Merge tag 'pull-xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull xattr updates from Al Viro:
 "Sanitize xattr and io_uring interactions with it, add *xattrat()
  syscalls, sanitize struct filename handling in there"

* tag 'pull-xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  xattr: remove redundant check on variable err
  fs/xattr: add *at family syscalls
  new helpers: file_removexattr(), filename_removexattr()
  new helpers: file_listxattr(), filename_listxattr()
  replace do_getxattr() with saner helpers.
  replace do_setxattr() with saner helpers.
  new helper: import_xattr_name()
  fs: rename struct xattr_ctx to kernel_xattr_ctx
  xattr: switch to CLASS(fd)
  io_[gs]etxattr_prep(): just use getname()
  io_uring: IORING_OP_F[GS]ETXATTR is fine with REQ_F_FIXED_FILE
  getname_maybe_null() - the third variant of pathname copy-in
  teach filename_lookup() to treat NULL filename as ""

6 files changed, 50 insertions, 1 deletions

diff --git a/include/asm-generic/audit_change_attr.h b/include/asm-generic/audit_change_attr.h
index 331670807cf0..cc840537885f 100644
--- a/include/asm-generic/audit_change_attr.h
+++ b/include/asm-generic/audit_change_attr.h
@@ -11,9 +11,15 @@ __NR_lchown,
 __NR_fchown,
 #endif
 __NR_setxattr,
+#ifdef __NR_setxattrat
+__NR_setxattrat,
+#endif
 __NR_lsetxattr,
 __NR_fsetxattr,
 __NR_removexattr,
+#ifdef __NR_removexattrat
+__NR_removexattrat,
+#endif
 __NR_lremovexattr,
 __NR_fremovexattr,
 #ifdef __NR_fchownat
diff --git a/include/linux/fs.h b/include/linux/fs.h
index db4c0d45107a..7e29433c5ecc 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2789,6 +2789,16 @@ extern struct filename *getname_flags(const char __user *, int);
 extern struct filename *getname_uflags(const char __user *, int);
 extern struct filename *getname(const char __user *);
 extern struct filename *getname_kernel(const char *);
+extern struct filename *__getname_maybe_null(const char __user *);
+static inline struct filename *getname_maybe_null(const char __user *name, int flags)
+{
+	if (!(flags & AT_EMPTY_PATH))
+		return getname(name);
+
+	if (!name)
+		return NULL;
+	return __getname_maybe_null(name);
+}
 extern void putname(struct filename *name);
 
 extern int finish_open(struct file *file, struct dentry *dentry,
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 5758104921e6..c6333204d451 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -77,6 +77,7 @@ struct cachestat_range;
 struct cachestat;
 struct statmount;
 struct mnt_id_req;
+struct xattr_args;
 
 #include <linux/types.h>
 #include <linux/aio_abi.h>
@@ -338,23 +339,35 @@ asmlinkage long sys_io_uring_register(unsigned int fd, unsigned int op,
 				void __user *arg, unsigned int nr_args);
 asmlinkage long sys_setxattr(const char __user *path, const char __user *name,
 			     const void __user *value, size_t size, int flags);
+asmlinkage long sys_setxattrat(int dfd, const char __user *path, unsigned int at_flags,
+			       const char __user *name,
+			       const struct xattr_args __user *args, size_t size);
 asmlinkage long sys_lsetxattr(const char __user *path, const char __user *name,
 			      const void __user *value, size_t size, int flags);
 asmlinkage long sys_fsetxattr(int fd, const char __user *name,
 			      const void __user *value, size_t size, int flags);
 asmlinkage long sys_getxattr(const char __user *path, const char __user *name,
 			     void __user *value, size_t size);
+asmlinkage long sys_getxattrat(int dfd, const char __user *path, unsigned int at_flags,
+			       const char __user *name,
+			       struct xattr_args __user *args, size_t size);
 asmlinkage long sys_lgetxattr(const char __user *path, const char __user *name,
 			      void __user *value, size_t size);
 asmlinkage long sys_fgetxattr(int fd, const char __user *name,
 			      void __user *value, size_t size);
 asmlinkage long sys_listxattr(const char __user *path, char __user *list,
 			      size_t size);
+asmlinkage long sys_listxattrat(int dfd, const char __user *path,
+				unsigned int at_flags,
+				char __user *list, size_t size);
 asmlinkage long sys_llistxattr(const char __user *path, char __user *list,
 			       size_t size);
 asmlinkage long sys_flistxattr(int fd, char __user *list, size_t size);
 asmlinkage long sys_removexattr(const char __user *path,
 				const char __user *name);
+asmlinkage long sys_removexattrat(int dfd, const char __user *path,
+				  unsigned int at_flags,
+				  const char __user *name);
 asmlinkage long sys_lremovexattr(const char __user *path,
 				 const char __user *name);
 asmlinkage long sys_fremovexattr(int fd, const char __user *name);
diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index d20051865800..86b0d47984a1 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -19,6 +19,10 @@
 #include <linux/user_namespace.h>
 #include <uapi/linux/xattr.h>
 
+/* List of all open_how "versions". */
+#define XATTR_ARGS_SIZE_VER0	16 /* sizeof first published struct */
+#define XATTR_ARGS_SIZE_LATEST	XATTR_ARGS_SIZE_VER0
+
 struct inode;
 struct dentry;
 
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index 5bf6148cac2b..88dc393c2bca 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -841,8 +841,17 @@ __SYSCALL(__NR_lsm_list_modules, sys_lsm_list_modules)
 #define __NR_mseal 462
 __SYSCALL(__NR_mseal, sys_mseal)
 
+#define __NR_setxattrat 463
+__SYSCALL(__NR_setxattrat, sys_setxattrat)
+#define __NR_getxattrat 464
+__SYSCALL(__NR_getxattrat, sys_getxattrat)
+#define __NR_listxattrat 465
+__SYSCALL(__NR_listxattrat, sys_listxattrat)
+#define __NR_removexattrat 466
+__SYSCALL(__NR_removexattrat, sys_removexattrat)
+
 #undef __NR_syscalls
-#define __NR_syscalls 463
+#define __NR_syscalls 467
 
 /*
  * 32 bit systems traditionally used different
diff --git a/include/uapi/linux/xattr.h b/include/uapi/linux/xattr.h
index 9463db2dfa9d..9854f9cff3c6 100644
--- a/include/uapi/linux/xattr.h
+++ b/include/uapi/linux/xattr.h
@@ -11,6 +11,7 @@
 */
 
 #include <linux/libc-compat.h>
+#include <linux/types.h>
 
 #ifndef _UAPI_LINUX_XATTR_H
 #define _UAPI_LINUX_XATTR_H
@@ -20,6 +21,12 @@
 
 #define XATTR_CREATE	0x1	/* set value, fail if attr already exists */
 #define XATTR_REPLACE	0x2	/* set value, fail if attr does not exist */
+
+struct xattr_args {
+	__aligned_u64 __user value;
+	__u32 size;
+	__u32 flags;
+};
 #endif
 
 /* Namespaces */