On 2020/05/16 0:18, Tetsuo Handa wrote: > This is > > if (sb->s_magic == PROC_SUPER_MAGIC && *pos == '/') { > char *ep; > const pid_t pid = (pid_t) simple_strtoul(pos + 1, &ep, 10); > struct pid_namespace *proc_pidns = proc_pid_ns(d_inode(dentry)); // <= here > > if (*ep == '/' && pid && pid == > task_tgid_nr_ns(current, proc_pidns)) { > > which was added by commit c59f415a7cb6e1e1 ("Use proc_pid_ns() to get pid_namespace from the proc superblock"). > > @@ -161,9 +162,10 @@ static char *tomoyo_get_local_path(struct dentry *dentry, char * const buffer, > if (sb->s_magic == PROC_SUPER_MAGIC && *pos == '/') { > char *ep; > const pid_t pid = (pid_t) simple_strtoul(pos + 1, &ep, 10); > + struct pid_namespace *proc_pidns = proc_pid_ns(d_inode(dentry)); > > if (*ep == '/' && pid && pid == > - task_tgid_nr_ns(current, sb->s_fs_info)) { > + task_tgid_nr_ns(current, proc_pidns)) { > pos = ep - 5; > if (pos < buffer) > goto out; > > Alexey and Eric, any clue? > A similar bug (racing inode destruction with open() on proc filesystem) was fixed as commit 6f7c41374b62fd80 ("tomoyo: Don't use nifty names on sockets."). Then, it might not be safe to replace dentry->d_sb->s_fs_info with dentry->d_inode->i_sb->s_fs_info .