linux-rng/security, branch master

Merge tag 'vfs-6.19-rc1.directory.locking' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2025-12-02T00:13:46Z

Pull directory locking updates from Christian Brauner: "This contains the work to add centralized APIs for directory locking operations. This series is part of a larger effort to change directory operation locking to allow multiple concurrent operations in a directory. The ultimate goal is to lock the target dentry(s) rather than the whole parent directory. To help with changing the locking protocol, this series centralizes locking and lookup in new helper functions. The helpers establish a pattern where it is the dentry that is being locked and unlocked (currently the lock is held on dentry->d_parent->d_inode, but that can change in the future). This also changes vfs_mkdir() to unlock the parent on failure, as well as dput()ing the dentry. This allows end_creating() to only require the target dentry (which may be IS_ERR() after vfs_mkdir()), not the parent" * tag 'vfs-6.19-rc1.directory.locking' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: nfsd: fix end_creating() conversion VFS: introduce end_creating_keep() VFS: change vfs_mkdir() to unlock on failure. ecryptfs: use new start_creating/start_removing APIs Add start_renaming_two_dentries() VFS/ovl/smb: introduce start_renaming_dentry() VFS/nfsd/ovl: introduce start_renaming() and end_renaming() VFS: add start_creating_killable() and start_removing_killable() VFS: introduce start_removing_dentry() smb/server: use end_removing_noperm for for target of smb2_create_link() VFS: introduce start_creating_noperm() and start_removing_noperm() VFS/nfsd/cachefiles/ovl: introduce start_removing() and end_removing() VFS/nfsd/cachefiles/ovl: add start_creating() and end_creating() VFS: tidy up do_unlinkat() VFS: introduce start_dirop() and end_dirop() debugfs: rename end_creating() to debugfs_end_creating()

Merge tag 'kernel-6.19-rc1.cred' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2025-12-01T21:45:41Z

Pull cred guard updates from Christian Brauner: "This contains substantial credential infrastructure improvements adding guard-based credential management that simplifies code and eliminates manual reference counting in many subsystems. Features: - Kernel Credential Guards Add with_kernel_creds() and scoped_with_kernel_creds() guards that allow using the kernel credentials without allocating and copying them. This was requested by Linus after seeing repeated prepare_kernel_creds() calls that duplicate the kernel credentials only to drop them again later. The new guards completely avoid the allocation and never expose the temporary variable to hold the kernel credentials anywhere in callers. - Generic Credential Guards Add scoped_with_creds() guards for the common override_creds() and revert_creds() pattern. This builds on earlier work that made override_creds()/revert_creds() completely reference count free. - Prepare Credential Guards Add prepare credential guards for the more complex pattern of preparing a new set of credentials and overriding the current credentials with them: - prepare_creds() - modify new creds - override_creds() - revert_creds() - put_cred() Cleanups: - Make init_cred static since it should not be directly accessed - Add kernel_cred() helper to properly access the kernel credentials - Fix scoped_class() macro that was introduced two cycles ago - coredump: split out do_coredump() from vfs_coredump() for cleaner credential handling - coredump: move revert_cred() before coredump_cleanup() - coredump: mark struct mm_struct as const - coredump: pass struct linux_binfmt as const - sev-dev: use guard for path" * tag 'kernel-6.19-rc1.cred' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (36 commits) trace: use override credential guard trace: use prepare credential guard coredump: use override credential guard coredump: use prepare credential guard coredump: split out do_coredump() from vfs_coredump() coredump: mark struct mm_struct as const coredump: pass struct linux_binfmt as const coredump: move revert_cred() before coredump_cleanup() sev-dev: use override credential guards sev-dev: use prepare credential guard sev-dev: use guard for path cred: add prepare credential guard net/dns_resolver: use credential guards in dns_query() cgroup: use credential guards in cgroup_attach_permissions() act: use credential guards in acct_write_process() smb: use credential guards in cifs_get_spnego_key() nfs: use credential guards in nfs_idmap_get_key() nfs: use credential guards in nfs_local_call_write() nfs: use credential guards in nfs_local_call_read() erofs: use credential guards ...

Merge tag 'vfs-6.19-rc1.inode' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2025-12-01T17:02:34Z

Pull vfs inode updates from Christian Brauner: "Features: - Hide inode->i_state behind accessors. Open-coded accesses prevent asserting they are done correctly. One obvious aspect is locking, but significantly more can be checked. For example it can be detected when the code is clearing flags which are already missing, or is setting flags when it is illegal (e.g., I_FREEING when ->i_count > 0) - Provide accessors for ->i_state, converts all filesystems using coccinelle and manual conversions (btrfs, ceph, smb, f2fs, gfs2, overlayfs, nilfs2, xfs), and makes plain ->i_state access fail to compile - Rework I_NEW handling to operate without fences, simplifying the code after the accessor infrastructure is in place Cleanups: - Move wait_on_inode() from writeback.h to fs.h - Spell out fenced ->i_state accesses with explicit smp_wmb/smp_rmb for clarity - Cosmetic fixes to LRU handling - Push list presence check into inode_io_list_del() - Touch up predicts in __d_lookup_rcu() - ocfs2: retire ocfs2_drop_inode() and I_WILL_FREE usage - Assert on ->i_count in iput_final() - Assert ->i_lock held in __iget() Fixes: - Add missing fences to I_NEW handling" * tag 'vfs-6.19-rc1.inode' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (22 commits) dcache: touch up predicts in __d_lookup_rcu() fs: push list presence check into inode_io_list_del() fs: cosmetic fixes to lru handling fs: rework I_NEW handling to operate without fences fs: make plain ->i_state access fail to compile xfs: use the new ->i_state accessors nilfs2: use the new ->i_state accessors overlayfs: use the new ->i_state accessors gfs2: use the new ->i_state accessors f2fs: use the new ->i_state accessors smb: use the new ->i_state accessors ceph: use the new ->i_state accessors btrfs: use the new ->i_state accessors Manual conversion to use ->i_state accessors of all places not covered by coccinelle Coccinelle-based conversion to use ->i_state accessors fs: provide accessors for ->i_state fs: spell out fenced ->i_state accesses with explicit smp_wmb/smp_rmb fs: move wait_on_inode() from writeback.h to fs.h fs: add missing fences to I_NEW handling ocfs2: retire ocfs2_drop_inode() and I_WILL_FREE usage ...

Merge tag 'selinux-pr-20251121' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

2025-11-22T17:24:36Z

Pull selinux fixes from Paul Moore: "Three SELinux patches for v6.18 to fix issues around accessing the per-task decision cache that we introduced in v6.16 to help reduce SELinux overhead on path walks. The problem was that despite the cache being located in the SELinux "task_security_struct", the parent struct wasn't actually tied to the task, it was tied to a cred. Historically SELinux did locate the task_security_struct in the task_struct's security blob, but it was later relocated to the cred struct when the cred work happened, as it made the most sense at the time. Unfortunately we never did the task_security_struct to cred_security_struct rename work (avoid code churn maybe? who knows) because it didn't really matter at the time. However, it suddenly became a problem when we added a per-task cache to a per-cred object and didn't notice because of the old, no-longer-correct struct naming. Thanks to KCSAN for flagging this, as the silly humans running things forgot that the task_security_struct was a big lie. This contains three patches, only one of which actually fixes the problem described above and moves the SELinux decision cache from the per-cred struct to a newly (re)created per-task struct. The other two patches, which form the bulk of the diffstat, take care of the associated renaming tasks so we can hopefully avoid making the same stupid mistake in the future. For the record, I did contemplate sending just a fix for the cache, leaving the renaming patches for the upcoming merge window, but the type/variable naming ended up being pretty awful and would have made v6.18 an outlier stuck between the "old" names and the "new" names in v6.19. The renaming patches are also fairly mechanical/trivial and shouldn't pose much risk despite their size. TLDR; naming things may be hard, but if you mess it up bad things happen" * tag 'selinux-pr-20251121' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: rename the cred_security_struct variables to "crsec" selinux: move avdcache to per-task security struct selinux: rename task_security_struct to cred_security_struct

selinux: rename the cred_security_struct variables to "crsec"

2025-11-20T21:47:50Z

Along with the renaming from task_security_struct to cred_security_struct, rename the local variables to "crsec" from "tsec". This both fits with existing conventions and helps distinguish between task and cred related variables. No functional changes. Acked-by: Stephen Smalley Signed-off-by: Paul Moore

selinux: move avdcache to per-task security struct

2025-11-20T21:43:51Z

The avdcache is meant to be per-task; move it to a new task_security_struct that is duplicated per-task. Cc: stable@vger.kernel.org Fixes: 5d7ddc59b3d89b724a5aa8f30d0db94ff8d2d93f ("selinux: reduce path walk overhead") Signed-off-by: Stephen Smalley [PM: line length fixes] Signed-off-by: Paul Moore

selinux: rename task_security_struct to cred_security_struct

2025-11-20T21:43:50Z

Before Linux had cred structures, the SELinux task_security_struct was per-task and although the structure was switched to being per-cred long ago, the name was never updated. This change renames it to cred_security_struct to avoid confusion and pave the way for the introduction of an actual per-task security structure for SELinux. No functional change. Cc: stable@vger.kernel.org Signed-off-by: Stephen Smalley Signed-off-by: Paul Moore

Add start_renaming_two_dentries()

2025-11-14T12:15:58Z

A few callers want to lock for a rename and already have both dentries. Also debugfs does want to perform a lookup but doesn't want permission checking, so start_renaming_dentry() cannot be used. This patch introduces start_renaming_two_dentries() which is given both dentries. debugfs performs one lookup itself. As it will only continue with a negative dentry and as those cannot be renamed or unlinked, it is safe to do the lookup before getting the rename locks. overlayfs uses start_renaming_two_dentries() in three places and selinux uses it twice in sel_make_policy_nodes(). In sel_make_policy_nodes() we now lock for rename twice instead of just once so the combined operation is no longer atomic w.r.t the parent directory locks. As selinux_state.policy_mutex is held across the whole operation this does not open up any interesting races. Reviewed-by: Amir Goldstein Reviewed-by: Jeff Layton Signed-off-by: NeilBrown Link: https://patch.msgid.link/20251113002050.676694-13-neilb@ownmail.net Signed-off-by: Christian Brauner

VFS: introduce start_removing_dentry()

2025-11-14T12:15:57Z

start_removing_dentry() is similar to start_removing() but instead of providing a name for lookup, the target dentry is given. start_removing_dentry() checks that the dentry is still hashed and in the parent, and if so it locks and increases the refcount so that end_removing() can be used to finish the operation. This is used in cachefiles, overlayfs, smb/server, and apparmor. There will be other users including ecryptfs. As start_removing_dentry() takes an extra reference to the dentry (to be put by end_removing()), there is no need to explicitly take an extra reference to stop d_delete() from using dentry_unlink_inode() to negate the dentry - as in cachefiles_delete_object(), and ksmbd_vfs_unlink(). cachefiles_bury_object() now gets an extra ref to the victim, which is drops. As it includes the needed end_removing() calls, the caller doesn't need them. Reviewed-by: Amir Goldstein Reviewed-by: Namjae Jeon Reviewed-by: Jeff Layton Signed-off-by: NeilBrown Link: https://patch.msgid.link/20251113002050.676694-9-neilb@ownmail.net Signed-off-by: Christian Brauner

landlock: fix splats from iput() after it started calling might_sleep()

2025-11-12T09:47:42Z

At this point it is guaranteed this is not the last reference. However, a recent addition of might_sleep() at top of iput() started generating false-positives as it was executing for all values. Remedy the problem by using the newly introduced iput_not_last(). Reported-by: syzbot+12479ae15958fc3f54ec@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/68d32659.a70a0220.4f78.0012.GAE@google.com/ Fixes: 2ef435a872ab ("fs: add might_sleep() annotation to iput() and more") Signed-off-by: Mateusz Guzik Link: https://patch.msgid.link/20251105212025.807549-2-mjguzik@gmail.com Reviewed-by: Mickaël Salaün Signed-off-by: Christian Brauner