Messages in this thread Patch in this message | | | From | Du Cheng <> | Subject | [PATCH] fs:minix: catch inode->i_nlink == 0 in minix_rename() | Date | Sun, 25 Apr 2021 15:48:51 +0800 |
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If the destination inode has i_nlink==0, it is invalid. Hence we should return an error instead of proceeding with drop_nlink() which causes WARN_ON().
Reported by syzkaller: https://syzkaller.appspot.com/bug?id=0b1ac5e39c478b05355e189451b5379dc925fd2e
Reported-by: syzbot+651ca866e5e2b4b5095b@syzkaller.appspotmail.com Signed-off-by: Du Cheng <ducheng2@gmail.com> --- This patch fixed the kernel panic on my testing envionment with the syzbot reproducer.
This patch works in a similar spirit with the following patch on bad inode: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=facb03dddec04e4aac1bb2139accdceb04deb1f3
fs/minix/namei.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/fs/minix/namei.c b/fs/minix/namei.c index 937fa5fae2b8..96761536b8d4 100644 --- a/fs/minix/namei.c +++ b/fs/minix/namei.c @@ -215,6 +215,10 @@ static int minix_rename(struct user_namespace *mnt_userns, struct page * new_page; struct minix_dir_entry * new_de; + err = -EINVAL; + if (new_inode->i_nlink == 0) + goto out_dir; + err = -ENOTEMPTY; if (dir_de && !minix_empty_dir(new_inode)) goto out_dir; -- 2.30.2
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