OGAWA Hirofumi wrote:
Could you review this? I've added ATTR_TIMES_SET to check explicit
utimes(), and tried it with minimum change.
[I'm not sure this handles notify_change() usage of nfsd (and perhaps
other network fs too) correctly, and whether selinux may want to check
it. I guess network fs _may_ try to change the multiple attributes at a
time. Well, even if it's true, it would be another topic...]
Ah, according to the discussion here, I know I misunderstood
ATTR_FORCE... sorry.
OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
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>
Great!
Some comments below.
---
security/selinux/hooks.c | 13 +++++++++----
1 file changed, 9 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 03:50:09.000000000 +0900
+++ linux-2.6-hirofumi/security/selinux/hooks.c 2009-08-18 05:35:11.000000000 +0900
@@ -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...
+ }
- 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);
_
I am not sure about ATTR_TIMES_SET here, but looks fine. :-/
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