mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2025-04-12 16:47:42 +00:00
Code Issues Packages Projects Releases Wiki Activity

fsnotify: disable notification by default for all pseudo files

Browse Source 
Most pseudo files are not applicable for fsnotify events at all,
let alone to the new pre-content events.

Disable notifications to all files allocated with alloc_file_pseudo()
and enable legacy inotify events for the specific cases of pipe and
socket, which have known users of inotify events.

Pre-content events are also kept disabled for sockets and pipes.

Fixes: 20bf82a898b6 ("mm: don't allow huge faults for files with pre content watches")
Reported-by: Alex Williamson <alex.williamson@redhat.com>
Closes: https://lore.kernel.org/linux-fsdevel/20250131121703.1e4d00a7.alex.williamson@redhat.com/
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/linux-fsdevel/CAHk-=wi2pThSVY=zhO=ZKxViBj5QCRX-=AS2+rVknQgJnHXDFg@mail.gmail.com/
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20250203223205.861346-3-amir73il@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Amir Goldstein 2025-02-03 23:32:04 +01:00 committed by Christian Brauner
parent 95101401bb
commit 2a42754b31
No known key found for this signature in database
GPG Key ID: 91C61BC06578DCA2
4 changed files with 24 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
fs/file_table.c
View File

@ -375,7 +375,13 @@ struct file *alloc_file_pseudo(struct inode *inode, struct vfsmount *mnt,
if (IS_ERR(file)) {
ihold(inode);
path_put(&path);
return file;
}
/*
* Disable all fsnotify events for pseudo files by default.
* They may be enabled by caller with file_set_fsnotify_mode().
*/
file_set_fsnotify_mode(file, FMODE_NONOTIFY);
return file;
}
EXPORT_SYMBOL(alloc_file_pseudo);
@ -400,6 +406,11 @@ struct file *alloc_file_pseudo_noaccount(struct inode *inode,
return file;
}
file_init_path(file, &path, fops);
/*
* Disable all fsnotify events for pseudo files by default.
* They may be enabled by caller with file_set_fsnotify_mode().
*/
file_set_fsnotify_mode(file, FMODE_NONOTIFY);
return file;
}
EXPORT_SYMBOL_GPL(alloc_file_pseudo_noaccount);

4
fs/open.c
View File

@ -936,8 +936,8 @@ static int do_dentry_open(struct file *f,
/*
* Set FMODE_NONOTIFY_* bits according to existing permission watches.
* If FMODE_NONOTIFY was already set for an fanotify fd, this doesn't
* change anything.
* If FMODE_NONOTIFY mode was already set for an fanotify fd or for a
* pseudo file, this call will not change the mode.
*/
file_set_fsnotify_mode_from_watchers(f);
error = fsnotify_open_perm(f);

6
fs/pipe.c
View File

@ -960,6 +960,12 @@ int create_pipe_files(struct file **res, int flags)
res[1] = f;
stream_open(inode, res[0]);
stream_open(inode, res[1]);
/*
* Disable permission and pre-content events, but enable legacy
* inotify events for legacy users.
*/
file_set_fsnotify_mode(res[0], FMODE_NONOTIFY_PERM);
file_set_fsnotify_mode(res[1], FMODE_NONOTIFY_PERM);
return 0;
}

5
net/socket.c
View File

@ -479,6 +479,11 @@ struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname)
sock->file = file;
file->private_data = sock;
stream_open(SOCK_INODE(sock), file);
/*
* Disable permission and pre-content events, but enable legacy
* inotify events for legacy users.
*/
file_set_fsnotify_mode(file, FMODE_NONOTIFY_PERM);
return file;
}
EXPORT_SYMBOL(sock_alloc_file);