ONCE(!fsid.val[0] && !fsid.val[1]))
+ if (!(mark->flags & FSNOTIFY_MARK_FLAG_WEAK_FSID) &&
+ WARN_ON_ONCE(!fsid.val[0] && !fsid.val[1]))
continue;
return fsid;
}
@@ -933,12 +928,8 @@ static int fanotify_handle_event(struct fsnotify_group *group, u32 mask,
return 0;
}
- if (FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS)) {
+ if (FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS))
fsid = fanotify_get_fsid(iter_info);
- /* Racing with mark destruction or creation? */
- if (!fsid.val[0] && !fsid.val[1])
- return 0;
- }
event = fanotify_alloc_event(group, mask, data, data_type, dir,
file_name, &fsid, match_mask);
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index f3b9ef60f0c0..e5ab33cae6a7 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -499,6 +499,12 @@ static inline struct fanotify_mark *FANOTIFY_MARK(struct fsnotify_mark *mark)
return container_of(mark, struct fanotify_mark, fsn_mark);
}
+static inline bool fanotify_fsid_equal(__kernel_fsid_t *fsid1,
+ __kernel_fsid_t *fsid2)
+{
+ return fsid1->val[0] == fsid2->val[0] && fsid1->val[1] == fsid2->val[1];
+}
+
static inline unsigned int fanotify_mark_user_flags(struct fsnotify_mark *mark)
{
unsigned int mflags = 0;
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index e3d836d4d156..f83e7cc5ccf2 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -23,7 +23,7 @@
#include <asm/ioctls.h>
-#include "../../mount.h"
+#include "../fsnotify.h"
#include "../fdinfo.h"
#include "fanotify.h"
@@ -1192,11 +1192,68 @@ 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,
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;
@@ -1225,20 +1282,21 @@ static struct fsnotify_mark *fanotify_add_new_mark(struct fsnotify_group *group,
/* Cache fsid of filesystem containing the marked object */
if (fsid) {
- fan_mark->fsid = *fsid;
- mark->flags |= FSNOTIFY_MARK_FLAG_HAS_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, connp, obj_type, 0);
- if (ret) {
- fsnotify_put_mark(mark);
- goto out_dec_ucounts;
- }
+ 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);
@@ -1289,7 +1347,7 @@ static int fanotify_may_update_existing_mark(struct fsnotify_mark *fsn_mark,
static int fanotify_add_mark(struct fsnotify_group *group,
fsnotify_connp_t *connp, 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;
@@ -1337,7 +1395,7 @@ out:
static int fanotify_add_vfsmount_mark(struct fsnotify_group *group,
struct vfsmount *mnt, __u32 mask,
- unsigned int flags, __kernel_fsid_t *fsid)
+ unsigned int flags, struct fan_fsid *fsid)
{
return fanotify_add_mark(group, &real_mount(mnt)->mnt_fsnotify_marks,
FSNOTIFY_OBJ_TYPE_VFSMOUNT, mask, flags, fsid);
@@ -1345,7 +1403,7 @@ static int fanotify_add_vfsmount_mark(struct fsnotify_group *group,
static int fanotify_add_sb_mark(struct fsnotify_group *group,
struct super_block *sb, __u32 mask,
- unsigned int flags, __kernel_fsid_t *fsid)
+ unsigned int flags, struct fan_fsid *fsid)
{
return fanotify_add_mark(group, &sb->s_fsnotify_marks,
FSNOTIFY_OBJ_TYPE_SB, mask, flags, fsid);
@@ -1353,7 +1411,7 @@ static int fanotify_add_sb_mark(struct fsnotify_group *group,
static int fanotify_add_inode_mark(struct fsnotify_group *group,
struct inode *inode, __u32 mask,
- unsigned int flags, __kernel_fsid_t *fsid)
+ unsigned int flags, struct fan_fsid *fsid)
{
pr_debug("%s: group=%p inode=%p\n", __func__, group, inode);
@@ -1564,20 +1622,25 @@ out_destroy_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)
@@ -1587,11 +1650,18 @@ 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 */
@@ -1675,7 +1745,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
struct fsnotify_group *group;
struct fd f;
struct path path;
- __kernel_fsid_t __fsid, *fsid = NULL;
+ struct fan_fsid __fsid, *fsid = NULL;
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;
@@ -1827,7 +1897,7 @@ 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;
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index a80b525ca653..7f63be5ca0f1 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -529,6 +529,7 @@ struct fsnotify_mark {
#define FSNOTIFY_MARK_FLAG_NO_IREF 0x0200
#define FSNOTIFY_MARK_FLAG_HAS_IGNORE_FLAGS 0x0400
#define FSNOTIFY_MARK_FLAG_HAS_FSID 0x0800
+#define FSNOTIFY_MARK_FLAG_WEAK_FSID 0x1000
unsigned int flags; /* flags [mark->lock] */
};
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-19 10:11:29 +0000