FAILED: patch "[PATCH] io_uring/rsrc: disallow multi-source reg buffers" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x edd478269640b360c6f301f2baa04abdda563ef3
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '1678099757152211@kroah.com' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

edd478269640 ("io_uring/rsrc: disallow multi-source reg buffers")
735729844819 ("io_uring: move rsrc related data, core, and commands")
3b77495a9723 ("io_uring: split provided buffers handling into its own file")
7aaff708a768 ("io_uring: move cancelation into its own file")
329061d3e2f9 ("io_uring: move poll handling into its own file")
cfd22e6b3319 ("io_uring: add opcode name to io_op_defs")
92ac8beaea1f ("io_uring: include and forward-declaration sanitation")
c9f06aa7de15 ("io_uring: move io_uring_task (tctx) helpers into its own file")
a4ad4f748ea9 ("io_uring: move fdinfo helpers to its own file")
e5550a1447bf ("io_uring: use io_is_uring_fops() consistently")
17437f311490 ("io_uring: move SQPOLL related handling into its own file")
59915143e89f ("io_uring: move timeout opcodes and handling into its own file")
e418bbc97bff ("io_uring: move our reference counting into a header")
36404b09aa60 ("io_uring: move msg_ring into its own file")
f9ead18c1058 ("io_uring: split network related opcodes into its own file")
e0da14def1ee ("io_uring: move statx handling to its own file")
a9c210cebe13 ("io_uring: move epoll handler to its own file")
4cf90495281b ("io_uring: add a dummy -EOPNOTSUPP prep handler")
99f15d8d6136 ("io_uring: move uring_cmd handling to its own file")
cd40cae29ef8 ("io_uring: split out open/close operations")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From edd478269640b360c6f301f2baa04abdda563ef3 Mon Sep 17 00:00:00 2001
From: Pavel Begunkov <asml.silence@gmail.com>
Date: Wed, 22 Feb 2023 14:36:48 +0000
Subject: [PATCH] io_uring/rsrc: disallow multi-source reg buffers

If two or more mappings go back to back to each other they can be passed
into io_uring to be registered as a single registered buffer. That would
even work if mappings came from different sources, e.g. it's possible to
mix in this way anon pages and pages from shmem or hugetlb. That is not
a problem but it'd rather be less prone if we forbid such mixing.

Cc: <stable@vger.kernel.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index 4e6191904c9e..53845e496881 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -1162,14 +1162,17 @@ struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages)
 	pret = pin_user_pages(ubuf, nr_pages, FOLL_WRITE | FOLL_LONGTERM,
 			      pages, vmas);
 	if (pret == nr_pages) {
+		struct file *file = vmas[0]->vm_file;
+
 		/* don't support file backed memory */
 		for (i = 0; i < nr_pages; i++) {
-			struct vm_area_struct *vma = vmas[i];
-
-			if (vma_is_shmem(vma))
+			if (vmas[i]->vm_file != file) {
+				ret = -EINVAL;
+				break;
+			}
+			if (!file)
 				continue;
-			if (vma->vm_file &&
-			    !is_file_hugepages(vma->vm_file)) {
+			if (!vma_is_shmem(vmas[i]) && !is_file_hugepages(file)) {
 				ret = -EOPNOTSUPP;
 				break;
 			}