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BUG: KASAN: use-after-free in rose_timer_expiry+0x470/0x490 net/rose/rose_timer.c:183
Read of size 2 at addr ffff88802584502a by task syz-executor/4172

CPU: 0 PID: 4172 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <IRQ>
 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+0x142/0x210 kernel/softirq.c:477
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x180/0x1c0 kernel/softirq.c:401
 lock_sock include/net/sock.h:1744 [inline]
 tcp_sendmsg+0x1d/0x40 net/ipv4/tcp.c:1459
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 sock_write_iter+0x2a6/0x3a0 net/socket.c:1089
 call_write_iter include/linux/fs.h:2173 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x745/0xd60 fs/read_write.c:594
 ksys_write+0x152/0x260 fs/read_write.c:647
 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: 0033:0x7f289b7fc997
Code: 48 89 fa 4c 89 df e8 a8 56 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffc23c4e130 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055558eb3c500 RCX: 00007f289b7fc997
RDX: 00000000000011a0 RSI: 00007f28952a3e60 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000011a0
R13: 000055558eb50fa0 R14: 00007ffc23c4e6d0 R15: 00007f28952a3e60
 </TASK>

Allocated by task 4172:
 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
 __napi_alloc_skb+0x151/0x2d0 net/core/skbuff.c:568
 napi_alloc_skb include/linux/skbuff.h:3081 [inline]
 page_to_skb+0x26a/0xcf0 drivers/net/virtio_net.c:474
 receive_mergeable drivers/net/virtio_net.c:1102 [inline]
 receive_buf+0x14db/0x58e0 drivers/net/virtio_net.c:1212
 virtnet_receive drivers/net/virtio_net.c:1504 [inline]
 virtnet_poll+0x571/0xf40 drivers/net/virtio_net.c:1617
 __napi_poll+0xc0/0x430 net/core/dev.c:7101
 napi_poll net/core/dev.c:7168 [inline]
 net_rx_action+0x4d4/0xa10 net/core/dev.c:7258
 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
 common_interrupt+0xb5/0xd0 arch/x86/kernel/irq.c:242
 asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:667

The buggy address belongs to the object at ffff888025845000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 512-byte region [ffff888025845000, ffff888025845200)
The buggy address belongs to the page:
page:ffffea0000961100 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888025847000 pfn:0x25844
head:ffffea0000961100 order:2 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea000183f808 ffffea00018c6c08 ffff888016c41c80
raw: ffff888025847000 000000000010000e 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 2411, ts 16065640851, free_ts 0
 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:5501
 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]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc_trace+0x1a5/0x2a0 mm/slub.c:3250
 kmalloc include/linux/slab.h:607 [inline]
 kzalloc include/linux/slab.h:738 [inline]
 alloc_bprm+0x56/0x6a0 fs/exec.c:1516
 kernel_execve+0x49/0x900 fs/exec.c:1978
 call_usermodehelper_exec_async+0x207/0x350 kernel/umh.c:112
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888025844f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888025844f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888025845000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff888025845080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888025845100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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