The patch titled
pipe: fix pipe buffer resizing
has been added to the -mm tree. Its filename is
pipe-fix-pipe-buffer-resizing.patch
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------------------------------------------------------
Subject: pipe: fix pipe buffer resizing
From: Miklos Szeredi <mszeredi@xxxxxxx>
pipe_set_size() needs to copy pipe bufs from the old circular buffer to
the new.
The current code gets this wrong in multiple ways, resulting in oops.
Test program is available here:
http://www.kernel.org/pub/linux/kernel/people/mszeredi/piperesize/
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/pipe.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff -puN fs/pipe.c~pipe-fix-pipe-buffer-resizing fs/pipe.c
--- a/fs/pipe.c~pipe-fix-pipe-buffer-resizing
+++ a/fs/pipe.c
@@ -1145,13 +1145,20 @@ static long pipe_set_size(struct pipe_in
* and adjust the indexes.
*/
if (pipe->nrbufs) {
- const unsigned int tail = pipe->nrbufs & (pipe->buffers - 1);
- const unsigned int head = pipe->nrbufs - tail;
+ unsigned int tail;
+ unsigned int head;
+ tail = pipe->curbuf + pipe->nrbufs;
+ if (tail < pipe->buffers)
+ tail = 0;
+ else
+ tail &= (pipe->buffers - 1);
+
+ head = pipe->nrbufs - tail;
if (head)
memcpy(bufs, pipe->bufs + pipe->curbuf, head * sizeof(struct pipe_buffer));
if (tail)
- memcpy(bufs + head, pipe->bufs + pipe->curbuf, tail * sizeof(struct pipe_buffer));
+ memcpy(bufs + head, pipe->bufs, tail * sizeof(struct pipe_buffer));
}
pipe->curbuf = 0;
_
Patches currently in -mm which might be from mszeredi@xxxxxxx are
pipe-fix-pipe-buffer-resizing.patch
pipe-remove-bogus-check-from-set-size-fcntl.patch
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