------------[ cut here ]------------ WARNING: CPU: 0 PID: 154 at mm/maccess.c:226 copy_from_user_nofault+0x160/0x1c0 mm/maccess.c:226 Modules linked in: CPU: 0 PID: 154 Comm: kworker/u4:2 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: writeback wb_workfn (flush-8:0) RIP: 0010:copy_from_user_nofault+0x160/0x1c0 mm/maccess.c:226 Code: 24 45 31 f6 31 ff 89 de e8 8d 94 d8 ff 85 db 48 c7 c0 f2 ff ff ff 49 0f 44 c6 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 10 91 d8 ff <0f> 0b e9 1c ff ff ff 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c ea fe RSP: 0018:ffffc90000007c20 EFLAGS: 00010006 RAX: ffffffff81a07f40 RBX: 0000000000000000 RCX: ffff88801bcd0000 RDX: 0000000000010000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: dffffc0000000000 R09: 1ffffffff2036e18 R10: dffffc0000000000 R11: fffffbfff2036e19 R12: ffff88801bcd1788 R13: dffffc0000000000 R14: ffffc90000007c88 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f21f0f426b8 CR3: 000000000c08e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: bpf_probe_read_user_common kernel/trace/bpf_trace.c:157 [inline] ____bpf_probe_read_user kernel/trace/bpf_trace.c:166 [inline] bpf_probe_read_user+0x26/0x70 kernel/trace/bpf_trace.c:163 bpf_prog_1ac23171ae95db47+0x34/0x5d8 bpf_dispatcher_nop_func include/linux/bpf.h:888 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline] bpf_trace_run2+0x163/0x2e0 kernel/trace/bpf_trace.c:1915 __traceiter_tlb_flush+0x69/0xb0 include/trace/events/tlb.h:38 trace_tlb_flush+0xe6/0x110 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x6f3/0x9b0 arch/x86/mm/tlb.c:-1 flush_tlb_func+0x1d9/0x5b0 arch/x86/mm/tlb.c:773 flush_smp_call_function_queue+0x2a9/0x760 kernel/smp.c:628 __sysvec_call_function_single+0x98/0x240 arch/x86/kernel/smp.c:248 instr_sysvec_call_function_single arch/x86/kernel/smp.c:243 [inline] sysvec_call_function_single+0x98/0xc0 arch/x86/kernel/smp.c:243 asm_sysvec_call_function_single+0x16/0x20 arch/x86/include/asm/idtentry.h:684 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xbc/0x120 kernel/locking/spinlock.c:194 Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 bf bc 8e f7 65 8b 05 40 d9 3e 76 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc90001f66ca0 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a02 RCX: 982bf516d8908d00 RDX: dffffc0000000000 RSI: ffffffff8a2b1c00 RDI: 0000000000000001 RBP: ffffc90001f66d30 R08: ffffffff901b716f R09: 1ffffffff2036e2d R10: dffffc0000000000 R11: fffffbfff2036e2e R12: dffffc0000000000 R13: 1ffff920003ecdb4 R14: ffff888073850ec8 R15: 1ffff920003ecd94 spin_unlock_irqrestore include/linux/spinlock.h:419 [inline] __test_set_page_writeback+0x80b/0xec0 mm/page-writeback.c:2881 ext4_bio_write_page+0x293/0x1f90 fs/ext4/page-io.c:-1 mpage_submit_page+0x17a/0x210 fs/ext4/inode.c:2113 mpage_map_and_submit_buffers fs/ext4/inode.c:2361 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2500 [inline] ext4_writepages+0x1ae0/0x2df0 fs/ext4/inode.c:2829 do_writepages+0x476/0x6e0 mm/page-writeback.c:2386 __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657 writeback_sb_inodes+0xa4e/0x1680 fs/fs-writeback.c:1940 __writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:2011 wb_writeback+0x46f/0xbe0 fs/fs-writeback.c:2116 wb_check_old_data_flush fs/fs-writeback.c:2216 [inline] wb_do_writeback fs/fs-writeback.c:2269 [inline] wb_workfn+0xb15/0xf20 fs/fs-writeback.c:2298 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 ---------------- Code disassembly (best guess): 0: c7 44 24 20 00 00 00 movl $0x0,0x20(%rsp) 7: 00 8: 9c pushf 9: 8f 44 24 20 pop 0x20(%rsp) d: f7 44 24 20 00 02 00 testl $0x200,0x20(%rsp) 14: 00 15: 41 c6 04 07 f8 movb $0xf8,(%r15,%rax,1) 1a: 75 4b jne 0x67 1c: f7 c3 00 02 00 00 test $0x200,%ebx 22: 74 01 je 0x25 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 bf bc 8e f7 call 0xf78ebcee <-- trapping instruction 2f: 65 8b 05 40 d9 3e 76 mov %gs:0x763ed940(%rip),%eax # 0x763ed976 36: 85 c0 test %eax,%eax 38: 74 3c je 0x76 3a: 48 rex.W 3b: c7 .byte 0xc7 3c: 04 24 add $0x24,%al 3e: 0e (bad) 3f: 36 ss