From: Steve French <smfrench@gmail.com>
To: Paulo Alcantara <pc@cjr.nz>
Cc: David Disseldorp <ddiss@suse.de>, CIFS <linux-cifs@vger.kernel.org>
Subject: Re: [PATCH] cifs: fix leak in cifs_smb3_do_mount() ctx
Date: Fri, 23 Apr 2021 18:51:23 -0500 [thread overview]
Message-ID: <CAH2r5mvg-2zaVsYnw-_iBSPXsbQekACJz+CYEviuNM3CjZJGXQ@mail.gmail.com> (raw)
In-Reply-To: <8735vi54nw.fsf@cjr.nz>
merged into cifs-2.6.git for-next and kicking off (buildbot) testing
run with it now
On Thu, Apr 22, 2021 at 5:36 PM Paulo Alcantara <pc@cjr.nz> wrote:
>
> David Disseldorp <ddiss@suse.de> writes:
>
> > cifs_smb3_do_mount() calls smb3_fs_context_dup() and then
> > cifs_setup_volume_info(). The latter's subsequent smb3_parse_devname()
> > call overwrites the cifs_sb->ctx->UNC string already dup'ed by
> > smb3_fs_context_dup(), resulting in a leak. E.g.
> >
> > unreferenced object 0xffff888002980420 (size 32):
> > comm "mount", pid 160, jiffies 4294892541 (age 30.416s)
> > hex dump (first 32 bytes):
> > 5c 5c 31 39 32 2e 31 36 38 2e 31 37 34 2e 31 30 \\192.168.174.10
> > 34 5c 72 61 70 69 64 6f 2d 73 68 61 72 65 00 00 4\rapido-share..
> > backtrace:
> > [<00000000069e12f6>] kstrdup+0x28/0x50
> > [<00000000b61f4032>] smb3_fs_context_dup+0x127/0x1d0 [cifs]
> > [<00000000c6e3e3bf>] cifs_smb3_do_mount+0x77/0x660 [cifs]
> > [<0000000063467a6b>] smb3_get_tree+0xdf/0x220 [cifs]
> > [<00000000716f731e>] vfs_get_tree+0x1b/0x90
> > [<00000000491d3892>] path_mount+0x62a/0x910
> > [<0000000046b2e774>] do_mount+0x50/0x70
> > [<00000000ca7b64dd>] __x64_sys_mount+0x81/0xd0
> > [<00000000b5122496>] do_syscall_64+0x33/0x40
> > [<000000002dd397af>] entry_SYSCALL_64_after_hwframe+0x44/0xae
> >
> > This change is a bandaid until the cifs_setup_volume_info() TODO and
> > error handling issues are resolved.
> >
> > Signed-off-by: David Disseldorp <ddiss@suse.de>
> > ---
> > fs/cifs/cifsfs.c | 6 ++++++
> > 1 file changed, 6 insertions(+)
>
> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
--
Thanks,
Steve
prev parent reply other threads:[~2021-04-23 23:51 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-22 22:14 [PATCH] cifs: fix leak in cifs_smb3_do_mount() ctx David Disseldorp
2021-04-22 22:16 ` ronnie sahlberg
2021-04-22 22:35 ` Paulo Alcantara
2021-04-23 23:51 ` Steve French [this message]
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