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| author | Christian Göttsche <cgzones@googlemail.com> | 2024-04-26 18:20:14 +0200 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2024-11-06 18:59:44 +0100 |
| commit | 6140be90ec70c39fa844741ca3cc807dd0866394 (patch) | |
| tree | ee8da12714f8705b50eb5b66abaa78ba43626a58 /scripts | |
| parent | new helpers: file_removexattr(), filename_removexattr() (diff) | |
| download | linux-6140be90ec70c39fa844741ca3cc807dd0866394.tar.xz linux-6140be90ec70c39fa844741ca3cc807dd0866394.zip | |
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>
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[brauner: slight tweaks]
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'scripts')
| -rw-r--r-- | scripts/syscall.tbl | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/scripts/syscall.tbl b/scripts/syscall.tbl index 845e24eb372e..ebbdb3c42e9f 100644 --- a/scripts/syscall.tbl +++ b/scripts/syscall.tbl @@ -403,3 +403,7 @@ 460 common lsm_set_self_attr sys_lsm_set_self_attr 461 common lsm_list_modules sys_lsm_list_modules 462 common mseal sys_mseal +463 common setxattrat sys_setxattrat +464 common getxattrat sys_getxattrat +465 common listxattrat sys_listxattrat +466 common removexattrat sys_removexattrat |