x86/kprobes: Fix crash when probing CS CALL instructionsgrafted

When using eBPF to probe CS CALL instructions within a function,
a crash can be triggered.

The eBPF tool probes offset 257 of the __hrtimer_run_queues()
function:

<__hrtimer_run_queues+249>:  nopl   0x0(%rax,%rax,1)
<__hrtimer_run_queues+254>:  mov    %r14,%rdi
<__hrtimer_run_queues+257>:  cs call <__x86_indirect_thunk_r12>
<__hrtimer_run_queues+263>:  mov    %eax,%r12d
<__hrtimer_run_queues+266>:  xchg   %ax,%ax
<__hrtimer_run_queues+268>:  mov    %r13,%rdi

Which triggers this crash:

  BUG: unable to handle page fault for address: 00000000000f41c9
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 0 P4D 0
  Oops: 0002 [#1] SMP NOPTI
  CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P
  RIP: 0010:__hrtimer_run_queues+0x106/0x230

Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is
at the 6th byte of the above CS CALL instruction. Since the CS CALL
instruction occupies 6 bytes, the exception occurred in the middle of that
call instruction.

The root cause is that when using eBPF tools to probe in the middle of a
function, a kprobe with INT3 is used as the underlying implementation.

During single-step emulation of the original CALL instruction,
int3_emulate_call() assumes that the probed CALL instruction is 5 bytes
long. However, the actual CS-prefixed CALL instruction occupies 6 bytes,
so it constructs an incorrect exception return address. When the CPU
returns from the kprobe handler, the next instruction to be executed is at
the address of the last byte of that CS CALL instruction. Coincidentally,
starting from that address, the CPU fetches and decodes a completely
different instruction, which ultimately triggers a kernel crash.

Fix the issue by using the actual instruction length obtained from
the instruction decoder when constructing the exception return
address, rather than relying on the hardcoded CALL_INSN_SIZE macro.

[ mingo: Refined the changelog ]

Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000

1 files changed, 1141 insertions, 0 deletions

diff --git a/fs/ntfs/ea.c b/fs/ntfs/ea.c
new file mode 100644
index 000000000..b4fcfbe2d
--- /dev/null
+++ b/fs/ntfs/ea.c
@@ -0,0 +1,1141 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Pocessing of EA's
+ *
+ * Part of this file is based on code from the NTFS-3G.
+ *
+ * Copyright (c) 2014-2021 Jean-Pierre Andre
+ * Copyright (c) 2025 LG Electronics Co., Ltd.
+ */
+
+#include <linux/fs.h>
+#include <linux/posix_acl.h>
+#include <linux/posix_acl_xattr.h>
+#include <linux/xattr.h>
+
+#include "layout.h"
+#include "attrib.h"
+#include "index.h"
+#include "dir.h"
+#include "ea.h"
+
+static int ntfs_write_ea(struct ntfs_inode *ni, __le32 type, char *value, s64 ea_off,
+		s64 ea_size, bool need_truncate)
+{
+	struct inode *ea_vi;
+	int err = 0;
+	s64 written;
+
+	ea_vi = ntfs_attr_iget(VFS_I(ni), type, AT_UNNAMED, 0);
+	if (IS_ERR(ea_vi))
+		return PTR_ERR(ea_vi);
+
+	written = ntfs_inode_attr_pwrite(ea_vi, ea_off, ea_size, value, false);
+	if (written != ea_size)
+		err = -EIO;
+	else {
+		struct ntfs_inode *ea_ni = NTFS_I(ea_vi);
+
+		if (need_truncate && ea_ni->data_size > ea_off + ea_size)
+			ntfs_attr_truncate(ea_ni, ea_off + ea_size);
+		mark_mft_record_dirty(ni);
+	}
+
+	iput(ea_vi);
+	return err;
+}
+
+static int ntfs_ea_lookup(char *ea_buf, s64 ea_buf_size, const char *name,
+			  int name_len, s64 *ea_offset, s64 *ea_size)
+{
+	const struct ea_attr *p_ea;
+	size_t actual_size;
+	loff_t offset, p_ea_size;
+	unsigned int next;
+
+	offset = 0;
+	do {
+		if (ea_buf_size - offset < sizeof(struct ea_attr))
+			break;
+
+		p_ea = (const struct ea_attr *)&ea_buf[offset];
+		next = le32_to_cpu(p_ea->next_entry_offset);
+		p_ea_size = next ? next : (ea_buf_size - offset);
+
+		if (p_ea_size < sizeof(struct ea_attr) ||
+		    offset + p_ea_size > ea_buf_size)
+			break;
+
+		if ((s64)p_ea->ea_name_length + 1 >
+		    p_ea_size - offsetof(struct ea_attr, ea_name))
+			break;
+
+		actual_size = ALIGN(struct_size(p_ea, ea_name, 1 + p_ea->ea_name_length +
+					le16_to_cpu(p_ea->ea_value_length)), 4);
+		if (actual_size > p_ea_size)
+			break;
+
+		if (p_ea->ea_name_length == name_len &&
+		    !memcmp(p_ea->ea_name, name, name_len)) {
+			*ea_offset = offset;
+			*ea_size = next ? next : actual_size;
+
+			if (ea_buf_size < *ea_offset + *ea_size)
+				goto out;
+
+			return 0;
+		}
+		offset += next;
+	} while (next > 0 && offset < ea_buf_size);
+
+out:
+	return -ENOENT;
+}
+
+/*
+ * Return the existing EA
+ *
+ * The EA_INFORMATION is not examined and the consistency of the
+ * existing EA is not checked.
+ *
+ * If successful, the full attribute is returned unchanged
+ * and its size is returned.
+ * If the designated buffer is too small, the needed size is
+ * returned, and the buffer is left unchanged.
+ * If there is an error, a negative value is returned and errno
+ * is set according to the error.
+ */
+static int ntfs_get_ea(struct inode *inode, const char *name, size_t name_len,
+		void *buffer, size_t size)
+{
+	struct ntfs_inode *ni = NTFS_I(inode);
+	const struct ea_attr *p_ea;
+	char *ea_buf;
+	s64 ea_off, ea_size, all_ea_size, ea_info_size;
+	int err;
+	u32 ea_info_qlen;
+	u16 ea_value_len;
+	struct ea_information *p_ea_info;
+
+	if (!NInoHasEA(ni))
+		return -ENODATA;
+
+	p_ea_info = ntfs_attr_readall(ni, AT_EA_INFORMATION, NULL, 0,
+			&ea_info_size);
+	if (IS_ERR(p_ea_info))
+		return PTR_ERR(p_ea_info);
+	if (ea_info_size != sizeof(struct ea_information)) {
+		kvfree(p_ea_info);
+		return -EIO;
+	}
+
+	ea_info_qlen = le32_to_cpu(p_ea_info->ea_query_length);
+	kvfree(p_ea_info);
+
+	ea_buf = ntfs_attr_readall(ni, AT_EA, NULL, 0, &all_ea_size);
+	if (IS_ERR(ea_buf))
+		return PTR_ERR(ea_buf);
+
+	if (ea_info_qlen > all_ea_size) {
+		err = -EIO;
+		goto free_ea_buf;
+	}
+
+	err = ntfs_ea_lookup(ea_buf, ea_info_qlen, name, name_len, &ea_off,
+			&ea_size);
+	if (!err) {
+		p_ea = (struct ea_attr *)&ea_buf[ea_off];
+		ea_value_len = le16_to_cpu(p_ea->ea_value_length);
+		if (!buffer) {
+			kvfree(ea_buf);
+			return ea_value_len;
+		}
+
+		if (ea_value_len > size) {
+			err = -ERANGE;
+			goto free_ea_buf;
+		}
+
+		memcpy(buffer, &p_ea->ea_name[p_ea->ea_name_length + 1],
+				ea_value_len);
+		kvfree(ea_buf);
+		return ea_value_len;
+	}
+
+	err = -ENODATA;
+free_ea_buf:
+	kvfree(ea_buf);
+	return err;
+}
+
+static inline int ea_packed_size(const struct ea_attr *p_ea)
+{
+	/*
+	 * 4 bytes for header (flags and lengths) + name length + 1 +
+	 * value length.
+	 */
+	return 5 + p_ea->ea_name_length + le16_to_cpu(p_ea->ea_value_length);
+}
+
+/*
+ * Set a new EA, and set EA_INFORMATION accordingly
+ *
+ * This is roughly the same as ZwSetEaFile() on Windows, however
+ * the "offset to next" of the last EA should not be cleared.
+ *
+ * Consistency of the new EA is first checked.
+ *
+ * EA_INFORMATION is set first, and it is restored to its former
+ * state if setting EA fails.
+ */
+static int ntfs_set_ea(struct inode *inode, const char *name, size_t name_len,
+		const void *value, size_t val_size, int flags,
+		__le16 *packed_ea_size)
+{
+	struct ntfs_inode *ni = NTFS_I(inode);
+	struct ea_information *p_ea_info = NULL;
+	int ea_packed, err = 0;
+	struct ea_attr *p_ea;
+	u32 ea_info_qsize = 0;
+	char *ea_buf = NULL;
+	char *new_ea_buf;
+	char *old_ea_buf = NULL;
+	struct ea_information old_ea_info;
+	size_t new_ea_size = ALIGN(struct_size(p_ea, ea_name, 1 + name_len + val_size), 4);
+	s64 ea_off, ea_info_size, all_ea_size, ea_size;
+
+	if (name_len > 255)
+		return -ENAMETOOLONG;
+
+	if (ntfs_attr_exist(ni, AT_EA_INFORMATION, AT_UNNAMED, 0)) {
+		p_ea_info = ntfs_attr_readall(ni, AT_EA_INFORMATION, NULL, 0,
+						&ea_info_size);
+		if (IS_ERR(p_ea_info)) {
+			err = PTR_ERR(p_ea_info);
+			p_ea_info = NULL;
+			goto out;
+		}
+		if (ea_info_size != sizeof(struct ea_information)) {
+			err = -EIO;
+			goto out;
+		}
+
+		ea_buf = ntfs_attr_readall(ni, AT_EA, NULL, 0, &all_ea_size);
+		if (IS_ERR(ea_buf)) {
+			err = PTR_ERR(ea_buf);
+			ea_buf = NULL;
+			goto out;
+		}
+		if (!ea_buf) {
+			ea_info_qsize = 0;
+			kvfree(p_ea_info);
+			goto create_ea_info;
+		}
+
+		ea_info_qsize = le32_to_cpu(p_ea_info->ea_query_length);
+	} else {
+create_ea_info:
+		p_ea_info = kzalloc_obj(struct ea_information, GFP_NOFS);
+		if (!p_ea_info)
+			return -ENOMEM;
+
+		ea_info_qsize = 0;
+		err = ntfs_attr_add(ni, AT_EA_INFORMATION, AT_UNNAMED, 0,
+				(char *)p_ea_info, sizeof(struct ea_information));
+		if (err)
+			goto out;
+
+		if (ntfs_attr_exist(ni, AT_EA, AT_UNNAMED, 0)) {
+			err = ntfs_attr_remove(ni, AT_EA, AT_UNNAMED, 0);
+			if (err)
+				goto out;
+		}
+
+		goto alloc_new_ea;
+	}
+
+	if (ea_info_qsize > all_ea_size) {
+		err = -EIO;
+		goto out;
+	}
+
+	err = ntfs_ea_lookup(ea_buf, ea_info_qsize, name, name_len, &ea_off,
+			&ea_size);
+	if (ea_info_qsize && !err) {
+		if (flags & XATTR_CREATE) {
+			err = -EEXIST;
+			goto out;
+		}
+		if ((flags & XATTR_REPLACE) && !val_size) {
+			old_ea_info = *p_ea_info;
+			old_ea_buf = kvmemdup(ea_buf, all_ea_size, GFP_NOFS);
+			if (!old_ea_buf) {
+				err = -ENOMEM;
+				goto out;
+			}
+		}
+
+		/* Check the final $EA size before removing the old entry. */
+		if (val_size &&
+		    ntfs_attr_size_bounds_check(ni->vol, AT_EA,
+					ea_info_qsize - ea_size + new_ea_size)) {
+			err = -EFBIG;
+			goto out;
+		}
+
+		p_ea = (struct ea_attr *)(ea_buf + ea_off);
+
+		if (val_size &&
+		    le16_to_cpu(p_ea->ea_value_length) == val_size &&
+		    !memcmp(p_ea->ea_name + p_ea->ea_name_length + 1, value,
+			    val_size))
+			goto out;
+
+		le16_add_cpu(&p_ea_info->ea_length, 0 - ea_packed_size(p_ea));
+
+		if (p_ea->flags & NEED_EA)
+			le16_add_cpu(&p_ea_info->need_ea_count, -1);
+
+		memmove((char *)p_ea, (char *)p_ea + ea_size, ea_info_qsize - (ea_off + ea_size));
+		ea_info_qsize -= ea_size;
+		p_ea_info->ea_query_length = cpu_to_le32(ea_info_qsize);
+
+		if ((flags & XATTR_REPLACE) && !val_size && !ea_info_qsize) {
+			err = ntfs_attr_remove(ni, AT_EA, AT_UNNAMED, 0);
+			if (err)
+				goto out;
+
+			err = ntfs_attr_remove(ni, AT_EA_INFORMATION, AT_UNNAMED, 0);
+			if (err) {
+				/* Restore the original $EA if $EA_INFORMATION removal failed. */
+				ntfs_attr_add(ni, AT_EA, AT_UNNAMED, 0, old_ea_buf,
+					      all_ea_size);
+				ea_info_qsize = le32_to_cpu(old_ea_info.ea_query_length);
+			}
+			goto out;
+		}
+
+		if ((flags & XATTR_REPLACE) && !val_size) {
+			err = ntfs_write_ea(ni, AT_EA, ea_buf, 0, ea_info_qsize,
+					true);
+			if (err) {
+				ntfs_write_ea(ni, AT_EA, old_ea_buf, 0,
+					      all_ea_size, false);
+				goto out;
+			}
+
+			err = ntfs_write_ea(ni, AT_EA_INFORMATION, (char *)p_ea_info,
+					0, sizeof(struct ea_information), false);
+			if (err) {
+				ntfs_write_ea(ni, AT_EA, old_ea_buf, 0,
+					      all_ea_size, false);
+				ntfs_write_ea(ni, AT_EA_INFORMATION,
+					      (char *)&old_ea_info, 0,
+					      sizeof(old_ea_info), false);
+			}
+			goto out;
+		}
+	} else {
+		if (flags & XATTR_REPLACE) {
+			err = -ENODATA;
+			goto out;
+		}
+
+		if (ntfs_attr_size_bounds_check(ni->vol, AT_EA,
+					ea_info_qsize + new_ea_size)) {
+			err = -EFBIG;
+			goto out;
+		}
+	}
+alloc_new_ea:
+	new_ea_buf = kvzalloc(ea_info_qsize + new_ea_size, GFP_NOFS);
+	if (!new_ea_buf) {
+		err = -ENOMEM;
+		goto out;
+	}
+	if (ea_info_qsize)
+		memcpy(new_ea_buf, ea_buf, ea_info_qsize);
+	kvfree(ea_buf);
+	ea_buf = new_ea_buf;
+	p_ea = (struct ea_attr *)(ea_buf + ea_info_qsize);
+
+	/*
+	 * EA and REPARSE_POINT compatibility not checked any more,
+	 * required by Windows 10, but having both may lead to
+	 * problems with earlier versions.
+	 */
+	memcpy(p_ea->ea_name, name, name_len);
+	p_ea->ea_name_length = name_len;
+	p_ea->ea_name[name_len] = 0;
+	memcpy(p_ea->ea_name + name_len + 1, value, val_size);
+	p_ea->ea_value_length = cpu_to_le16(val_size);
+	p_ea->next_entry_offset = cpu_to_le32(new_ea_size);
+
+	ea_packed = le16_to_cpu(p_ea_info->ea_length) + ea_packed_size(p_ea);
+	p_ea_info->ea_length = cpu_to_le16(ea_packed);
+	p_ea_info->ea_query_length = cpu_to_le32(ea_info_qsize + new_ea_size);
+
+	if (ea_packed > 0xffff) {
+		err = -EFBIG;
+		goto out;
+	}
+
+	/*
+	 * no EA or EA_INFORMATION : add them
+	 */
+	if (!ntfs_attr_exist(ni, AT_EA, AT_UNNAMED, 0)) {
+		err = ntfs_attr_add(ni, AT_EA, AT_UNNAMED, 0, ea_buf,
+				ea_info_qsize + new_ea_size);
+		if (err)
+			goto out;
+	} else {
+		err = ntfs_write_ea(ni, AT_EA, ea_buf, 0,
+				ea_info_qsize + new_ea_size, true);
+		if (err)
+			goto out;
+	}
+
+	err = ntfs_write_ea(ni, AT_EA_INFORMATION, (char *)p_ea_info, 0,
+			sizeof(struct ea_information), false);
+	if (err)
+		goto out;
+
+	if (packed_ea_size)
+		*packed_ea_size = p_ea_info->ea_length;
+	mark_mft_record_dirty(ni);
+out:
+	if (!err) {
+		if (ea_info_qsize > 0)
+			NInoSetHasEA(ni);
+		else
+			NInoClearHasEA(ni);
+	}
+
+	kvfree(ea_buf);
+	kvfree(old_ea_buf);
+	kvfree(p_ea_info);
+
+	return err;
+}
+
+/*
+ * Check for the presence of an EA "$LXDEV" (used by WSL)
+ * and return its value as a device address
+ */
+int ntfs_ea_get_wsl_inode(struct inode *inode, dev_t *rdevp, unsigned int flags,
+			  bool *has_lxmod)
+{
+	int err;
+	__le32 v;
+
+	*has_lxmod = false;
+
+	if (!(flags & NTFS_VOL_UID)) {
+		/* Load uid to lxuid EA */
+		err = ntfs_get_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &v,
+				sizeof(v));
+		if (err == sizeof(v))
+			i_uid_write(inode, le32_to_cpu(v));
+	}
+
+	if (!(flags & NTFS_VOL_GID)) {
+		/* Load gid to lxgid EA */
+		err = ntfs_get_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &v,
+				sizeof(v));
+		if (err == sizeof(v))
+			i_gid_write(inode, le32_to_cpu(v));
+	}
+
+	/* Load mode to lxmod EA */
+	err = ntfs_get_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &v, sizeof(v));
+	if (err == sizeof(v)) {
+		inode->i_mode = le32_to_cpu(v);
+		*has_lxmod = true;
+	} else {
+		/* Everyone gets all permissions. */
+		inode->i_mode |= 0777;
+	}
+
+	/* Load mode to lxdev EA */
+	err = ntfs_get_ea(inode, "$LXDEV", sizeof("$LXDEV") - 1, &v, sizeof(v));
+	if (err == sizeof(v))
+		*rdevp = le32_to_cpu(v);
+	err = 0;
+
+	return err;
+}
+
+int ntfs_ea_set_wsl_inode(struct inode *inode, dev_t rdev, __le16 *ea_size,
+		unsigned int flags)
+{
+	__le32 v;
+	int err = 0;
+
+	if (ea_size)
+		*ea_size = 0;
+
+	if (flags & NTFS_EA_UID) {
+		/* Store uid to lxuid EA */
+		v = cpu_to_le32(i_uid_read(inode));
+		err = ntfs_set_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &v,
+				sizeof(v), 0, ea_size);
+		if (err)
+			return err;
+	}
+
+	if (flags & NTFS_EA_GID) {
+		/* Store gid to lxgid EA */
+		v = cpu_to_le32(i_gid_read(inode));
+		err = ntfs_set_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &v,
+				sizeof(v), 0, ea_size);
+		if (err)
+			return err;
+	}
+
+	if (flags & NTFS_EA_MODE) {
+		/* Store mode to lxmod EA */
+		v = cpu_to_le32(inode->i_mode);
+		err = ntfs_set_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &v,
+				sizeof(v), 0, ea_size);
+		if (err)
+			return err;
+	}
+
+	if (rdev) {
+		v = cpu_to_le32(rdev);
+		err = ntfs_set_ea(inode, "$LXDEV", sizeof("$LXDEV") - 1, &v, sizeof(v),
+				0, ea_size);
+	}
+
+	return err;
+}
+
+ssize_t ntfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
+{
+	struct inode *inode = d_inode(dentry);
+	struct ntfs_inode *ni = NTFS_I(inode);
+	const struct ea_attr *p_ea;
+	s64 offset, ea_buf_size, ea_info_size;
+	s64 ea_size;
+	u32 next;
+	int err = 0;
+	u32 ea_info_qsize;
+	char *ea_buf = NULL;
+	ssize_t ret = 0;
+	struct ea_information *ea_info;
+
+	if (!NInoHasEA(ni))
+		return 0;
+
+	mutex_lock(&NTFS_I(inode)->mrec_lock);
+	ea_info = ntfs_attr_readall(ni, AT_EA_INFORMATION, NULL, 0,
+			&ea_info_size);
+	if (IS_ERR(ea_info)) {
+		err = PTR_ERR(ea_info);
+		ea_info = NULL;
+		goto out;
+	}
+	if (ea_info_size != sizeof(struct ea_information)) {
+		err = -EIO;
+		goto out;
+	}
+
+	ea_info_qsize = le32_to_cpu(ea_info->ea_query_length);
+
+	ea_buf = ntfs_attr_readall(ni, AT_EA, NULL, 0, &ea_buf_size);
+	if (IS_ERR(ea_buf)) {
+		err = PTR_ERR(ea_buf);
+		ea_buf = NULL;
+		goto out;
+	}
+
+	if (ea_info_qsize > ea_buf_size || ea_info_qsize == 0)
+		goto out;
+
+	offset = 0;
+	do {
+		if (ea_info_qsize - offset < sizeof(struct ea_attr)) {
+			err = -EIO;
+			goto out;
+		}
+
+		p_ea = (const struct ea_attr *)&ea_buf[offset];
+		next = le32_to_cpu(p_ea->next_entry_offset);
+		ea_size = next ? next : (ea_info_qsize - offset);
+
+		if (ea_size < sizeof(struct ea_attr) ||
+		    offset + ea_size > ea_info_qsize) {
+			err = -EIO;
+			goto out;
+		}
+
+		if ((int)p_ea->ea_name_length + 1 >
+			ea_size - offsetof(struct ea_attr, ea_name)) {
+			err = -EIO;
+			goto out;
+		}
+
+		if (buffer) {
+			if (ret + p_ea->ea_name_length + 1 > size) {
+				err = -ERANGE;
+				goto out;
+			}
+
+			memcpy(buffer + ret, p_ea->ea_name, p_ea->ea_name_length);
+			buffer[ret + p_ea->ea_name_length] = 0;
+		}
+
+		ret += p_ea->ea_name_length + 1;
+		offset += ea_size;
+	} while (next > 0 && offset < ea_info_qsize);
+
+out:
+	mutex_unlock(&NTFS_I(inode)->mrec_lock);
+	kvfree(ea_info);
+	kvfree(ea_buf);
+
+	return err ? err : ret;
+}
+
+// clang-format off
+#define SYSTEM_DOS_ATTRIB     "system.dos_attrib"
+#define SYSTEM_NTFS_ATTRIB    "system.ntfs_attrib"
+#define SYSTEM_NTFS_ATTRIB_BE "system.ntfs_attrib_be"
+// clang-format on
+
+static int ntfs_getxattr(const struct xattr_handler *handler,
+		struct dentry *unused, struct inode *inode, const char *name,
+		void *buffer, size_t size)
+{
+	struct ntfs_inode *ni = NTFS_I(inode);
+	int err;
+
+	if (NVolShutdown(ni->vol))
+		return -EIO;
+
+	if (!strcmp(name, SYSTEM_DOS_ATTRIB)) {
+		if (!buffer) {
+			err = sizeof(u8);
+		} else if (size < sizeof(u8)) {
+			err = -ERANGE;
+		} else {
+			err = sizeof(u8);
+			*(u8 *)buffer = (u8)(le32_to_cpu(ni->flags) & 0x3F);
+		}
+		goto out;
+	}
+
+	if (!strcmp(name, SYSTEM_NTFS_ATTRIB) ||
+	    !strcmp(name, SYSTEM_NTFS_ATTRIB_BE)) {
+		if (!buffer) {
+			err = sizeof(u32);
+		} else if (size < sizeof(u32)) {
+			err = -ERANGE;
+		} else {
+			err = sizeof(u32);
+			*(u32 *)buffer = le32_to_cpu(ni->flags);
+			if (!strcmp(name, SYSTEM_NTFS_ATTRIB_BE))
+				*(__be32 *)buffer = cpu_to_be32(*(u32 *)buffer);
+		}
+		goto out;
+	}
+
+	mutex_lock(&ni->mrec_lock);
+	err = ntfs_get_ea(inode, name, strlen(name), buffer, size);
+	mutex_unlock(&ni->mrec_lock);
+
+out:
+	return err;
+}
+
+static int ntfs_new_attr_flags(struct ntfs_inode *ni, __le32 fattr)
+{
+	struct ntfs_attr_search_ctx *ctx;
+	struct mft_record *m;
+	struct attr_record *a;
+	__le16 new_aflags;
+	u16 old_name_ofs, old_mp_ofs;
+	int mp_size, mp_ofs, name_ofs, old_arec_size, arec_size, err;
+
+	m = map_mft_record(ni);
+	if (IS_ERR(m))
+		return PTR_ERR(m);
+
+	ctx = ntfs_attr_get_search_ctx(ni, m);
+	if (!ctx) {
+		err = -ENOMEM;
+		goto err_out;
+	}
+
+	err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
+			CASE_SENSITIVE, 0, NULL, 0, ctx);
+	if (err) {
+		err = -EINVAL;
+		goto err_out;
+	}
+
+	a = ctx->attr;
+	new_aflags = ctx->attr->flags;
+
+	if (fattr & FILE_ATTR_SPARSE_FILE)
+		new_aflags |= ATTR_IS_SPARSE;
+	else
+		new_aflags &= ~ATTR_IS_SPARSE;
+
+	if (fattr & FILE_ATTR_COMPRESSED)
+		new_aflags |= ATTR_IS_COMPRESSED;
+	else
+		new_aflags &= ~ATTR_IS_COMPRESSED;
+
+	if (new_aflags == a->flags) {
+		err = 0;
+		goto err_out;
+	}
+
+	if ((new_aflags & (ATTR_IS_SPARSE | ATTR_IS_COMPRESSED)) ==
+			  (ATTR_IS_SPARSE | ATTR_IS_COMPRESSED)) {
+		pr_err("file can't be sparsed and compressed\n");
+		err = -EOPNOTSUPP;
+		goto err_out;
+	}
+
+	if (!a->non_resident) {
+		if (!(new_aflags & (ATTR_IS_SPARSE | ATTR_IS_COMPRESSED))) {
+			err = 0;
+			goto err_out;
+		}
+
+		if (le32_to_cpu(a->data.resident.value_length)) {
+			pr_err("Can't change sparse/compressed for non-empty file");
+			err = -EOPNOTSUPP;
+			goto err_out;
+		}
+
+		err = ntfs_attr_make_non_resident(ni, 0);
+		if (err)
+			goto err_out;
+
+		ntfs_attr_reinit_search_ctx(ctx);
+		err = ntfs_attr_lookup(ni->type, ni->name,
+				ni->name_len, CASE_SENSITIVE,
+				0, NULL, 0, ctx);
+		if (err) {
+			err = -EINVAL;
+			goto err_out;
+		}
+		a = ctx->attr;
+	} else {
+		if (a->data.non_resident.data_size) {
+			pr_err("Can't change sparsed/compressed for non-empty file");
+			err = -EOPNOTSUPP;
+			goto err_out;
+		}
+	}
+
+	old_name_ofs = le16_to_cpu(a->name_offset);
+	old_mp_ofs = le16_to_cpu(a->data.non_resident.mapping_pairs_offset);
+
+	if (new_aflags & (ATTR_IS_SPARSE | ATTR_IS_COMPRESSED))
+		name_ofs = (offsetof(struct attr_record,
+				     data.non_resident.compressed_size) +
+					sizeof(a->data.non_resident.compressed_size) + 7) & ~7;
+	else
+		name_ofs = (offsetof(struct attr_record,
+				     data.non_resident.compressed_size) + 7) & ~7;
+
+	mp_size = ntfs_get_size_for_mapping_pairs(ni->vol, ni->runlist.rl, 0, -1, -1);
+	if (unlikely(mp_size < 0)) {
+		err = mp_size;
+		ntfs_debug("Failed to get size for mapping pairs array, error code %i.\n", err);
+		goto err_out;
+	}
+
+	mp_ofs = (name_ofs + a->name_length * sizeof(__le16) + 7) & ~7;
+	arec_size = (mp_ofs + mp_size + 7) & ~7;
+	old_arec_size = le32_to_cpu(a->length);
+
+	/*
+	 * Move payloads before shrinking the record. Otherwise resizing moves
+	 * the following attribute over the old payload before it can be copied.
+	 *
+	 * When offsets increase, move mapping_pairs first to avoid name
+	 * overwriting the start of mapping_pairs.
+	 */
+	if (arec_size < old_arec_size) {
+		if (name_ofs > old_name_ofs) {
+			/* Payload offsets increased: move mapping pairs first. */
+			if (mp_ofs != old_mp_ofs)
+				memmove((u8 *)a + mp_ofs,
+						(u8 *)a + old_mp_ofs,
+						mp_size);
+			if (a->name_length && name_ofs != old_name_ofs)
+				memmove((u8 *)a + name_ofs,
+						(u8 *)a + old_name_ofs,
+						a->name_length *
+							sizeof(__le16));
+		} else {
+			/* Payload offsets decreased or unchanged: move name first. */
+			if (a->name_length && name_ofs != old_name_ofs)
+				memmove((u8 *)a + name_ofs,
+						(u8 *)a + old_name_ofs,
+						a->name_length *
+							sizeof(__le16));
+			if (mp_ofs != old_mp_ofs)
+				memmove((u8 *)a + mp_ofs,
+						(u8 *)a + old_mp_ofs,
+						mp_size);
+		}
+	}
+
+	err = ntfs_attr_record_resize(ctx->mrec, a, arec_size);
+	if (unlikely(err))
+		goto err_out;
+
+	/*
+	 * When compressed/sparse state changes, the non-resident header grows or
+	 * shrinks by the compressed_size field. Update the in-record payload layout
+	 * to match the new offsets before exposing the new mapping_pairs_offset.
+	 */
+	if (arec_size > old_arec_size) {
+		if (mp_ofs != old_mp_ofs)
+			memmove((u8 *)a + mp_ofs, (u8 *)a + old_mp_ofs, mp_size);
+		if (a->name_length)
+			memmove((u8 *)a + name_ofs, (u8 *)a + old_name_ofs,
+				a->name_length * sizeof(__le16));
+	}
+
+	if (new_aflags & (ATTR_IS_SPARSE | ATTR_IS_COMPRESSED)) {
+		a->data.non_resident.compression_unit = 0;
+		if (new_aflags & ATTR_IS_COMPRESSED || ni->vol->major_ver < 3)
+			a->data.non_resident.compression_unit = 4;
+		a->data.non_resident.compressed_size = 0;
+		ni->itype.compressed.size = 0;
+		if (a->data.non_resident.compression_unit) {
+			ni->itype.compressed.block_size = 1U <<
+				(a->data.non_resident.compression_unit +
+				 ni->vol->cluster_size_bits);
+			ni->itype.compressed.block_size_bits =
+					ffs(ni->itype.compressed.block_size) -
+					1;
+			ni->itype.compressed.block_clusters = 1U <<
+					a->data.non_resident.compression_unit;
+		} else {
+			ni->itype.compressed.block_size = 0;
+			ni->itype.compressed.block_size_bits = 0;
+			ni->itype.compressed.block_clusters = 0;
+		}
+	} else {
+		a->data.non_resident.compression_unit = 0;
+	}
+
+	a->name_offset = cpu_to_le16(name_ofs);
+	a->data.non_resident.mapping_pairs_offset = cpu_to_le16(mp_ofs);
+
+	a->flags = new_aflags;
+
+	if (new_aflags & ATTR_IS_SPARSE) {
+		NInoSetSparse(ni);
+		ni->flags |= FILE_ATTR_SPARSE_FILE;
+	} else {
+		NInoClearSparse(ni);
+		ni->flags &= ~FILE_ATTR_SPARSE_FILE;
+	}
+
+	if (new_aflags & ATTR_IS_COMPRESSED) {
+		NInoSetCompressed(ni);
+		ni->flags |= FILE_ATTR_COMPRESSED;
+	} else {
+		NInoClearCompressed(ni);
+		ni->flags &= ~FILE_ATTR_COMPRESSED;
+	}
+
+	mark_mft_record_dirty(ctx->ntfs_ino);
+err_out:
+	if (ctx)
+		ntfs_attr_put_search_ctx(ctx);
+	unmap_mft_record(ni);
+	return err;
+}
+
+static bool ntfs_is_reserved_lxattr(const char *name)
+{
+	return !strcmp(name, "$LXUID") || !strcmp(name, "$LXGID") ||
+	       !strcmp(name, "$LXMOD") || !strcmp(name, "$LXDEV");
+}
+
+static int ntfs_validate_fattr(struct ntfs_inode *ni, __le32 fattr)
+{
+	const __le32 wof_flags = FILE_ATTR_SPARSE_FILE |
+				 FILE_ATTR_REPARSE_POINT;
+
+	if (NInoWofCompressed(ni) && ((ni->flags ^ fattr) & wof_flags))
+		return -EPERM;
+
+	return 0;
+}
+
+static int ntfs_setxattr(const struct xattr_handler *handler,
+		struct mnt_idmap *idmap, struct dentry *unused,
+		struct inode *inode, const char *name, const void *value,
+		size_t size, int flags)
+{
+	struct ntfs_inode *ni = NTFS_I(inode);
+	int err;
+	__le32 fattr;
+
+	if (NVolShutdown(ni->vol))
+		return -EIO;
+
+	if (ntfs_is_reserved_lxattr(name) && !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (!strcmp(name, SYSTEM_DOS_ATTRIB)) {
+		if (sizeof(u8) != size) {
+			err = -EINVAL;
+			goto out;
+		}
+		fattr = cpu_to_le32((le32_to_cpu(ni->flags) & ~0xffU) |
+				    *(u8 *)value);
+		goto set_fattr;
+	}
+
+	if (!strcmp(name, SYSTEM_NTFS_ATTRIB) ||
+	    !strcmp(name, SYSTEM_NTFS_ATTRIB_BE)) {
+		if (size != sizeof(u32)) {
+			err = -EINVAL;
+			goto out;
+		}
+		if (!strcmp(name, SYSTEM_NTFS_ATTRIB_BE))
+			fattr = cpu_to_le32(be32_to_cpu(*(__be32 *)value));
+		else
+			fattr = cpu_to_le32(*(u32 *)value);
+
+		err = ntfs_validate_fattr(ni, fattr);
+		if (err)
+			goto out;
+
+		if (S_ISREG(inode->i_mode)) {
+			mutex_lock(&ni->mrec_lock);
+			err = ntfs_new_attr_flags(ni, fattr);
+			mutex_unlock(&ni->mrec_lock);
+			if (err)
+				goto out;
+		}
+
+set_fattr:
+		if (S_ISDIR(inode->i_mode))
+			fattr |= FILE_ATTR_DIRECTORY;
+		else
+			fattr &= ~FILE_ATTR_DIRECTORY;
+
+		err = ntfs_validate_fattr(ni, fattr);
+		if (err)
+			goto out;
+
+		if (ni->flags != fattr) {
+			ni->flags = fattr;
+			if (fattr & FILE_ATTR_READONLY)
+				inode->i_mode &= ~0222;
+			else
+				inode->i_mode |= 0222;
+			NInoSetFileNameDirty(ni);
+			mark_inode_dirty(inode);
+		}
+		err = 0;
+		goto out;
+	}
+
+	mutex_lock(&ni->mrec_lock);
+	err = ntfs_set_ea(inode, name, strlen(name), value, size, flags, NULL);
+	mutex_unlock(&ni->mrec_lock);
+
+out:
+	if (!err) {
+		inode_set_ctime_current(inode);
+		mark_inode_dirty(inode);
+	}
+	return err;
+}
+
+static bool ntfs_xattr_user_list(struct dentry *dentry)
+{
+	return true;
+}
+
+// clang-format off
+static const struct xattr_handler ntfs_other_xattr_handler = {
+	.prefix	= "",
+	.get	= ntfs_getxattr,
+	.set	= ntfs_setxattr,
+	.list	= ntfs_xattr_user_list,
+};
+
+const struct xattr_handler * const ntfs_xattr_handlers[] = {
+	&ntfs_other_xattr_handler,
+	NULL,
+};
+// clang-format on
+
+#ifdef CONFIG_NTFS_FS_POSIX_ACL
+struct posix_acl *ntfs_get_acl(struct mnt_idmap *idmap, struct dentry *dentry,
+			       int type)
+{
+	struct inode *inode = d_inode(dentry);
+	struct ntfs_inode *ni = NTFS_I(inode);
+	const char *name;
+	size_t name_len;
+	struct posix_acl *acl;
+	int err;
+	void *buf;
+
+	buf = kmalloc(PATH_MAX, GFP_KERNEL);
+	if (!buf)
+		return ERR_PTR(-ENOMEM);
+
+	/* Possible values of 'type' was already checked above. */
+	if (type == ACL_TYPE_ACCESS) {
+		name = XATTR_NAME_POSIX_ACL_ACCESS;
+		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
+	} else {
+		name = XATTR_NAME_POSIX_ACL_DEFAULT;
+		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
+	}
+
+	mutex_lock(&ni->mrec_lock);
+	err = ntfs_get_ea(inode, name, name_len, buf, PATH_MAX);
+	mutex_unlock(&ni->mrec_lock);
+
+	/* Translate extended attribute to acl. */
+	if (err >= 0)
+		acl = posix_acl_from_xattr(&init_user_ns, buf, err);
+	else if (err == -ENODATA)
+		acl = NULL;
+	else
+		acl = ERR_PTR(err);
+
+	if (!IS_ERR(acl))
+		set_cached_acl(inode, type, acl);
+
+	kfree(buf);
+
+	return acl;
+}
+
+static noinline int ntfs_set_acl_ex(struct mnt_idmap *idmap,
+				    struct inode *inode, struct posix_acl *acl,
+				    int type, bool init_acl)
+{
+	const char *name;
+	size_t size, name_len;
+	void *value;
+	int err;
+	int flags;
+	umode_t mode;
+
+	if (S_ISLNK(inode->i_mode))
+		return -EOPNOTSUPP;
+
+	mode = inode->i_mode;
+	switch (type) {
+	case ACL_TYPE_ACCESS:
+		/* Do not change i_mode if we are in init_acl */
+		if (acl && !init_acl) {
+			err = posix_acl_update_mode(idmap, inode, &mode, &acl);
+			if (err)
+				return err;
+		}
+		name = XATTR_NAME_POSIX_ACL_ACCESS;
+		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
+		break;
+
+	case ACL_TYPE_DEFAULT:
+		if (!S_ISDIR(inode->i_mode))
+			return acl ? -EACCES : 0;
+		name = XATTR_NAME_POSIX_ACL_DEFAULT;
+		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	if (!acl) {
+		/* Remove xattr if it can be presented via mode. */
+		size = 0;
+		value = NULL;
+		flags = XATTR_REPLACE;
+	} else {
+		value = posix_acl_to_xattr(&init_user_ns, acl, &size, GFP_NOFS);
+		if (!value)
+			return -ENOMEM;
+		flags = 0;
+	}
+
+	mutex_lock(&NTFS_I(inode)->mrec_lock);
+	err = ntfs_set_ea(inode, name, name_len, value, size, flags, NULL);
+	mutex_unlock(&NTFS_I(inode)->mrec_lock);
+	if (err == -ENODATA && !size)
+		err = 0; /* Removing non existed xattr. */
+	if (!err) {
+		__le16 ea_size = 0;
+		umode_t old_mode = inode->i_mode;
+
+		inode->i_mode = mode;
+		mutex_lock(&NTFS_I(inode)->mrec_lock);
+		err = ntfs_ea_set_wsl_inode(inode, 0, &ea_size, NTFS_EA_MODE);
+		if (err) {
+			ntfs_set_ea(inode, name, name_len, NULL, 0,
+				    XATTR_REPLACE, NULL);
+			mutex_unlock(&NTFS_I(inode)->mrec_lock);
+			inode->i_mode = old_mode;
+			goto out;
+		}
+		mutex_unlock(&NTFS_I(inode)->mrec_lock);
+
+		set_cached_acl(inode, type, acl);
+		inode_set_ctime_current(inode);
+		mark_inode_dirty(inode);
+	}
+
+out:
+	kfree(value);
+
+	return err;
+}
+
+int ntfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
+		 struct posix_acl *acl, int type)
+{
+	return ntfs_set_acl_ex(idmap, d_inode(dentry), acl, type, false);
+}
+
+int ntfs_init_acl(struct mnt_idmap *idmap, struct inode *inode,
+		  struct inode *dir)
+{
+	struct posix_acl *default_acl, *acl;
+	int err;
+
+	err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
+	if (err)
+		return err;
+
+	if (default_acl) {
+		err = ntfs_set_acl_ex(idmap, inode, default_acl,
+				      ACL_TYPE_DEFAULT, true);
+		posix_acl_release(default_acl);
+	} else {
+		inode->i_default_acl = NULL;
+	}
+
+	if (acl) {
+		if (!err)
+			err = ntfs_set_acl_ex(idmap, inode, acl,
+					      ACL_TYPE_ACCESS, true);
+		posix_acl_release(acl);
+	} else {
+		inode->i_acl = NULL;
+	}
+
+	return err;
+}
+#endif