diff options
| author | Amir Goldstein <amir73il@gmail.com> | 2024-11-15 10:30:22 -0500 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2024-12-10 12:03:17 +0100 |
| commit | 4acf3bc76e521b47acebcefc6312c97992f4ca29 (patch) | |
| tree | ae148909ac181f0784eb79c68122a5867cf41269 /fs/open.c | |
| parent | 9740d17162deca7138fad7dcf3ef52324832c32b (diff) | |
fsnotify: generate pre-content permission event on truncate
Generate FS_PRE_ACCESS event before truncate, without sb_writers held.
Move the security hooks also before sb_start_write() to conform with
other security hooks (e.g. in write, fallocate).
The event will have a range info of the page surrounding the new size
to provide an opportunity to fill the conetnt at the end of file before
truncating to non-page aligned size.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/23af8201db6ac2efdea94f09ab067d81ba5de7a7.1731684329.git.josef@toxicpanda.com
Diffstat (limited to 'fs/open.c')
| -rw-r--r-- | fs/open.c | 31 |
1 files changed, 21 insertions, 10 deletions
diff --git a/fs/open.c b/fs/open.c index 1a9483872e1f..d11d373dca80 100644 --- a/fs/open.c +++ b/fs/open.c @@ -81,14 +81,18 @@ long vfs_truncate(const struct path *path, loff_t length) if (!S_ISREG(inode->i_mode)) return -EINVAL; - error = mnt_want_write(path->mnt); - if (error) - goto out; - idmap = mnt_idmap(path->mnt); error = inode_permission(idmap, inode, MAY_WRITE); if (error) - goto mnt_drop_write_and_out; + return error; + + error = fsnotify_truncate_perm(path, length); + if (error) + return error; + + error = mnt_want_write(path->mnt); + if (error) + return error; error = -EPERM; if (IS_APPEND(inode)) @@ -114,7 +118,7 @@ put_write_and_out: put_write_access(inode); mnt_drop_write_and_out: mnt_drop_write(path->mnt); -out: + return error; } EXPORT_SYMBOL_GPL(vfs_truncate); @@ -175,11 +179,18 @@ long do_ftruncate(struct file *file, loff_t length, int small) /* Check IS_APPEND on real upper inode */ if (IS_APPEND(file_inode(file))) return -EPERM; - sb_start_write(inode->i_sb); + error = security_file_truncate(file); - if (!error) - error = do_truncate(file_mnt_idmap(file), dentry, length, - ATTR_MTIME | ATTR_CTIME, file); + if (error) + return error; + + error = fsnotify_truncate_perm(&file->f_path, length); + if (error) + return error; + + sb_start_write(inode->i_sb); + error = do_truncate(file_mnt_idmap(file), dentry, length, + ATTR_MTIME | ATTR_CTIME, file); sb_end_write(inode->i_sb); return error; |