Linux CIFS filesystem development
 help / color / mirror / Atom feed
From: Dominik Brodowski <linux@dominikbrodowski.net>
To: sfrench@samba.org
Cc: linux-cifs@vger.kernel.org
Subject: v5.1-rc1 cifs bug: underflow; use-after-free.
Date: Tue, 19 Mar 2019 12:51:51 +0100	[thread overview]
Message-ID: <20190319115151.GA2092@light.dominikbrodowski.net> (raw)

Steve,

when mounting a cifs (vers=2.0, unfortunately...) volume on v5.1-rc1, I get
the following warning (slightly edited to avoid information leaks):

[  118.326535] CIFS: Attempting to mount //some/what
[  118.667347] ------------[ cut here ]------------
[  118.667367] refcount_t: underflow; use-after-free.
[  118.667384] WARNING: CPU: 1 PID: 1966 at lib/refcount.c:190 refcount_sub_and_test_checked+0x5c/0x70
[  118.667387] Modules linked in:
[  118.667392] CPU: 1 PID: 1966 Comm: mount.cifs Tainted: G                T 5.1.0-rc1 #1
[  118.667395] Hardware name: Dell Inc. XPS 13 9343/0TM99H, BIOS A11 12/08/2016
[  118.667400] RIP: 0010:refcount_sub_and_test_checked+0x5c/0x70
[  118.667432] Call Trace:
[  118.667439]  close_shroot+0x21/0xa0
[  118.667444]  smb2_query_path_info+0x16b/0x1f0
[  118.667454]  cifs_get_inode_info+0x2b3/0x860
[  118.667467]  cifs_root_iget+0x12c/0x670
[  118.667473]  cifs_smb3_do_mount+0x4f7/0x680
[  118.667479]  ? rcu_read_lock_sched_held+0x74/0x80
[  118.667483]  ? kfree+0x248/0x290
[  118.667490]  legacy_get_tree+0x24/0x40
[  118.667494]  vfs_get_tree+0x3d/0x110
[  118.667500]  do_mount+0x30a/0xef0
[  118.667504]  ? rcu_read_lock_sched_held+0x74/0x80
[  118.667512]  ksys_mount+0xbd/0xe0
[  118.667517]  __x64_sys_mount+0x22/0x30
[  118.667522]  do_syscall_64+0x50/0x160
[  118.667527]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  118.667531] RIP: 0033:0x754fd3d1d68e

Thanks,
	Dominik

             reply	other threads:[~2019-03-19 12:01 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-19 11:51 Dominik Brodowski [this message]
2019-03-19 15:26 ` v5.1-rc1 cifs bug: underflow; use-after-free Aurélien Aptel
2019-03-19 15:47   ` Aurélien Aptel
2019-03-19 16:26   ` Dominik Brodowski
2019-03-20 11:12     ` Aurélien Aptel
2019-03-26  7:18       ` Dominik Brodowski
2019-03-26 12:39         ` [PATCH v1] CIFS: prevent refcount underflow Aurelien Aptel
2019-03-26 15:46           ` Dominik Brodowski
2019-03-26 16:53             ` Aurélien Aptel
2019-03-26 16:53               ` Dominik Brodowski
2019-03-27 22:36           ` Pavel Shilovsky
2019-03-27 23:44             ` ronnie sahlberg

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=20190319115151.GA2092@light.dominikbrodowski.net \
    --to=linux@dominikbrodowski.net \
    --cc=linux-cifs@vger.kernel.org \
    --cc=sfrench@samba.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