kernel/linux.git/fs/configfs, branch v6.12.97

configfs: fix lockless traversals of ->s_children

2026-07-24T14:10:56+00:00

[ Upstream commit 9b9e8bb81c41fd27e7b57a1c936fde140548535f ] Having the parent directory locked protects entries from removal by another thread, but it does *not* protect cursors from being moved around by lseek() - or freed, for that matter. Fixes: 6f6107640625 ("configfs: Introduce configfs_dirent_lock") Reviewed-by: Jan Kara Signed-off-by: Al Viro Signed-off-by: Sasha Levin

configfs_lookup(): don't leave ->s_dentry dangling on failure

2026-07-24T14:10:53+00:00

[ Upstream commit 10da12d352b7b2bb330a8609fdda9a58bf0e9856 ] Normally ->s_dentry is cleared when dentry it's pointing to becomes negative (on eviction, realistically). However, that only happens if dentry gets to be positive in the first place; in case of inode allocation failure dentry never becomes positive, so ->d_iput() is not called at all. We do part of what normally would've been done by configfs_d_iput() (dropping the reference to configfs_dirent) manually, but we do not clear ->s_dentry there. Sloppy as it is, it does not matter in case of configfs_create_{dir,link}() - there configfs_dirent does not survive dropping the sole reference to it. However, for configfs_lookup() it *does* survive, with a dangling pointer to soon to be freed dentry sitting it its ->s_dentry. Subsequent getdents(2) in that directory will end up dereferencing that pointer in order to pick the inode number. Use after free... This is the minimal fix; the right approach is to set the linkage between dentry and configfs_dirent only after we know that we have an inode, but that takes more surgery and the bug had been there since 2006, so... Fixes: 3d0f89bb1694 ("configfs: Add permission and ownership to configfs objects") # 2.6.16-rc3 Reviewed-by: Jan Kara Reviewed-by: Breno Leitao Signed-off-by: Al Viro Signed-off-by: Sasha Levin

configfs: Do not override creating attribute file failure in populate_attrs()

2025-06-27T10:11:12+00:00

commit f830edbae247b89228c3e09294151b21e0dc849c upstream. populate_attrs() may override failure for creating attribute files by success for creating subsequent bin attribute files, and have wrong return value. Fix by creating bin attribute files under successfully creating attribute files. Fixes: 03607ace807b ("configfs: implement binary attributes") Cc: stable@vger.kernel.org Reviewed-by: Joel Becker Reviewed-by: Breno Leitao Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20250507-fix_configfs-v3-2-fe2d96de8dc4@quicinc.com Signed-off-by: Andreas Hindborg Signed-off-by: Greg Kroah-Hartman

fs/configfs: Add a callback to determine attribute visibility

2024-06-17T18:42:57+00:00

In order to support dynamic decisions as to whether an attribute should be created, add a callback that returns a bool to indicate whether the attribute should be displayed. If no callback is registered, the attribute is displayed by default. Co-developed-by: Dan Williams Signed-off-by: Dan Williams Signed-off-by: Tom Lendacky Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/e555c8740a263fab9f83b2cbb44da1af49a2813c.1717600736.git.thomas.lendacky@amd.com

configfs: convert to new timestamp accessors

2023-10-18T11:26:19+00:00

Convert to using the new inode timestamp accessor functions. Signed-off-by: Jeff Layton Link: https://lore.kernel.org/r/20231004185347.80880-24-jlayton@kernel.org Signed-off-by: Christian Brauner

configfs: convert to ctime accessor functions

2023-07-13T08:28:05+00:00

In later patches, we're going to change how the inode's ctime field is used. Switch to using accessor functions instead of raw accesses of inode->i_ctime. Signed-off-by: Jeff Layton Acked-by: Joel Becker Reviewed-by: Jan Kara Message-Id: <20230705190309.579783-30-jlayton@kernel.org> Signed-off-by: Christian Brauner

fs: consolidate duplicate dt_type helpers

2023-04-03T07:23:54+00:00

There are three copies of the same dt_type helper sprinkled around the tree. Convert them to use the common fs_umode_to_dtype function instead, which has the added advantage of properly returning DT_UNKNOWN when given a mode that contains an unrecognized type. Cc: Chuck Lever Cc: Phillip Potter Suggested-by: Christian Brauner Signed-off-by: Jeff Layton Acked-by: Greg Kroah-Hartman Reviewed-by: Christian Brauner Message-Id: <20230330104144.75547-1-jlayton@kernel.org> Signed-off-by: Christian Brauner

fs: port ->permission() to pass mnt_idmap

2023-01-19T08:24:28+00:00

Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner (Microsoft)

fs: port ->mkdir() to pass mnt_idmap

2023-01-19T08:24:26+00:00

fs: port ->symlink() to pass mnt_idmap

2023-01-19T08:24:25+00:00