================================================================== 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 ffff88807d66aa40 by task syz-executor/19217 CPU: 1 UID: 0 PID: 19217 Comm: syz-executor Not tainted 6.16.0-rc4-next-20250630-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+0x9e/0xc0 arch/x86/kernel/smp.c:266 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:709 RIP: 0010:console_flush_all+0x7f7/0xc40 kernel/printk/printk.c:3227 Code: 48 21 c3 0f 85 e9 01 00 00 e8 65 2d 1f 00 48 8b 5c 24 20 4d 85 f6 75 07 e8 56 2d 1f 00 eb 06 e8 4f 2d 1f 00 fb 48 8b 44 24 28 <42> 80 3c 20 00 74 08 48 89 df e8 3a 41 83 00 48 8b 1b 48 8b 44 24 RSP: 0018:ffffc90002e969a0 EFLAGS: 00000293 RAX: 1ffffffff1d78deb RBX: ffffffff8ebc6f58 RCX: ffff888026988000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90002e96af0 R08: ffffffff8fc29737 R09: 1ffffffff1f852e6 R10: dffffc0000000000 R11: fffffbfff1f852e7 R12: dffffc0000000000 R13: 0000000000000001 R14: 0000000000000200 R15: ffffffff8ebc6f00 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xc4/0x270 kernel/printk/printk.c:3325 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450 _printk+0xcf/0x120 kernel/printk/printk.c:2475 batadv_hardif_enable_interface+0x7b9/0xa30 net/batman-adv/hard-interface.c:758 batadv_meshif_slave_add+0x79/0x100 net/batman-adv/mesh-interface.c:845 do_set_master+0x533/0x6d0 net/core/rtnetlink.c:2946 do_setlink+0xcf0/0x41c0 net/core/rtnetlink.c:3148 rtnl_changelink net/core/rtnetlink.c:3759 [inline] __rtnl_newlink net/core/rtnetlink.c:3918 [inline] rtnl_newlink+0x160b/0x1c70 net/core/rtnetlink.c:4055 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6944 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:729 __sys_sendto+0x3bd/0x520 net/socket.c:2228 __do_sys_sendto net/socket.c:2235 [inline] __se_sys_sendto net/socket.c:2231 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2231 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 RIP: 0033:0x7fbdbff907bc Code: 2a 5f 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5f 02 00 48 8b RSP: 002b:00007fff84a60a20 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fbdc0ce4620 RCX: 00007fbdbff907bc RDX: 0000000000000028 RSI: 00007fbdc0ce4670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007fff84a60a74 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007fbdc0ce4670 R15: 0000000000000000 Allocated by task 17760: 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 17055: 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 mmdrop include/linux/sched/mm.h:55 [inline] mmdrop_sched include/linux/sched/mm.h:83 [inline] mmdrop_lazy_tlb_sched include/linux/sched/mm.h:110 [inline] finish_task_switch+0x3ee/0x950 kernel/sched/core.c:5206 context_switch kernel/sched/core.c:5316 [inline] __schedule+0x16fd/0x4d00 kernel/sched/core.c:6696 __schedule_loop kernel/sched/core.c:6774 [inline] schedule+0x165/0x360 kernel/sched/core.c:6789 do_nanosleep+0x1c7/0x600 kernel/time/hrtimer.c:2100 hrtimer_nanosleep+0x169/0x360 kernel/time/hrtimer.c:2147 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1399 [inline] __se_sys_clock_nanosleep+0x2ee/0x380 kernel/time/posix-timers.c:1376 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 ffff88807d66a040 which belongs to the cache mm_struct of size 2584 The buggy address is located 2560 bytes inside of freed 2584-byte region [ffff88807d66a040, ffff88807d66aa58) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7d668 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888074dd0181 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801a84bb40 ffffea0000d0c000 dead000000000002 raw: 0000000000000000 00000000000b000b 00000000f5000000 ffff888074dd0181 head: 00fff00000000040 ffff88801a84bb40 ffffea0000d0c000 dead000000000002 head: 0000000000000000 00000000000b000b 00000000f5000000 ffff888074dd0181 head: 00fff00000000003 ffffea0001f59a01 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 17687, tgid 17687 (kworker/u8:2), ts 435381476197, free_ts 435343407120 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 kernel_execve+0x9b/0x9f0 fs/exec.c:1880 call_usermodehelper_exec_async+0x210/0x360 kernel/umh.c:109 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 page last free pid 17684 tgid 17684 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 discard_slab mm/slub.c:2753 [inline] __put_partials+0x156/0x1a0 mm/slub.c:3218 put_cpu_partial+0x17c/0x250 mm/slub.c:3293 __slab_free+0x2d5/0x3c0 mm/slub.c:4550 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329 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 getname_flags+0xb8/0x540 fs/namei.c:146 getname include/linux/fs.h:2909 [inline] __do_sys_symlinkat fs/namei.c:4772 [inline] __se_sys_symlinkat fs/namei.c:4769 [inline] __x64_sys_symlinkat+0x7a/0xb0 fs/namei.c:4769 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 Memory state around the buggy address: ffff88807d66a900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807d66a980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807d66aa00: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc ^ ffff88807d66aa80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807d66ab00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 48 21 c3 and %rax,%rbx 3: 0f 85 e9 01 00 00 jne 0x1f2 9: e8 65 2d 1f 00 call 0x1f2d73 e: 48 8b 5c 24 20 mov 0x20(%rsp),%rbx 13: 4d 85 f6 test %r14,%r14 16: 75 07 jne 0x1f 18: e8 56 2d 1f 00 call 0x1f2d73 1d: eb 06 jmp 0x25 1f: e8 4f 2d 1f 00 call 0x1f2d73 24: fb sti 25: 48 8b 44 24 28 mov 0x28(%rsp),%rax * 2a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 48 89 df mov %rbx,%rdi 34: e8 3a 41 83 00 call 0x834173 39: 48 8b 1b mov (%rbx),%rbx 3c: 48 rex.W 3d: 8b .byte 0x8b 3e: 44 rex.R 3f: 24 .byte 0x24