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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /fs/fuse/acl.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'fs/fuse/acl.c')
-rw-r--r--fs/fuse/acl.c161
1 files changed, 161 insertions, 0 deletions
diff --git a/fs/fuse/acl.c b/fs/fuse/acl.c
new file mode 100644
index 000000000..31fb50e16
--- /dev/null
+++ b/fs/fuse/acl.c
@@ -0,0 +1,161 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * FUSE: Filesystem in Userspace
+ * Copyright (C) 2016 Canonical Ltd. <seth.forshee@canonical.com>
+ */
+
+#include "fuse_i.h"
+
+#include <linux/posix_acl.h>
+#include <linux/posix_acl_xattr.h>
+
+static struct posix_acl *__fuse_get_acl(struct fuse_conn *fc,
+ struct inode *inode, int type, bool rcu)
+{
+ int size;
+ const char *name;
+ void *value = NULL;
+ struct posix_acl *acl;
+
+ if (rcu)
+ return ERR_PTR(-ECHILD);
+
+ if (fuse_is_bad(inode))
+ return ERR_PTR(-EIO);
+
+ if (fc->no_getxattr)
+ return NULL;
+
+ if (type == ACL_TYPE_ACCESS)
+ name = XATTR_NAME_POSIX_ACL_ACCESS;
+ else if (type == ACL_TYPE_DEFAULT)
+ name = XATTR_NAME_POSIX_ACL_DEFAULT;
+ else
+ return ERR_PTR(-EOPNOTSUPP);
+
+ value = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!value)
+ return ERR_PTR(-ENOMEM);
+ size = fuse_getxattr(inode, name, value, PAGE_SIZE);
+ if (size > 0)
+ acl = posix_acl_from_xattr(fc->user_ns, value, size);
+ else if ((size == 0) || (size == -ENODATA) ||
+ (size == -EOPNOTSUPP && fc->no_getxattr))
+ acl = NULL;
+ else if (size == -ERANGE)
+ acl = ERR_PTR(-E2BIG);
+ else
+ acl = ERR_PTR(size);
+
+ kfree(value);
+ return acl;
+}
+
+static inline bool fuse_no_acl(const struct fuse_conn *fc,
+ const struct inode *inode)
+{
+ /*
+ * Refuse interacting with POSIX ACLs for daemons that
+ * don't support FUSE_POSIX_ACL and are not mounted on
+ * the host to retain backwards compatibility.
+ */
+ return !fc->posix_acl && (i_user_ns(inode) != &init_user_ns);
+}
+
+struct posix_acl *fuse_get_acl(struct mnt_idmap *idmap,
+ struct dentry *dentry, int type)
+{
+ struct inode *inode = d_inode(dentry);
+ struct fuse_conn *fc = get_fuse_conn(inode);
+
+ if (fuse_no_acl(fc, inode))
+ return ERR_PTR(-EOPNOTSUPP);
+
+ return __fuse_get_acl(fc, inode, type, false);
+}
+
+struct posix_acl *fuse_get_inode_acl(struct inode *inode, int type, bool rcu)
+{
+ struct fuse_conn *fc = get_fuse_conn(inode);
+
+ /*
+ * FUSE daemons before FUSE_POSIX_ACL was introduced could get and set
+ * POSIX ACLs without them being used for permission checking by the
+ * vfs. Retain that behavior for backwards compatibility as there are
+ * filesystems that do all permission checking for acls in the daemon
+ * and not in the kernel.
+ */
+ if (!fc->posix_acl)
+ return NULL;
+ return __fuse_get_acl(fc, inode, type, rcu);
+}
+
+int fuse_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
+ struct posix_acl *acl, int type)
+{
+ struct inode *inode = d_inode(dentry);
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ const char *name;
+ int ret;
+
+ if (fuse_is_bad(inode))
+ return -EIO;
+
+ if (fc->no_setxattr || fuse_no_acl(fc, inode))
+ return -EOPNOTSUPP;
+
+ if (type == ACL_TYPE_ACCESS)
+ name = XATTR_NAME_POSIX_ACL_ACCESS;
+ else if (type == ACL_TYPE_DEFAULT)
+ name = XATTR_NAME_POSIX_ACL_DEFAULT;
+ else
+ return -EINVAL;
+
+ if (acl) {
+ unsigned int extra_flags = 0;
+ /*
+ * Fuse userspace is responsible for updating access
+ * permissions in the inode, if needed. fuse_setxattr
+ * invalidates the inode attributes, which will force
+ * them to be refreshed the next time they are used,
+ * and it also updates i_ctime.
+ */
+ size_t size;
+ void *value;
+
+ value = posix_acl_to_xattr(fc->user_ns, acl, &size, GFP_KERNEL);
+ if (!value)
+ return -ENOMEM;
+
+ if (size > PAGE_SIZE) {
+ kfree(value);
+ return -E2BIG;
+ }
+
+ /*
+ * Fuse daemons without FUSE_POSIX_ACL never changed the passed
+ * through POSIX ACLs. Such daemons don't expect setgid bits to
+ * be stripped.
+ */
+ if (fc->posix_acl &&
+ !in_group_or_capable(idmap, inode,
+ i_gid_into_vfsgid(idmap, inode)))
+ extra_flags |= FUSE_SETXATTR_ACL_KILL_SGID;
+
+ ret = fuse_setxattr(inode, name, value, size, 0, extra_flags);
+ kfree(value);
+ } else {
+ ret = fuse_removexattr(inode, name);
+ }
+
+ if (fc->posix_acl) {
+ /*
+ * Fuse daemons without FUSE_POSIX_ACL never cached POSIX ACLs
+ * and didn't invalidate attributes. Retain that behavior.
+ */
+ forget_all_cached_acls(inode);
+ fuse_invalidate_attr(inode);
+ }
+
+ return ret;
+}