Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754470AbYKMATd (ORCPT ); Wed, 12 Nov 2008 19:19:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752221AbYKMATX (ORCPT ); Wed, 12 Nov 2008 19:19:23 -0500 Received: from e35.co.us.ibm.com ([32.97.110.153]:54948 "EHLO e35.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752064AbYKMATW (ORCPT ); Wed, 12 Nov 2008 19:19:22 -0500 Subject: Re: [PATCH] filesystems: use has_capability_noaudit interface for reserved blocks checks From: Mingming Cao To: Eric Paris Cc: linux-kernel@vger.kernel.org, sct@redhat.com, akpm@linux-foundation.org, adilger@sun.com, tytso@mit.edu, linux-ext4@vger.kernel.org, dedekind@infradead.org, ext-adrian.hunter@nokia.com, linux-mtd@lists.infradead.org, dushistov@mail.ru, jmorris@namei.org In-Reply-To: <1226430769.3353.5.camel@localhost.localdomain> References: <1226430769.3353.5.camel@localhost.localdomain> Content-Type: text/plain; charset=UTF-8 Organization: IBM Date: Wed, 12 Nov 2008 16:19:18 -0800 Message-Id: <1226535558.12488.30.camel@mingming-laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.12.1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5344 Lines: 140 在 2008-11-11二的 14:12 -0500，Eric Paris写道： > ext[2,3,4], ufs, and ubifs all check for CAP_SYS_RESOURCE to determine > if they should allow reserved blocks to be used. A process not having > this capability is not failing some security decision and should not be > audited. Thus move to using has_capability_noaudit. > Looks fine to me. Eric Sandeen has mentioned earlier about the security audit issue with ext4. We fixed it in ext4, with this it is even better. Reviewed-by: Mingming Cao > Signed-off-by: Eric Paris > --- > > I would like to push this patch through the security tree (since that's > the only place the new cap_noaudit interface exists), but I'd like to > get an ACK from each subsystem maintainer. > > fs/ext2/balloc.c | 2 +- > fs/ext3/balloc.c | 2 +- > fs/ext4/balloc.c | 2 +- > fs/ubifs/budget.c | 3 ++- > fs/ufs/balloc.c | 2 +- > security/commoncap.c | 1 + > security/security.c | 1 + > 7 files changed, 8 insertions(+), 5 deletions(-) > > > diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c > index 6dac7ba..e06d96d 100644 > --- a/fs/ext2/balloc.c > +++ b/fs/ext2/balloc.c > @@ -1192,7 +1192,7 @@ static int ext2_has_free_blocks(struct ext2_sb_info *sbi) > > free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter); > root_blocks = le32_to_cpu(sbi->s_es->s_r_blocks_count); > - if (free_blocks < root_blocks + 1 && !capable(CAP_SYS_RESOURCE) && > + if (free_blocks < root_blocks + 1 && !has_capability_noaudit(current, CAP_SYS_RESOURCE) && > sbi->s_resuid != current->fsuid && > (sbi->s_resgid == 0 || !in_group_p (sbi->s_resgid))) { > return 0; > diff --git a/fs/ext3/balloc.c b/fs/ext3/balloc.c > index f5b57a2..f224ee4 100644 > --- a/fs/ext3/balloc.c > +++ b/fs/ext3/balloc.c > @@ -1421,7 +1421,7 @@ static int ext3_has_free_blocks(struct ext3_sb_info *sbi) > > free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter); > root_blocks = le32_to_cpu(sbi->s_es->s_r_blocks_count); > - if (free_blocks < root_blocks + 1 && !capable(CAP_SYS_RESOURCE) && > + if (free_blocks < root_blocks + 1 && !has_capability_noaudit(current, CAP_SYS_RESOURCE) && > sbi->s_resuid != current->fsuid && > (sbi->s_resgid == 0 || !in_group_p (sbi->s_resgid))) { > return 0; > diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c > index d2003cd..a7c7c52 100644 > --- a/fs/ext4/balloc.c > +++ b/fs/ext4/balloc.c > @@ -626,7 +626,7 @@ int ext4_has_free_blocks(struct ext4_sb_info *sbi, s64 nblocks) > /* Hm, nope. Are (enough) root reserved blocks available? */ > if (sbi->s_resuid == current->fsuid || > ((sbi->s_resgid != 0) && in_group_p(sbi->s_resgid)) || > - capable(CAP_SYS_RESOURCE)) { > + has_capability_noaudit(current, CAP_SYS_RESOURCE)) { > if (free_blocks >= (nblocks + dirty_blocks)) > return 1; > } > diff --git a/fs/ubifs/budget.c b/fs/ubifs/budget.c > index 1a4973e..d17b8b4 100644 > --- a/fs/ubifs/budget.c > +++ b/fs/ubifs/budget.c > @@ -32,6 +32,7 @@ > > #include "ubifs.h" > #include > +#include > #include > > /* > @@ -363,7 +364,7 @@ long long ubifs_calc_available(const struct ubifs_info *c, int min_idx_lebs) > */ > static int can_use_rp(struct ubifs_info *c) > { > - if (current->fsuid == c->rp_uid || capable(CAP_SYS_RESOURCE) || > + if (current->fsuid == c->rp_uid || has_capability_noaudit(current, CAP_SYS_RESOURCE) || > (c->rp_gid != 0 && in_group_p(c->rp_gid))) > return 1; > return 0; > diff --git a/fs/ufs/balloc.c b/fs/ufs/balloc.c > index 0d9ada1..ad4398b 100644 > --- a/fs/ufs/balloc.c > +++ b/fs/ufs/balloc.c > @@ -411,7 +411,7 @@ u64 ufs_new_fragments(struct inode *inode, void *p, u64 fragment, > /* > * There is not enough space for user on the device > */ > - if (!capable(CAP_SYS_RESOURCE) && ufs_freespace(uspi, UFS_MINFREE) <= 0) { > + if (!has_capability_noaudit(current, CAP_SYS_RESOURCE) && ufs_freespace(uspi, UFS_MINFREE) <= 0) { > unlock_super (sb); > UFSD("EXIT (FAILED)\n"); > return 0; > diff --git a/security/commoncap.c b/security/commoncap.c > index 73999f6..5401e77 100644 > --- a/security/commoncap.c > +++ b/security/commoncap.c > @@ -55,6 +55,7 @@ int cap_capable(struct task_struct *tsk, int cap, int audit) > return 0; > return -EPERM; > } > +EXPORT_SYMBOL(cap_capable); > > int cap_settime(struct timespec *ts, struct timezone *tz) > { > diff --git a/security/security.c b/security/security.c > index 346f21e..d061eb1 100644 > --- a/security/security.c > +++ b/security/security.c > @@ -170,6 +170,7 @@ int security_capable_noaudit(struct task_struct *tsk, int cap) > { > return security_ops->capable(tsk, cap, SECURITY_CAP_NOAUDIT); > } > +EXPORT_SYMBOL(security_capable_noaudit); > > int security_acct(struct file *file) > { > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/