commit: 7c6175afc50eb106b1dbb9712e638fe2cf976c85 Author: Anthony G. Basile <blueness <AT> gentoo <DOT> org> AuthorDate: Tue Oct 7 01:40:44 2014 +0000 Commit: Anthony G. Basile <blueness <AT> gentoo <DOT> org> CommitDate: Tue Oct 7 01:41:07 2014 +0000 URL: http://sources.gentoo.org/gitweb/?p=proj/linux-patches.git;a=commit;h=7c6175af
Add patch to support namespace user.pax.* on tmpfs, bug #470644 This patch is needed on all Gentoo to preserve end-to-end support of PaX flags held in the extended attribute namespace user.pax.* Even non-hardened Gentoo users need this in case they switch from a gentoo-sources kernel to hardened. With the XATTR_PAX markings already in place, they do not need to remake the PaX flags on all their ELF objects because it will already be done. --- 0000_README | 4 ++++ 1500_XATTR_USER_PREFIX.patch | 54 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 58 insertions(+) diff --git a/0000_README b/0000_README index 9018993..36c2b96 100644 --- a/0000_README +++ b/0000_README @@ -43,6 +43,10 @@ EXPERIMENTAL Individual Patch Descriptions: -------------------------------------------------------------------------- +Patch: 1500_XATTR_USER_PREFIX.patch +From: https://bugs.gentoo.org/show_bug.cgi?id=470644 +Desc: Support for namespace user.pax.* on tmpfs. + Patch: 4567_distro-Gentoo-Kconfig.patch From: Tom Wijsman <tom...@gentoo.org> Desc: Add Gentoo Linux support config settings and defaults. diff --git a/1500_XATTR_USER_PREFIX.patch b/1500_XATTR_USER_PREFIX.patch new file mode 100644 index 0000000..cc15cd5 --- /dev/null +++ b/1500_XATTR_USER_PREFIX.patch @@ -0,0 +1,54 @@ +From: Anthony G. Basile <bluen...@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 e4629b9..6958086 100644 +--- a/include/uapi/linux/xattr.h ++++ b/include/uapi/linux/xattr.h +@@ -63,5 +63,9 @@ + #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 */ +diff --git a/mm/shmem.c b/mm/shmem.c +index 1c44af7..f23bb1b 100644 +--- a/mm/shmem.c ++++ b/mm/shmem.c +@@ -2201,6 +2201,7 @@ static const struct xattr_handler *shmem_xattr_handlers[] = { + static int shmem_xattr_validate(const char *name) + { + struct { const char *prefix; size_t len; } arr[] = { ++ { XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN}, + { XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN }, + { XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN } + }; +@@ -2256,6 +2257,12 @@ static int shmem_setxattr(struct dentry *dentry, const char *name, + if (err) + return err; + ++ 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); + } +
