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> --- fs/pipe.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) Index: linux.git/fs/pipe.c =================================================================== --- linux.git.orig/fs/pipe.c 2010-06-08 15:02:16.000000000 +0200 +++ linux.git/fs/pipe.c 2010-06-08 15:50:07.000000000 +0200 @@ -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; -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
