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 linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Tue, 10 May 2011 18:20:50 -0700 From: Joe Perches <joe@...ches.com> To: John Stultz <john.stultz@...aro.org> Cc: LKML <linux-kernel@...r.kernel.org>, Ted Ts'o <tytso@....edu>, KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>, David Rientjes <rientjes@...gle.com>, Dave Hansen <dave@...ux.vnet.ibm.com>, Andrew Morton <akpm@...ux-foundation.org>, linux-mm@...ck.org Subject: Re: [PATCH 2/3] printk: Add %ptc to safely print a task's comm On Tue, 2011-05-10 at 18:10 -0700, John Stultz wrote: > On Tue, 2011-05-10 at 17:51 -0700, Joe Perches wrote: > > On Tue, 2011-05-10 at 17:23 -0700, John Stultz wrote: > > > Acessing task->comm requires proper locking. However in the past > > > access to current->comm could be done without locking. This > > > is no longer the case, so all comm access needs to be done > > > while holding the comm_lock. > > Could misuse of %ptc (not using current) cause system lockup? > It very well could. Although I don't see other %p options tring to > handle invalid pointers. Any suggestions on how to best handle this? The only one I know of is ipv6 which copies a 16 byte buffer in case the pointed to value is unaligned. I suppose %pI6c could be a problem or maybe %pS too, but it hasn't been in practice. The use of %ptc somehow seemed more error prone. > Most users are current, so forcing the more rare > non-current users to copy it to a buffer first and use the normal %s > would not be of much impact. > > Although I'm not sure if there's precedent for a %p value that didn't > take a argument. Thoughts on that? Anyone else have an opinion here? The uses of %ptc must add an argument or else gcc will complain. I suggest you just ignore the argument value and use current. -- 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