[RFC][PATCH 2/2] add the user namespace to the unshare syscall [try #2]
This patch allows a process to unshare its user namespace through the unshare() syscall. Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Cc: Andrew Morton <akpm@osdl.org> Cc: Kirill Korotaev <dev@openvz.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> --- kernel/fork.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) Index: 2.6.18-rc4-mm3/kernel/fork.c =================================================================== --- 2.6.18-rc4-mm3.orig/kernel/fork.c +++ 2.6.18-rc4-mm3/kernel/fork.c @@ -1603,6 +1603,7 @@ asmlinkage long sys_unshare(unsigned lon struct nsproxy *new_nsproxy = NULL, *old_nsproxy = NULL; struct uts_namespace *uts, *new_uts = NULL; struct ipc_namespace *ipc, *new_ipc = NULL; + struct user_namespace *user, *new_user = NULL; check_unshare_flags(&unshare_flags); @@ -1610,7 +1611,7 @@ asmlinkage long sys_unshare(unsigned lon err = -EINVAL; if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND| CLONE_VM|CLONE_FILES|CLONE_SYSVSEM| - CLONE_NEWUTS|CLONE_NEWIPC)) + CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWUSER)) goto bad_unshare_out; if ((err = unshare_thread(unshare_flags))) @@ -1631,18 +1632,20 @@ asmlinkage long sys_unshare(unsigned lon goto bad_unshare_cleanup_semundo; if ((err = unshare_ipcs(unshare_flags, &new_ipc))) goto bad_unshare_cleanup_uts; + if ((err = unshare_user_ns(unshare_flags, &new_user))) + goto bad_unshare_cleanup_ipc; - if (new_ns || new_uts || new_ipc) { + if (new_ns || new_uts || new_ipc || new_user) { old_nsproxy = current->nsproxy; new_nsproxy = dup_namespaces(old_nsproxy); if (!new_nsproxy) { err = -ENOMEM; - goto bad_unshare_cleanup_ipc; + goto bad_unshare_cleanup_user; } } if (new_fs || new_ns || new_sigh || new_mm || new_fd || new_ulist || - new_uts || new_ipc) { + new_uts || new_ipc || new_user) { task_lock(current); @@ -1696,12 +1699,22 @@ asmlinkage long sys_unshare(unsigned lon new_ipc = ipc; } + if (new_user) { + user = current->nsproxy->user_ns; + current->nsproxy->user_ns = new_user; + new_user = user; + } + task_unlock(current); } if (new_nsproxy) put_nsproxy(new_nsproxy); +bad_unshare_cleanup_user: + if (new_user) + put_user_ns(new_user); + bad_unshare_cleanup_ipc: if (new_ipc) put_ipc_ns(new_ipc); _______________________________________________ Containers mailing list Containers@lists.osdl.org https://lists.osdl.org/mailman/listinfo/containers