linux.git/fs/proc/base.c, branch v2.6.39

proc: do proper range check on readdir offset

2011-04-18T17:36:54+00:00

Rather than pass in some random truncated offset to the pid-related
functions, check that the offset is in range up-front.

This is just cleanup, the previous commit fixed the real problem.

Cc: stable@kernel.org
Signed-off-by: Linus Torvalds

Fix common misspellings

2011-03-31T14:26:23+00:00

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6

2011-03-24T03:51:42+00:00

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  deal with races in /proc/*/{syscall,stack,personality}
  proc: enable writing to /proc/pid/mem
  proc: make check_mem_permission() return an mm_struct on success
  proc: hold cred_guard_mutex in check_mem_permission()
  proc: disable mem_write after exec
  mm: implement access_remote_vm
  mm: factor out main logic of access_process_vm
  mm: use mm_struct to resolve gate vma's in __get_user_pages
  mm: arch: rename in_gate_area_no_task to in_gate_area_no_mm
  mm: arch: make in_gate_area take an mm_struct instead of a task_struct
  mm: arch: make get_gate_vma take an mm_struct instead of a task_struct
  x86: mark associated mm when running a task in 32 bit compatibility mode
  x86: add context tag to mark mm when running a task in 32-bit compatibility mode
  auxv: require the target to be tracable (or yourself)
  close race in /proc/*/environ
  report errors in /proc/*/*map* sanely
  pagemap: close races with suid execve
  make sessionid permissions in /proc/*/task/* match those in /proc/*
  fix leaks in path_lookupat()

Fix up trivial conflicts in fs/proc/base.c

procfs: fix some wrong error code usage

2011-03-24T02:46:36+00:00

[root@wei 1]# cat /proc/1/mem
cat: /proc/1/mem: No such process

error code -ESRCH is wrong in this situation.  Return -EPERM instead.

Signed-off-by: Jovi Zhang 
Reviewed-by: KOSAKI Motohiro 
Cc: Alexey Dobriyan 
Cc: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

proc: hide kernel addresses via %pK in /proc//stack

2011-03-24T02:46:36+00:00

This file is readable for the task owner.  Hide kernel addresses from
unprivileged users, leave them function names and offsets.

Signed-off-by: Konstantin Khlebnikov 
Acked-by: Kees Cook 
Cc: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

deal with races in /proc/*/{syscall,stack,personality}

2011-03-23T21:01:18+00:00

All of those are rw-r--r-- and all are broken for suid - if you open
a file before the target does suid-root exec, you'll be still able
to access it.  For personality it's not a big deal, but for syscall
and stack it's a real problem.

Fix: check that task is tracable for you at the time of read().

Signed-off-by: Al Viro

proc: enable writing to /proc/pid/mem

2011-03-23T20:36:59+00:00

With recent changes there is no longer a security hazard with writing to
/proc/pid/mem.  Remove the #ifdef.

Signed-off-by: Stephen Wilson 
Signed-off-by: Al Viro

proc: make check_mem_permission() return an mm_struct on success

2011-03-23T20:36:59+00:00

This change allows us to take advantage of access_remote_vm(), which in turn
eliminates a security issue with the mem_write() implementation.

The previous implementation of mem_write() was insecure since the target task
could exec a setuid-root binary between the permission check and the actual
write.  Holding a reference to the target mm_struct eliminates this
vulnerability.

Signed-off-by: Stephen Wilson 
Signed-off-by: Al Viro

proc: hold cred_guard_mutex in check_mem_permission()

2011-03-23T20:36:58+00:00

Avoid a potential race when task exec's and we get a new ->mm but check against
the old credentials in ptrace_may_access().

Holding of the mutex is implemented by factoring out the body of the code into a
helper function __check_mem_permission().  Performing this factorization now
simplifies upcoming changes and minimizes churn in the diff's.

Signed-off-by: Stephen Wilson 
Signed-off-by: Al Viro

proc: disable mem_write after exec

2011-03-23T20:36:58+00:00

This change makes mem_write() observe the same constraints as mem_read().  This
is particularly important for mem_write as an accidental leak of the fd across
an exec could result in arbitrary modification of the target process' memory.
IOW, /proc/pid/mem is implicitly close-on-exec.

Signed-off-by: Stephen Wilson 
Signed-off-by: Al Viro