--- /dev/null
+From stable+bounces-118455-greg=kroah.com@vger.kernel.org Thu Feb 20 07:27:34 2025
+From: Max Kellermann <max.kellermann@ionos.com>
+Date: Thu, 20 Feb 2025 16:24:50 +0100
+Subject: fs/netfs/read_collect: add to next->prev_donated
+To: dhowells@redhat.com, netfs@lists.linux.dev, linux-kernel@vger.kernel.org
+Cc: Max Kellermann <max.kellermann@ionos.com>, stable@vger.kernel.org
+Message-ID: <20250220152450.1075727-1-max.kellermann@ionos.com>
+
+From: Max Kellermann <max.kellermann@ionos.com>
+
+If multiple subrequests donate data to the same "next" request
+(depending on the subrequest completion order), each of them would
+overwrite the `prev_donated` field, causing data corruption and a
+BUG() crash ("Can't donate prior to front").
+
+Fixes: ee4cdf7ba857 ("netfs: Speed up buffered reading")
+Closes: https://lore.kernel.org/netfs/CAKPOu+_4mUwYgQtRTbXCmi+-k3PGvLysnPadkmHOyB7Gz0iSMA@mail.gmail.com/
+Cc: stable@vger.kernel.org
+Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
+Signed-off-by: David Howells <dhowells@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ fs/netfs/read_collect.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/fs/netfs/read_collect.c
++++ b/fs/netfs/read_collect.c
+@@ -284,7 +284,7 @@ donation_changed:
+ netfs_trace_donate_to_deferred_next);
+ } else {
+ next = list_next_entry(subreq, rreq_link);
+- WRITE_ONCE(next->prev_donated, excess);
++ WRITE_ONCE(next->prev_donated, next->prev_donated + excess);
+ trace_netfs_donate(rreq, subreq, next, excess,
+ netfs_trace_donate_to_next);
+ }