From 6bc733e9f71c937f3c64159bf1e569321726a44c Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Thu, 1 Dec 2005 20:21:57 +0000 Subject: [PATCH] [SCSI] st: fix a bug in sgl_map_user_pages failure path Nick and I had already been looking at drivers/scsi/{sg.c,st.c}, brought there by __put_page in sg.c's peculiar sg_rb_correct4mmap, which we'd like to remove. But that's irrelevant to your pain, except... One extract from the patches I'd like to send Doug and Kai for 2.6.15 or 2.6.16 is this below: since the incomplete get_user_pages path omits to reset res, but has already released all the pages, it will result in premature freeing of user pages, and behaviour just like you've seen. Though I'd have thought incomplete get_user_pages was an exceptional case, and a bit surprised you'd encounter it. Perhaps there's some other premature freeing in the driver, and this instance has nothing whatever to do with it. If the problem were easily reproducible, it'd be great if you could try this patch; but I think you've said it's not :-( Signed-off-by: Kai Makisara Signed-off-by: James Bottomley --- drivers/scsi/st.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c index 770c4324f3d5..b1056d290ae2 100644 --- a/drivers/scsi/st.c +++ b/drivers/scsi/st.c @@ -4509,6 +4509,7 @@ static int sgl_map_user_pages(struct scatterlist *sgl, const unsigned int max_pa if (res > 0) { for (j=0; j < res; j++) page_cache_release(pages[j]); + res = 0; } kfree(pages); return res; -- 2.30.2