+ mm-mprotect-fix-successful-vma_merge-of-next-in-do_mprotect_pkey.patch added to mm-unstable branch

+ mm-mprotect-fix-successful-vma_merge-of-next-in-do_mprotect_pkey.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/mprotect: Fix successful vma_merge() of next in do_mprotect_pkey()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-mprotect-fix-successful-vma_merge-of-next-in-do_mprotect_pkey.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mprotect-fix-successful-vma_merge-of-next-in-do_mprotect_pkey.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: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Subject: mm/mprotect: Fix successful vma_merge() of next in do_mprotect_pkey()
Date: Fri, 24 Feb 2023 16:20:55 -0500

If mprotect_fixup() successfully calls vma_merge() and replaces vma and
the next vma, then the tmp variable in the do_mprotect_pkey() is not
updated to point to the new vma end.  This results in the loop detecting a
gap between VMAs that does not exist.  Fix the faulty value of tmp by
setting it to the end location of the vma iterator at the end of the loop.

Link: https://lkml.kernel.org/r/20230224212055.1786100-1-Liam.Howlett@oracle.com
Fixes: 2286a6914c77 ("mm: change mprotect_fixup to vma iterator")
Link: https://lore.kernel.org/linux-mm/20230223120407.729110a6ecd1416ac59d9cb0@linux-foundation.org/
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: Bert Karwatzki <spasswolf@web.de>
  Link: https://bugzilla.kernel.org/show_bug.cgi?id=217061
Tested-by: Bert Karwatzki <spasswolf@web.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---


--- a/mm/mprotect.c~mm-mprotect-fix-successful-vma_merge-of-next-in-do_mprotect_pkey
+++ b/mm/mprotect.c
@@ -832,6 +832,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
 		if (error)
 			break;
 
+		tmp = vma_iter_end(&vmi);
 		nstart = tmp;
 		prot = reqprot;
 	}
_

Patches currently in -mm which might be from Liam.Howlett@oracle.com are

mm-mprotect-fix-successful-vma_merge-of-next-in-do_mprotect_pkey.patch