pty03 from pty / cve-2020-14416 from cve fails on focal 5.8.0-49.55~20.04.1 host rumford (lowlatency only)

[Kelsey Steele]

ptyo3 from pty in ubuntu_ltp_stable is failing on focal/hwe-5.8 5.8.0-49.55~20.04.1

only failing on host rumford and passes on others.

Seems to be a new test to check on Focal/linux (at least in recent times), so I would not consider this to be a regression.

 pty03.c:93: TFAIL: Failed to set the CAIF line discipline: ENODEV (19)
 pty03.c:106: TINFO: Creating PTY with GSM line discipline
 ../../../include/tst_fuzzy_sync.h:507: TINFO: Minimum sampling period ended
 ../../../include/tst_fuzzy_sync.h:330: TINFO: loop = 20, delay_bias = 0
 ../../../include/tst_fuzzy_sync.h:318: TINFO: start_a - start_b: { avg = 149ns, avg_dev = 65ns, dev_ratio = 0.43 }
 ../../../include/tst_fuzzy_sync.h:318: TINFO: end_a - start_a : { avg = 2296263ns, avg_dev = 84143ns, dev_ratio = 0.04 }
 ../../../include/tst_fuzzy_sync.h:318: TINFO: end_b - start_b : { avg = 13013ns, avg_dev = 489ns, dev_ratio = 0.04 }
 ../../../include/tst_fuzzy_sync.h:318: TINFO: end_a - end_b : { avg = 2283399ns, avg_dev = 83810ns, dev_ratio = 0.04 }
 ../../../include/tst_fuzzy_sync.h:318: TINFO: spins : { avg = 780052 , avg_dev = 38302 , dev_ratio = 0.05 }
 ../../../include/tst_fuzzy_sync.h:636: TINFO: Exceeded execution time, requesting exit
 pty03.c:132: TPASS: Did not crash with GSM TTY discipline

 HINT: You _MAY_ be missing kernel fixes, see:

 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0ace17d568241
 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=dd42bf1197144

 HINT: You _MAY_ be vulnerable to CVE(s), see:

 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-14416

 Summary:
 passed 8
 failed 1
 broken 0
 skipped 0
 warnings 0
 tag=pty03 stime=1616874034 dur=174 exit=exited stat=1 core=no cu=18506 cs=7917

[Kelsey Steele (kelsey-steele)]

Same failure on Focal/linux 5.4.0-71.79 - lowlatency, also only on host rumford

[Po-Hsu Lin (cypressyew)]

hmm interesting, I can't reproduce this manually on host rumford:
Linux rumford 5.8.0-49-generic #55~20.04.1-Ubuntu

I ran a test subset from pty:
pty01 pty01
pty02 pty02
pty03 pty03

Probably caused by some other tests executed before this test.

[Po-Hsu Lin (cypressyew)]

I tried the following:
 1. fs_perms_simple + pty03
 2. fsx + pty03
 3. dio + pty03
 4. io + pty03
 5. ipc + pty03
 6. sched + pty03
 7. math + pty03
 8. nptl + pty03

And running the whole ubuntu_ltp_stable suite, I didn't see this failure.

[Po-Hsu Lin (cypressyew)]

I checked again on the jenkins, it looks like these failure are only specific to the lowlatency kernel:
focal-linux-hwe-5.8-lowlatency-amd64-5.8.0-rumford-ubuntu_ltp_stable
focal-linux-lowlatency-amd64-5.4.0-rumford-ubuntu_ltp_stable
groovy-linux-lowlatency-amd64-5.8.0-rumford-ubuntu_ltp_stable

And this test has passed with their generic flavour counterpart.

Also note that all the tests performed above in comment #3 and #4 are for generic flavour, this may explains why I can't reproduce this error.

Trying again on lowlatency kernel now.

[Po-Hsu Lin (cypressyew)]

Yes this is specific to the lowlatency kernel on node "rumford"

Tested with H-5.11.0-37

It can pass with the generic kernel.

[Po-Hsu Lin (cypressyew)]

Note that cve:cve-2020-14416 is the same test with pty:pty03:

ltp/runtest$ grep pty03 *
cve:cve-2020-14416 pty03
pty:pty03 pty03

[Joseph Salisbury (jsalisbury)]

Issue is seen on the focal:linux-oracle kernel for cycle 2022.11.14.
Only failing for BM.Standard.A1.160 instance type and passing for other instance types:

pty03.c:108: TINFO: Creating PTY with CAIF line discipline
../../../include/tst_fuzzy_sync.h:484: TINFO: Minimum sampling period ended
../../../include/tst_fuzzy_sync.h:307: TINFO: loop = 20, delay_bias = 0
../../../include/tst_fuzzy_sync.h:295: TINFO: start_a - start_b: { avg = 1242ns, avg_dev = 328ns, dev_ratio = 0.26 }
../../../include/tst_fuzzy_sync.h:295: TINFO: end_a - start_a : { avg = 173947ns, avg_dev = 168368ns, dev_ratio = 0.97 }
../../../include/tst_fuzzy_sync.h:295: TINFO: end_b - start_b : { avg = 8319ns, avg_dev = 2174ns, dev_ratio = 0.26 }
../../../include/tst_fuzzy_sync.h:295: TINFO: end_a - end_b : { avg = 166870ns, avg_dev = 168372ns, dev_ratio = 1.01 }
../../../include/tst_fuzzy_sync.h:295: TINFO: spins : { avg = 93823 , avg_dev = 94944 , dev_ratio = 1.01 }

pty03.c:95: TFAIL: Failed to set the CAIF line discipline: ENODEV (19)

pty03.c:108: TINFO: Creating PTY with GSM line discipline
../../../include/tst_fuzzy_sync.h:484: TINFO: Minimum sampling period ended
../../../include/tst_fuzzy_sync.h:307: TINFO: loop = 20, delay_bias = 0
../../../include/tst_fuzzy_sync.h:295: TINFO: start_a - start_b: { avg = -21422ns, avg_dev = 121898ns, dev_ratio = 5.69 }
../../../include/tst_fuzzy_sync.h:295: TINFO: end_a - start_a : { avg = 1579000ns, avg_dev = 51670ns, dev_ratio = 0.03 }
../../../include/tst_fuzzy_sync.h:295: TINFO: end_b - start_b : { avg = 7847ns, avg_dev = 1561ns, dev_ratio = 0.20 }
../../../include/tst_fuzzy_sync.h:295: TINFO: end_a - end_b : { avg = 1549731ns, avg_dev = 156401ns, dev_ratio = 0.10 }
../../../include/tst_fuzzy_sync.h:295: TINFO: spins : { avg = 878071 , avg_dev = 29026 , dev_ratio = 0.03 }
../../../include/tst_fuzzy_sync.h:648: TINFO: Exceeded execution time, requesting exit
pty03.c:134: TPASS: Did not crash with GSM TTY discipline

[Po-Hsu Lin (cypressyew)]

Looks like this issue will gone with LTP 20230516, commit 3ebc2dfa85c