On Fri, 21 Aug 2020 04:26:12 +0800 kernel test robot <lkp@xxxxxxxxx> wrote: > tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master > branch HEAD: 605cbf3d5f20470ec303b79feda3202935f4a142 Add linux-next specific files for 20200820 > > Error/Warning in current branch: > > fs/notify/fsnotify.c:460 fsnotify() warn: variable dereferenced before check 'inode' (see line 449) Yes, this: : if (!inode) { : /* Dirent event - report on TYPE_INODE to dir */ : inode = dir; : } else if (mask & FS_EVENT_ON_CHILD) { : /* : * Event on child - report on TYPE_INODE to dir if it is : * watching children and on TYPE_CHILD to child. : */ : child = inode; : inode = dir; : } `inode' is non-NULL here. : sb = inode->i_sb; So this is OK. : /* : * Optimization: srcu_read_lock() has a memory barrier which can : * be expensive. It protects walking the *_fsnotify_marks lists. : * However, if we do not walk the lists, we do not have to do : * SRCU because we have no references to any objects and do not : * need SRCU to keep them "alive". : */ : if (!sb->s_fsnotify_marks && : (!mnt || !mnt->mnt_fsnotify_marks) && : (!inode || !inode->i_fsnotify_marks) && So !inode is always false. : (!child || !child->i_fsnotify_marks)) : return 0; I assume we can just zap the "!inode ||". Amir & Jan, can you please take a look?
