From 3b4c0371928c17af03e8397ac842346624017ce6 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 11 Mar 2022 13:24:22 +0000 Subject: watch_queue: Fix the alloc bitmap size to reflect notes allocated Currently, watch_queue_set_size() sets the number of notes available in wqueue->nr_notes according to the number of notes allocated, but sets the size of the bitmap to the unrounded number of notes originally asked for. Fix this by setting the bitmap size to the number of notes we're actually going to make available (ie. the number allocated). Fixes: c73be61cede5 ("pipe: Add general notification queue support") Reported-by: Jann Horn Signed-off-by: David Howells Signed-off-by: Linus Torvalds --- kernel/watch_queue.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/watch_queue.c b/kernel/watch_queue.c index 5b516eb2c7cc..9c476d2cbac0 100644 --- a/kernel/watch_queue.c +++ b/kernel/watch_queue.c @@ -243,6 +243,7 @@ long watch_queue_set_size(struct pipe_inode_info *pipe, unsigned int nr_notes) goto error; } + nr_notes = nr_pages * WATCH_QUEUE_NOTES_PER_PAGE; ret = pipe_resize_ring(pipe, roundup_pow_of_two(nr_notes)); if (ret < 0) goto error; @@ -266,7 +267,7 @@ long watch_queue_set_size(struct pipe_inode_info *pipe, unsigned int nr_notes) wqueue->notes = pages; wqueue->notes_bitmap = bitmap; wqueue->nr_pages = nr_pages; - wqueue->nr_notes = nr_pages * WATCH_QUEUE_NOTES_PER_PAGE; + wqueue->nr_notes = nr_notes; return 0; error_p: -- cgit v1.2.3