================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_write include/linux/instrumented.h:82 [inline] BUG: KASAN: slab-use-after-free in clear_bit include/asm-generic/bitops/instrumented-atomic.h:41 [inline] BUG: KASAN: slab-use-after-free in cpumask_clear_cpu include/linux/cpumask.h:628 [inline] BUG: KASAN: slab-use-after-free in flush_tlb_func+0x23d/0x6c0 arch/x86/mm/tlb.c:1132 Write of size 8 at addr ffff88807de96ac0 by task swapper/1/0 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.16.0-rc4-next-20250702-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xd2/0x2b0 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:189 instrument_atomic_write include/linux/instrumented.h:82 [inline] clear_bit include/asm-generic/bitops/instrumented-atomic.h:41 [inline] cpumask_clear_cpu include/linux/cpumask.h:628 [inline] flush_tlb_func+0x23d/0x6c0 arch/x86/mm/tlb.c:1132 csd_do_func kernel/smp.c:134 [inline] __flush_smp_call_function_queue+0x370/0xaa0 kernel/smp.c:540 __sysvec_call_function_single+0xa8/0x3d0 arch/x86/kernel/smp.c:271 instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline] sysvec_call_function_single+0x4f/0xc0 arch/x86/kernel/smp.c:266 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:709 RIP: 0010:variable_ffs arch/x86/include/asm/bitops.h:318 [inline] RIP: 0010:handle_softirqs+0x1b0/0x870 kernel/softirq.c:567 Code: 89 64 24 30 0f b7 db 48 c7 c7 a0 99 89 8b e8 87 55 f1 09 65 66 c7 05 c5 4e 3e 11 00 00 e8 f8 55 42 00 fb 49 c7 c7 c0 c0 00 8e ff ff ff ff 0f bc c3 41 89 c5 41 ff c5 0f 84 c2 03 00 00 89 5c RSP: 0018:ffffc90000a08e40 EFLAGS: 00000286 RAX: 574809cd86862400 RBX: 0000000000000382 RCX: 574809cd86862400 RDX: 0000000000000000 RSI: ffffffff8da6993f RDI: ffffffff8be4b100 RBP: ffffc90000a08f50 R08: ffffffff8fc29e37 R09: 1ffffffff1f853c6 R10: dffffc0000000000 R11: fffffbfff1f853c7 R12: 000000000000000a R13: 0000000000000000 R14: dffffc0000000000 R15: ffffffff8e00c0c0 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 83 86 11 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6 RAX: 574809cd86862400 RBX: ffffffff81971188 RCX: 574809cd86862400 RDX: 0000000000000001 RSI: ffffffff8da6993f RDI: ffffffff8be4b100 RBP: ffffc90000197f20 R08: ffff8880b8732f1b R09: 1ffff110170e65e3 R10: dffffc0000000000 R11: ffffed10170e65e4 R12: ffffffff8fc29e30 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003a57b40 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:757 default_idle_call+0x74/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147 Allocated by task 5833: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4180 [inline] slab_alloc_node mm/slub.c:4229 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4236 dup_mm kernel/fork.c:1466 [inline] copy_mm+0xdb/0x4b0 kernel/fork.c:1528 copy_process+0x1706/0x3c00 kernel/fork.c:2168 kernel_clone+0x21e/0x870 kernel/fork.c:2598 __do_sys_clone kernel/fork.c:2741 [inline] __se_sys_clone kernel/fork.c:2725 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2725 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 8250: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2417 [inline] slab_free mm/slub.c:4680 [inline] kmem_cache_free+0x18f/0x400 mm/slub.c:4782 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x648/0x2300 kernel/exit.c:947 do_group_exit+0x21c/0x2d0 kernel/exit.c:1100 __do_sys_exit_group kernel/exit.c:1111 [inline] __se_sys_exit_group kernel/exit.c:1109 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1109 x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88807de960c0 which belongs to the cache mm_struct of size 2584 The buggy address is located 2560 bytes inside of freed 2584-byte region [ffff88807de960c0, ffff88807de96ad8) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7de90 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88803374c401 ksm flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801a84bb40 ffffea0000cfc400 dead000000000003 raw: 0000000000000000 00000000800b000b 00000000f5000000 ffff88803374c401 head: 00fff00000000040 ffff88801a84bb40 ffffea0000cfc400 dead000000000003 head: 0000000000000000 00000000800b000b 00000000f5000000 ffff88803374c401 head: 00fff00000000003 ffffea0001f7a401 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5203, tgid 5203 (S02sysctl), ts 33653808155, free_ts 30898579963 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1848 prep_new_page mm/page_alloc.c:1856 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3855 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5145 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2487 [inline] allocate_slab+0x8a/0x370 mm/slub.c:2655 new_slab mm/slub.c:2709 [inline] ___slab_alloc+0xbeb/0x1410 mm/slub.c:3891 __slab_alloc mm/slub.c:3981 [inline] __slab_alloc_node mm/slub.c:4056 [inline] slab_alloc_node mm/slub.c:4217 [inline] kmem_cache_alloc_noprof+0x283/0x3c0 mm/slub.c:4236 mm_alloc+0x23/0xd0 kernel/fork.c:1103 bprm_mm_init fs/exec.c:258 [inline] alloc_bprm+0x378/0x5b0 fs/exec.c:1461 do_execveat_common+0x1b3/0x6a0 fs/exec.c:1806 do_execve fs/exec.c:1929 [inline] __do_sys_execve fs/exec.c:2005 [inline] __se_sys_execve fs/exec.c:2000 [inline] __x64_sys_execve+0x94/0xb0 fs/exec.c:2000 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1392 [inline] __free_frozen_pages+0xb80/0xd80 mm/page_alloc.c:2892 __free_pages mm/page_alloc.c:5257 [inline] free_contig_range+0x1bd/0x4a0 mm/page_alloc.c:7114 destroy_args+0x7e/0x5d0 mm/debug_vm_pgtable.c:953 debug_vm_pgtable+0x3fa/0x430 mm/debug_vm_pgtable.c:1329 do_one_initcall+0x233/0x820 init/main.c:1269 do_initcall_level+0x137/0x1f0 init/main.c:1331 do_initcalls+0x69/0xd0 init/main.c:1347 kernel_init_freeable+0x3d9/0x570 init/main.c:1579 kernel_init+0x1d/0x1d0 init/main.c:1469 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff88807de96980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807de96a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807de96a80: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc ^ ffff88807de96b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807de96b80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 89 64 24 30 mov %esp,0x30(%rsp) 4: 0f b7 db movzwl %bx,%ebx 7: 48 c7 c7 a0 99 89 8b mov $0xffffffff8b8999a0,%rdi e: e8 87 55 f1 09 call 0x9f1559a 13: 65 66 c7 05 c5 4e 3e movw $0x0,%gs:0x113e4ec5(%rip) # 0x113e4ee2 1a: 11 00 00 1d: e8 f8 55 42 00 call 0x42561a 22: fb sti 23: 49 c7 c7 c0 c0 00 8e mov $0xffffffff8e00c0c0,%r15 * 2a: b8 ff ff ff ff mov $0xffffffff,%eax <-- trapping instruction 2f: 0f bc c3 bsf %ebx,%eax 32: 41 89 c5 mov %eax,%r13d 35: 41 ff c5 inc %r13d 38: 0f 84 c2 03 00 00 je 0x400 3e: 89 .byte 0x89 3f: 5c pop %rsp