+pve-kernel (5.15.19-3) bullseye; urgency=medium
+
+ * backport "lib/iov_iter: initialize "flags" in new pipe_buffer"
+ fixing CVE-2022-0847 "dirty pipe"
+
+ -- Proxmox Support Team <support@proxmox.com> Mon, 07 Mar 2022 16:23:02 +0100
+
pve-kernel (5.15.19-2) bullseye; urgency=medium
* backport fbdev memory region release improvements
--- /dev/null
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Max Kellermann <max.kellermann@ionos.com>
+Date: Mon, 21 Feb 2022 11:03:13 +0100
+Subject: [PATCH] lib/iov_iter: initialize "flags" in new pipe_buffer
+
+commit 9d2231c5d74e13b2a0546fee6737ee4446017903 upstream.
+
+The functions copy_page_to_iter_pipe() and push_pipe() can both
+allocate a new pipe_buffer, but the "flags" member initializer is
+missing.
+
+Fixes: 241699cd72a8 ("new iov_iter flavour: pipe-backed")
+To: Alexander Viro <viro@zeniv.linux.org.uk>
+To: linux-fsdevel@vger.kernel.org
+To: linux-kernel@vger.kernel.org
+Cc: stable@vger.kernel.org
+Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
+Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
+---
+ lib/iov_iter.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/lib/iov_iter.c b/lib/iov_iter.c
+index 9ffa7dc197be..fa5827e2e9a3 100644
+--- a/lib/iov_iter.c
++++ b/lib/iov_iter.c
+@@ -449,6 +449,7 @@ static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t by
+ return 0;
+
+ buf->ops = &page_cache_pipe_buf_ops;
++ buf->flags = 0;
+ get_page(page);
+ buf->page = page;
+ buf->offset = offset;
+@@ -564,6 +565,7 @@ static size_t push_pipe(struct iov_iter *i, size_t size,
+ break;
+
+ buf->ops = &default_pipe_buf_ops;
++ buf->flags = 0;
+ buf->page = page;
+ buf->offset = 0;
+ buf->len = min_t(ssize_t, left, PAGE_SIZE);