diff options
author | Serge Hallyn | 2020-11-15 21:55:31 -0600 |
---|---|---|
committer | James Morris | 2020-12-04 16:24:11 -0800 |
commit | ed9b25d1970a4787ac6a39c2091e63b127ecbfc1 (patch) | |
tree | c211ce51c5ce295de01d86d82fa5d04a4009d27e /include | |
parent | bbf5c979011a099af5dc76498918ed7df445635b (diff) |
[SECURITY] fix namespaced fscaps when !CONFIG_SECURITY
Namespaced file capabilities were introduced in 8db6c34f1dbc .
When userspace reads an xattr for a namespaced capability, a
virtualized representation of it is returned if the caller is
in a user namespace owned by the capability's owning rootid.
The function which performs this virtualization was not hooked
up if CONFIG_SECURITY=n. Therefore in that case the original
xattr was shown instead of the virtualized one.
To test this using libcap-bin (*1),
$ v=$(mktemp)
$ unshare -Ur setcap cap_sys_admin-eip $v
$ unshare -Ur setcap -v cap_sys_admin-eip $v
/tmp/tmp.lSiIFRvt8Y: OK
"setcap -v" verifies the values instead of setting them, and
will check whether the rootid value is set. Therefore, with
this bug un-fixed, and with CONFIG_SECURITY=n, setcap -v will
fail:
$ v=$(mktemp)
$ unshare -Ur setcap cap_sys_admin=eip $v
$ unshare -Ur setcap -v cap_sys_admin=eip $v
nsowner[got=1000, want=0],/tmp/tmp.HHDiOOl9fY differs in []
Fix this bug by calling cap_inode_getsecurity() in
security_inode_getsecurity() instead of returning
-EOPNOTSUPP, when CONFIG_SECURITY=n.
*1 - note, if libcap is too old for getcap to have the '-n'
option, then use verify-caps instead.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=209689
Cc: Hervé Guillemet <herve@guillemet.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Serge Hallyn <shallyn@cisco.com>
Signed-off-by: Andrew G. Morgan <morgan@kernel.org>
Signed-off-by: James Morris <jamorris@linux.microsoft.com>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/security.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/security.h b/include/linux/security.h index 0a0a03b36a3b..2befc0a25eb3 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -864,7 +864,7 @@ static inline int security_inode_killpriv(struct dentry *dentry) static inline int security_inode_getsecurity(struct inode *inode, const char *name, void **buffer, bool alloc) { - return -EOPNOTSUPP; + return cap_inode_getsecurity(inode, name, buffer, alloc); } static inline int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags) |