Messages in this thread Patch in this message | | | Subject | [PATCH 1/6] afs: Fix missing put on afs_read objects and missing get on the key therein | From | David Howells <> | Date | Wed, 08 Sep 2021 16:57:39 +0100 |
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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 <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/163010394740.3035676.8516846193899793357.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)
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