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| author | Peter Xu <peterx@redhat.com> | 2023-11-16 15:15:46 -0500 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-12-06 16:12:45 -0800 |
| commit | 4980e837cab7e2acc4dad18dba656c6896c531aa (patch) | |
| tree | e07ae75831c0cf96220f9d1ac15a5fcbb160a4f2 | |
| parent | 0dff1b407def32452a0d80148172889862c64fe7 (diff) | |
| download | linux-stable-4980e837cab7e2acc4dad18dba656c6896c531aa.tar.gz linux-stable-4980e837cab7e2acc4dad18dba656c6896c531aa.tar.bz2 linux-stable-4980e837cab7e2acc4dad18dba656c6896c531aa.zip | |
mm/pagemap: fix wr-protect even if PM_SCAN_WP_MATCHING not set
The new pagemap ioctl contains a fast path for wr-protections without
looking into category masks. It forgets to check PM_SCAN_WP_MATCHING
before applying the wr-protections. It can cause, e.g., pte markers
installed on archs that do not even support uffd wr-protect.
WARNING: CPU: 0 PID: 5059 at mm/memory.c:1520 zap_pte_range mm/memory.c:1520 [inline]
Link: https://lkml.kernel.org/r/20231116201547.536857-3-peterx@redhat.com
Fixes: 12f6b01a0bcb ("fs/proc/task_mmu: add fast paths to get/clear PAGE_IS_WRITTEN flag")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reported-by: syzbot+7ca4b2719dc742b8d0a4@syzkaller.appspotmail.com
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Andrei Vagin <avagin@gmail.com>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | fs/proc/task_mmu.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index a6f88cbfb689..435b61054b5b 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -2156,7 +2156,7 @@ static int pagemap_scan_pmd_entry(pmd_t *pmd, unsigned long start, return 0; } - if (!p->vec_out) { + if ((p->arg.flags & PM_SCAN_WP_MATCHING) && !p->vec_out) { /* Fast path for performing exclusive WP */ for (addr = start; addr != end; pte++, addr += PAGE_SIZE) { if (pte_uffd_wp(ptep_get(pte))) |