From 1f24b8302c77dcaf79c64c073877a3b9f4dd25d2 Mon Sep 17 00:00:00 2001 From: Wentao Liang Date: Mon, 18 May 2026 13:10:36 +0000 Subject: pNFS: Fix use-after-free in pnfs_update_layout() commit 13e198a90ca4050f4bee8a3f23680389a6563ccc upstream. When hitting the NFS_LAYOUT_RETURN branch in pnfs_update_layout(), the code calls pnfs_prepare_to_retry_layoutget(lo). If it succeeds, pnfs_put_layout_hdr(lo) is called before trace_pnfs_update_layout(), which still references 'lo'. This results in a use-after-free when the tracepoint accesses lo's fields. Fix this by moving the tracepoint call before pnfs_put_layout_hdr(lo). Fixes: 2c8d5fc37fe2 ("pNFS: Stricter ordering of layoutget and layoutreturn") Cc: stable@vger.kernel.org Signed-off-by: Wentao Liang Signed-off-by: Anna Schumaker Signed-off-by: Greg Kroah-Hartman --- fs/nfs/pnfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index 041cb7a96e8d..2b70a40d613a 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -2067,11 +2067,11 @@ lookup_again: dprintk("%s wait for layoutreturn\n", __func__); lseg = ERR_PTR(pnfs_prepare_to_retry_layoutget(lo)); if (!IS_ERR(lseg)) { - pnfs_put_layout_hdr(lo); dprintk("%s retrying\n", __func__); trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg, PNFS_UPDATE_LAYOUT_RETRY); + pnfs_put_layout_hdr(lo); goto lookup_again; } trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg, -- cgit v1.2.3