Syzbot reports a NULL dereference in ni_write_inode. When creating a new inode, if allocation fails in mi_init function (called in mi_format_new function), mi->mrec is set to NULL. In the error path of this inode creation, mi->mrec is later dereferenced in ni_write_inode. Add a NULL check to prevent NULL dereference. Link: https://syzkaller.appspot.com/bug?extid=f45957555ed4a808cc7a Reported-and-tested-by: syzbot+f45957555ed4a808cc7a@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Abdun Nihaal <abdun.nihaal@xxxxxxxxx> --- fs/ntfs3/frecord.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/ntfs3/frecord.c b/fs/ntfs3/frecord.c index 70a80f9412f7..e55bbd209ef8 100644 --- a/fs/ntfs3/frecord.c +++ b/fs/ntfs3/frecord.c @@ -3243,6 +3243,9 @@ int ni_write_inode(struct inode *inode, int sync, const char *hint) return 0; } + if (!ni->mi.mrec) + goto out; + if (is_rec_inuse(ni->mi.mrec) && !(sbi->flags & NTFS_FLAGS_LOG_REPLAYING) && inode->i_nlink) { bool modified = false; -- 2.37.3
