linux-mtd.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Jia-Ju Bai <baijiaju1990@gmail.com>
To: dwmw2@infradead.org
Cc: linux-mtd@lists.infradead.org
Subject: [BUG] fs: jffs2: possible sleep-in-atomic-context bugs in jffs2_iget
Date: Mon, 13 Aug 2018 18:02:54 +0800	[thread overview]
Message-ID: <7888c227-0c6b-aa56-297f-a6ec2777a76c@gmail.com> (raw)

The kernel may sleep with holding a spinlock.

The function call paths (from bottom to top) in Linux-4.16 are:

[FUNC] schedule
fs/inode.c, 1916: schedule in __wait_on_freeing_inode
fs/inode.c, 826: __wait_on_freeing_inode in find_inode_fast
fs/inode.c, 1107: find_inode_fast in iget_locked
fs/jffs2/fs.c, 263: iget_locked in jffs2_iget
fs/jffs2/fs.c, 665: jffs2_iget in jffs2_gc_fetch_inode
fs/jffs2/wbuf.c, 505: jffs2_gc_fetch_inode in jffs2_wbuf_recover
fs/jffs2/wbuf.c, 462: spin_lock in jffs2_wbuf_recover

[FUNC] mutex_lock_nested
fs/jffs2/fs.c, 273: mutex_lock_nested in jffs2_iget
fs/jffs2/fs.c, 665: jffs2_iget in jffs2_gc_fetch_inode
fs/jffs2/wbuf.c, 505: jffs2_gc_fetch_inode in jffs2_wbuf_recover
fs/jffs2/wbuf.c, 462: spin_lock in jffs2_wbuf_recover

I do not find a good way to fix, so I only report.
Maybe the spinlock should be released before calling jffs2_iget(), and 
then be acquired again.
This is found by my static analysis tool (DSAC).


Thanks,
Jia-Ju Bai

                 reply	other threads:[~2018-08-13 10:03 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=7888c227-0c6b-aa56-297f-a6ec2777a76c@gmail.com \
    --to=baijiaju1990@gmail.com \
    --cc=dwmw2@infradead.org \
    --cc=linux-mtd@lists.infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).