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: Wed, 10 Apr 2019 01:33:46 +0100 From: Al Viro <viro@...iv.linux.org.uk> To: Eric Biggers <ebiggers@...nel.org> Cc: linux-fscrypt@...r.kernel.org, linux-fsdevel@...r.kernel.org, linux-ext4@...r.kernel.org, linux-f2fs-devel@...ts.sourceforge.net Subject: Re: [PATCH] fscrypt: cache decrypted symlink target in ->i_link On Tue, Apr 09, 2019 at 04:35:44PM -0700, Eric Biggers wrote: > From: Eric Biggers <ebiggers@...gle.com> > > Path lookups that traverse encrypted symlink(s) are very slow because > each encrypted symlink needs to be decrypted each time it's followed. > > Make encrypted symlinks faster by caching the decrypted symlink target > in ->i_link. The first call to ->get_link() sets it; later calls simply > return it. ->symlink() also sets it when the symlink is created. > > When the inode's ->i_crypt_info is freed, ->i_link is freed too. > > Note: RCU-delayed freeing of ->i_link is not yet implemented. > Therefore, for now even when ->i_link is set, path lookups must continue > to drop out of RCU-walk mode when following an encrypted symlink. And how the devil would they continue to do that, if I might ask? ->get_link() is *NOT* called if ->i_link is non-NULL, period.
Powered by blists - more mailing lists