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| author | Jens Axboe <jens.axboe@oracle.com> | 2008-03-17 09:04:59 +0100 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2008-03-17 09:04:59 +0100 |
| commit | 16d54669427069ef2823752c365d695b0cc4748f (patch) | |
| tree | ab971bc703f790b90697d29a1e65a793b7f87628 /kernel | |
| parent | 2af3e6017e53065ddf40bb19190a29199b7ffee3 (diff) | |
| download | lwn-16d54669427069ef2823752c365d695b0cc4748f.tar.gz lwn-16d54669427069ef2823752c365d695b0cc4748f.zip | |
relay: fix subbuf_splice_actor() adding too many pages
If subbuf_pages was larger than the max number of pages the pipe
buffer will hold, subbuf_splice_actor() would happily go beyond
the array size.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/relay.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/relay.c b/kernel/relay.c index d080b9d161a7..4c035a8a248c 100644 --- a/kernel/relay.c +++ b/kernel/relay.c @@ -1066,7 +1066,7 @@ static int subbuf_splice_actor(struct file *in, unsigned int flags, int *nonpad_ret) { - unsigned int pidx, poff, total_len, subbuf_pages, ret; + unsigned int pidx, poff, total_len, subbuf_pages, nr_pages, ret; struct rchan_buf *rbuf = in->private_data; unsigned int subbuf_size = rbuf->chan->subbuf_size; uint64_t pos = (uint64_t) *ppos; @@ -1097,8 +1097,9 @@ static int subbuf_splice_actor(struct file *in, subbuf_pages = rbuf->chan->alloc_size >> PAGE_SHIFT; pidx = (read_start / PAGE_SIZE) % subbuf_pages; poff = read_start & ~PAGE_MASK; + nr_pages = min_t(unsigned int, subbuf_pages, PIPE_BUFFERS); - for (total_len = 0; spd.nr_pages < subbuf_pages; spd.nr_pages++) { + for (total_len = 0; spd.nr_pages < nr_pages; spd.nr_pages++) { unsigned int this_len, this_end, private; unsigned int cur_pos = read_start + total_len; |