Commit 4fe595cf authored by Gabriel Krisman Bertazi's avatar Gabriel Krisman Bertazi Committed by Jan Kara
Browse files

fanotify: Require fid_mode for any non-fd event 

Like inode events, FAN_FS_ERROR will require fid mode.  Therefore,
convert the verification during fanotify_mark(2) to require fid for any
non-fd event.  This means fid_mode will not only be required for inode
events, but for any event that doesn't provide a descriptor.

Link: https://lore.kernel.org/r/20211025192746.66445-17-krisman@collabora.com


Suggested-by: default avatarAmir Goldstein <amir73il@gmail.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarGabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 272531ac

fs/notify/fanotify/fanotify_user.c

+6 −6
Original line number Diff line number Diff line
@@ -1458,14 +1458,14 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask, 
		goto fput_and_out;



	/*

	 * Events with data type inode do not carry enough information to report

	 * event->fd, so we do not allow setting a mask for inode events unless

	 * group supports reporting fid.

	 * inode events are not supported on a mount mark, because they do not

	 * carry enough information (i.e. path) to be filtered by mount point.

	 * Events that do not carry enough information to report

	 * event->fd require a group that supports reporting fid.  Those

	 * events are not supported on a mount mark, because they do not

	 * carry enough information (i.e. path) to be filtered by mount

	 * point.

	 */

	fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS);

	if (mask & FANOTIFY_INODE_EVENTS &&

	if (mask & ~(FANOTIFY_FD_EVENTS|FANOTIFY_EVENT_FLAGS) &&

	    (!fid_mode || mark_type == FAN_MARK_MOUNT))

		goto fput_and_out;

include/linux/fanotify.h

+3 −0
Original line number Diff line number Diff line
@@ -84,6 +84,9 @@ extern struct ctl_table fanotify_table[]; /* for sysctl */ 
 */

#define FANOTIFY_DIRENT_EVENTS	(FAN_MOVE | FAN_CREATE | FAN_DELETE)



/* Events that can be reported with event->fd */

#define FANOTIFY_FD_EVENTS (FANOTIFY_PATH_EVENTS | FANOTIFY_PERM_EVENTS)



/* Events that can only be reported with data type FSNOTIFY_EVENT_INODE */

#define FANOTIFY_INODE_EVENTS	(FANOTIFY_DIRENT_EVENTS | \

				 FAN_ATTRIB | FAN_MOVE_SELF | FAN_DELETE_SELF)