linux/fs/proc/root.c, branch v3.4.96

proc: fix mount -t proc -o AAA

2012-04-05T22:25:50Z

The proc_parse_options() call from proc_mount() runs only once at boot time. So on any later mount attempt, any mount options are ignored because ->s_root is already initialized. As a consequence, "mount -o " will ignore the options. The only way to change mount options is "mount -o remount,". To fix this, parse the mount options unconditionally. Signed-off-by: Vasiliy Kulikov Reported-by: Arkadiusz Miskiewicz Tested-by: Arkadiusz Miskiewicz Cc: Alexey Dobriyan Cc: Al Viro Cc: Valdis Kletnieks Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

procfs: add hidepid= and gid= mount options

2012-01-11T00:30:54Z

Add support for mount options to restrict access to /proc/PID/ directories. The default backward-compatible "relaxed" behaviour is left untouched. The first mount option is called "hidepid" and its value defines how much info about processes we want to be available for non-owners: hidepid=0 (default) means the old behavior - anybody may read all world-readable /proc/PID/* files. hidepid=1 means users may not access any /proc// directories, but their own. Sensitive files like cmdline, sched*, status are now protected against other users. As permission checking done in proc_pid_permission() and files' permissions are left untouched, programs expecting specific files' modes are not confused. hidepid=2 means hidepid=1 plus all /proc/PID/ will be invisible to other users. It doesn't mean that it hides whether a process exists (it can be learned by other means, e.g. by kill -0 $PID), but it hides process' euid and egid. It compicates intruder's task of gathering info about running processes, whether some daemon runs with elevated privileges, whether another user runs some sensitive program, whether other users run any program at all, etc. gid=XXX defines a group that will be able to gather all processes' info (as in hidepid=0 mode). This group should be used instead of putting nonroot user in sudoers file or something. However, untrusted users (like daemons, etc.) which are not supposed to monitor the tasks in the whole system should not be added to the group. hidepid=1 or higher is designed to restrict access to procfs files, which might reveal some sensitive private information like precise keystrokes timings: http://www.openwall.com/lists/oss-security/2011/11/05/3 hidepid=1/2 doesn't break monitoring userspace tools. ps, top, pgrep, and conky gracefully handle EPERM/ENOENT and behave as if the current user is the only user running processes. pstree shows the process subtree which contains "pstree" process. Note: the patch doesn't deal with setuid/setgid issues of keeping preopened descriptors of procfs files (like https://lkml.org/lkml/2011/2/7/368). We rely on that the leaked information like the scheduling counters of setuid apps doesn't threaten anybody's privacy - only the user started the setuid program may read the counters. Signed-off-by: Vasiliy Kulikov Cc: Alexey Dobriyan Cc: Al Viro Cc: Randy Dunlap Cc: "H. Peter Anvin" Cc: Greg KH Cc: Theodore Tso Cc: Alan Cox Cc: James Morris Cc: Oleg Nesterov Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

procfs: parse mount options

2012-01-11T00:30:54Z

Add support for procfs mount options. Actual mount options are coming in the next patches. Signed-off-by: Vasiliy Kulikov Cc: Alexey Dobriyan Cc: Al Viro Cc: Randy Dunlap Cc: "H. Peter Anvin" Cc: Greg KH Cc: Theodore Tso Cc: Alan Cox Cc: James Morris Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

procfs: fix a vfsmount longterm reference leak

2011-12-09T05:40:19Z

kern_mount() doesn't pair with plain mntput()... Signed-off-by: Al Viro

proc: make struct proc_dir_entry::name a terminal array rather than a pointer

2011-07-27T19:50:45Z

Since __proc_create() appends the name it is given to the end of the PDE structure that it allocates, there isn't a need to store a name pointer. Instead we can just replace the name pointer with a terminal char array of _unspecified_ length. The compiler will simply append the string to statically defined variables of PDE type overlapping any hole at the end of the structure and, unlike specifying an explicitly _zero_ length array, won't give a warning if you try to statically initialise it with a string of more than zero length. Also, whilst we're at it: (1) Move namelen to end just prior to name and reduce it to a single byte (name shouldn't be longer than NAME_MAX). (2) Move pde_unload_lock two places further on so that if it's four bytes in size on a 64-bit machine, it won't cause an unused hole in the PDE struct. Signed-off-by: David Howells Signed-off-by: Alexey Dobriyan Signed-off-by: Linus Torvalds

fix leak in proc_set_super()

2011-06-12T21:45:28Z

set_anon_super() can fail... Signed-off-by: Al Viro

procfs: kill the global proc_mnt variable

2011-03-24T02:46:58Z

After the previous cleanup in proc_get_sb() the global proc_mnt has no reasons to exists, kill it. Signed-off-by: Oleg Nesterov Signed-off-by: Eric W. Biederman Signed-off-by: Daniel Lezcano Cc: Alexey Dobriyan Acked-by: Serge E. Hallyn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

pidns: call pid_ns_prepare_proc() from create_pid_namespace()

2011-03-24T02:46:58Z

Reorganize proc_get_sb() so it can be called before the struct pid of the first process is allocated. Signed-off-by: Eric W. Biederman Signed-off-by: Daniel Lezcano Cc: Oleg Nesterov Cc: Alexey Dobriyan Acked-by: Serge E. Hallyn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

switch procfs to ->mount()

2010-10-29T08:17:01Z

Signed-off-by: Al Viro

setting ->proc_mnt doesn't belong in proc_get_sb()

2010-10-29T08:16:58Z

take that to kern_mount_data()-using callers Signed-off-by: Al Viro