FYI, we noticed the following commit (built with gcc-7): commit: e984eb51083c9ed14780ecebcf041452aae489a5 ("[PATCH v14 1/5] Add flags option to get xattr method paired to __vfs_getxattr") url: https://github.com/0day-ci/linux/commits/Mark-Salyzyn/overlayfs-override_creds-off-nested-get-xattr-fix/20191025-004342 in testcase: xfstests with following parameters: disk: 4HDD fs: xfs test: generic-group04 test-description: xfstests is a regression test suite for xfs and other files ystems. test-url: git://git.kernel.org/pub/scm/fs/xfs/xfstests-dev.git on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 8G caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +------------------------------------------------+------------+------------+ | | f116b96685 | e984eb5108 | +------------------------------------------------+------------+------------+ | boot_successes | 224 | 0 | | boot_failures | 2 | 19 | | BUG:soft_lockup-CPU##stuck_for#s | 1 | | | RIP:copy_page | 1 | | | Kernel_panic-not_syncing:softlockup:hung_tasks | 1 | | | BUG:kernel_hang_in_boot_stage | 1 | 1 | | Assertion_failed | 0 | 12 | | kernel_BUG_at_fs/xfs/xfs_message.c | 0 | 12 | | invalid_opcode:#[##] | 0 | 12 | | RIP:assfail[xfs] | 0 | 12 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 18 | | BUG:kernel_NULL_pointer_dereference,address | 0 | 6 | | Oops:#[##] | 0 | 6 | | RIP:xfs_attr_get[xfs] | 0 | 6 | +------------------------------------------------+------------+------------+ If you fix the issue, kindly add following tag Reported-by: kernel test robot [ 30.021216] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 30.024251] #PF: supervisor read access in kernel mode [ 30.026682] #PF: error_code(0x0000) - not-present page [ 30.029302] PGD 0 P4D 0 [ 30.031081] Oops: 0000 [#1] SMP PTI [ 30.033012] CPU: 0 PID: 1577 Comm: t_mtab Not tainted 5.4.0-rc4-00086-ge984eb51083c9 #1 [ 30.036276] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 30.039548] RIP: 0010:xfs_attr_get+0x135/0x1d0 [xfs] [ 30.041936] Code: 8c 24 80 00 00 00 65 48 33 0c 25 28 00 00 00 44 89 f0 0f 85 9f 00 00 00 48 81 c4 88 00 00 00 5b 5d 41 5c 41 5d 41 5e 41 5f c3 <48> 8b 55 00 4c 89 e7 89 44 24 20 48 89 54 24 18 e8 f6 0f 07 00 4c [ 30.049011] RSP: 0018:ffffc31780d2fc90 EFLAGS: 00010246 [ 30.051621] RAX: 0000000000000000 RBX: ffffc31780d2fd54 RCX: 0000000000000079 [ 30.054667] RDX: 000000007c7bfd5e RSI: 0000000000000002 RDI: ffffffffa492e52e [ 30.057702] RBP: 0000000000000000 R08: 000000007c7bfd5e R09: ffffffffa492e52e [ 30.060730] R10: 00000000ffffffff R11: 6f6e6e616300706d R12: ffffa0bf59395800 [ 30.063929] R13: 0000000000000000 R14: 0000000000000000 R15: ffffa0bf59395950 [ 30.067127] FS: 00007f416fffa700(0000) GS:ffffa0bfbfc00000(0000) knlGS:0000000000000000 [ 30.070633] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 30.073402] CR2: 0000000000000000 CR3: 0000000229292000 CR4: 00000000000406f0 [ 30.076552] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 30.079690] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 30.082952] Call Trace: [ 30.084885] xfs_xattr_get+0x47/0x80 [xfs] [ 30.087163] __vfs_getxattr+0xa6/0x160 [ 30.089408] cap_inode_need_killpriv+0x5a/0x80 [ 30.091825] security_inode_need_killpriv+0x22/0x40 [ 30.094425] notify_change+0x18c/0x440 [ 30.096690] chown_common+0x19e/0x1c0 [ 30.098949] do_fchownat+0xc7/0xe0 [ 30.101030] __x64_sys_chown+0x1e/0x30 [ 30.103150] do_syscall_64+0x5b/0x1d0 [ 30.105302] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 30.107924] RIP: 0033:0x7f416eadc957 [ 30.110086] Code: 48 39 84 24 90 00 00 00 75 bd 48 8b 44 24 08 48 39 84 24 98 00 00 00 75 ae 48 89 df e8 52 3a fa ff eb ad b8 5c 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 11 c5 2b 00 f7 d8 64 89 01 48 [ 30.117485] RSP: 002b:00007ffc2dc92348 EFLAGS: 00000206 ORIG_RAX: 000000000000005c [ 30.121077] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f416eadc957 [ 30.124380] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000055921e44b756 [ 30.127688] RBP: 00007ffc2dc923e0 R08: 00007f416fffa700 R09: 0000000000000001 [ 30.130952] R10: 0000000000000612 R11: 0000000000000206 R12: 000055921eef0240 [ 30.134296] R13: 000055921eef0010 R14: 0000000000000000 R15: 0000000000000000 [ 30.137470] Modules linked in: xfs libcrc32c dm_mod bochs_drm drm_vram_helper intel_rapl_msr intel_rapl_common ttm drm_kms_helper sr_mod crct10dif_pclmul cdrom crc32_pclmul crc32c_intel sg ghash_clmulni_intel syscopyarea sysfillrect sysimgblt fb_sys_fops ppdev drm ata_generic pata_acpi snd_pcm aesni_intel snd_timer crypto_simd snd cryptd glue_helper soundcore joydev pcspkr serio_raw i2c_piix4 ata_piix parport_pc floppy parport ip_tables [ 30.152129] CR2: 0000000000000000 [ 30.154197] ---[ end trace 64dccd3aaa617377 ]--- To reproduce: # build kernel cd linux cp config-5.4.0-rc4-00086-ge984eb51083c9 .config make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 olddefconfig prepare modules_prepare bzImage modules make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 INSTALL_MOD_PATH= modules_install cd find lib/ | cpio -o -H newc --quiet | gzip > modules.cgz git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp qemu -k -m modules.cgz job-script # job-script is attached in this email Thanks, lkp