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| author | SeongJae Park <sj@kernel.org> | 2021-12-25 08:12:54 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-12-29 14:28:58 +0300 |
| commit | 330c6117a82c16a9a365a51cec5c9ab30b13245c (patch) | |
| tree | fa94120d37820db163bd10dabf5a1649a24a7465 /mm | |
| parent | c691e7575eff76e563b0199c23ec46bd454f43e3 (diff) | |
| download | linux-330c6117a82c16a9a365a51cec5c9ab30b13245c.tar.xz | |
mm/damon/dbgfs: protect targets destructions with kdamond_lock
commit 34796417964b8d0aef45a99cf6c2d20cebe33733 upstream.
DAMON debugfs interface iterates current monitoring targets in
'dbgfs_target_ids_read()' while holding the corresponding
'kdamond_lock'. However, it also destructs the monitoring targets in
'dbgfs_before_terminate()' without holding the lock. This can result in
a use_after_free bug. This commit avoids the race by protecting the
destruction with the corresponding 'kdamond_lock'.
Link: https://lkml.kernel.org/r/20211221094447.2241-1-sj@kernel.org
Reported-by: Sangwoo Bae <sangwoob@amazon.com>
Fixes: 4bc05954d007 ("mm/damon: implement a debugfs-based user space interface")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> [5.15.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/damon/dbgfs.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c index f94d19a690df..d3bc110430f9 100644 --- a/mm/damon/dbgfs.c +++ b/mm/damon/dbgfs.c @@ -309,10 +309,12 @@ static int dbgfs_before_terminate(struct damon_ctx *ctx) if (!targetid_is_pid(ctx)) return 0; + mutex_lock(&ctx->kdamond_lock); damon_for_each_target_safe(t, next, ctx) { put_pid((struct pid *)t->id); damon_destroy_target(t); } + mutex_unlock(&ctx->kdamond_lock); return 0; } |