This is a note to let you know that I've just added the patch titled
pNFS: Fix use after free issues in pnfs_do_read()
to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: pnfs-fix-use-after-free-issues-in-pnfs_do_read.patch and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Thu Mar 22 14:40:23 CET 2018
From: Trond Myklebust trond.myklebust@primarydata.com Date: Tue, 25 Apr 2017 11:26:53 -0400 Subject: pNFS: Fix use after free issues in pnfs_do_read()
From: Trond Myklebust trond.myklebust@primarydata.com
[ Upstream commit 6aeafd05eca9bc8ab6b03d7e56d09ffd18190f44 ]
The assumption should be that if the caller returns PNFS_ATTEMPTED, then hdr has been consumed, and so we should not be testing hdr->task.tk_status. If the caller returns PNFS_TRY_AGAIN, then we need to recoalesce and free hdr.
Signed-off-by: Trond Myklebust trond.myklebust@primarydata.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/nfs/pnfs.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-)
--- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -2308,10 +2308,20 @@ pnfs_do_read(struct nfs_pageio_descripto enum pnfs_try_status trypnfs;
trypnfs = pnfs_try_to_read_data(hdr, call_ops, lseg); - if (trypnfs == PNFS_TRY_AGAIN) - pnfs_read_resend_pnfs(hdr); - if (trypnfs == PNFS_NOT_ATTEMPTED || hdr->task.tk_status) + switch (trypnfs) { + case PNFS_NOT_ATTEMPTED: pnfs_read_through_mds(desc, hdr); + case PNFS_ATTEMPTED: + break; + case PNFS_TRY_AGAIN: + /* cleanup hdr and prepare to redo pnfs */ + if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) { + struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc); + list_splice_init(&hdr->pages, &mirror->pg_list); + mirror->pg_recoalesce = 1; + } + hdr->mds_ops->rpc_release(hdr); + } }
static void pnfs_readhdr_free(struct nfs_pgio_header *hdr)
Patches currently in stable-queue which might be from trond.myklebust@primarydata.com are
queue-4.9/pnfs-fix-use-after-free-issues-in-pnfs_do_read.patch queue-4.9/pnfs-fix-a-deadlock-when-coalescing-writes-and-returning-the-layout.patch queue-4.9/nfs-fix-missing-pg_cleanup-after-nfs_pageio_cond_complete.patch