From d5e72c4e3256335d6fb75c2e321144f93141f4f5 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Thu, 27 Apr 2023 19:18:01 -0400 Subject: [PATCH] ext4: fix lost error code reporting in __ext4_fill_super() When code was factored out of __ext4_fill_super() into ext4_percpu_param_init() the error return was discarded. This meant that it was possible for __ext4_fill_super() to return zero, indicating success, without the struct super getting completely filled in, leading to a potential NULL pointer dereference. Reported-by: syzbot+bbf0f9a213c94f283a5c@syzkaller.appspotmail.com Fixes: 1f79467c8a6b ("ext4: factor out ext4_percpu_param_init() ...") Link: https://syzkaller.appspot.com/bug?id=6dac47d5e58af770c0055f680369586ec32e144c Signed-off-by: Theodore Ts'o Reviewed-by: Jason Yan --- fs/ext4/super.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index f16492b..8ed6450 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -5502,7 +5502,8 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) sbi->s_journal->j_commit_callback = ext4_journal_commit_callback; - if (ext4_percpu_param_init(sbi)) + err = ext4_percpu_param_init(sbi); + if (err) goto failed_mount6; if (ext4_has_feature_flex_bg(sb)) -- 2.7.4