TITLE: KMSAN: uninit-value in prepare_task_switch
ALT: bad-access in prepare_task_switch
TYPE: KMSAN-UNINIT-VALUE
PANICKED: Y

[  567.476354][    T1] =====================================================
[  567.483452][    T1] BUG: KMSAN: uninit-value in prepare_task_switch+0x284/0xd00
[  567.490925][    T1]  prepare_task_switch+0x284/0xd00
[  567.496040][    T1]  __schedule+0x2da/0x520
[  567.500419][    T1]  __cond_resched+0x43/0xa0
[  567.505008][    T1]  __dentry_kill+0xdc2/0xe90
[  567.509631][    T1]  dentry_kill+0x22c/0x710
[  567.514066][    T1]  dput+0x3e1/0x640
[  567.517883][    T1]  step_into+0x923/0x1a00
[  567.522249][    T1]  path_openat+0x3603/0x64c0
[  567.526845][    T1]  do_filp_open+0x2cb/0x720
[  567.531348][    T1]  do_sys_openat2+0x273/0x870
[  567.536051][    T1]  __x64_sys_open+0x314/0x380
[  567.540732][    T1]  do_syscall_64+0x53/0xc0
[  567.545153][    T1]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  567.551059][    T1] 
[  567.553376][    T1] Local variable ----path@step_into created at:
[  567.559600][    T1]  step_into+0xbc/0x1a00
[  567.563850][    T1]  path_openat+0x3603/0x64c0
[  567.568441][    T1] =====================================================
[  567.575370][    T1] Disabling lock debugging due to kernel taint
[  567.581610][    T1] Kernel panic - not syncing: panic_on_kmsan set ...
[  567.588283][    T1] CPU: 1 PID: 1 Comm: systemd Tainted: G    B             5.13.0-syzkaller #0c
[  567.588283][    T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[  567.588283][    T1] Call Trace:
[  567.588283][    T1]  __dump_stack lib/dump_stack.c:79 [inline]
[  567.588283][    T1]  dump_stack+0x25a/0x2f6 lib/dump_stack.c:120
[  567.588283][    T1]  panic+0x4c7/0xe98 kernel/panic.c:231
[  567.588283][    T1]  kmsan_report+0x2ee/0x300 mm/kmsan/report.c:179
[  567.588283][    T1]  __msan_warning+0xd7/0x150 mm/kmsan/instrumentation.c:205
[  567.588283][    T1]  prepare_task_switch+0x284/0xd00 kernel/sched/core.c:4146
[  567.588283][    T1]  context_switch kernel/sched/core.c:4302 [inline]

REPORT:
=====================================================
BUG: KMSAN: uninit-value in prepare_task_switch+0x284/0xd00
 prepare_task_switch+0x284/0xd00
 __schedule+0x2da/0x520
 __cond_resched+0x43/0xa0
 __dentry_kill+0xdc2/0xe90
 dentry_kill+0x22c/0x710
 dput+0x3e1/0x640
 step_into+0x923/0x1a00
 path_openat+0x3603/0x64c0
 do_filp_open+0x2cb/0x720
 do_sys_openat2+0x273/0x870
 __x64_sys_open+0x314/0x380
 do_syscall_64+0x53/0xc0
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Local variable ----path@step_into created at:
 step_into+0xbc/0x1a00
 path_openat+0x3603/0x64c0
=====================================================
