loop0: detected capacity change from 0 to 512
==================================================================
BUG: KCSAN: data-race in __set_task_comm / strlen

write to 0xffff888104594cd8 of 10 bytes by task 11764 on cpu 0:
 __set_task_comm+0x78/0x180 fs/exec.c:1102
 __do_sys_prctl kernel/sys.c:2608 [inline]
 __se_sys_prctl+0xcb3/0x13b0 kernel/sys.c:2534
 __x64_sys_prctl+0x67/0x80 kernel/sys.c:2534
 x64_sys_call+0x2421/0x2550 arch/x86/include/generated/asm/syscalls_64.h:158
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888104594ce1 of 1 bytes by task 11761 on cpu 1:
 strlen+0x19/0x40 lib/string.c:402
 __fortify_strlen include/linux/fortify-string.h:218 [inline]
 trace_event_get_offsets_sched_stat_runtime include/trace/events/sched.h:560 [inline]
 do_trace_event_raw_event_sched_stat_runtime include/trace/events/sched.h:553 [inline]
 trace_event_raw_event_sched_stat_runtime+0x5a/0x150 include/trace/events/sched.h:553
 __do_trace_sched_stat_runtime include/trace/events/sched.h:576 [inline]
 trace_sched_stat_runtime include/trace/events/sched.h:576 [inline]
 update_se+0x14f/0x450 kernel/sched/fair.c:1425
 update_curr+0x1e/0x210 kernel/sched/fair.c:2048
 update_curr_eevdf kernel/sched/fair.c:7980 [inline]
 enqueue_task_fair+0x77/0x850 kernel/sched/fair.c:8010
 enqueue_task kernel/sched/core.c:2194 [inline]
 activate_task kernel/sched/core.c:2234 [inline]
 ttwu_do_activate+0xa7/0x230 kernel/sched/core.c:3840
 ttwu_queue kernel/sched/core.c:4093 [inline]
 try_to_wake_up+0x44f/0x6d0 kernel/sched/core.c:4431
 ext4_multi_mount_protect+0x55b/0x600 fs/ext4/mmp.c:387
 __ext4_fill_super fs/ext4/super.c:5522 [inline]
 ext4_fill_super+0x227f/0x37b0 fs/ext4/super.c:5855
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1873
 get_tree_bdev+0x1f/0x30 fs/super.c:1896
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5887
 vfs_get_tree+0x57/0x1d0 fs/super.c:1933
 fc_mount fs/namespace.c:1198 [inline]
 do_new_mount_fc fs/namespace.c:3772 [inline]
 do_new_mount+0x288/0x8d0 fs/namespace.c:3848
 path_mount+0x4ad/0xb90 fs/namespace.c:4168
 do_mount fs/namespace.c:4181 [inline]
 __do_sys_mount fs/namespace.c:4397 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4374
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4374
 x64_sys_call+0xc3b/0x2550 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x74 -> 0x32

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 11761 Comm: syz.0.2091 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
==================================================================
[EXT4 FS bs=4096, gc=1, bpg=32768, ipg=32, mo=e842c11c, mo2=0002]
System zones: 0-2, 18-18, 34-34
EXT4-fs error (device loop0): ext4_validate_block_bitmap:445: comm syz.0.2091: bg 0: block 248: padding at end of block bitmap is not set
loop0: lost filesystem error report for type 5 error -117
EXT4-fs error (device loop0): ext4_acquire_dquot:7069: comm syz.0.2091: Failed to acquire dquot type 1
loop0: lost filesystem error report for type 5 error -117
EXT4-fs (loop0): 1 truncate cleaned up
EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback.
ext4 filesystem being mounted at /432/file0 supports timestamps until 2038-01-19 (0x7fffffff)