================================================================== BUG: KASAN: use-after-free in rose_timer_expiry+0x470/0x490 net/rose/rose_timer.c:183 Read of size 2 at addr ffff88807954102a by task swapper/0/0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.1.148-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x210 mm/kasan/report.c:420 kasan_report+0x10b/0x140 mm/kasan/report.c:524 rose_timer_expiry+0x470/0x490 net/rose/rose_timer.c:183 call_timer_fn+0x1a0/0x670 kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1549 [inline] __run_timers+0x525/0x7c0 kernel/time/timer.c:1820 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833 handle_softirqs+0x2a1/0x920 kernel/softirq.c:596 __do_softirq kernel/softirq.c:630 [inline] invoke_softirq kernel/softirq.c:470 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:679 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:flush_smp_call_function_queue+0x1f7/0x340 kernel/smp.c:728 Code: 00 4d 85 f6 75 16 e8 d8 f2 0a 00 eb 15 e8 d1 f2 0a 00 e8 5c 86 a0 08 4d 85 f6 74 ea e8 c2 f2 0a 00 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 66 43 c7 44 25 09 00 00 43 c6 44 25 0b RSP: 0018:ffffffff8c807ce0 EFLAGS: 00000293 RAX: ffffffff8175cb9e RBX: 0000000000000000 RCX: ffffffff8c8bc680 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff8c807d90 R08: dffffc0000000000 R09: fffff52000944f6e R10: fffff52000944f6e R11: 1ffff92000944f6d R12: dffffc0000000000 R13: 1ffffffff1900f9c R14: 0000000000000200 R15: 1ffffffff1c3ead6 do_idle+0x520/0x570 kernel/sched/idle.c:330 cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:401 rest_init+0x2dc/0x300 init/main.c:733 arch_call_rest_init+0xa/0xa init/main.c:893 start_kernel+0x490/0x539 init/main.c:1140 secondary_startup_64_no_verify+0xcf/0xdb Allocated by task 16314: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:563 [inline] rose_add_node+0x227/0xdb0 net/rose/rose_route.c:85 rose_rt_ioctl+0xa4c/0xe90 net/rose/rose_route.c:740 rose_ioctl+0x27a/0x790 net/rose/af_rose.c:1380 sock_do_ioctl+0xd3/0x2f0 net/socket.c:1204 sock_ioctl+0x4ed/0x6e0 net/socket.c:1321 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 18822: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1750 slab_free mm/slub.c:3661 [inline] __kmem_cache_free+0xb6/0x1f0 mm/slub.c:3674 rose_rt_device_down+0x4e2/0x530 net/rose/rose_route.c:515 rose_device_event+0x600/0x690 net/rose/af_rose.c:248 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2039 [inline] call_netdevice_notifiers net/core/dev.c:2053 [inline] __dev_notify_flags+0x178/0x2d0 net/core/dev.c:-1 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8702 dev_ifsioc+0x159/0xe90 net/core/dev_ioctl.c:327 dev_ioctl+0x578/0xea0 net/core/dev_ioctl.c:588 sock_do_ioctl+0x222/0x2f0 net/socket.c:1218 sock_ioctl+0x4ed/0x6e0 net/socket.c:1321 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888079541000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 42 bytes inside of 512-byte region [ffff888079541000, ffff888079541200) The buggy address belongs to the physical page: page:ffffea0001e55000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x79540 head:ffffea0001e55000 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888017441c80 raw: 0000000000000000 0000000000100010 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 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 16278, tgid 16275 (syz.3.3212), ts 1257850412642, free_ts 1195792359090 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614 alloc_slab_page+0x5d/0x160 mm/slub.c:1794 allocate_slab mm/slub.c:1939 [inline] new_slab+0x87/0x2c0 mm/slub.c:1992 ___slab_alloc+0xbc6/0x1220 mm/slub.c:3180 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc_node_track_caller+0x9e/0x230 mm/slab_common.c:956 kmalloc_reserve net/core/skbuff.c:446 [inline] __alloc_skb+0x22a/0x7e0 net/core/skbuff.c:515 alloc_skb include/linux/skbuff.h:1271 [inline] nlmsg_new include/net/netlink.h:991 [inline] fdb_notify+0xa6/0x160 net/bridge/br_fdb.c:191 fdb_add_local+0x155/0x250 net/bridge/br_fdb.c:434 br_fdb_add_local+0x36/0x50 net/bridge/br_fdb.c:834 __vlan_add+0x585/0x26e0 net/bridge/br_vlan.c:334 nbp_vlan_add+0x25e/0x3b0 net/bridge/br_vlan.c:1341 br_vlan_info+0xf7/0x450 net/bridge/br_netlink.c:689 br_process_vlan_info+0x545/0x7f0 net/bridge/br_netlink.c:752 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3479 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737 slab_alloc_node mm/slub.c:3398 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x123/0x2f0 mm/slub.c:3422 ptlock_alloc+0x1c/0x60 mm/memory.c:6047 ptlock_init include/linux/mm.h:2415 [inline] pgtable_pte_page_ctor include/linux/mm.h:2442 [inline] __pte_alloc_one include/asm-generic/pgalloc.h:66 [inline] pte_alloc_one+0xc5/0x2f0 arch/x86/mm/pgtable.c:33 do_fault_around mm/memory.c:4595 [inline] do_read_fault mm/memory.c:4626 [inline] do_fault mm/memory.c:4760 [inline] handle_pte_fault mm/memory.c:5031 [inline] __handle_mm_fault mm/memory.c:5173 [inline] handle_mm_fault+0x280a/0x3e70 mm/memory.c:5294 faultin_page mm/gup.c:1026 [inline] __get_user_pages+0x3ff/0xeb0 mm/gup.c:1250 populate_vma_page_range+0x214/0x2b0 mm/gup.c:1607 __mm_populate+0x248/0x370 mm/gup.c:1721 mm_populate include/linux/mm.h:2826 [inline] vm_mmap_pgoff+0x203/0x2b0 mm/util.c:525 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Memory state around the buggy address: ffff888079540f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888079540f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888079541000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888079541080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888079541100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 00 4d 85 add %cl,-0x7b(%rbp) 3: f6 75 16 divb 0x16(%rbp) 6: e8 d8 f2 0a 00 call 0xaf2e3 b: eb 15 jmp 0x22 d: e8 d1 f2 0a 00 call 0xaf2e3 12: e8 5c 86 a0 08 call 0x8a08673 17: 4d 85 f6 test %r14,%r14 1a: 74 ea je 0x6 1c: e8 c2 f2 0a 00 call 0xaf2e3 21: fb sti 22: 48 c7 04 24 0e 36 e0 movq $0x45e0360e,(%rsp) 29: 45 * 2a: 4b c7 44 25 00 00 00 movq $0x0,0x0(%r13,%r12,1) <-- trapping instruction 31: 00 00 33: 66 43 c7 44 25 09 00 movw $0x0,0x9(%r13,%r12,1) 3a: 00 3b: 43 rex.XB 3c: c6 .byte 0xc6 3d: 44 rex.R 3e: 25 .byte 0x25 3f: 0b .byte 0xb