lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Sat, 18 Feb 2012 17:36:36 -0800 From: Kees Cook <keescook@...omium.org> To: Marcin Slusarz <marcin.slusarz@...il.com> Cc: Andrew Morton <akpm@...ux-foundation.org>, linux-kernel@...r.kernel.org, Randy Dunlap <rdunlap@...otime.net>, Alexander Viro <viro@...iv.linux.org.uk>, Ingo Molnar <mingo@...e.hu>, linux-doc@...r.kernel.org, linux-fsdevel@...r.kernel.org, kernel-hardening@...ts.openwall.com Subject: Re: [PATCH] fs: hardlink creation restrictions On Sat, Feb 18, 2012 at 12:56 PM, Marcin Slusarz <marcin.slusarz@...il.com> wrote: > On Sat, Feb 18, 2012 at 11:38:57AM -0800, Kees Cook wrote: >> @@ -3052,6 +3119,9 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, >> error = mnt_want_write(new_path.mnt); >> if (error) >> goto out_dput; >> + error = may_linkat(&old_path); >> + if (error) >> + goto out_dput; >> error = security_path_link(old_path.dentry, &new_path, new_dentry); >> if (error) >> goto out_drop_write; > > You should give up write access after check failure (i.e. goto out_drop_write). Ah! Thanks, yes, good catch. I will move the check before mnt_want_write(). -Kees -- Kees Cook ChromeOS Security -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists