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
