[PATCH][5.15.y] gfs2: Fix slab-use-after-free in gfs2_qd_dealloc

[PATCH][5.15.y] gfs2: Fix slab-use-after-free in gfs2_qd_dealloc

[guocai.he.cn]

From: Juntong Deng <juntong.deng@outlook.com>

commit 7ad4e0a4f61c57c3ca291ee010a9d677d0199fba upstream.

In gfs2_put_super(), whether withdrawn or not, the quota should
be cleaned up by gfs2_quota_cleanup().

Otherwise, struct gfs2_sbd will be freed before gfs2_qd_dealloc (rcu
callback) has run for all gfs2_quota_data objects, resulting in
use-after-free.

Also, gfs2_destroy_threads() and gfs2_quota_cleanup() is already called
by gfs2_make_fs_ro(), so in gfs2_put_super(), after calling
gfs2_make_fs_ro(), there is no need to call them again.

Reported-by: syzbot+29c47e9e51895928698c@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=29c47e9e51895928698c
Signed-off-by: Juntong Deng <juntong.deng@outlook.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Clayton Casciato <majortomtosourcecontrol@gmail.com>
Signed-off-by: Guocai He <guocai.he.cn@windriver.com>
---
This commit is backporting 7ad4e0a4f61c7ad4e0a4f61c57c3ca291ee010a9d677d0199fba to the branch linux-5.15.y to
solve the CVE-2024-52760. Please merge this commit to linux-5.15.y.

 fs/gfs2/super.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index 268651ac9fc8..98158559893f 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -590,6 +590,8 @@ static void gfs2_put_super(struct super_block *sb)
 
 	if (!sb_rdonly(sb)) {
 		gfs2_make_fs_ro(sdp);
+	} else {
+		gfs2_quota_cleanup(sdp);
 	}
 	WARN_ON(gfs2_withdrawing(sdp));
 
-- 
2.34.1

Re: [PATCH][5.15.y] gfs2: Fix slab-use-after-free in gfs2_qd_dealloc

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

The claimed upstream commit SHA1 (7ad4e0a4f61c57c3ca291ee010a9d677d0199fba) was not found.
However, I found a matching commit: bdcb8aa434c6d36b5c215d02a9ef07551be25a37

WARNING: Author mismatch between patch and found commit:
Backport author: guocai.he.cn@windriver.com
Commit author: Juntong Deng <juntong.deng@outlook.com>


Status in newer kernel trees:
6.12.y | Present (exact SHA1)
6.6.y | Present (different SHA1: 08a28272faa7)
6.1.y | Present (different SHA1: 7ad4e0a4f61c)
5.15.y | Not found

Note: The patch differs from the upstream commit:
---
1:  bdcb8aa434c6d < -:  ------------- gfs2: Fix slab-use-after-free in gfs2_qd_dealloc
-:  ------------- > 1:  0f941fc07b046 gfs2: Fix slab-use-after-free in gfs2_qd_dealloc
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-5.15.y       |  Success    |  Success   |

Re: [PATCH][5.15.y] gfs2: Fix slab-use-after-free in gfs2_qd_dealloc

[Greg KH]

On Wed, Dec 11, 2024 at 04:39:54PM +0800, guocai.he.cn@windriver.com wrote:
> From: Juntong Deng <juntong.deng@outlook.com>
> 
> commit 7ad4e0a4f61c57c3ca291ee010a9d677d0199fba upstream.

No it is not.

[PATCH][5.15.y] gfs2: Fix slab-use-after-free in gfs2_qd_dealloc

[guocai.he.cn]

From: Juntong Deng <juntong.deng@outlook.com>

commit 7ad4e0a4f61c57c3ca291ee010a9d677d0199fba upstream.

In gfs2_put_super(), whether withdrawn or not, the quota should
be cleaned up by gfs2_quota_cleanup().

Otherwise, struct gfs2_sbd will be freed before gfs2_qd_dealloc (rcu
callback) has run for all gfs2_quota_data objects, resulting in
use-after-free.

Also, gfs2_destroy_threads() and gfs2_quota_cleanup() is already called
by gfs2_make_fs_ro(), so in gfs2_put_super(), after calling
gfs2_make_fs_ro(), there is no need to call them again.

Reported-by: syzbot+29c47e9e51895928698c@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=29c47e9e51895928698c
Signed-off-by: Juntong Deng <juntong.deng@outlook.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Clayton Casciato <majortomtosourcecontrol@gmail.com>
Signed-off-by: Guocai He <guocai.he.cn@windriver.com>
---
This commit is backporting 7ad4e0a4f61c7ad4e0a4f61c57c3ca291ee010a9d677d0199fba to the branch linux-5.15.y to
solve the CVE-2024-52760. Please merge this commit to linux-5.15.y.

 fs/gfs2/super.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index 268651ac9fc8..98158559893f 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -590,6 +590,8 @@ static void gfs2_put_super(struct super_block *sb)
 
 	if (!sb_rdonly(sb)) {
 		gfs2_make_fs_ro(sdp);
+	} else {
+		gfs2_quota_cleanup(sdp);
 	}
 	WARN_ON(gfs2_withdrawing(sdp));
 
-- 
2.34.1

Re: [PATCH][5.15.y] gfs2: Fix slab-use-after-free in gfs2_qd_dealloc

[Greg KH]

On Wed, Dec 11, 2024 at 03:54:58PM +0800, guocai.he.cn@windriver.com wrote:
> From: Juntong Deng <juntong.deng@outlook.com>
> 
> commit 7ad4e0a4f61c57c3ca291ee010a9d677d0199fba upstream.

No it is not :(

And why did you not cc: everyone involved in this change?

thanks,

greg k-h

Re: [PATCH][5.15.y] gfs2: Fix slab-use-after-free in gfs2_qd_dealloc

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

The claimed upstream commit SHA1 (7ad4e0a4f61c57c3ca291ee010a9d677d0199fba) was not found.
However, I found a matching commit: bdcb8aa434c6d36b5c215d02a9ef07551be25a37

WARNING: Author mismatch between patch and found commit:
Backport author: guocai.he.cn@windriver.com
Commit author: Juntong Deng <juntong.deng@outlook.com>


Status in newer kernel trees:
6.12.y | Present (exact SHA1)
6.6.y | Present (different SHA1: 08a28272faa7)
6.1.y | Present (different SHA1: 7ad4e0a4f61c)
5.15.y | Not found

Note: The patch differs from the upstream commit:
---
1:  bdcb8aa434c6d < -:  ------------- gfs2: Fix slab-use-after-free in gfs2_qd_dealloc
-:  ------------- > 1:  984007af06c33 gfs2: Fix slab-use-after-free in gfs2_qd_dealloc
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-5.15.y       |  Success    |  Success   |