From c7b96acf1456ef127fef461fcfedb54b81fecfbb Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 20 Mar 2013 12:49:49 -0700 Subject: [PATCH] userns: Kill nsown_capable it makes the wrong thing easy nsown_capable is a special case of ns_capable essentially for just CAP_SETUID and CAP_SETGID. For the existing users it doesn't noticably simplify things and from the suggested patches I have seen it encourages people to do the wrong thing. So remove nsown_capable. Acked-by: Serge Hallyn Signed-off-by: "Eric W. Biederman" --- fs/namespace.c | 4 ++-- fs/open.c | 2 +- include/linux/capability.h | 1 - ipc/namespace.c | 2 +- kernel/capability.c | 12 ------------ kernel/groups.c | 2 +- kernel/pid_namespace.c | 2 +- kernel/sys.c | 20 ++++++++++---------- kernel/uid16.c | 2 +- kernel/utsname.c | 2 +- net/core/net_namespace.c | 2 +- net/core/scm.c | 4 ++-- 12 files changed, 21 insertions(+), 34 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 877e427..dc519a1 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2929,8 +2929,8 @@ static int mntns_install(struct nsproxy *nsproxy, void *ns) struct path root; if (!ns_capable(mnt_ns->user_ns, CAP_SYS_ADMIN) || - !nsown_capable(CAP_SYS_CHROOT) || - !nsown_capable(CAP_SYS_ADMIN)) + !ns_capable(current_user_ns(), CAP_SYS_CHROOT) || + !ns_capable(current_user_ns(), CAP_SYS_ADMIN)) return -EPERM; if (fs->users != 1) diff --git a/fs/open.c b/fs/open.c index 9156cb0..1c9d23f 100644 --- a/fs/open.c +++ b/fs/open.c @@ -443,7 +443,7 @@ retry: goto dput_and_out; error = -EPERM; - if (!nsown_capable(CAP_SYS_CHROOT)) + if (!ns_capable(current_user_ns(), CAP_SYS_CHROOT)) goto dput_and_out; error = security_path_chroot(&path); if (error) diff --git a/include/linux/capability.h b/include/linux/capability.h index d9a4f7f4..a6ee1f9 100644 --- a/include/linux/capability.h +++ b/include/linux/capability.h @@ -210,7 +210,6 @@ extern bool has_ns_capability_noaudit(struct task_struct *t, struct user_namespace *ns, int cap); extern bool capable(int cap); extern bool ns_capable(struct user_namespace *ns, int cap); -extern bool nsown_capable(int cap); extern bool inode_capable(const struct inode *inode, int cap); extern bool file_ns_capable(const struct file *file, struct user_namespace *ns, int cap); diff --git a/ipc/namespace.c b/ipc/namespace.c index 7ee61bf..4be6581 100644 --- a/ipc/namespace.c +++ b/ipc/namespace.c @@ -171,7 +171,7 @@ static int ipcns_install(struct nsproxy *nsproxy, void *new) { struct ipc_namespace *ns = new; if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) || - !nsown_capable(CAP_SYS_ADMIN)) + !ns_capable(current_user_ns(), CAP_SYS_ADMIN)) return -EPERM; /* Ditch state from the old ipc namespace */ diff --git a/kernel/capability.c b/kernel/capability.c index f6c2ce5..6fc1c8a 100644 --- a/kernel/capability.c +++ b/kernel/capability.c @@ -433,18 +433,6 @@ bool capable(int cap) EXPORT_SYMBOL(capable); /** - * nsown_capable - Check superior capability to one's own user_ns - * @cap: The capability in question - * - * Return true if the current task has the given superior capability - * targeted at its own user namespace. - */ -bool nsown_capable(int cap) -{ - return ns_capable(current_user_ns(), cap); -} - -/** * inode_capable - Check superior capability over inode * @inode: The inode in question * @cap: The capability in question diff --git a/kernel/groups.c b/kernel/groups.c index 6b2588d..90cf1c3 100644 --- a/kernel/groups.c +++ b/kernel/groups.c @@ -233,7 +233,7 @@ SYSCALL_DEFINE2(setgroups, int, gidsetsize, gid_t __user *, grouplist) struct group_info *group_info; int retval; - if (!nsown_capable(CAP_SETGID)) + if (!ns_capable(current_user_ns(), CAP_SETGID)) return -EPERM; if ((unsigned)gidsetsize > NGROUPS_MAX) return -EINVAL; diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index 6917e8e..ee1f6bb 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -329,7 +329,7 @@ static int pidns_install(struct nsproxy *nsproxy, void *ns) struct pid_namespace *ancestor, *new = ns; if (!ns_capable(new->user_ns, CAP_SYS_ADMIN) || - !nsown_capable(CAP_SYS_ADMIN)) + !ns_capable(current_user_ns(), CAP_SYS_ADMIN)) return -EPERM; /* diff --git a/kernel/sys.c b/kernel/sys.c index 771129b..c18ecca 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -337,7 +337,7 @@ SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) if (rgid != (gid_t) -1) { if (gid_eq(old->gid, krgid) || gid_eq(old->egid, krgid) || - nsown_capable(CAP_SETGID)) + ns_capable(old->user_ns, CAP_SETGID)) new->gid = krgid; else goto error; @@ -346,7 +346,7 @@ SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) if (gid_eq(old->gid, kegid) || gid_eq(old->egid, kegid) || gid_eq(old->sgid, kegid) || - nsown_capable(CAP_SETGID)) + ns_capable(old->user_ns, CAP_SETGID)) new->egid = kegid; else goto error; @@ -387,7 +387,7 @@ SYSCALL_DEFINE1(setgid, gid_t, gid) old = current_cred(); retval = -EPERM; - if (nsown_capable(CAP_SETGID)) + if (ns_capable(old->user_ns, CAP_SETGID)) new->gid = new->egid = new->sgid = new->fsgid = kgid; else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid)) new->egid = new->fsgid = kgid; @@ -471,7 +471,7 @@ SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) new->uid = kruid; if (!uid_eq(old->uid, kruid) && !uid_eq(old->euid, kruid) && - !nsown_capable(CAP_SETUID)) + !ns_capable(old->user_ns, CAP_SETUID)) goto error; } @@ -480,7 +480,7 @@ SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) if (!uid_eq(old->uid, keuid) && !uid_eq(old->euid, keuid) && !uid_eq(old->suid, keuid) && - !nsown_capable(CAP_SETUID)) + !ns_capable(old->user_ns, CAP_SETUID)) goto error; } @@ -534,7 +534,7 @@ SYSCALL_DEFINE1(setuid, uid_t, uid) old = current_cred(); retval = -EPERM; - if (nsown_capable(CAP_SETUID)) { + if (ns_capable(old->user_ns, CAP_SETUID)) { new->suid = new->uid = kuid; if (!uid_eq(kuid, old->uid)) { retval = set_user(new); @@ -591,7 +591,7 @@ SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) old = current_cred(); retval = -EPERM; - if (!nsown_capable(CAP_SETUID)) { + if (!ns_capable(old->user_ns, CAP_SETUID)) { if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) && !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid)) goto error; @@ -673,7 +673,7 @@ SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) old = current_cred(); retval = -EPERM; - if (!nsown_capable(CAP_SETGID)) { + if (!ns_capable(old->user_ns, CAP_SETGID)) { if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) && !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid)) goto error; @@ -744,7 +744,7 @@ SYSCALL_DEFINE1(setfsuid, uid_t, uid) if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) || uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) || - nsown_capable(CAP_SETUID)) { + ns_capable(old->user_ns, CAP_SETUID)) { if (!uid_eq(kuid, old->fsuid)) { new->fsuid = kuid; if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) @@ -783,7 +783,7 @@ SYSCALL_DEFINE1(setfsgid, gid_t, gid) if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) || gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) || - nsown_capable(CAP_SETGID)) { + ns_capable(old->user_ns, CAP_SETGID)) { if (!gid_eq(kgid, old->fsgid)) { new->fsgid = kgid; goto change_okay; diff --git a/kernel/uid16.c b/kernel/uid16.c index f6c83d7..602e5bb 100644 --- a/kernel/uid16.c +++ b/kernel/uid16.c @@ -176,7 +176,7 @@ SYSCALL_DEFINE2(setgroups16, int, gidsetsize, old_gid_t __user *, grouplist) struct group_info *group_info; int retval; - if (!nsown_capable(CAP_SETGID)) + if (!ns_capable(current_user_ns(), CAP_SETGID)) return -EPERM; if ((unsigned)gidsetsize > NGROUPS_MAX) return -EINVAL; diff --git a/kernel/utsname.c b/kernel/utsname.c index 2fc8576..fd39312 100644 --- a/kernel/utsname.c +++ b/kernel/utsname.c @@ -114,7 +114,7 @@ static int utsns_install(struct nsproxy *nsproxy, void *new) struct uts_namespace *ns = new; if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) || - !nsown_capable(CAP_SYS_ADMIN)) + !ns_capable(current_user_ns(), CAP_SYS_ADMIN)) return -EPERM; get_uts_ns(ns); diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index f9765203..81d3a9a 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -651,7 +651,7 @@ static int netns_install(struct nsproxy *nsproxy, void *ns) struct net *net = ns; if (!ns_capable(net->user_ns, CAP_SYS_ADMIN) || - !nsown_capable(CAP_SYS_ADMIN)) + !ns_capable(current_user_ns(), CAP_SYS_ADMIN)) return -EPERM; put_net(nsproxy->net_ns); diff --git a/net/core/scm.c b/net/core/scm.c index 03795d0..c346f58 100644 --- a/net/core/scm.c +++ b/net/core/scm.c @@ -56,9 +56,9 @@ static __inline__ int scm_check_creds(struct ucred *creds) if ((creds->pid == task_tgid_vnr(current) || ns_capable(current->nsproxy->pid_ns->user_ns, CAP_SYS_ADMIN)) && ((uid_eq(uid, cred->uid) || uid_eq(uid, cred->euid) || - uid_eq(uid, cred->suid)) || nsown_capable(CAP_SETUID)) && + uid_eq(uid, cred->suid)) || ns_capable(cred->user_ns, CAP_SETUID)) && ((gid_eq(gid, cred->gid) || gid_eq(gid, cred->egid) || - gid_eq(gid, cred->sgid)) || nsown_capable(CAP_SETGID))) { + gid_eq(gid, cred->sgid)) || ns_capable(cred->user_ns, CAP_SETGID))) { return 0; } return -EPERM; -- 2.7.4