[PATCH v2 0/7] pipe: buffer limits fixes and cleanups

[Eric Biggers <ebiggers3@gmail.com>]

This series simplifies the sysctl handler for pipe-max-size and fixes
another set of bugs related to the pipe buffer limits:

- The root user wasn't allowed to exceed the limits when creating new
  pipes.

- There was an off-by-one error when checking the limits, so a limit of
  N was actually treated as N - 1.

- F_SETPIPE_SZ accepted values over UINT_MAX.

- Reading the pipe buffer limits could be racy.

Changed since v1:

  - Added "Fixes" tag to "pipe: fix off-by-one error when checking buffer limits"
  - In pipe_set_size(), checked 'nr_pages' rather than 'size'
  - Fixed commit message for "pipe: simplify round_pipe_size()"

Eric Biggers (7):
  pipe, sysctl: drop 'min' parameter from pipe-max-size converter
  pipe, sysctl: remove pipe_proc_fn()
  pipe: actually allow root to exceed the pipe buffer limits
  pipe: fix off-by-one error when checking buffer limits
  pipe: reject F_SETPIPE_SZ with size over UINT_MAX
  pipe: simplify round_pipe_size()
  pipe: read buffer limits atomically

 fs/pipe.c                 | 57 ++++++++++++++++++++---------------------------
 include/linux/pipe_fs_i.h |  5 ++---
 include/linux/sysctl.h    |  3 ---
 kernel/sysctl.c           | 33 +++++----------------------
 4 files changed, 32 insertions(+), 66 deletions(-)

-- 
2.15.1