path: root/include/linux/security.h
diff options
authorSerge Hallyn <shallyn@cisco.com>2020-11-15 21:55:31 -0600
committerJames Morris <jamorris@linux.microsoft.com>2020-12-04 16:24:11 -0800
commited9b25d1970a4787ac6a39c2091e63b127ecbfc1 (patch)
treec211ce51c5ce295de01d86d82fa5d04a4009d27e /include/linux/security.h
parentbbf5c979011a099af5dc76498918ed7df445635b (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/linux/security.h')
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)