syzbot

==================================================================
BUG: KASAN: slab-use-after-free in rose_send_frame net/rose/rose_link.c:101 [inline]
BUG: KASAN: slab-use-after-free in rose_transmit_restart_request net/rose/rose_link.c:198 [inline]
BUG: KASAN: slab-use-after-free in rose_t0timer_expiry+0x1aa/0x560 net/rose/rose_link.c:83
Read of size 8 at addr ffff8880342f8c20 by task syz.3.962/10213

CPU: 0 UID: 0 PID: 10213 Comm: syz.3.962 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 rose_send_frame net/rose/rose_link.c:101 [inline]
 rose_transmit_restart_request net/rose/rose_link.c:198 [inline]
 rose_t0timer_expiry+0x1aa/0x560 net/rose/rose_link.c:83
 call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2374 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
 run_timer_base kernel/time/timer.c:2395 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
 handle_softirqs+0x22a/0x840 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__schedule+0x17bc/0x5680 kernel/sched/core.c:7148
Code: d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 0a 47 78 f6 4c 89 23 4c 89 ef 4c 89 e6 e8 3c ac 7a f5 48 89 c7 e8 04 49 dc f5 <31> ff 4d 39 e5 40 0f 95 c7 e8 e6 54 dc f5 48 8b 84 24 00 01 00 00
RSP: 0018:ffffc900037d7460 EFLAGS: 00000206
RAX: 000000000000f055 RBX: ffff8880b863ae88 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8dfd5677 RDI: ffffffff8c289ce0
RBP: ffffc900037d7678 R08: ffffffff903364f7 R09: 1ffffffff2066c9e
R10: dffffc0000000000 R11: fffffbfff2066c9f R12: ffff88803355dc40
R13: ffff88803355dc40 R14: dffffc0000000000 R15: ffff8880b863bcc8
 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7369
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
 _raw_spin_unlock_irqrestore+0x74/0x80 kernel/locking/spinlock.c:198
 rcu_preempt_deferred_qs_irqrestore+0x7b9/0xbc0 kernel/rcu/tree_plugin.h:-1
 __rcu_read_unlock+0x83/0xe0 kernel/rcu/tree_plugin.h:438
 rcu_read_unlock include/linux/rcupdate.h:871 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1181 [inline]
 unwind_next_frame+0x1bbf/0x2550 arch/x86/kernel/unwind_orc.c:709
 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2689 [inline]
 slab_free mm/slub.c:6246 [inline]
 kmem_cache_free+0x182/0x650 mm/slub.c:6373
 __dentry_kill+0x469/0x5e0 fs/dcache.c:689
 finish_dput+0xc9/0x480 fs/dcache.c:879
 __fput+0x691/0xa60 fs/file_table.c:518
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline]
 do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe5c779c819
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcd45d6348 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fe5c7a17da0 RCX: 00007fe5c779c819
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fe5c7a17da0 R08: 0000000000000006 R09: 0000000000000000
R10: 00007fe5c7a17cb0 R11: 0000000000000246 R12: 000000000007f2fb
R13: 00007fe5c7a1609c R14: 000000000007f2c5 R15: 00007fe5c7a16090
 </TASK>

Allocated by task 6081:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x31c/0x660 mm/slub.c:5415
 kmalloc_noprof include/linux/slab.h:950 [inline]
 rose_add_node+0x23c/0xf00 net/rose/rose_route.c:85
 rose_rt_ioctl+0xd35/0x12a0 net/rose/rose_route.c:748
 rose_ioctl+0x3fb/0x8f0 net/rose/af_rose.c:1387
 sock_do_ioctl+0x101/0x320 net/socket.c:1313
 sock_ioctl+0x5c6/0x7f0 net/socket.c:1434
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 10214:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2689 [inline]
 slab_free mm/slub.c:6246 [inline]
 kfree+0x1c5/0x640 mm/slub.c:6561
 rose_neigh_put include/net/rose.h:166 [inline]
 rose_timer_expiry+0x4cb/0x600 net/rose/rose_timer.c:183
 call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2374 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
 run_timer_base kernel/time/timer.c:2395 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
 handle_softirqs+0x22a/0x840 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697

The buggy address belongs to the object at ffff8880342f8c00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 32 bytes inside of
 freed 512-byte region [ffff8880342f8c00, ffff8880342f8e00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880342fa800 pfn:0x342f8
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 ffff88813fe2dc80 ffffea0001e77510 ffffea0000c5c710
raw: ffff8880342fa800 000000080010000a 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88813fe2dc80 ffffea0001e77510 ffffea0000c5c710
head: ffff8880342fa800 000000080010000a 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffffffffffff01 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5215, tgid 5215 (udevadm), ts 34393537440, free_ts 32803487810
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1858
 prep_new_page mm/page_alloc.c:1866 [inline]
 get_page_from_freelist+0x24ba/0x2540 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226
 alloc_slab_page mm/slub.c:3278 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3467
 new_slab mm/slub.c:3525 [inline]
 refill_objects+0x339/0x3d0 mm/slub.c:7251
 refill_sheaf mm/slub.c:2816 [inline]
 __pcs_replace_empty_main+0x321/0x720 mm/slub.c:4651
 alloc_from_pcs mm/slub.c:4749 [inline]
 slab_alloc_node mm/slub.c:4883 [inline]
 __kmalloc_cache_noprof+0x392/0x660 mm/slub.c:5410
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 kernfs_fop_open+0x3f0/0xda0 fs/kernfs/file.c:641
 do_dentry_open+0x785/0x14e0 fs/open.c:947
 vfs_open+0x3b/0x340 fs/open.c:1079
 do_open fs/namei.c:4699 [inline]
 path_openat+0x2e08/0x3860 fs/namei.c:4858
 do_file_open+0x23e/0x4a0 fs/namei.c:4887
 do_sys_openat2+0x113/0x200 fs/open.c:1364
 do_sys_open fs/open.c:1370 [inline]
 __do_sys_openat fs/open.c:1386 [inline]
 __se_sys_openat fs/open.c:1381 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1381
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5247 tgid 5247 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1402 [inline]
 __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943
 __slab_free+0x274/0x2c0 mm/slub.c:5608
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4569 [inline]
 slab_alloc_node mm/slub.c:4898 [inline]
 __kmalloc_cache_noprof+0x2ba/0x660 mm/slub.c:5410
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 v4l2_fh_open+0x62/0x420 drivers/media/v4l2-core/v4l2-fh.c:60
 v4l2_open+0x1bf/0x3a0 drivers/media/v4l2-core/v4l2-dev.c:433
 chrdev_open+0x4cd/0x5e0 fs/char_dev.c:411
 do_dentry_open+0x785/0x14e0 fs/open.c:947
 vfs_open+0x3b/0x340 fs/open.c:1079
 do_open fs/namei.c:4699 [inline]
 path_openat+0x2e08/0x3860 fs/namei.c:4858
 do_file_open+0x23e/0x4a0 fs/namei.c:4887
 do_sys_openat2+0x113/0x200 fs/open.c:1364
 do_sys_open fs/open.c:1370 [inline]
 __do_sys_openat fs/open.c:1386 [inline]
 __se_sys_openat fs/open.c:1381 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1381
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94

Memory state around the buggy address:
 ffff8880342f8b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880342f8b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880342f8c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff8880342f8c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880342f8d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	d8 48 c1             	fmuls  -0x3f(%rax)
   3:	e8 03 42 80 3c       	call   0x3c80420b
   8:	30 00                	xor    %al,(%rax)
   a:	74 08                	je     0x14
   c:	48 89 df             	mov    %rbx,%rdi
   f:	e8 0a 47 78 f6       	call   0xf678471e
  14:	4c 89 23             	mov    %r12,(%rbx)
  17:	4c 89 ef             	mov    %r13,%rdi
  1a:	4c 89 e6             	mov    %r12,%rsi
  1d:	e8 3c ac 7a f5       	call   0xf57aac5e
  22:	48 89 c7             	mov    %rax,%rdi
  25:	e8 04 49 dc f5       	call   0xf5dc492e
* 2a:	31 ff                	xor    %edi,%edi <-- trapping instruction
  2c:	4d 39 e5             	cmp    %r12,%r13
  2f:	40 0f 95 c7          	setne  %dil
  33:	e8 e6 54 dc f5       	call   0xf5dc551e
  38:	48 8b 84 24 00 01 00 	mov    0x100(%rsp),%rax
  3f:	00