------------[ cut here ]------------ WARNING: CPU: 0 PID: 4358 at mm/maccess.c:226 copy_from_user_nofault+0x160/0x1c0 mm/maccess.c:226 Modules linked in: CPU: 0 PID: 4358 Comm: syz.4.19 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:copy_from_user_nofault+0x160/0x1c0 mm/maccess.c:226 Code: 24 45 31 f6 31 ff 89 de e8 3d f7 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 c0 f3 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:ffffc90000007998 EFLAGS: 00010246 RAX: ffffffff819ed760 RBX: 0000000000000008 RCX: ffff8880779e1dc0 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed100ef3c3b9 R10: ffffed100ef3c3b9 R11: 1ffff1100ef3c3b8 R12: ffff8880779e3548 R13: 00007ffffffff000 R14: ffffc90000007a08 R15: 0000000000000000 FS: 00007f25a90dc6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000219000 CR3: 0000000023829000 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_compat kernel/trace/bpf_trace.c:281 [inline] bpf_probe_read_compat+0xdd/0x170 kernel/trace/bpf_trace.c:277 bpf_prog_ee60aafa828f4cb7+0x35/0x784 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+0x15b/0x2d0 kernel/trace/bpf_trace.c:1915 __bpf_trace_kfree+0x6e/0x90 include/trace/events/kmem.h:118 trace_kfree include/trace/events/kmem.h:118 [inline] kfree+0x25f/0x2a0 mm/slub.c:4554 security_cred_free+0xbc/0xf0 security/security.c:1719 put_cred_rcu+0xdd/0x3e0 kernel/cred.c:115 rcu_do_batch kernel/rcu/tree.c:2523 [inline] rcu_core+0x962/0x15d0 kernel/rcu/tree.c:2763 handle_softirqs+0x328/0x820 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194 Code: 74 05 e8 5e 8d cb f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 c6 15 9f f7 65 8b 05 a7 13 50 76 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc9000353f780 EFLAGS: 00000206 RAX: 855da2b47e68e900 RBX: 0000000000000a06 RCX: 855da2b47e68e900 RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: 0000000000000001 RBP: ffffc9000353f800 R08: dffffc0000000000 R09: fffffbfff1ff782e R10: fffffbfff1ff782e R11: 1ffffffff1ff782d R12: dffffc0000000000 R13: dffffc0000000000 R14: ffff888075bce880 R15: 1ffff920006a7ef0 mark_buffer_dirty+0x2d7/0x490 fs/buffer.c:1108 __block_commit_write+0x1eb/0x320 fs/buffer.c:2085 block_write_end fs/buffer.c:2164 [inline] generic_write_end+0xa7/0x3d0 fs/buffer.c:2178 ext4_da_write_end+0x6f6/0x9c0 fs/ext4/inode.c:3096 generic_perform_write+0x344/0x530 mm/filemap.c:3796 ext4_buffered_write_iter+0x25f/0x3b0 fs/ext4/file.c:268 ext4_file_write_iter+0x773/0x17b0 fs/ext4/file.c:-1 call_write_iter include/linux/fs.h:2172 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x712/0xd00 fs/read_write.c:594 ksys_write+0x14d/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f25aae74ba9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f25a90dc038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f25ab0bbfa0 RCX: 00007f25aae74ba9 RDX: 000000000208e24b RSI: 0000200000000000 RDI: 0000000000000004 RBP: 00007f25aaef7e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f25ab0bc038 R14: 00007f25ab0bbfa0 R15: 00007ffc2b8949f8 ---------------- Code disassembly (best guess): 0: 74 05 je 0x7 2: e8 5e 8d cb f7 call 0xf7cb8d65 7: 48 c7 44 24 20 00 00 movq $0x0,0x20(%rsp) e: 00 00 10: 9c pushf 11: 8f 44 24 20 pop 0x20(%rsp) 15: f6 44 24 21 02 testb $0x2,0x21(%rsp) 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 c6 15 9f f7 call 0xf79f15f5 <-- trapping instruction 2f: 65 8b 05 a7 13 50 76 mov %gs:0x765013a7(%rip),%eax # 0x765013dd 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