================================================================== BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0 net/rose/rose_timer.c:183 Read of size 2 at addr ffff8880273e402a by task syz.4.4370/19832 CPU: 0 UID: 0 PID: 19832 Comm: syz.4.4370 Not tainted 6.15.0-rc5-syzkaller-00984-gd97e2634fbdc #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xb4/0x290 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 rose_timer_expiry+0x471/0x4b0 net/rose/rose_timer.c:183 call_timer_fn+0x17b/0x5f0 kernel/time/timer.c:1789 expire_timers kernel/time/timer.c:1840 [inline] __run_timers kernel/time/timer.c:2414 [inline] __run_timer_base+0x61a/0x860 kernel/time/timer.c:2426 run_timer_base kernel/time/timer.c:2435 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2445 handle_softirqs+0x283/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_write_unlock_irq include/linux/rwlock_api_smp.h:274 [inline] RIP: 0010:_raw_write_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:358 Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 aa 77 44 f6 48 89 df e8 b2 17 45 f6 e8 9d 96 6d f6 fb bf 01 00 00 00 e2 18 37 f6 65 8b 05 4b 49 1c 07 85 c0 74 07 5b c3 cc cc cc cc RSP: 0018:ffffc9000bf17ad0 EFLAGS: 00000286 RAX: 37e181f637c92700 RBX: ffff88802f7a2940 RCX: 37e181f637c92700 RDX: 0000000000000006 RSI: ffffffff8d75179c RDI: 0000000000000001 RBP: ffffc9000bf17c10 R08: ffffffff8f7f2c77 R09: 1ffffffff1efe58e R10: dffffc0000000000 R11: fffffbfff1efe58f R12: ffffc9000bf17b80 R13: dffffc0000000000 R14: ffff88802f7a2800 R15: 0000000000000000 ep_send_events fs/eventpoll.c:1937 [inline] ep_try_send_events+0xd93/0xf40 fs/eventpoll.c:1993 ep_poll fs/eventpoll.c:2058 [inline] do_epoll_wait+0x53f/0xf30 fs/eventpoll.c:2531 __do_sys_epoll_wait fs/eventpoll.c:2539 [inline] __se_sys_epoll_wait fs/eventpoll.c:2534 [inline] __x64_sys_epoll_wait+0x1be/0x210 fs/eventpoll.c:2534 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f329138e969 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f329221f038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 00007f32915b6160 RCX: 00007f329138e969 RDX: 0000000000000003 RSI: 0000200000000240 RDI: 0000000000000007 RBP: 00007f3291410ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000009 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f32915b6160 R15: 00007ffdded41628 Allocated by task 18616: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4339 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] copy_splice_read+0x143/0x9b0 fs/splice.c:337 do_splice_read fs/splice.c:978 [inline] splice_direct_to_actor+0x4d0/0xcc0 fs/splice.c:1083 do_splice_direct_actor fs/splice.c:1201 [inline] do_splice_direct+0x181/0x270 fs/splice.c:1227 do_sendfile+0x4da/0x7d0 fs/read_write.c:1368 __do_sys_sendfile64 fs/read_write.c:1429 [inline] __se_sys_sendfile64+0x13e/0x190 fs/read_write.c:1415 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 18616: 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:2380 [inline] slab_free mm/slub.c:4642 [inline] kfree+0x193/0x440 mm/slub.c:4841 copy_splice_read+0x881/0x9b0 fs/splice.c:397 do_splice_read fs/splice.c:978 [inline] splice_direct_to_actor+0x4d0/0xcc0 fs/splice.c:1083 do_splice_direct_actor fs/splice.c:1201 [inline] do_splice_direct+0x181/0x270 fs/splice.c:1227 do_sendfile+0x4da/0x7d0 fs/read_write.c:1368 __do_sys_sendfile64 fs/read_write.c:1429 [inline] __se_sys_sendfile64+0x13e/0x190 fs/read_write.c:1415 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880273e4000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 42 bytes inside of freed 512-byte region [ffff8880273e4000, ffff8880273e4200) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880273e6000 pfn:0x273e4 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88801a041c80 ffffea0001f20010 ffffea0001918610 raw: ffff8880273e6000 0000000000100008 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801a041c80 ffffea0001f20010 ffffea0001918610 head: ffff8880273e6000 0000000000100008 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea00009cf901 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5839, tgid 5839 (syz-executor), ts 95957388481, free_ts 95816553239 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1714 prep_new_page mm/page_alloc.c:1722 [inline] get_page_from_freelist+0x21e0/0x22c0 mm/page_alloc.c:3684 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4966 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2450 [inline] allocate_slab+0x8a/0x3b0 mm/slub.c:2618 new_slab mm/slub.c:2672 [inline] ___slab_alloc+0xbfc/0x1480 mm/slub.c:3858 __slab_alloc mm/slub.c:3948 [inline] __slab_alloc_node mm/slub.c:4023 [inline] slab_alloc_node mm/slub.c:4184 [inline] __do_kmalloc_node mm/slub.c:4326 [inline] __kmalloc_noprof+0x305/0x4f0 mm/slub.c:4339 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] fib6_info_alloc+0x30/0xf0 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x147/0xa70 net/ipv6/route.c:3782 ip6_route_add+0x29/0x2f0 net/ipv6/route.c:3909 addrconf_prefix_route net/ipv6/addrconf.c:2487 [inline] addrconf_add_linklocal+0x45f/0x6c0 net/ipv6/addrconf.c:3312 addrconf_addr_gen+0x490/0x580 net/ipv6/addrconf.c:3441 addrconf_init_auto_addrs+0x711/0xb50 net/ipv6/addrconf.c:-1 addrconf_notify+0xacc/0x1010 net/ipv6/addrconf.c:3744 notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2266 [inline] call_netdevice_notifiers net/core/dev.c:2280 [inline] __dev_notify_flags+0x18d/0x2e0 net/core/dev.c:-1 page last free pid 5913 tgid 5913 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1258 [inline] __free_frozen_pages+0xb14/0xce0 mm/page_alloc.c:2721 __slab_free+0x326/0x400 mm/slub.c:4553 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/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:4147 [inline] slab_alloc_node mm/slub.c:4196 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4203 new_handle fs/jbd2/transaction.c:457 [inline] jbd2__journal_start+0x146/0x5b0 fs/jbd2/transaction.c:484 __ext4_journal_start_sb+0x227/0x5c0 fs/ext4/ext4_jbd2.c:114 __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline] ext4_dirty_inode+0x93/0x110 fs/ext4/inode.c:6100 __mark_inode_dirty+0x2ce/0xdf0 fs/fs-writeback.c:2527 generic_update_time fs/inode.c:2064 [inline] inode_update_time fs/inode.c:2077 [inline] __file_update_time fs/inode.c:2305 [inline] file_update_time+0x40c/0x490 fs/inode.c:2335 ext4_page_mkwrite+0x1f5/0x1110 fs/ext4/inode.c:6221 do_page_mkwrite+0x14a/0x310 mm/memory.c:3287 do_shared_fault mm/memory.c:5594 [inline] do_fault mm/memory.c:5656 [inline] do_pte_missing mm/memory.c:4160 [inline] handle_pte_fault mm/memory.c:5997 [inline] __handle_mm_fault+0x18d2/0x5380 mm/memory.c:6140 handle_mm_fault+0x3f6/0x8c0 mm/memory.c:6309 do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1337 Memory state around the buggy address: ffff8880273e3f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880273e3f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880273e4000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880273e4080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880273e4100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 90 nop 1: f3 0f 1e fa endbr64 5: 53 push %rbx 6: 48 89 fb mov %rdi,%rbx 9: 48 83 c7 18 add $0x18,%rdi d: 48 8b 74 24 08 mov 0x8(%rsp),%rsi 12: e8 aa 77 44 f6 call 0xf64477c1 17: 48 89 df mov %rbx,%rdi 1a: e8 b2 17 45 f6 call 0xf64517d1 1f: e8 9d 96 6d f6 call 0xf66d96c1 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 e2 18 37 f6 call 0xf6371911 <-- trapping instruction 2f: 65 8b 05 4b 49 1c 07 mov %gs:0x71c494b(%rip),%eax # 0x71c4981 36: 85 c0 test %eax,%eax 38: 74 07 je 0x41 3a: 5b pop %rbx 3b: c3 ret 3c: cc int3 3d: cc int3 3e: cc int3 3f: cc int3