linux/include/asm-generic/audit_change_attr.h
Christian Göttsche 6140be90ec fs/xattr: add *at family syscalls
Add the four syscalls setxattrat(), getxattrat(), listxattrat() and
removexattrat().  Those can be used to operate on extended attributes,
especially security related ones, either relative to a pinned directory
or on a file descriptor without read access, avoiding a
/proc/<pid>/fd/<fd> detour, requiring a mounted procfs.

One use case will be setfiles(8) setting SELinux file contexts
("security.selinux") without race conditions and without a file
descriptor opened with read access requiring SELinux read permission.

Use the do_{name}at() pattern from fs/open.c.

Pass the value of the extended attribute, its length, and for
setxattrat(2) the command (XATTR_CREATE or XATTR_REPLACE) via an added
struct xattr_args to not exceed six syscall arguments and not
merging the AT_* and XATTR_* flags.

[AV: fixes by Christian Brauner folded in, the entire thing rebased on
top of {filename,file}_...xattr() primitives, treatment of empty
pathnames regularized.  As the result, AT_EMPTY_PATH+NULL handling
is cheap, so f...(2) can use it]

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Link: https://lore.kernel.org/r/20240426162042.191916-1-cgoettsche@seltendoof.de
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
CC: x86@kernel.org
CC: linux-alpha@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: linux-arm-kernel@lists.infradead.org
CC: linux-ia64@vger.kernel.org
CC: linux-m68k@lists.linux-m68k.org
CC: linux-mips@vger.kernel.org
CC: linux-parisc@vger.kernel.org
CC: linuxppc-dev@lists.ozlabs.org
CC: linux-s390@vger.kernel.org
CC: linux-sh@vger.kernel.org
CC: sparclinux@vger.kernel.org
CC: linux-fsdevel@vger.kernel.org
CC: audit@vger.kernel.org
CC: linux-arch@vger.kernel.org
CC: linux-api@vger.kernel.org
CC: linux-security-module@vger.kernel.org
CC: selinux@vger.kernel.org
[brauner: slight tweaks]
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-11-06 12:59:44 -05:00

40 lines
584 B
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifdef __NR_chmod
__NR_chmod,
#endif
__NR_fchmod,
#ifdef __NR_chown
__NR_chown,
__NR_lchown,
#endif
#ifdef __NR_fchown
__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
__NR_fchownat,
__NR_fchmodat,
#endif
#ifdef __NR_chown32
__NR_chown32,
__NR_fchown32,
__NR_lchown32,
#endif
#ifdef __NR_link
__NR_link,
#endif
#ifdef __NR_linkat
__NR_linkat,
#endif