+ mm-shrinker-use-kvzalloc_node-from-expand_one_shrinker_info.patch added to mm-hotfixes-unstable branch

+ mm-shrinker-use-kvzalloc_node-from-expand_one_shrinker_info.patch added to mm-hotfixes-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm: shrinker: use kvzalloc_node() from expand_one_shrinker_info()
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     mm-shrinker-use-kvzalloc_node-from-expand_one_shrinker_info.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-shrinker-use-kvzalloc_node-from-expand_one_shrinker_info.patch

This patch will later appear in the mm-hotfixes-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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 via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Subject: mm: shrinker: use kvzalloc_node() from expand_one_shrinker_info()
Date: Wed, 3 Jan 2024 10:52:22 +0900

syzbot is reporting uninit-value at shrinker_alloc(), for commit
307bececcd12 ("mm: shrinker: add a secondary array for
shrinker_info::{map, nr_deferred}") which assumed that the ->unit was
allocated with __GFP_ZERO forgot to replace kvmalloc_node() in
expand_one_shrinker_info() with kvzalloc_node().

Link: https://lkml.kernel.org/r/9226cc0a-10e0-4489-80c5-58c3b5b4359c@I-love.SAKURA.ne.jp
Reported-by: syzbot <syzbot+1e0ed05798af62917464@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=1e0ed05798af62917464
Fixes: 307bececcd12 ("mm: shrinker: add a secondary array for shrinker_info::{map, nr_deferred}")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/shrinker.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/shrinker.c~mm-shrinker-use-kvzalloc_node-from-expand_one_shrinker_info
+++ a/mm/shrinker.c
@@ -126,7 +126,7 @@ static int expand_one_shrinker_info(stru
 		if (new_nr_max <= old->map_nr_max)
 			continue;
 
-		new = kvmalloc_node(sizeof(*new) + new_size, GFP_KERNEL, nid);
+		new = kvzalloc_node(sizeof(*new) + new_size, GFP_KERNEL, nid);
 		if (!new)
 			return -ENOMEM;
 
_

Patches currently in -mm which might be from penguin-kernel@I-love.SAKURA.ne.jp are

mm-shrinker-use-kvzalloc_node-from-expand_one_shrinker_info.patch

Re: + mm-shrinker-use-kvzalloc_node-from-expand_one_shrinker_info.patch added to mm-hotfixes-unstable branch

[Qi Zheng]

On 2024/1/4 02:17, Andrew Morton wrote:
> The patch titled
>       Subject: mm: shrinker: use kvzalloc_node() from expand_one_shrinker_info()
> has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
>       mm-shrinker-use-kvzalloc_node-from-expand_one_shrinker_info.patch
> 
> This patch will shortly appear at
>       https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-shrinker-use-kvzalloc_node-from-expand_one_shrinker_info.patch
> 
> This patch will later appear in the mm-hotfixes-unstable branch at
>      git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
> 
> 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 via the mm-everything
> branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
> and is updated there every 2-3 working days
> 
> ------------------------------------------------------
> From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Subject: mm: shrinker: use kvzalloc_node() from expand_one_shrinker_info()
> Date: Wed, 3 Jan 2024 10:52:22 +0900
> 
> syzbot is reporting uninit-value at shrinker_alloc(), for commit
> 307bececcd12 ("mm: shrinker: add a secondary array for
> shrinker_info::{map, nr_deferred}") which assumed that the ->unit was
> allocated with __GFP_ZERO forgot to replace kvmalloc_node() in
> expand_one_shrinker_info() with kvzalloc_node().
> 
> Link: https://lkml.kernel.org/r/9226cc0a-10e0-4489-80c5-58c3b5b4359c@I-love.SAKURA.ne.jp

Very strange, the above link is still invalid, and this v2 still cannot
be found in LKML or linux-mm. It can only be found in mm-commits.

And I cannot receive emails from Tetsuo, including the one below, but
I can receive emails from Andrew normally.

https://lore.kernel.org/all/c3cdc9b3-a06f-4be7-af3b-44abb8d72c7d@I-love.SAKURA.ne.jp/

But anyway, this patch LGTM, thanks.

> Reported-by: syzbot <syzbot+1e0ed05798af62917464@syzkaller.appspotmail.com>
> Closes: https://syzkaller.appspot.com/bug?extid=1e0ed05798af62917464
> Fixes: 307bececcd12 ("mm: shrinker: add a secondary array for shrinker_info::{map, nr_deferred}")
> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Cc: Qi Zheng <zhengqi.arch@bytedance.com>
> Cc: Muchun Song <songmuchun@bytedance.com>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
> 
>   mm/shrinker.c |    2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- a/mm/shrinker.c~mm-shrinker-use-kvzalloc_node-from-expand_one_shrinker_info
> +++ a/mm/shrinker.c
> @@ -126,7 +126,7 @@ static int expand_one_shrinker_info(stru
>   		if (new_nr_max <= old->map_nr_max)
>   			continue;
>   
> -		new = kvmalloc_node(sizeof(*new) + new_size, GFP_KERNEL, nid);
> +		new = kvzalloc_node(sizeof(*new) + new_size, GFP_KERNEL, nid);
>   		if (!new)
>   			return -ENOMEM;
>   
> _
> 
> Patches currently in -mm which might be from penguin-kernel@I-love.SAKURA.ne.jp are
> 
> mm-shrinker-use-kvzalloc_node-from-expand_one_shrinker_info.patch
>