revert "memfd: improve userspace warnings for missing exec-related flags"

This is generating far too much noise in the logs, so keep it at once
per boot until we (and other user space tools) adapted to the kernel
wanting user space to chose memfd execution behavior very explicitly.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

diff --git a/patches/kernel/0017-revert-memfd-improve-userspace-warnings-for-missing-.patch b/patches/kernel/0017-revert-memfd-improve-userspace-warnings-for-missing-.patch
new file mode 100644 (file)
index 0000000..fec2af2
--- /dev/null
+++ b/patches/kernel/0017-revert-memfd-improve-userspace-warnings-for-missing-.patch
@@ -0,0 +1,44 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Thomas Lamprecht <t.lamprecht@proxmox.com>
+Date: Mon, 6 Nov 2023 10:17:02 +0100
+Subject: [PATCH] revert "memfd: improve userspace warnings for missing
+ exec-related flags".
+
+This warning is telling userspace developers to pass MFD_EXEC and
+MFD_NOEXEC_SEAL to memfd_create().  Commit 434ed3350f57 ("memfd: improve
+userspace warnings for missing exec-related flags") made the warning more
+frequent and visible in the hope that this would accelerate the fixing of
+errant userspace.
+
+But the overall effect is to generate far too much dmesg noise.
+
+Fixes: 434ed3350f57 ("memfd: improve userspace warnings for missing exec-related flags")
+Reported-by: Damian Tometzki <dtometzki@fedoraproject.org>
+Closes: https://lkml.kernel.org/r/ZPFzCSIgZ4QuHsSC@fedora.fritz.box
+Cc: Aleksa Sarai <cyphar@cyphar.com>
+Cc: Christian Brauner <brauner@kernel.org>
+Cc: Daniel Verkamp <dverkamp@chromium.org>
+Cc: Jeff Xu <jeffxu@google.com>
+Cc: Kees Cook <keescook@chromium.org>
+Cc: Shuah Khan <shuah@kernel.org>
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+ (cherry picked from commit 2562d67b1bdf91c7395b0225d60fdeb26b4bc5a0)
+Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
+---
+ mm/memfd.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/mm/memfd.c b/mm/memfd.c
+index 2dba2cb6f0d0..1c077e98e116 100644
+--- a/mm/memfd.c
++++ b/mm/memfd.c
+@@ -282,7 +282,7 @@ static int check_sysctl_memfd_noexec(unsigned int *flags)
+       }
+ 
+       if (!(*flags & MFD_NOEXEC_SEAL) && sysctl >= MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED) {
+-              pr_err_ratelimited(
++              pr_warn_once(
+                       "%s[%d]: memfd_create() requires MFD_NOEXEC_SEAL with vm.memfd_noexec=%d\n",
+                       current->comm, task_pid_nr(current), sysctl);
+               return -EACCES;