================================================================== BUG: KASAN: use-after-free in rose_timer_expiry+0x470/0x490 net/rose/rose_timer.c:183 Read of size 2 at addr ffff8880611d6c2a by task syz.4.1179/7735 CPU: 0 PID: 7735 Comm: syz.4.1179 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 rose_timer_expiry+0x470/0x490 net/rose/rose_timer.c:183 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648 expire_timers kernel/time/timer.c:1699 [inline] __run_timers+0x53e/0x800 kernel/time/timer.c:1970 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983 handle_softirqs+0x339/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 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:free_pages_and_swap_cache+0x4c/0x90 mm/swap_state.c:319 Code: db 7e 4e 89 d8 4c 8d 3c c5 f8 ff ff ff 45 31 e4 49 bd 00 00 00 00 00 fc ff df 4b 8d 3c 26 48 89 f8 48 c1 e8 03 42 80 3c 28 00 <74> 05 e8 8d 96 07 00 4b 8b 3c 26 e8 84 fa ff ff 4d 39 e7 74 0b e8 RSP: 0018:ffffc9000337f830 EFLAGS: 00000246 RAX: 1ffff1100f4ecb55 RBX: 00000000000001fe RCX: ffff88801ee59dc0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88807a765aa8 RBP: 00000000000001fe R08: ffffea0001933c47 R09: 1ffffd4000326788 R10: dffffc0000000000 R11: fffff94000326789 R12: 0000000000000a98 R13: dffffc0000000000 R14: ffff88807a765010 R15: 0000000000000fe8 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:240 [inline] tlb_flush_mmu+0xce/0x180 mm/mmu_gather.c:247 zap_pte_range mm/memory.c:1456 [inline] zap_pmd_range mm/memory.c:1505 [inline] zap_pud_range mm/memory.c:1534 [inline] zap_p4d_range mm/memory.c:1555 [inline] unmap_page_range+0x207a/0x2500 mm/memory.c:1576 unmap_vmas+0x131/0x250 mm/memory.c:1653 exit_mmap+0x3b9/0x640 mm/mmap.c:3216 __mmput+0x115/0x3b0 kernel/fork.c:1127 exit_mm+0x588/0x6e0 kernel/exit.c:550 do_exit+0x5a9/0x20c0 kernel/exit.c:870 do_group_exit+0x12e/0x300 kernel/exit.c:997 __do_sys_exit_group kernel/exit.c:1008 [inline] __se_sys_exit_group kernel/exit.c:1006 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006 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: 0033:0x7f1bb7e25799 Code: Unable to access opcode bytes at RIP 0x7f1bb7e2576f. RSP: 002b:00007ffe6868e128 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1bb7e25799 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffe6868e18c R08: 0000000000000000 R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 00000000000000d7 R13: 00000000000927c0 R14: 000000000004207a R15: 00007ffe6868e1e0 Allocated by task 21: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522 kmalloc_reserve net/core/skbuff.c:356 [inline] __alloc_skb+0x22c/0x750 net/core/skbuff.c:427 alloc_skb include/linux/skbuff.h:1162 [inline] nlmsg_new include/net/netlink.h:953 [inline] __neigh_notify+0x142/0x2e0 net/core/neighbour.c:3379 neigh_cleanup_and_release+0x9d/0x250 net/core/neighbour.c:101 neigh_periodic_work+0x407/0xc70 net/core/neighbour.c:947 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 The buggy address belongs to the object at ffff8880611d6c00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 42 bytes inside of 512-byte region [ffff8880611d6c00, ffff8880611d6e00) The buggy address belongs to the page: page:ffffea0001847500 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880611d5400 pfn:0x611d4 head:ffffea0001847500 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea000188e908 ffffea0001821808 ffff888016c41c80 raw: ffff8880611d5400 0000000000100005 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4198, ts 57471710507, free_ts 16521001497 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5487 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x80a/0xdd0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] __kmalloc_node_track_caller+0x1fc/0x3a0 mm/slub.c:4963 kmalloc_reserve net/core/skbuff.c:356 [inline] __alloc_skb+0x22c/0x750 net/core/skbuff.c:427 alloc_skb include/linux/skbuff.h:1162 [inline] nlmsg_new include/net/netlink.h:953 [inline] mpls_netconf_notify_devconf+0x46/0xf0 net/mpls/af_mpls.c:1188 mpls_dev_sysctl_register+0x249/0x2f0 net/mpls/af_mpls.c:1425 mpls_dev_notify+0x67a/0x780 net/mpls/af_mpls.c:1672 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391 call_netdevice_notifiers_extack net/core/dev.c:2074 [inline] call_netdevice_notifiers net/core/dev.c:2088 [inline] dev_change_name+0x695/0xbf0 net/core/dev.c:1345 do_setlink+0xa4e/0x3d60 net/core/rtnetlink.c:2761 __rtnl_newlink net/core/rtnetlink.c:3452 [inline] rtnl_newlink+0x1658/0x1a50 net/core/rtnetlink.c:3574 rtnetlink_rcv_msg+0x844/0xf30 net/core/rtnetlink.c:5684 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2507 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396 free_contig_range+0x96/0xf0 mm/page_alloc.c:9414 destroy_args+0xf0/0xa00 mm/debug_vm_pgtable.c:1018 debug_vm_pgtable+0x321/0x380 mm/debug_vm_pgtable.c:1336 do_one_initcall+0x272/0x730 init/main.c:1316 do_initcall_level+0x137/0x1f0 init/main.c:1389 do_initcalls+0x4b/0x90 init/main.c:1405 kernel_init_freeable+0x3e9/0x570 init/main.c:1629 kernel_init+0x19/0x1b0 init/main.c:1520 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Memory state around the buggy address: ffff8880611d6b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880611d6b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880611d6c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880611d6c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880611d6d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: db 7e 4e fstpt 0x4e(%rsi) 3: 89 d8 mov %ebx,%eax 5: 4c 8d 3c c5 f8 ff ff lea -0x8(,%rax,8),%r15 c: ff d: 45 31 e4 xor %r12d,%r12d 10: 49 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%r13 17: fc ff df 1a: 4b 8d 3c 26 lea (%r14,%r12,1),%rdi 1e: 48 89 f8 mov %rdi,%rax 21: 48 c1 e8 03 shr $0x3,%rax 25: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) * 2a: 74 05 je 0x31 <-- trapping instruction 2c: e8 8d 96 07 00 call 0x796be 31: 4b 8b 3c 26 mov (%r14,%r12,1),%rdi 35: e8 84 fa ff ff call 0xfffffabe 3a: 4d 39 e7 cmp %r12,%r15 3d: 74 0b je 0x4a 3f: e8 .byte 0xe8