Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 0 UID: 0 PID: 5757 Comm: syz.3.5 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:task_cpu include/linux/sched.h:2268 [inline] RIP: 0010:is_task_rq_idle kernel/sched/core.c:6169 [inline] RIP: 0010:cookie_equals kernel/sched/core.c:6174 [inline] RIP: 0010:pick_next_task kernel/sched/core.c:6355 [inline] RIP: 0010:__schedule+0x4030/0x5550 kernel/sched/core.c:7143 Code: 24 80 00 00 00 e8 80 97 f2 f6 48 8b 84 24 80 00 00 00 48 8b 18 4c 8d 7b 14 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 87 04 00 00 45 8b 3f 49 83 ff 08 0f 83 98 RSP: 0018:ffffc900058662c0 EFLAGS: 00010003 RAX: 0000000000000002 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff8880b8620c60 RBP: ffffc900058664b8 R08: ffffffff8fcf38f7 R09: 1ffffffff1f9e71e R10: dffffc0000000000 R11: ffffffff8199feb0 R12: ffff8880b863c658 R13: ffff888125a6b000 R14: 1ffff110170c7922 R15: 0000000000000014 FS: 00007efdeebed6c0(0000) GS:ffff888125a6b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007efdf0a0a540 CR3: 0000000022f90000 CR4: 00000000003526f0 Call Trace: preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7552 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8c0 kernel/entry/common.c:167 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:679 RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5874 Code: ff ff ff e8 b1 bd 9c 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 5b 18 1a 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 80 85 a0 09 cc 48 8d 3d e8 62 31 RSP: 0018:ffffc900058665e0 EFLAGS: 00000282 RAX: 3c6c5c532781c300 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 000000002637a3a4 RSI: ffffffff8dbdec30 RDI: ffffffff8bcc4d80 RBP: ffffffff8234d915 R08: ffffffff8234d915 R09: ffffffff8e3cb2a0 R10: dffffc0000000000 R11: fffffbfff1f9e71f R12: 0000000000000002 R13: ffffffff8e3cb2a0 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] get_non_dying_memcg_start mm/memcontrol.c:817 [inline] mod_memcg_lruvec_state+0xf5/0x270 mm/memcontrol.c:947 mod_lruvec_state mm/memcontrol.c:973 [inline] lruvec_stat_mod_folio+0x239/0x3e0 mm/memcontrol.c:993 shmem_update_stats mm/shmem.c:875 [inline] shmem_add_to_page_cache+0x8eb/0xbf0 mm/shmem.c:925 shmem_alloc_and_add_folio mm/shmem.c:1975 [inline] shmem_get_folio_gfp+0x7e4/0x1ad0 mm/shmem.c:2502 shmem_get_folio mm/shmem.c:2608 [inline] shmem_write_begin+0x166/0x320 mm/shmem.c:3239 generic_perform_write+0x2af/0x8b0 mm/filemap.c:4362 shmem_file_write_iter+0xfb/0x120 mm/shmem.c:3414 __kernel_write_iter+0x427/0x890 fs/read_write.c:621 dump_emit_page fs/coredump.c:1298 [inline] dump_user_range+0xc1c/0x12c0 fs/coredump.c:1372 elf_core_dump+0x34c2/0x3ad0 fs/binfmt_elf.c:2109 coredump_write+0x12bc/0x19e0 fs/coredump.c:1052 do_coredump fs/coredump.c:1131 [inline] vfs_coredump+0x37c0/0x4510 fs/coredump.c:1200 get_signal+0x1107/0x1330 kernel/signal.c:3023 arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop kernel/entry/common.c:101 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline] irqentry_exit+0x2ba/0x8c0 kernel/entry/common.c:165 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7efdf09bce59 Code: Unable to access opcode bytes at 0x7efdf09bce2f. RSP: 002b:00007efdeebecfd8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 00007efdf0c36090 RCX: 00007efdf09bce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007efdf0a52d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007efdf0c36128 R14: 00007efdf0c36090 R15: 00007ffc5b2f3f48 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:task_cpu include/linux/sched.h:2268 [inline] RIP: 0010:is_task_rq_idle kernel/sched/core.c:6169 [inline] RIP: 0010:cookie_equals kernel/sched/core.c:6174 [inline] RIP: 0010:pick_next_task kernel/sched/core.c:6355 [inline] RIP: 0010:__schedule+0x4030/0x5550 kernel/sched/core.c:7143 Code: 24 80 00 00 00 e8 80 97 f2 f6 48 8b 84 24 80 00 00 00 48 8b 18 4c 8d 7b 14 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 87 04 00 00 45 8b 3f 49 83 ff 08 0f 83 98 RSP: 0018:ffffc900058662c0 EFLAGS: 00010003 RAX: 0000000000000002 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff8880b8620c60 RBP: ffffc900058664b8 R08: ffffffff8fcf38f7 R09: 1ffffffff1f9e71e R10: dffffc0000000000 R11: ffffffff8199feb0 R12: ffff8880b863c658 R13: ffff888125a6b000 R14: 1ffff110170c7922 R15: 0000000000000014 FS: 00007efdeebed6c0(0000) GS:ffff888125a6b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007efdf09bce2f CR3: 0000000022f90000 CR4: 00000000003526f0 ---------------- Code disassembly (best guess): 0: 24 80 and $0x80,%al 2: 00 00 add %al,(%rax) 4: 00 e8 add %ch,%al 6: 80 97 f2 f6 48 8b 84 adcb $0x84,-0x74b7090e(%rdi) d: 24 80 and $0x80,%al f: 00 00 add %al,(%rax) 11: 00 48 8b add %cl,-0x75(%rax) 14: 18 4c 8d 7b sbb %cl,0x7b(%rbp,%rcx,4) 18: 14 4c adc $0x4c,%al 1a: 89 f8 mov %edi,%eax 1c: 48 c1 e8 03 shr $0x3,%rax 20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 27: fc ff df * 2a: 0f b6 04 08 movzbl (%rax,%rcx,1),%eax <-- trapping instruction 2e: 84 c0 test %al,%al 30: 0f 85 87 04 00 00 jne 0x4bd 36: 45 8b 3f mov (%r15),%r15d 39: 49 83 ff 08 cmp $0x8,%r15 3d: 0f .byte 0xf 3e: 83 .byte 0x83 3f: 98 cwtl