[LU-4101] mdt_reint_setxattr allows removal of trusted xattrs

• Type: Bug
• Resolution: Fixed
• Priority: Critical
• Fix Version/s: Lustre 2.6.0, Lustre 2.5.1, Lustre 2.4.3
• Affects Version/s: Lustre 2.5.0
• Labels: mdt
• Severity: 3
• Assignee: John Hammond
• Reporter: John Hammond

Description

In mdt_reint_setxattr() the permissions checking is all dead code because we first test to see if the xattr name starts with "user" then we compare it to the "trusted.xxx" names:

        if (strncmp(xattr_name, XATTR_USER_PREFIX,
                    sizeof(XATTR_USER_PREFIX) - 1) == 0) {
                if (!(exp_connect_flags(req->rq_export) & OBD_CONNECT_XATTR))
                        GOTO(out, rc = -EOPNOTSUPP);
                if (strcmp(xattr_name, XATTR_NAME_LOV) == 0)
                        GOTO(out, rc = -EACCES);
                if (strcmp(xattr_name, XATTR_NAME_LMA) == 0)
                        GOTO(out, rc = 0);
                if (strcmp(xattr_name, XATTR_NAME_LINK) == 0)
                        GOTO(out, rc = 0);

# touch f0
# getfattr -d -m- f0
# file: f0
lustre.lov=0s0AvRCwEAAAAPAAAAAAAAAAAEAAACAAAAAAAQAAEAAAAGAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
trusted.link=0s3/HqEQEAAAAsAAAAAAAAAAAAAAAAAAAAABQAAAACAAAABwAAAAEAAAAAZjA=
trusted.lma=0sAAAAAAAAAAAABAAAAgAAAA8AAAAAAAAA
trusted.lov=0s0AvRCwEAAAAPAAAAAAAAAAAEAAACAAAAAAAQAAEAAAAGAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=

# setfattr -x trusted.link f0
# getfattr -d -m- f0
# file: f0
lustre.lov=0s0AvRCwEAAAAPAAAAAAAAAAAEAAACAAAAAAAQAAEAAAAGAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
trusted.lma=0sAAAAAAAAAAAABAAAAgAAAA8AAAAAAAAA
trusted.lov=0s0AvRCwEAAAAPAAAAAAAAAAAEAAACAAAAAAAQAAEAAAAGAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=

# lfs path2fid f0
[0x200000400:0xf:0x0]
# lfs fid2path /mnt/lustre 0x200000400:0xf:0x0
ioctl err -61: No data available (61)
fid2path: error on FID 0x200000400:0xf:0x0: No data available
t:lustre# getfattr -d -m- f0
# file: f0
lustre.lov=0s0AvRCwEAAAAPAAAAAAAAAAAEAAACAAAAAAAQAAEAAAAGAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
trusted.lma=0sAAAAAAAAAAAABAAAAgAAAA8AAAAAAAAA
trusted.lov=0s0AvRCwEAAAAPAAAAAAAAAAAEAAACAAAAAAAQAAEAAAAGAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=

t:lustre# setfattr -x trusted.lma f0
t:lustre# getfattr -d -m- f0
# file: f0
lustre.lov=0s0AvRCwEAAAAPAAAAAAAAAAAEAAACAAAAAAAQAAEAAAAGAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
trusted.lov=0s0AvRCwEAAAAPAAAAAAAAAAAEAAACAAAAAAAQAAEAAAAGAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
t:lustre# lfs hsm_archive f0
t:lustre# getfattr -d -m- f0
# file: f0
lustre.lov=0s0AvRCwEAAAAPAAAAAAAAAAAEAAACAAAAAAAQAAEAAAAGAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
trusted.hsm=0sAAAAAAEAAAABAAAAAAAAAAAAAAAAAAAA
trusted.lov=0s0AvRCwEAAAAPAAAAAAAAAAAEAAACAAAAAAAQAAEAAAAGAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=

t:lustre# setfattr -x trusted.hsm f0
t:lustre# getfattr -d -m- f0
# file: f0
lustre.lov=0s0AvRCwEAAAAPAAAAAAAAAAAEAAACAAAAAAAQAAEAAAAGAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
trusted.lov=0s0AvRCwEAAAAPAAAAAAAAAAAEAAACAAAAAAAQAAEAAAAGAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
# cd /mnt/lustre2
t:lustre2# getfattr -d -m- f0
# file: f0
lustre.lov=0s0AvRCwEAAAAPAAAAAAAAAAAEAAACAAAAAAAQAAEAAAAGAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
trusted.lov=0s0AvRCwEAAAAPAAAAAAAAAAAEAAACAAAAAAAQAAEAAAAGAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=