3.5.7.18 -stable review patch. If anyone has any objections, please let me know. ------------------ From: NeilBrown <neilb@xxxxxxx> commit 0eb25bb027a100f5a9df8991f2f628e7d851bc1e upstream. We always need to be careful when calling generic_make_request, as it can start a chain of events which might free something that we are using. Here is one place I wasn't careful enough. If the wbio2 is not in use, then it might get freed at the first generic_make_request call. So perform all necessary tests first. This bug was introduced in 3.3-rc3 (24afd80d99) and can cause an oops, so fix is suitable for any -stable since then. Signed-off-by: NeilBrown <neilb@xxxxxxx> [ luis: backported to 3.5: adjusted context ] Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx> --- drivers/md/raid10.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index a829557..5ad042c 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -2130,12 +2130,18 @@ static void recovery_request_write(struct mddev *mddev, struct r10bio *r10_bio) d = r10_bio->devs[1].devnum; wbio = r10_bio->devs[1].bio; wbio2 = r10_bio->devs[1].repl_bio; + /* Need to test wbio2->bi_end_io before we call + * generic_make_request as if the former is NULL, + * the latter is free to free wbio2. + */ + if (wbio2 && !wbio2->bi_end_io) + wbio2 = NULL; if (wbio->bi_end_io) { atomic_inc(&conf->mirrors[d].rdev->nr_pending); md_sync_acct(conf->mirrors[d].rdev->bdev, wbio->bi_size >> 9); generic_make_request(wbio); } - if (wbio2 && wbio2->bi_end_io) { + if (wbio2) { atomic_inc(&conf->mirrors[d].replacement->nr_pending); md_sync_acct(conf->mirrors[d].replacement->bdev, wbio2->bi_size >> 9); -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html