diff options
Diffstat (limited to 'system/test-kernel/0120-XATTR_USER_PREFIX.patch')
| -rw-r--r-- | system/test-kernel/0120-XATTR_USER_PREFIX.patch | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/system/test-kernel/0120-XATTR_USER_PREFIX.patch b/system/test-kernel/0120-XATTR_USER_PREFIX.patch new file mode 100644 index 000000000..245dcc29f --- /dev/null +++ b/system/test-kernel/0120-XATTR_USER_PREFIX.patch @@ -0,0 +1,67 @@ +From: Anthony G. Basile <blueness@gentoo.org> + +This patch adds support for a restricted user-controlled namespace on +tmpfs filesystem used to house PaX flags. The namespace must be of the +form user.pax.* and its value cannot exceed a size of 8 bytes. + +This is needed even on all Gentoo systems so that XATTR_PAX flags +are preserved for users who might build packages using portage on +a tmpfs system with a non-hardened kernel and then switch to a +hardened kernel with XATTR_PAX enabled. + +The namespace is added to any user with Extended Attribute support +enabled for tmpfs. Users who do not enable xattrs will not have +the XATTR_PAX flags preserved. + +diff --git a/include/uapi/linux/xattr.h b/include/uapi/linux/xattr.h +index 1590c49..5eab462 100644 +--- a/include/uapi/linux/xattr.h ++++ b/include/uapi/linux/xattr.h +@@ -73,5 +73,9 @@ + #define XATTR_POSIX_ACL_DEFAULT "posix_acl_default" + #define XATTR_NAME_POSIX_ACL_DEFAULT XATTR_SYSTEM_PREFIX XATTR_POSIX_ACL_DEFAULT + ++/* User namespace */ ++#define XATTR_PAX_PREFIX XATTR_USER_PREFIX "pax." ++#define XATTR_PAX_FLAGS_SUFFIX "flags" ++#define XATTR_NAME_PAX_FLAGS XATTR_PAX_PREFIX XATTR_PAX_FLAGS_SUFFIX + + #endif /* _UAPI_LINUX_XATTR_H */ +--- a/mm/shmem.c 2020-05-04 15:30:27.042035334 -0400 ++++ b/mm/shmem.c 2020-05-04 15:34:57.013881725 -0400 +@@ -3238,6 +3238,14 @@ static int shmem_xattr_handler_set(const + struct shmem_inode_info *info = SHMEM_I(inode); + + name = xattr_full_name(handler, name); ++ ++ if (!strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)) { ++ if (strcmp(name, XATTR_NAME_PAX_FLAGS)) ++ return -EOPNOTSUPP; ++ if (size > 8) ++ return -EINVAL; ++ } ++ + return simple_xattr_set(&info->xattrs, name, value, size, flags, NULL); + } + +@@ -3253,6 +3261,12 @@ static const struct xattr_handler shmem_ + .set = shmem_xattr_handler_set, + }; + ++static const struct xattr_handler shmem_user_xattr_handler = { ++ .prefix = XATTR_USER_PREFIX, ++ .get = shmem_xattr_handler_get, ++ .set = shmem_xattr_handler_set, ++}; ++ + static const struct xattr_handler *shmem_xattr_handlers[] = { + #ifdef CONFIG_TMPFS_POSIX_ACL + &posix_acl_access_xattr_handler, +@@ -3260,6 +3274,7 @@ static const struct xattr_handler *shmem + #endif + &shmem_security_xattr_handler, + &shmem_trusted_xattr_handler, ++ &shmem_user_xattr_handler, + NULL + }; + |