Vasiliy Kulikov aa6afca5bc proc: fix races against execve() of /proc/PID/fd** ... fd* files are restricted to the task's owner, and other users may not get direct access to them. But one may open any of these files and run any setuid program, keeping opened file descriptors. As there are permission checks on open(), but not on readdir() and read(), operations on the kept file descriptors will not be checked. It makes it possible to violate procfs permission model. Reading fdinfo/* may disclosure current fds' position and flags, reading directory contents of fdinfo/ and fd/ may disclosure the number of opened files by the target task. This information is not sensible per se, but it can reveal some private information (like length of a password stored in a file) under certain conditions. Used existing (un)lock_trace functions to check for ptrace_may_access(), but instead of using EPERM return code from it use EACCES to be consistent with existing proc_pid_follow_link()/proc_pid_readlink() return code. If they differ, attacker can guess what fds exist by analyzing stat() return code. Patched handlers: stat() for fd/*, stat() and read() for fdindo/*, readdir() and lookup() for fd/ and fdinfo/. Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Cc: <stable@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2011-11-02 16:07:00 -07:00
..
array.c	ptrace: s/tracehook_tracer_task()/ptrace_parent()/	2011-06-22 19:26:29 +02:00
base.c	proc: fix races against execve() of /proc/PID/fd**	2011-11-02 16:07:00 -07:00
cmdline.c
consoles.c
cpuinfo.c
devices.c
generic.c	proc: make struct proc_dir_entry::name a terminal array rather than a pointer	2011-07-27 12:50:45 -07:00
inode.c	procfs: return ENOENT on opening a being-removed proc entry	2011-07-26 16:49:43 -07:00
internal.h	Merge git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/linux-2.6-nsfd	2011-05-25 18:10:16 -07:00
interrupts.c
Kconfig
kcore.c
kmsg.c
loadavg.c
Makefile
meminfo.c	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
mmu.c
namespaces.c	proc: Fix Oops on stat of /proc/<zombie pid>/ns/net	2011-06-15 14:35:29 -07:00
nommu.c
page.c
proc_devtree.c
proc_net.c	proc: make struct proc_dir_entry::name a terminal array rather than a pointer	2011-07-27 12:50:45 -07:00
proc_sysctl.c	procfs: report EISDIR when reading sysctl dirs in proc	2011-11-02 16:07:00 -07:00
proc_tty.c
root.c	proc: make struct proc_dir_entry::name a terminal array rather than a pointer	2011-07-27 12:50:45 -07:00
softirqs.c
stat.c	proc: Consider NO_HZ when printing idle and iowait times	2011-09-08 11:10:55 +02:00
task_mmu.c	mm: distinguish between mlocked and pinned pages	2011-10-31 17:30:46 -07:00
task_nommu.c
uptime.c
version.c
vmcore.c	fs/proc/vmcore.c: add hook to read_from_oldmem() to check for non-ram pages	2011-05-26 17:12:37 -07:00