From: Leo Stone <leocst...@gmail.com> The syzbot reproducer mounts a f2fs image, then tries to unlink an existing file. However, the unlinked file already has a link count of 0 when it is read for the first time in do_read_inode().
Add a check to sanity_check_inode() for i_nlink == 0. [Chao Yu: rebase the code and fix orphan inode recovery issue] Reported-by: syzbot+b01a36acd7007e273...@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=b01a36acd7007e273a83 Fixes: 39a53e0ce0df ("f2fs: add superblock and major in-memory structure") Signed-off-by: Leo Stone <leocst...@gmail.com> Signed-off-by: Chao Yu <c...@kernel.org> --- v5: - only check i_nlink in lookup() fs/f2fs/namei.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c index 949621bc0d07..e39533482b45 100644 --- a/fs/f2fs/namei.c +++ b/fs/f2fs/namei.c @@ -502,6 +502,14 @@ static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry, goto out; } + if (inode->i_nlink == 0) { + f2fs_warn(F2FS_I_SB(inode), "%s: inode (ino=%lx) has zero i_nlink", + __func__, inode->i_ino); + err = -EFSCORRUPTED; + set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_FSCK); + goto out_iput; + } + if (IS_ENCRYPTED(dir) && (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) && !fscrypt_has_permitted_context(dir, inode)) { -- 2.40.1 _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
