Stephen Smalley <sds@xxxxxxxxxxxxx> writes: > On Mon, 2009-08-17 at 03:07 -0400, Amerigo Wang wrote: >> 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. [...] > > This will only apply the setattr check if ATTR_FORCE was specified, > which is not the current behavior nor what we want. > > NAK. How about this? I tweaked Amerigo's patch, and it is based on the original code is doing. This is only compile-test though. [I'm still not sure what selinux want to do. normally inode_permission() should check truncate() permission, and this FILE__SIZE checks something again...? And we want to check FILE__WRITE for ATTR_[AMC]TIME?] Thanks. -- OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx> [PATCH] selinux: adjust rules for ATTR_FORCE From: Amerigo Wang <amwang@xxxxxxxxxx> 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@xxxxxxxxxxxxx> Cc: Eric Paris <eparis@xxxxxxxxxx> Signed-off-by: WANG Cong <amwang@xxxxxxxxxx> [tweaks] Signed-off-by: OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx> --- security/selinux/hooks.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 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 01:01:13.000000000 +0900 +++ linux-2.6-hirofumi/security/selinux/hooks.c 2009-08-18 03:23:52.000000000 +0900 @@ -2710,16 +2710,28 @@ static int selinux_inode_permission(stru static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr) { - const struct cred *cred = current_cred(); - - if (iattr->ia_valid & ATTR_FORCE) - return 0; +#define SELINUX_F_SETATTR_MASK (ATTR_MODE | ATTR_UID | ATTR_GID | \ + ATTR_ATIME_SET | ATTR_MTIME_SET | \ + ATTR_TIMES_SET) +#define SELINUX_F_WRITE_MASK (ATTR_CTIME | ATTR_MTIME | ATTR_ATIME | \ + ATTR_SIZE) - if (iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | - ATTR_ATIME_SET | ATTR_MTIME_SET)) - return dentry_has_perm(cred, NULL, dentry, FILE__SETATTR); + const struct cred *cred = current_cred(); + unsigned int ia_valid = iattr->ia_valid; - return dentry_has_perm(cred, NULL, dentry, FILE__WRITE); + if (!(ia_valid & ATTR_FORCE) && (ia_valid & SELINUX_F_SETATTR_MASK)) { + int err = dentry_has_perm(cred, NULL, dentry, FILE__SETATTR); + if (err) + return err; + /* Assume timestamp was changed by attributes or utimes(). */ + ia_valid &= ~(ATTR_CTIME | ATTR_MTIME | ATTR_ATIME); + } + if (ia_valid & SELINUX_F_WRITE_MASK) { + int err = dentry_has_perm(cred, NULL, dentry, FILE__WRITE); + if (err) + return err; + } + return 0; } static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) _ -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
