| Message ID | 20211221220539.x5Uvm%akpm@linux-foundation.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | + mm-damon-dbgfs-protect-targets-destructions-with-kdamond_lock.patch added to -mm tree | expand |
--- a/mm/damon/dbgfs.c~mm-damon-dbgfs-protect-targets-destructions-with-kdamond_lock +++ a/mm/damon/dbgfs.c @@ -650,10 +650,12 @@ static void dbgfs_before_terminate(struc if (!targetid_is_pid(ctx)) return; + 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); } static struct damon_ctx *dbgfs_new_ctx(void)
The patch titled Subject: mm/damon/dbgfs: protect targets destructions with kdamond_lock has been added to the -mm tree. Its filename is mm-damon-dbgfs-protect-targets-destructions-with-kdamond_lock.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-damon-dbgfs-protect-targets-destructions-with-kdamond_lock.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-damon-dbgfs-protect-targets-destructions-with-kdamond_lock.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: SeongJae Park <sj@kernel.org> Subject: mm/damon/dbgfs: protect targets destructions with kdamond_lock 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> --- mm/damon/dbgfs.c | 2 ++ 1 file changed, 2 insertions(+)