Messages in this thread Patch in this message | | | From | OGAWA Hirofumi <> | Subject | Re: [Patch 1/2] selinux: ajust rules for ATTR_FORCE | Date | Tue, 18 Aug 2009 16:39:00 +0900 |
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[Sorry if this killed thread. My ISP seems to be stopping email server now. I've read this email from web archive.]
>> @@ -2711,12 +2711,17 @@ static int selinux_inode_permission(stru >> static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr) >> { >> const struct cred *cred = current_cred(); >> + unsigned int ia_valid = iattr->ia_valid; >> >> - if (iattr->ia_valid & ATTR_FORCE) >> - return 0; >> + /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */ >> + if (ia_valid & ATTR_FORCE) { >> + ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE); >> + if (!ia_valid) >> + return 0; >> > > So if I read this correctly, (ATTR_FORCE| ATTR_KILL_SUID|ATTR_MODE) will > not return here, since 'ia_valid' will be ATTR_FORCE finally. > > I think you forgot to clear ATTR_FORCE here...
Whoops, good catch. Fortunately, it doesn't seem to have actual problem, but it's bug obviously, and sorry for that. Fixed patch was attached.
Thanks. -- OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
[PATCH] selinux: adjust rules for ATTR_FORCE
From: Amerigo Wang <amwang@redhat.com>
As suggested by OGAWA Hirofumi in thread: http://lkml.org/lkml/2009/8/7/132, we should let selinux_inode_setattr() to match our ATTR_* rules. ATTR_FORCE should not force things like ATTR_SIZE.
Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: WANG Cong <amwang@redhat.com> [tweaks] Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> ---
security/selinux/hooks.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)
diff -puN security/selinux/hooks.c~selinux-truncate-fix security/selinux/hooks.c --- linux-2.6/security/selinux/hooks.c~selinux-truncate-fix 2009-08-18 06:27:58.000000000 +0900 +++ linux-2.6-hirofumi/security/selinux/hooks.c 2009-08-18 16:10:50.000000000 +0900 @@ -2711,12 +2711,18 @@ static int selinux_inode_permission(stru static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr) { const struct cred *cred = current_cred(); + unsigned int ia_valid = iattr->ia_valid; - if (iattr->ia_valid & ATTR_FORCE) - return 0; + /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */ + if (ia_valid & ATTR_FORCE) { + ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE | + ATTR_FORCE); + if (!ia_valid) + return 0; + } - if (iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | - ATTR_ATIME_SET | ATTR_MTIME_SET)) + if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | + ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET)) return dentry_has_perm(cred, NULL, dentry, FILE__SETATTR); return dentry_has_perm(cred, NULL, dentry, FILE__WRITE); _
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