EXT4-fs (loop1): Free/Dirty block details
EXT4-fs (loop1): free_blocks=2415919104
EXT4-fs (loop1): dirty_blocks=8208
EXT4-fs (loop1): Block reservation details
EXT4-fs (loop1): i_reserved_data_blocks=513
==================================================================
BUG: KCSAN: data-race in __bpf_get_stackid / bcmp

write to 0xffff8881362fbab0 of 96 bytes by task 1086 on cpu 1:
 __bpf_get_stackid+0x761/0x800 kernel/bpf/stackmap.c:288
 ____bpf_get_stackid kernel/bpf/stackmap.c:324 [inline]
 bpf_get_stackid+0xee/0x120 kernel/bpf/stackmap.c:300
 ____bpf_get_stackid_raw_tp kernel/trace/bpf_trace.c:1811 [inline]
 bpf_get_stackid_raw_tp+0xf6/0x120 kernel/trace/bpf_trace.c:1800
 bpf_prog_e6fc920cfeff8120+0x2a/0x32
 bpf_dispatcher_nop_func include/linux/bpf.h:1322 [inline]
 __bpf_prog_run include/linux/filter.h:718 [inline]
 bpf_prog_run include/linux/filter.h:725 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2258 [inline]
 bpf_trace_run3+0x10f/0x1d0 kernel/trace/bpf_trace.c:2300
 __traceiter_kmem_cache_free+0x35/0x60 include/trace/events/kmem.h:114
 __do_trace_kmem_cache_free include/trace/events/kmem.h:114 [inline]
 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline]
 kmem_cache_free+0x257/0x300 mm/slub.c:4744
 inotify_free_mark+0x28/0x30 fs/notify/inotify/inotify_fsnotify.c:200
 fsnotify_final_mark_destroy fs/notify/mark.c:372 [inline]
 fsnotify_mark_destroy_workfn+0x183/0x1e0 fs/notify/mark.c:1000
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff8881362fbaf8 of 8 bytes by task 7002 on cpu 0:
 memcmp lib/string.c:683 [inline]
 bcmp+0x23/0x90 lib/string.c:715
 memcmp include/linux/fortify-string.h:727 [inline]
 __bpf_get_stackid+0x371/0x800 kernel/bpf/stackmap.c:279
 ____bpf_get_stackid kernel/bpf/stackmap.c:324 [inline]
 bpf_get_stackid+0xee/0x120 kernel/bpf/stackmap.c:300
 ____bpf_get_stackid_raw_tp kernel/trace/bpf_trace.c:1811 [inline]
 bpf_get_stackid_raw_tp+0xf6/0x120 kernel/trace/bpf_trace.c:1800
 bpf_prog_e6fc920cfeff8120+0x2a/0x32
 bpf_dispatcher_nop_func include/linux/bpf.h:1322 [inline]
 __bpf_prog_run include/linux/filter.h:718 [inline]
 bpf_prog_run include/linux/filter.h:725 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2258 [inline]
 bpf_trace_run3+0x10f/0x1d0 kernel/trace/bpf_trace.c:2300
 __traceiter_kmem_cache_free+0x35/0x60 include/trace/events/kmem.h:114
 __do_trace_kmem_cache_free include/trace/events/kmem.h:114 [inline]
 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline]
 kmem_cache_free+0x257/0x300 mm/slub.c:4744
 free_buffer_head+0x48/0x1c0 fs/buffer.c:3048
 try_to_free_buffers+0x11e/0x170 fs/buffer.c:2989
 ext4_release_folio+0xb8/0x180 fs/ext4/inode.c:3388
 filemap_release_folio+0xcd/0x150 mm/filemap.c:4292
 block_invalidate_folio+0x35f/0x3b0 fs/buffer.c:1680
 mpage_release_unused_pages+0x35f/0x440 fs/ext4/inode.c:1732
 ext4_do_writepages+0xb12/0x21c0 fs/ext4/inode.c:2881
 ext4_writepages+0x176/0x300 fs/ext4/inode.c:2953
 do_writepages+0x1c3/0x310 mm/page-writeback.c:2636
 filemap_fdatawrite_wbc mm/filemap.c:386 [inline]
 __filemap_fdatawrite_range mm/filemap.c:419 [inline]
 filemap_write_and_wait_range+0x144/0x340 mm/filemap.c:691
 filemap_write_and_wait include/linux/pagemap.h:68 [inline]
 ext4_ioctl_setflags fs/ext4/ioctl.c:644 [inline]
 ext4_fileattr_set+0x4e6/0xe30 fs/ext4/ioctl.c:1021
 vfs_fileattr_set+0x54e/0x5a0 fs/ioctl.c:696
 do_vfs_ioctl+0x10f2/0x11d0 fs/ioctl.c:-1
 __do_sys_ioctl fs/ioctl.c:905 [inline]
 __se_sys_ioctl+0x82/0x140 fs/ioctl.c:893
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:893
 x64_sys_call+0x19a8/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffffffff819ca7df -> 0xffffffff813eac19

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 7002 Comm: syz.1.1257 Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================
syz.1.1257 (7002) used greatest stack depth: 9336 bytes left