linux-stable.git/fs/ext2/acl.c, branch linux-3.16.y

ext2: preserve i_mode if ext2_set_acl() fails

2017-10-12T14:28:07+00:00

commit fe26569eb9197d845d73abe7dd20f603d79eb031 upstream.

When changing a file's acl mask, ext2_set_acl() will first set the group
bits of i_mode to the value of the mask, and only then set the actual
extended attribute representing the new acl.

If the second part fails (due to lack of space, for example) and the file
had no acl attribute to begin with, the system will from now on assume
that the mask permission bits are actual group permission bits, potentially
granting access to the wrong users.

Prevent this by only changing the inode mode after the acl has been set.

[JK: Rebased on top of "ext2: Don't clear SGID when inheriting ACLs"]
Signed-off-by: Ernesto A. Fernández 
Signed-off-by: Jan Kara 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

ext2: Don't clear SGID when inheriting ACLs

2017-10-12T14:28:07+00:00

commit a992f2d38e4ce17b8c7d1f7f67b2de0eebdea069 upstream.

When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit
set, DIR1 is expected to have SGID bit set (and owning group equal to
the owning group of 'DIR0'). However when 'DIR0' also has some default
ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on
'DIR1' to get cleared if user is not member of the owning group.

Fix the problem by creating __ext2_set_acl() function that does not call
posix_acl_update_mode() and use it when inheriting ACLs. That prevents
SGID bit clearing and the mode has been properly set by
posix_acl_create() anyway.

Fixes: 073931017b49d9458aa351605b43a7e34598caef
CC: linux-ext4@vger.kernel.org
Signed-off-by: Jan Kara 
[bwh: Backported to 3.16: keep using CURRENT_TIME_SEC]
Signed-off-by: Ben Hutchings

posix_acl: Clear SGID bit when setting file permissions

2016-11-20T01:17:38+00:00

commit 073931017b49d9458aa351605b43a7e34598caef upstream.

When file permissions are modified via chmod(2) and the user is not in
the owning group or capable of CAP_FSETID, the setgid bit is cleared in
inode_change_ok().  Setting a POSIX ACL via setxattr(2) sets the file
permissions as well as the new ACL, but doesn't clear the setgid bit in
a similar way; this allows to bypass the check in chmod(2).  Fix that.

References: CVE-2016-7097
Reviewed-by: Christoph Hellwig 
Reviewed-by: Jeff Layton 
Signed-off-by: Jan Kara 
Signed-off-by: Andreas Gruenbacher 
[bwh: Backported to 3.16:
 - Drop changes to orangefs
 - Adjust context
 - Update ext3 as well]
Signed-off-by: Ben Hutchings

ext2: acl: remove unneeded include of linux/capability.h

2014-04-01T21:36:43+00:00

acl.c has not been (directly) using the interface defined by
linux/capability.h header since commit 3bd858ab1c451725c07a
("Introduce is_owner_or_cap() to wrap CAP_FOWNER use with fsuid
check"). Remove it.

Signed-off-by: Jakub Sitnicki 
Signed-off-by: Jan Kara

ext2/3/4: use generic posix ACL infrastructure

2014-01-26T04:58:19+00:00

Signed-off-by: Christoph Hellwig 
Reviewed-by: Jan Kara 
Signed-off-by: Al Viro

fs: make posix_acl_create more useful

2014-01-26T04:58:18+00:00

Rename the current posix_acl_created to __posix_acl_create and add
a fully featured helper to set up the ACLs on file creation that
uses get_acl().

Signed-off-by: Christoph Hellwig 
Reviewed-by: Jan Kara 
Signed-off-by: Al Viro

fs: make posix_acl_chmod more useful

2014-01-26T04:58:18+00:00

Rename the current posix_acl_chmod to __posix_acl_chmod and add
a fully featured ACL chmod helper that uses the ->set_acl inode
operation.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Jan Kara 
Signed-off-by: Al Viro

userns: Convert extN to support kuids and kgids in posix acls

2012-09-18T08:01:36+00:00

Convert ext2, ext3, and ext4 to fully support the posix acl changes,
using e_uid e_gid instead e_id.

Enabled building with posix acls enabled, all filesystems supporting
user namespaces, now also support posix acls when user namespaces are enabled.

Cc: Theodore Tso 
Cc: Andrew Morton 
Cc: Andreas Dilger 
Cc: Jan Kara 
Cc: Al Viro 
Signed-off-by: Eric W. Biederman

userns: Pass a userns parameter into posix_acl_to_xattr and posix_acl_from_xattr

2012-09-18T08:01:35+00:00

 - Pass the user namespace the uid and gid values in the xattr are stored
   in into posix_acl_from_xattr.

 - Pass the user namespace kuid and kgid values should be converted into
   when storing uid and gid values in an xattr in posix_acl_to_xattr.

- Modify all callers of posix_acl_from_xattr and posix_acl_to_xattr to
  pass in &init_user_ns.

In the short term this change is not strictly needed but it makes the
code clearer.  In the longer term this change is necessary to be able to
mount filesystems outside of the initial user namespace that natively
store posix acls in the linux xattr format.

Cc: Theodore Tso 
Cc: Andrew Morton 
Cc: Andreas Dilger 
Cc: Jan Kara 
Cc: Al Viro 
Signed-off-by: "Eric W. Biederman"

switch posix_acl_equiv_mode() to umode_t *

2011-08-01T06:10:06+00:00

... so that &inode->i_mode could be passed to it

Signed-off-by: Al Viro