[PATCH 1/1] ext4: fix incorrect function call when initializing s_resgid

[PATCH 1/1] ext4: fix incorrect function call when initializing s_resgid

[Jiazi Liu]

In __ext4_fill_super(), s_resgid is initialized by calling
ext4_get_resuid() instead of ext4_get_resgid(), resulting in the
reserved GID being set to the same value as the reserved UID rather
than the value stored in the superblock.

Fixes: 12c84dd4d308 ("ext4: add support for 32-bit default reserved uid and gid values")
Cc: stable@vger.kernel.org
Signed-off-by: Jiazi Liu <liujiazi@amazon.com>
---
 fs/ext4/super.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 6c18b5adffca..a187112cafaf 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -5380,7 +5380,7 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
 	ext4_set_def_opts(sb, es);
 
 	sbi->s_resuid = make_kuid(&init_user_ns, ext4_get_resuid(es));
-	sbi->s_resgid = make_kgid(&init_user_ns, ext4_get_resuid(es));
+	sbi->s_resgid = make_kgid(&init_user_ns, ext4_get_resgid(es));
 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
-- 
2.50.1 (Apple Git-155)

Re: [PATCH 1/1] ext4: fix incorrect function call when initializing s_resgid

[Ritesh Harjani]

Jiazi Liu <jiazi.liu1984@gmail.com> writes:

> In __ext4_fill_super(), s_resgid is initialized by calling
> ext4_get_resuid() instead of ext4_get_resgid(), resulting in the
> reserved GID being set to the same value as the reserved UID rather
> than the value stored in the superblock.
>
> Fixes: 12c84dd4d308 ("ext4: add support for 32-bit default reserved uid and gid values")
> Cc: stable@vger.kernel.org
> Signed-off-by: Jiazi Liu <liujiazi@amazon.com>

yup, that clearly looks like a simple miss. 

Nice catch! Wondering whether this was caught by code review or did you
hit an issue due to this?

Looks good to me. Feel free to add:
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>

Re: [PATCH 1/1] ext4: fix incorrect function call when initializing s_resgid

[Liu Jiazi]

Thanks for the review.

This was actually caught in our product. We use gid as the reserve
size id, and we hit this issue there.

Brs
Jiazi

Ritesh Harjani <ritesh.list@gmail.com> 于2026年7月28日周二 12:43写道：
>
> Jiazi Liu <jiazi.liu1984@gmail.com> writes:
>
> > In __ext4_fill_super(), s_resgid is initialized by calling
> > ext4_get_resuid() instead of ext4_get_resgid(), resulting in the
> > reserved GID being set to the same value as the reserved UID rather
> > than the value stored in the superblock.
> >
> > Fixes: 12c84dd4d308 ("ext4: add support for 32-bit default reserved uid and gid values")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Jiazi Liu <liujiazi@amazon.com>
>
> yup, that clearly looks like a simple miss.
>
> Nice catch! Wondering whether this was caught by code review or did you
> hit an issue due to this?
>
> Looks good to me. Feel free to add:
> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
>

Re: [PATCH 1/1] ext4: fix incorrect function call when initializing s_resgid

[Theodore Ts'o]

On Mon, 27 Jul 2026 18:41:03 +0800, Jiazi Liu wrote:
> In __ext4_fill_super(), s_resgid is initialized by calling
> ext4_get_resuid() instead of ext4_get_resgid(), resulting in the
> reserved GID being set to the same value as the reserved UID rather
> than the value stored in the superblock.

Applied, thanks!

[1/1] ext4: fix incorrect function call when initializing s_resgid
      commit: c87abbab6147dcc5aa1fd8f2a61734d58d8b99ec

Best regards,
-- 
Theodore Ts'o <tytso@mit.edu>