FYI, we noticed the following commit: commit: 99f64a2676f0bec4ad32e39fc76eb0914ee091b8 ("fs: Harden against open(..., O_CREAT, 02777) in a setgid directory") https://git.kernel.org/pub/scm/linux/kernel/git/luto/linux.git vfs/suid in testcase: ltp with following parameters: test: ltplite test-description: The LTP testsuite contains a collection of tools for testing the Linux kernel and related features. test-url: http://linux-test-project.github.io/ on test machine: 88 threads Intel(R) Xeon(R) CPU E5-2699 v4 @ 2.20GHz with 128G memory caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): user :notice: [ 113.810232] tag=creat08 stime=1485669539 user :notice: [ 113.810724] cmdline="creat08" user :notice: [ 113.811048] contacts="" user :notice: [ 113.811427] analysis=exit user :notice: [ 113.811919] <<<test_output>>> user :notice: [ 113.813322] creat08 1 TPASS : Test passed in block0. user :notice: [ 113.814681] creat08 2 TPASS : Test passed in block1. user :notice: [ 113.817942] creat08 3 TFAIL : creat08.c:366: testdir.B.2467/setgid: Incorrect modes, setgid bit should be set user :notice: [ 113.819664] creat08 4 TFAIL : creat08.c:374: Test failed in block2. [...] user :notice: [ 244.775233] tag=open10 stime=1485669670 user :notice: [ 244.775505] cmdline="open10" user :notice: [ 244.775695] contacts="" user :notice: [ 244.775923] analysis=exit user :notice: [ 244.776216] <<<test_output>>> user :notice: [ 244.777045] open10 1 TPASS : Test passed in block0. user :notice: [ 244.777883] open10 2 TPASS : Test passed in block1. user :notice: [ 244.779876] open10 3 TFAIL : open10.c:352: open10.testdir.B.5503/setgid: Incorrect modes, setgid bit not set user :notice: [ 244.780976] open10 4 TFAIL : open10.c:359: Test failed in block2. user :notice: [ 244.781811] open10 5 TPASS : Test passed in block3. user :notice: [ 244.783235] open10 6 TFAIL : open10.c:443: Test failed because of above failures. user :notice: [ 244.775233] tag=open10 stime=1485669670 user :notice: [ 244.775505] cmdline="open10" user :notice: [ 244.775695] contacts="" user :notice: [ 244.775923] analysis=exit user :notice: [ 244.776216] <<<test_output>>> user :notice: [ 244.777045] open10 1 TPASS : Test passed in block0. user :notice: [ 244.777883] open10 2 TPASS : Test passed in block1. user :notice: [ 244.779876] open10 3 TFAIL : open10.c:352: open10.testdir.B.5503/setgid: Incorrect modes, setgid bit not set user :notice: [ 244.780976] open10 4 TFAIL : open10.c:359: Test failed in block2. user :notice: [ 244.781811] open10 5 TPASS : Test passed in block3. user :notice: [ 244.783235] open10 6 TFAIL : open10.c:443: Test failed because of above failures. To reproduce: git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git cd lkp-tests bin/lkp install job.yaml # job file is attached in this email bin/lkp run job.yaml Thanks, Xiaolong