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| author | Eric Biggers <ebiggers@google.com> | 2018-02-06 15:41:45 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-02-06 18:32:47 -0800 |
| commit | 4c2e4befb3cc9ce42d506aa537c9ab504723e98c (patch) | |
| tree | 5419e5965a7f07a39d1db8767148d547907f9c0d /fs/pipe.c | |
| parent | e7c52b84fb18f08ce49b6067ae6285aca79084a8 (diff) | |
| download | linux-4c2e4befb3cc9ce42d506aa537c9ab504723e98c.tar.bz2 | |
pipe, sysctl: drop 'min' parameter from pipe-max-size converter
Patch series "pipe: buffer limits fixes and cleanups", v2.
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.
This patch (of 7):
Before validating the given value against pipe_min_size,
do_proc_dopipe_max_size_conv() calls round_pipe_size(), which rounds the
value up to pipe_min_size. Therefore, the second check against
pipe_min_size is redundant. Remove it.
Link: http://lkml.kernel.org/r/20180111052902.14409-2-ebiggers3@gmail.com
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "Luis R . Rodriguez" <mcgrof@kernel.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/pipe.c')
| -rw-r--r-- | fs/pipe.c | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/fs/pipe.c b/fs/pipe.c index a449ca0ec0c6..1f6ec1051e59 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -35,11 +35,6 @@ */ unsigned int pipe_max_size = 1048576; -/* - * Minimum pipe size, as required by POSIX - */ -unsigned int pipe_min_size = PAGE_SIZE; - /* Maximum allocatable pages per user. Hard limit is unset by default, soft * matches default values. */ @@ -1024,8 +1019,9 @@ unsigned int round_pipe_size(unsigned int size) { unsigned long nr_pages; - if (size < pipe_min_size) - size = pipe_min_size; + /* Minimum pipe size, as required by POSIX */ + if (size < PAGE_SIZE) + size = PAGE_SIZE; nr_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; if (nr_pages == 0) |