=====================================================
BUG: KMSAN: uninit-value in strnchr+0x90/0xd0 lib/string.c:403
 strnchr+0x90/0xd0 lib/string.c:403
 bpf_bprintf_prepare+0x1cb/0x2470 kernel/bpf/helpers.c:822
 ____bpf_trace_printk kernel/trace/bpf_trace.c:385 [inline]
 bpf_trace_printk+0xfc/0x410 kernel/trace/bpf_trace.c:375
 ___bpf_prog_run+0x805/0xb260 kernel/bpf/core.c:1822
 __bpf_prog_run32+0xc6/0x110 kernel/bpf/core.c:2043
 bpf_dispatcher_nop_func include/linux/bpf.h:1124 [inline]
 __bpf_prog_run include/linux/filter.h:601 [inline]
 bpf_prog_run include/linux/filter.h:608 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2263 [inline]
 bpf_trace_run1+0xff/0x320 kernel/trace/bpf_trace.c:2301
 __bpf_trace_rcu_utilization+0x21/0x30 include/trace/events/rcu.h:27
 trace_rcu_utilization include/trace/events/rcu.h:27 [inline]
 rcu_sched_clock_irq+0x4add/0x4f00 kernel/rcu/tree.c:2196
 update_process_times+0x1cc/0x260 kernel/time/timer.c:2071
 tick_sched_handle kernel/time/tick-sched.c:243 [inline]
 tick_sched_timer+0x5e0/0x700 kernel/time/tick-sched.c:1480
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x583/0x1140 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x4f8/0x1eb0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1096 [inline]
 __sysvec_apic_timer_interrupt+0x14f/0x5b0 arch/x86/kernel/apic/apic.c:1113
 sysvec_apic_timer_interrupt+0x99/0xc0 arch/x86/kernel/apic/apic.c:1107
 asm_sysvec_apic_timer_interrupt+0x1f/0x30 arch/x86/include/asm/idtentry.h:645
 smap_restore arch/x86/include/asm/smap.h:56 [inline]
 get_shadow_origin_ptr mm/kmsan/instrumentation.c:37 [inline]
 __msan_metadata_ptr_for_load_4+0x2c/0x40 mm/kmsan/instrumentation.c:91
 crc32_body lib/crc32.c:110 [inline]
 crc32_le_generic lib/crc32.c:179 [inline]
 __crc32c_le_base+0x170/0xd80 lib/crc32.c:201
 chksum_update+0x5b/0xd0 crypto/crc32c_generic.c:88
 crypto_shash_update+0x28f/0x400 crypto/shash.c:121
 ext4_chksum fs/ext4/ext4.h:2464 [inline]
 ext4_block_bitmap_csum_set+0x2db/0x6a0 fs/ext4/bitmap.c:94
 ext4_mb_clear_bb fs/ext4/mballoc.c:6026 [inline]
 ext4_free_blocks+0x3ece/0x5620 fs/ext4/mballoc.c:6173
 ext4_remove_blocks fs/ext4/extents.c:2545 [inline]
 ext4_ext_rm_leaf fs/ext4/extents.c:2710 [inline]
 ext4_ext_remove_space+0x48b8/0x8600 fs/ext4/extents.c:2958
 ext4_ext_truncate+0x2ad/0x430 fs/ext4/extents.c:4416
 ext4_truncate+0x1529/0x1ec0 fs/ext4/inode.c:4342
 ext4_evict_inode+0x1c95/0x2730 fs/ext4/inode.c:286
 evict+0x365/0x9a0 fs/inode.c:665
 iput_final fs/inode.c:1748 [inline]
 iput+0x9c2/0xe00 fs/inode.c:1774
 d_delete_notify include/linux/fsnotify.h:261 [inline]
 vfs_rmdir+0x538/0x780 fs/namei.c:4134
 do_rmdir+0x643/0x920 fs/namei.c:4180
 __do_sys_unlinkat fs/namei.c:4358 [inline]
 __se_sys_unlinkat fs/namei.c:4352 [inline]
 __ia32_sys_unlinkat+0x1bc/0x220 fs/namei.c:4352
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

Local variable stack created at:
 __bpf_prog_run32+0x56/0x110 kernel/bpf/core.c:2043
 bpf_dispatcher_nop_func include/linux/bpf.h:1124 [inline]
 __bpf_prog_run include/linux/filter.h:601 [inline]
 bpf_prog_run include/linux/filter.h:608 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2263 [inline]
 bpf_trace_run1+0xff/0x320 kernel/trace/bpf_trace.c:2301

CPU: 0 PID: 5043 Comm: syz-executor.5 Not tainted 6.3.0-rc7-syzkaller-g0255004d2a8e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
=====================================================