Merge tag 'mm-hotfixes-stable-2023-04-19-16-36' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "22 hotfixes.

  19 are cc:stable and the remainder address issues which were
  introduced during this merge cycle, or aren't considered suitable for
  -stable backporting.

  19 are for MM and the remainder are for other subsystems"

* tag 'mm-hotfixes-stable-2023-04-19-16-36' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (22 commits)
  nilfs2: initialize unused bytes in segment summary blocks
  mm: page_alloc: skip regions with hugetlbfs pages when allocating 1G pages
  mm/mmap: regression fix for unmapped_area{_topdown}
  maple_tree: fix mas_empty_area() search
  maple_tree: make maple state reusable after mas_empty_area_rev()
  mm: kmsan: handle alloc failures in kmsan_ioremap_page_range()
  mm: kmsan: handle alloc failures in kmsan_vmap_pages_range_noflush()
  tools/Makefile: do missed s/vm/mm/
  mm: fix memory leak on mm_init error handling
  mm/page_alloc: fix potential deadlock on zonelist_update_seq seqlock
  kernel/sys.c: fix and improve control flow in __sys_setres[ug]id()
  Revert "userfaultfd: don't fail on unrecognized features"
  writeback, cgroup: fix null-ptr-deref write in bdi_split_work_to_wbs
  maple_tree: fix a potential memory leak, OOB access, or other unpredictable bug
  tools/mm/page_owner_sort.c: fix TGID output when cull=tg is used
  mailmap: update jtoppins' entry to reference correct email
  mm/mempolicy: fix use-after-free of VMA iterator
  mm/huge_memory.c: warn with pr_warn_ratelimited instead of VM_WARN_ON_ONCE_FOLIO
  mm/mprotect: fix do_mprotect_pkey() return on error
  mm/khugepaged: check again on anon uffd-wp during isolation
  ...

2 files changed, 41 insertions, 29 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index 0c92f224c68c..ea332319dffe 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1174,6 +1174,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p,
 fail_pcpu:
 	while (i > 0)
 		percpu_counter_destroy(&mm->rss_stat[--i]);
+	destroy_context(mm);
 fail_nocontext:
 	mm_free_pgd(mm);
 fail_nopgd:
diff --git a/kernel/sys.c b/kernel/sys.c
index 495cd87d9bf4..351de7916302 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -664,6 +664,7 @@ long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
 	struct cred *new;
 	int retval;
 	kuid_t kruid, keuid, ksuid;
+	bool ruid_new, euid_new, suid_new;
 
 	kruid = make_kuid(ns, ruid);
 	keuid = make_kuid(ns, euid);
@@ -678,25 +679,29 @@ long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
 	if ((suid != (uid_t) -1) && !uid_valid(ksuid))
 		return -EINVAL;
 
+	old = current_cred();
+
+	/* check for no-op */
+	if ((ruid == (uid_t) -1 || uid_eq(kruid, old->uid)) &&
+	    (euid == (uid_t) -1 || (uid_eq(keuid, old->euid) &&
+				    uid_eq(keuid, old->fsuid))) &&
+	    (suid == (uid_t) -1 || uid_eq(ksuid, old->suid)))
+		return 0;
+
+	ruid_new = ruid != (uid_t) -1        && !uid_eq(kruid, old->uid) &&
+		   !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid);
+	euid_new = euid != (uid_t) -1        && !uid_eq(keuid, old->uid) &&
+		   !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid);
+	suid_new = suid != (uid_t) -1        && !uid_eq(ksuid, old->uid) &&
+		   !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid);
+	if ((ruid_new || euid_new || suid_new) &&
+	    !ns_capable_setid(old->user_ns, CAP_SETUID))
+		return -EPERM;
+
 	new = prepare_creds();
 	if (!new)
 		return -ENOMEM;
 
-	old = current_cred();
-
-	retval = -EPERM;
-	if (!ns_capable_setid(old->user_ns, CAP_SETUID)) {
-		if (ruid != (uid_t) -1        && !uid_eq(kruid, old->uid) &&
-		    !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
-			goto error;
-		if (euid != (uid_t) -1        && !uid_eq(keuid, old->uid) &&
-		    !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid))
-			goto error;
-		if (suid != (uid_t) -1        && !uid_eq(ksuid, old->uid) &&
-		    !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid))
-			goto error;
-	}
-
 	if (ruid != (uid_t) -1) {
 		new->uid = kruid;
 		if (!uid_eq(kruid, old->uid)) {
@@ -761,6 +766,7 @@ long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
 	struct cred *new;
 	int retval;
 	kgid_t krgid, kegid, ksgid;
+	bool rgid_new, egid_new, sgid_new;
 
 	krgid = make_kgid(ns, rgid);
 	kegid = make_kgid(ns, egid);
@@ -773,23 +779,28 @@ long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
 	if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
 		return -EINVAL;
 
+	old = current_cred();
+
+	/* check for no-op */
+	if ((rgid == (gid_t) -1 || gid_eq(krgid, old->gid)) &&
+	    (egid == (gid_t) -1 || (gid_eq(kegid, old->egid) &&
+				    gid_eq(kegid, old->fsgid))) &&
+	    (sgid == (gid_t) -1 || gid_eq(ksgid, old->sgid)))
+		return 0;
+
+	rgid_new = rgid != (gid_t) -1        && !gid_eq(krgid, old->gid) &&
+		   !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid);
+	egid_new = egid != (gid_t) -1        && !gid_eq(kegid, old->gid) &&
+		   !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid);
+	sgid_new = sgid != (gid_t) -1        && !gid_eq(ksgid, old->gid) &&
+		   !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid);
+	if ((rgid_new || egid_new || sgid_new) &&
+	    !ns_capable_setid(old->user_ns, CAP_SETGID))
+		return -EPERM;
+
 	new = prepare_creds();
 	if (!new)
 		return -ENOMEM;
-	old = current_cred();
-
-	retval = -EPERM;
-	if (!ns_capable_setid(old->user_ns, CAP_SETGID)) {
-		if (rgid != (gid_t) -1        && !gid_eq(krgid, old->gid) &&
-		    !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
-			goto error;
-		if (egid != (gid_t) -1        && !gid_eq(kegid, old->gid) &&
-		    !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid))
-			goto error;
-		if (sgid != (gid_t) -1        && !gid_eq(ksgid, old->gid) &&
-		    !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid))
-			goto error;
-	}
 
 	if (rgid != (gid_t) -1)
 		new->gid = krgid;