From: Vegard Nossum <vegard.nossum@oracle.com>
To: Richard Weinberger <richard@nod.at>
Cc: Al Viro <viro@zeniv.linux.org.uk>, Jeff Dike <jdike@addtoit.com>,
user-mode-linux-devel@lists.sourceforge.net,
linux-kernel@vger.kernel.org
Subject: [PATCH] uml: fix hostfs mknod()
Date: Wed, 16 Dec 2015 21:59:56 +0100 [thread overview]
Message-ID: <1450299596-10780-1-git-send-email-vegard.nossum@oracle.com> (raw)
An inverted return value check in hostfs_mknod() caused the function
to return success after handling it as an error (and cleaning up).
It resulted in the following segfault when trying to bind() a named
unix socket:
Pid: 198, comm: a.out Not tainted 4.4.0-rc4
RIP: 0033:[<0000000061077df6>]
RSP: 00000000daae5d60 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 000000006092a460 RCX: 00000000dfc54208
RDX: 0000000061073ef1 RSI: 0000000000000070 RDI: 00000000e027d600
RBP: 00000000daae5de0 R08: 00000000da980ac0 R09: 0000000000000000
R10: 0000000000000003 R11: 00007fb1ae08f72a R12: 0000000000000000
R13: 000000006092a460 R14: 00000000daaa97c0 R15: 00000000daaa9a88
Kernel panic - not syncing: Kernel mode fault at addr 0x40, ip 0x61077df6
CPU: 0 PID: 198 Comm: a.out Not tainted 4.4.0-rc4 #1
Stack:
e027d620 dfc54208 0000006f da981398
61bee000 0000c1ed daae5de0 0000006e
e027d620 dfcd4208 00000005 6092a460
Call Trace:
[<60dedc67>] SyS_bind+0xf7/0x110
[<600587be>] handle_syscall+0x7e/0x80
[<60066ad7>] userspace+0x3e7/0x4e0
[<6006321f>] ? save_registers+0x1f/0x40
[<6006c88e>] ? arch_prctl+0x1be/0x1f0
[<60054985>] fork_handler+0x85/0x90
Let's also get rid of the "cosmic ray protection" while we're at it.
Fixes: e9193059b1b3 "hostfs: fix races in dentry_name() and inode_name()"
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@vger.kernel.org
---
fs/hostfs/hostfs_kern.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git fs/hostfs/hostfs_kern.c fs/hostfs/hostfs_kern.c
index 2ac99db..5a7b322 100644
--- fs/hostfs/hostfs_kern.c
+++ fs/hostfs/hostfs_kern.c
@@ -730,15 +730,13 @@ static int hostfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode,
init_special_inode(inode, mode, dev);
err = do_mknod(name, mode, MAJOR(dev), MINOR(dev));
- if (!err)
+ if (err)
goto out_free;
err = read_name(inode, name);
__putname(name);
if (err)
goto out_put;
- if (err)
- goto out_put;
d_instantiate(dentry, inode);
return 0;
--
1.9.1
next reply other threads:[~2015-12-16 20:59 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-16 20:59 Vegard Nossum [this message]
2015-12-16 22:17 ` [PATCH] uml: fix hostfs mknod() Richard Weinberger
2015-12-16 22:21 ` Vegard Nossum
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=1450299596-10780-1-git-send-email-vegard.nossum@oracle.com \
--to=vegard.nossum@oracle.com \
--cc=jdike@addtoit.com \
--cc=linux-kernel@vger.kernel.org \
--cc=richard@nod.at \
--cc=user-mode-linux-devel@lists.sourceforge.net \
--cc=viro@zeniv.linux.org.uk \
/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).