Commit 058f2e4d authored by Alexey Gladkov's avatar Alexey Gladkov Committed by Eric W. Biederman

proc: s_fs_info may be NULL when proc_kill_sb is called

syzbot found that proc_fill_super() fails before filling up sb->s_fs_info,
deactivate_locked_super() will be called and sb->s_fs_info will be NULL.
The proc_kill_sb() does not expect fs_info to be NULL which is wrong.

Link: https://lore.kernel.org/lkml/0000000000002d7ca605a7b8b1c5@google.com
Reported-by: syzbot+4abac52934a48af5ff19@syzkaller.appspotmail.com
Fixes: fa10fed3 ("proc: allow to mount many instances of proc in one pid namespace")
Signed-off-by: default avatarAlexey Gladkov <gladkov.alexey@gmail.com>
Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
parent 9d78edea
...@@ -264,11 +264,13 @@ static void proc_kill_sb(struct super_block *sb) ...@@ -264,11 +264,13 @@ static void proc_kill_sb(struct super_block *sb)
{ {
struct proc_fs_info *fs_info = proc_sb_info(sb); struct proc_fs_info *fs_info = proc_sb_info(sb);
if (fs_info->proc_self) if (!fs_info) {
dput(fs_info->proc_self); kill_anon_super(sb);
return;
}
if (fs_info->proc_thread_self) dput(fs_info->proc_self);
dput(fs_info->proc_thread_self); dput(fs_info->proc_thread_self);
kill_anon_super(sb); kill_anon_super(sb);
put_pid_ns(fs_info->pid_ns); put_pid_ns(fs_info->pid_ns);
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment