The patch titled
Subject: memfd: drop warning for missing exec-related flags
has been added to the -mm mm-unstable branch. Its filename is
memfd-drop-warning-for-missing-exec-related-flags.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/memfd-drop-warning-for-missing-exec-related-flags.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Aleksa Sarai <cyphar@xxxxxxxxxx>
Subject: memfd: drop warning for missing exec-related flags
Date: Tue, 12 Sep 2023 01:17:20 +1000
Commit 434ed3350f57 ("memfd: improve userspace warnings for missing
exec-related flags") attempted to make these warnings more useful (so
they would work as an incentive to get users to switch to specifying
these flags -- as intended by the original MFD_NOEXEC_SEAL patchset).
Unfortunately, it turns out that even INFO-level logging is too extreme
to enable by default and alternative solutions to the spam issue (such
as doing more extreme rate-limiting per-task) are either too ugly or
overkill for something as simple as emitting a log as a developer aid.
Given that the flags are new and there is no harm to not specifying them
(after all, we maintain backwards compatibility) we can just drop the
warnings for now until some time in the future when most programs have
migrated and distributions start using vm.memfd_noexec=1 (where failing
to pass the flag would result in unexpected errors for programs that use
executable memfds).
Link: https://lkml.kernel.org/r/20230912-memfd-reduce-spam-v2-1-7d92a4964b6a@xxxxxxxxxx
Fixes: 434ed3350f57 ("memfd: improve userspace warnings for missing exec-related flags")
Fixes: 2562d67b1bdf ("revert "memfd: improve userspace warnings for missing exec-related flags".")
Signed-off-by: Aleksa Sarai <cyphar@xxxxxxxxxx>
Reported-by: Damian Tometzki <dtometzki@xxxxxxxxxxxxxxxxx>
Reviewed-by: Christian Brauner <brauner@xxxxxxxxxx>
Cc: Daniel Verkamp <dverkamp@xxxxxxxxxxxx>
Cc: Jeff Xu <jeffxu@xxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memfd.c | 6 ------
1 file changed, 6 deletions(-)
--- a/mm/memfd.c~memfd-drop-warning-for-missing-exec-related-flags
+++ a/mm/memfd.c
@@ -315,12 +315,6 @@ SYSCALL_DEFINE2(memfd_create,
if ((flags & MFD_EXEC) && (flags & MFD_NOEXEC_SEAL))
return -EINVAL;
- if (!(flags & (MFD_EXEC | MFD_NOEXEC_SEAL))) {
- pr_warn_once(
- "%s[%d]: memfd_create() called without MFD_EXEC or MFD_NOEXEC_SEAL set\n",
- current->comm, task_pid_nr(current));
- }
-
error = check_sysctl_memfd_noexec(&flags);
if (error < 0)
return error;
_
Patches currently in -mm which might be from cyphar@xxxxxxxxxx are
memfd-drop-warning-for-missing-exec-related-flags.patch
