This is a note to let you know that I've just added the patch titled mm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer allocation to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mm-damon-dbgfs-use-__gfp_nowarn-for-user-specified-size-buffer-allocation.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From db7a347b26fe05d2e8c115bb24dfd908d0252bc3 Mon Sep 17 00:00:00 2001 From: SeongJae Park <sj@xxxxxxxxxx> Date: Fri, 19 Nov 2021 16:43:49 -0800 Subject: mm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer allocation From: SeongJae Park <sj@xxxxxxxxxx> commit db7a347b26fe05d2e8c115bb24dfd908d0252bc3 upstream. Patch series "DAMON fixes". This patch (of 2): DAMON users can trigger below warning in '__alloc_pages()' by invoking write() to some DAMON debugfs files with arbitrarily high count argument, because DAMON debugfs interface allocates some buffers based on the user-specified 'count'. if (unlikely(order >= MAX_ORDER)) { WARN_ON_ONCE(!(gfp & __GFP_NOWARN)); return NULL; } Because the DAMON debugfs interface code checks failure of the 'kmalloc()', this commit simply suppresses the warnings by adding '__GFP_NOWARN' flag. Link: https://lkml.kernel.org/r/20211110145758.16558-1-sj@xxxxxxxxxx Link: https://lkml.kernel.org/r/20211110145758.16558-2-sj@xxxxxxxxxx Fixes: 4bc05954d007 ("mm/damon: implement a debugfs-based user space interface") Signed-off-by: SeongJae Park <sj@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- mm/damon/dbgfs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/mm/damon/dbgfs.c +++ b/mm/damon/dbgfs.c @@ -32,7 +32,7 @@ static char *user_input_str(const char _ if (*ppos) return ERR_PTR(-EINVAL); - kbuf = kmalloc(count + 1, GFP_KERNEL); + kbuf = kmalloc(count + 1, GFP_KERNEL | __GFP_NOWARN); if (!kbuf) return ERR_PTR(-ENOMEM); @@ -247,7 +247,7 @@ static ssize_t dbgfs_kdamond_pid_read(st char *kbuf; ssize_t len; - kbuf = kmalloc(count, GFP_KERNEL); + kbuf = kmalloc(count, GFP_KERNEL | __GFP_NOWARN); if (!kbuf) return -ENOMEM; Patches currently in stable-queue which might be from sj@xxxxxxxxxx are queue-5.15/mm-damon-dbgfs-fix-missed-use-of-damon_dbgfs_lock.patch queue-5.15/mm-damon-dbgfs-use-__gfp_nowarn-for-user-specified-size-buffer-allocation.patch