kernel/linux.git/fs/btrfs/acl.c, branch linux-4.4.y

btrfs: preserve i_mode if __btrfs_set_acl() fails

2018-03-11T15:19:47+00:00

commit d7d824966530acfe32b94d1ed672e6fe1638cd68 upstream. When changing a file's acl mask, btrfs_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 restoring the original mode bits if __btrfs_set_acl fails. Signed-off-by: Ernesto A. Fernández Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Nikolay Borisov Signed-off-by: Greg Kroah-Hartman

btrfs: Don't clear SGID when inheriting ACLs

2018-03-11T15:19:45+00:00

commit b7f8a09f8097db776b8d160862540e4fc1f51296 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 moving posix_acl_update_mode() out of __btrfs_set_acl() into btrfs_set_acl(). That way the function will not be called when inheriting ACLs which is what we want as it prevents SGID bit clearing and the mode has been properly set by posix_acl_create() anyway. Fixes: 073931017b49d9458aa351605b43a7e34598caef CC: stable@vger.kernel.org CC: linux-btrfs@vger.kernel.org CC: David Sterba Signed-off-by: Jan Kara Signed-off-by: David Sterba Signed-off-by: Nikolay Borisov Signed-off-by: Greg Kroah-Hartman

posix_acl: Clear SGID bit when setting file permissions

2016-10-31T10:13:58+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 Signed-off-by: Greg Kroah-Hartman

btrfs: remove useless ACL check

2014-06-10T00:20:42+00:00

posix_acl_xattr_set() already does the check, and it's the only way to feed in an ACL from userspace. So the check here is useless, remove it. Signed-off-by: zhang zhen Signed-off-by: Chris Mason

btrfs: use generic posix ACL infrastructure

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

Also don't bother to set up a .get_acl method for symlinks as we do not support access control (ACLs or even mode bits) for symlinks in Linux. Signed-off-by: Christoph Hellwig 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

Btrfs: fix incorrect inode acl reset

2013-11-12T03:02:51+00:00

When a directory has a default ACL and a subdirectory is created under that directory, btrfs_init_acl() is called when the subdirectory's inode is created to initialize the inode's ACL (inherited from the parent directory) but it was clearing the ACL from the inode after setting it if posix_acl_create() returned success, instead of clearing it only if it returned an error. To reproduce this issue: $ mkfs.btrfs -f /dev/loop0 $ mount /dev/loop0 /mnt $ mkdir /mnt/acl $ setfacl -d --set u::rwx,g::rwx,o::- /mnt/acl $ getfacl /mnt/acl user::rwx group::rwx other::r-x default:user::rwx default:group::rwx default:other::--- $ mkdir /mnt/acl/dir1 $ getfacl /mnt/acl/dir1 user::rwx group::rwx other::--- After unmounting and mounting again the filesystem, fgetacl returned the expected ACL: $ umount /mnt/acl $ mount /dev/loop0 /mnt $ getfacl /mnt/acl/dir1 user::rwx group::rwx other::--- default:user::rwx default:group::rwx default:other::--- Meaning that the underlying xattr was persisted. Reported-by: Giuseppe Fierro Signed-off-by: Filipe David Borba Manana Signed-off-by: Josef Bacik Signed-off-by: Chris Mason

Btrfs: skip adding an acl attribute if we don't have to

2012-12-17T01:46:15+00:00

If the acl can be exactly represented in the traditional file mode permission bits, we don't set another acl attribute. Signed-off-by: Liu Bo Signed-off-by: Chris Mason

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"