syzbot

==================================================================
BUG: KASAN: use-after-free in rose_timer_expiry+0x470/0x490 net/rose/rose_timer.c:183
Read of size 2 at addr ffff888060dc302a by task syz.4.389/5765

CPU: 0 PID: 5765 Comm: syz.4.389 Not tainted 5.15.188-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x168/0x230 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+0x16c/0x530 kernel/time/timer.c:1451
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x525/0x7c0 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x328/0x820 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
Code: 74 05 e8 be e5 ca f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 86 64 9e f7 65 8b 05 27 64 4f 76 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc90003a0f140 EFLAGS: 00000206
RAX: 37089a17a692df00 RBX: 0000000000000a06 RCX: 37089a17a692df00
RDX: dffffc0000000000 RSI: ffffffff8a0b15c0 RDI: 0000000000000001
RBP: ffffc90003a0f1d8 R08: dffffc0000000000 R09: fffffbfff2c641fd
R10: fffffbfff2c641fd R11: 1ffffffff2c641fc R12: dffffc0000000000
R13: ffff888070d32000 R14: ffffffff96320fe0 R15: 1ffff92000741e28
 __debug_check_no_obj_freed lib/debugobjects.c:982 [inline]
 debug_check_no_obj_freed+0x515/0x530 lib/debugobjects.c:1003
 free_pages_prepare mm/page_alloc.c:1345 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x237/0x6c0 mm/page_alloc.c:3317
 free_unref_page_list+0x122/0x7e0 mm/page_alloc.c:3433
 release_pages+0x184b/0x1bb0 mm/swap.c:963
 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:240 [inline]
 tlb_flush_mmu+0xc5/0x170 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+0x2096/0x2520 mm/memory.c:1576
 unmap_vmas+0x11b/0x230 mm/memory.c:1653
 exit_mmap+0x38f/0x5f0 mm/mmap.c:3212
 __mmput+0x115/0x3b0 kernel/fork.c:1127
 exit_mm+0x567/0x6c0 kernel/exit.c:550
 do_exit+0x5a1/0x20a0 kernel/exit.c:870
 do_group_exit+0x12e/0x300 kernel/exit.c:997
 get_signal+0x6ca/0x12c0 kernel/signal.c:2900
 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fb4d56af929
Code: Unable to access opcode bytes at RIP 0x7fb4d56af8ff.
RSP: 002b:00007fb4d34f60e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fb4d58d7088 RCX: 00007fb4d56af929
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb4d58d7088
RBP: 00007fb4d58d7080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb4d58d708c
R13: 0000000000000000 R14: 00007ffc1aac6e60 R15: 00007ffc1aac6f48
 </TASK>

Allocated by task 3562:
 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 include/linux/slab.h:604 [inline]
 kzalloc include/linux/slab.h:735 [inline]
 kernfs_fop_open+0x3da/0xbf0 fs/kernfs/file.c:628
 do_dentry_open+0x7ff/0xf80 fs/open.c:826
 do_open fs/namei.c:3608 [inline]
 path_openat+0x2682/0x2f30 fs/namei.c:3742
 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769
 do_sys_openat2+0x142/0x4a0 fs/open.c:1253
 do_sys_open fs/open.c:1269 [inline]
 __do_sys_openat fs/open.c:1285 [inline]
 __se_sys_openat fs/open.c:1280 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1280
 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

The buggy address belongs to the object at ffff888060dc3000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 512-byte region [ffff888060dc3000, ffff888060dc3200)
The buggy address belongs to the page:
page:ffffea0001837000 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888060dc3000 pfn:0x60dc0
head:ffffea0001837000 order:2 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea00018b9608 ffffea0001e4f608 ffff888016841c80
raw: ffff888060dc3000 0000000000100008 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 4190, ts 62003173375, free_ts 20163919301
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5474
 alloc_slab_page mm/slub.c:1775 [inline]
 allocate_slab mm/slub.c:1912 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1975
 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3008
 __slab_alloc mm/slub.c:3095 [inline]
 slab_alloc_node mm/slub.c:3186 [inline]
 __kmalloc_node_track_caller+0x1fc/0x3a0 mm/slub.c:4958
 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]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1183 [inline]
 netlink_sendmsg+0x645/0xbc0 net/netlink/af_netlink.c:1880
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 __sys_sendto+0x423/0x580 net/socket.c:2063
 __do_sys_sendto net/socket.c:2075 [inline]
 __se_sys_sendto net/socket.c:2071 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2071
 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
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+0x94/0x280 mm/page_alloc.c:3396
 free_contig_range+0x96/0xf0 mm/page_alloc.c:9393
 destroy_args+0xef/0x8b0 mm/debug_vm_pgtable.c:1018
 debug_vm_pgtable+0x318/0x370 mm/debug_vm_pgtable.c:1331
 do_one_initcall+0x1ee/0x680 init/main.c:1302
 do_initcall_level+0x137/0x1f0 init/main.c:1375
 do_initcalls+0x4b/0x90 init/main.c:1391
 kernel_init_freeable+0x3ce/0x560 init/main.c:1615
 kernel_init+0x19/0x1b0 init/main.c:1506
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Memory state around the buggy address:
 ffff888060dc2f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888060dc2f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888060dc3000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff888060dc3080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888060dc3100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
sched: RT throttling activated
----------------
Code disassembly (best guess):
   0:	74 05                	je     0x7
   2:	e8 be e5 ca f7       	call   0xf7cae5c5
   7:	48 c7 44 24 20 00 00 	movq   $0x0,0x20(%rsp)
   e:	00 00
  10:	9c                   	pushf
  11:	8f 44 24 20          	pop    0x20(%rsp)
  15:	f6 44 24 21 02       	testb  $0x2,0x21(%rsp)
  1a:	75 4b                	jne    0x67
  1c:	f7 c3 00 02 00 00    	test   $0x200,%ebx
  22:	74 01                	je     0x25
  24:	fb                   	sti
  25:	bf 01 00 00 00       	mov    $0x1,%edi
* 2a:	e8 86 64 9e f7       	call   0xf79e64b5 <-- trapping instruction
  2f:	65 8b 05 27 64 4f 76 	mov    %gs:0x764f6427(%rip),%eax        # 0x764f645d
  36:	85 c0                	test   %eax,%eax
  38:	74 3c                	je     0x76
  3a:	48                   	rex.W
  3b:	c7                   	.byte 0xc7
  3c:	04 24                	add    $0x24,%al
  3e:	0e                   	(bad)
  3f:	36                   	ss