On Mon, May 18, 2020 at 07:08:57AM -0500, Eric W. Biederman wrote: > Alexey Gladkov <gladkov.alexey@xxxxxxxxx> writes: > > > The proc_pid_ns() can be used for both inode and dentry. To avoid making > > two identical functions, change the argument type of the proc_pid_ns(). > > > > Link: https://lore.kernel.org/lkml/c3461e26-1407-2262-c709-dac0df3da2d0@xxxxxxxxxxxxxxxxxxx/ > > Reported-by: syzbot+c1af344512918c61362c@xxxxxxxxxxxxxxxxxxxxxxxxx > > Signed-off-by: Alexey Gladkov <gladkov.alexey@xxxxxxxxx> > > So overall this looks good. > > However, the description leaves a little bit to be desired as it does > not describe why it is bad to use dentry->d_sb. A fixes tag would be > nice if for no other reason than to help anyone who decides to backport > this. OK. I will add it. > And can you please compile test this? > > There is a very silly typo in proc that keeps this from compiling. I compiled the kernel with this patch and ran the kernel, but accidentally did not check children_seq_show(). Sorry. > Thank you, > Eric > > > --- > > fs/locks.c | 4 ++-- > > fs/proc/array.c | 2 +- > > fs/proc/base.c | 10 +++++----- > > fs/proc/self.c | 2 +- > > fs/proc/thread_self.c | 2 +- > > include/linux/proc_fs.h | 4 ++-- > > kernel/fork.c | 2 +- > > net/ipv6/ip6_flowlabel.c | 2 +- > > security/tomoyo/realpath.c | 2 +- > > 9 files changed, 15 insertions(+), 15 deletions(-) > > > > diff --git a/fs/locks.c b/fs/locks.c > > index 399c5dbb72c4..ab702d6efb55 100644 > > --- a/fs/locks.c > > +++ b/fs/locks.c > > @@ -2823,7 +2823,7 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl, > > { > > struct inode *inode = NULL; > > unsigned int fl_pid; > > - struct pid_namespace *proc_pidns = proc_pid_ns(file_inode(f->file)); > > + struct pid_namespace *proc_pidns = proc_pid_ns(file_inode(f->file)->i_sb); > > > > fl_pid = locks_translate_pid(fl, proc_pidns); > > /* > > @@ -2901,7 +2901,7 @@ static int locks_show(struct seq_file *f, void *v) > > { > > struct locks_iterator *iter = f->private; > > struct file_lock *fl, *bfl; > > - struct pid_namespace *proc_pidns = proc_pid_ns(file_inode(f->file)); > > + struct pid_namespace *proc_pidns = proc_pid_ns(file_inode(f->file)->i_sb); > > > > fl = hlist_entry(v, struct file_lock, fl_link); > > > > diff --git a/fs/proc/array.c b/fs/proc/array.c > > index 8e16f14bb05a..a4d4763731e0 100644 > > --- a/fs/proc/array.c > > +++ b/fs/proc/array.c > > @@ -728,7 +728,7 @@ static int children_seq_show(struct seq_file *seq, void *v) > > { > > struct inode *inode = file_inode(seq->file); > > > > - seq_printf(seq, "%d ", pid_nr_ns(v, proc_pid_ns(inode))); > > + seq_printf(seq, "%d ", pid_nr_ns(v, proc_pid_ns(inode)->i_sb)); > > return 0; > > } > > > > diff --git a/fs/proc/base.c b/fs/proc/base.c > > index 5a307b3bb2d1..30c9fceca0b7 100644 > > --- a/fs/proc/base.c > > +++ b/fs/proc/base.c > > @@ -754,7 +754,7 @@ static const struct inode_operations proc_def_inode_operations = { > > static int proc_single_show(struct seq_file *m, void *v) > > { > > struct inode *inode = m->private; > > - struct pid_namespace *ns = proc_pid_ns(inode); > > + struct pid_namespace *ns = proc_pid_ns(inode->i_sb); > > struct pid *pid = proc_pid(inode); > > struct task_struct *task; > > int ret; > > @@ -1423,7 +1423,7 @@ static const struct file_operations proc_fail_nth_operations = { > > static int sched_show(struct seq_file *m, void *v) > > { > > struct inode *inode = m->private; > > - struct pid_namespace *ns = proc_pid_ns(inode); > > + struct pid_namespace *ns = proc_pid_ns(inode->i_sb); > > struct task_struct *p; > > > > p = get_proc_task(inode); > > @@ -2466,7 +2466,7 @@ static int proc_timers_open(struct inode *inode, struct file *file) > > return -ENOMEM; > > > > tp->pid = proc_pid(inode); > > - tp->ns = proc_pid_ns(inode); > > + tp->ns = proc_pid_ns(inode->i_sb); > > return 0; > > } > > > > @@ -3377,7 +3377,7 @@ int proc_pid_readdir(struct file *file, struct dir_context *ctx) > > { > > struct tgid_iter iter; > > struct proc_fs_info *fs_info = proc_sb_info(file_inode(file)->i_sb); > > - struct pid_namespace *ns = proc_pid_ns(file_inode(file)); > > + struct pid_namespace *ns = proc_pid_ns(file_inode(file)->i_sb); > > loff_t pos = ctx->pos; > > > > if (pos >= PID_MAX_LIMIT + TGID_OFFSET) > > @@ -3730,7 +3730,7 @@ static int proc_task_readdir(struct file *file, struct dir_context *ctx) > > /* f_version caches the tgid value that the last readdir call couldn't > > * return. lseek aka telldir automagically resets f_version to 0. > > */ > > - ns = proc_pid_ns(inode); > > + ns = proc_pid_ns(inode->i_sb); > > tid = (int)file->f_version; > > file->f_version = 0; > > for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns); > > diff --git a/fs/proc/self.c b/fs/proc/self.c > > index 309301ac0136..ca5158fa561c 100644 > > --- a/fs/proc/self.c > > +++ b/fs/proc/self.c > > @@ -12,7 +12,7 @@ static const char *proc_self_get_link(struct dentry *dentry, > > struct inode *inode, > > struct delayed_call *done) > > { > > - struct pid_namespace *ns = proc_pid_ns(inode); > > + struct pid_namespace *ns = proc_pid_ns(inode->i_sb); > > pid_t tgid = task_tgid_nr_ns(current, ns); > > char *name; > > > > diff --git a/fs/proc/thread_self.c b/fs/proc/thread_self.c > > index 2493cbbdfa6f..ac284f409568 100644 > > --- a/fs/proc/thread_self.c > > +++ b/fs/proc/thread_self.c > > @@ -12,7 +12,7 @@ static const char *proc_thread_self_get_link(struct dentry *dentry, > > struct inode *inode, > > struct delayed_call *done) > > { > > - struct pid_namespace *ns = proc_pid_ns(inode); > > + struct pid_namespace *ns = proc_pid_ns(inode->i_sb); > > pid_t tgid = task_tgid_nr_ns(current, ns); > > pid_t pid = task_pid_nr_ns(current, ns); > > char *name; > > diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h > > index 2cb424e6f36a..6ec524d8842c 100644 > > --- a/include/linux/proc_fs.h > > +++ b/include/linux/proc_fs.h > > @@ -202,9 +202,9 @@ int open_related_ns(struct ns_common *ns, > > struct ns_common *(*get_ns)(struct ns_common *ns)); > > > > /* get the associated pid namespace for a file in procfs */ > > -static inline struct pid_namespace *proc_pid_ns(const struct inode *inode) > > +static inline struct pid_namespace *proc_pid_ns(struct super_block *sb) > > { > > - return proc_sb_info(inode->i_sb)->pid_ns; > > + return proc_sb_info(sb)->pid_ns; > > } > > > > #endif /* _LINUX_PROC_FS_H */ > > diff --git a/kernel/fork.c b/kernel/fork.c > > index 4385f3d639f2..e7bdaccad942 100644 > > --- a/kernel/fork.c > > +++ b/kernel/fork.c > > @@ -1745,7 +1745,7 @@ static void pidfd_show_fdinfo(struct seq_file *m, struct file *f) > > pid_t nr = -1; > > > > if (likely(pid_has_task(pid, PIDTYPE_PID))) { > > - ns = proc_pid_ns(file_inode(m->file)); > > + ns = proc_pid_ns(file_inode(m->file)->i_sb); > > nr = pid_nr_ns(pid, ns); > > } > > > > diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c > > index d64b83e85642..ce4fbba4acce 100644 > > --- a/net/ipv6/ip6_flowlabel.c > > +++ b/net/ipv6/ip6_flowlabel.c > > @@ -779,7 +779,7 @@ static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos) > > { > > struct ip6fl_iter_state *state = ip6fl_seq_private(seq); > > > > - state->pid_ns = proc_pid_ns(file_inode(seq->file)); > > + state->pid_ns = proc_pid_ns(file_inode(seq->file)->i_sb); > > > > rcu_read_lock_bh(); > > return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN; > > diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c > > index 08b096e2f7e3..df4798980416 100644 > > --- a/security/tomoyo/realpath.c > > +++ b/security/tomoyo/realpath.c > > @@ -162,7 +162,7 @@ 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)); > > + struct pid_namespace *proc_pidns = proc_pid_ns(sb); > > > > if (*ep == '/' && pid && pid == > > task_tgid_nr_ns(current, proc_pidns)) { > -- Rgrds, legion
