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| author | Jan Kara <jack@suse.cz> | 2016-09-19 17:39:09 +0200 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2016-09-22 10:55:32 +0200 |
| commit | 073931017b49d9458aa351605b43a7e34598caef (patch) | |
| tree | 8c4374e82e5cad92bdb589e5be417f1a94870399 /fs/gfs2/acl.c | |
| parent | 5d3ddd84eaefffd23c028bce5610dac8726f71c1 (diff) | |
| download | linux-073931017b49d9458aa351605b43a7e34598caef.tar.gz | |
posix_acl: Clear SGID bit when setting file permissions
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 <hch@lst.de> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Diffstat (limited to 'fs/gfs2/acl.c')
| -rw-r--r-- | fs/gfs2/acl.c | 12 |
1 files changed, 3 insertions, 9 deletions
diff --git a/fs/gfs2/acl.c b/fs/gfs2/acl.c index 363ba9e9d8d0..2524807ee070 100644 --- a/fs/gfs2/acl.c +++ b/fs/gfs2/acl.c @@ -92,17 +92,11 @@ int __gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type) if (type == ACL_TYPE_ACCESS) { umode_t mode = inode->i_mode; - error = posix_acl_equiv_mode(acl, &mode); - if (error < 0) + error = posix_acl_update_mode(inode, &inode->i_mode, &acl); + if (error) return error; - - if (error == 0) - acl = NULL; - - if (mode != inode->i_mode) { - inode->i_mode = mode; + if (mode != inode->i_mode) mark_inode_dirty(inode); - } } if (acl) { |