| Message ID | 20200719100418.2112740-5-areber@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | capabilities: Introduce CAP_CHECKPOINT_RESTORE | expand |
On Sun, Jul 19, 2020 at 12:04:14PM +0200, Adrian Reber wrote: > Opening files in /proc/pid/map_files when the current user is > CAP_CHECKPOINT_RESTORE capable in the root namespace is useful for > checkpointing and restoring to recover files that are unreachable via > the file system such as deleted files, or memfd files. > > Signed-off-by: Adrian Reber <areber@redhat.com> Reviewed-by: Serge Hallyn <serge@hallyn.com> > Signed-off-by: Nicolas Viennot <Nicolas.Viennot@twosigma.com> > Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com> > --- > fs/proc/base.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/fs/proc/base.c b/fs/proc/base.c > index 65893686d1f1..b824a8c89011 100644 > --- a/fs/proc/base.c > +++ b/fs/proc/base.c > @@ -2194,16 +2194,16 @@ struct map_files_info { > }; > > /* > - * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the > - * symlinks may be used to bypass permissions on ancestor directories in the > - * path to the file in question. > + * Only allow CAP_SYS_ADMIN and CAP_CHECKPOINT_RESTORE to follow the links, due > + * to concerns about how the symlinks may be used to bypass permissions on > + * ancestor directories in the path to the file in question. > */ > static const char * > proc_map_files_get_link(struct dentry *dentry, > struct inode *inode, > struct delayed_call *done) > { > - if (!capable(CAP_SYS_ADMIN)) > + if (!checkpoint_restore_ns_capable(&init_user_ns)) > return ERR_PTR(-EPERM); > > return proc_pid_get_link(dentry, inode, done); > -- > 2.26.2
diff --git a/fs/proc/base.c b/fs/proc/base.c index 65893686d1f1..b824a8c89011 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2194,16 +2194,16 @@ struct map_files_info { }; /* - * Only allow CAP_SYS_ADMIN to follow the links, due to concerns about how the - * symlinks may be used to bypass permissions on ancestor directories in the - * path to the file in question. + * Only allow CAP_SYS_ADMIN and CAP_CHECKPOINT_RESTORE to follow the links, due + * to concerns about how the symlinks may be used to bypass permissions on + * ancestor directories in the path to the file in question. */ static const char * proc_map_files_get_link(struct dentry *dentry, struct inode *inode, struct delayed_call *done) { - if (!capable(CAP_SYS_ADMIN)) + if (!checkpoint_restore_ns_capable(&init_user_ns)) return ERR_PTR(-EPERM); return proc_pid_get_link(dentry, inode, done);