From 345e1ae0c6ba54f6a4d32154e80cadc2ee2ef1af Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 27 Aug 2021 23:22:02 +0100 Subject: [PATCH] afs: Fix missing put on afs_read objects and missing get on the key therein The afs_read objects created by afs_req_issue_op() get leaked because afs_alloc_read() returns a ref and then afs_fetch_data() gets its own ref which is released when the operation completes, but the initial ref is never released. Fix this by discarding the initial ref at the end of afs_req_issue_op(). This leak also covered another bug whereby a ref isn't got on the key attached to the read record by afs_req_issue_op(). This isn't a problem as long as the afs_read req never goes away... Fix this by calling key_get() in afs_req_issue_op(). This was found by the generic/074 test. It leaks a bunch of kmalloc-192 objects each time it is run, which can be observed by watching /proc/slabinfo. Fixes: f7605fa869cf ("afs: Fix leak of afs_read objects") Reported-by: Marc Dionne Signed-off-by: David Howells Reviewed-and-tested-by: Marc Dionne cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/163010394740.3035676.8516846193899793357.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/163111665914.283156.3038561975681836591.stgit@warthog.procyon.org.uk/ --- fs/afs/file.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/afs/file.c b/fs/afs/file.c index db035ae2a134..6688fff14b0b 100644 --- a/fs/afs/file.c +++ b/fs/afs/file.c @@ -295,7 +295,7 @@ static void afs_req_issue_op(struct netfs_read_subrequest *subreq) fsreq->subreq = subreq; fsreq->pos = subreq->start + subreq->transferred; fsreq->len = subreq->len - subreq->transferred; - fsreq->key = subreq->rreq->netfs_priv; + fsreq->key = key_get(subreq->rreq->netfs_priv); fsreq->vnode = vnode; fsreq->iter = &fsreq->def_iter; @@ -304,6 +304,7 @@ static void afs_req_issue_op(struct netfs_read_subrequest *subreq) fsreq->pos, fsreq->len); afs_fetch_data(fsreq->vnode, fsreq); + afs_put_read(fsreq); } static int afs_symlink_readpage(struct page *page)