syzbot

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BUG: KASAN: slab-out-of-bounds in nsim_dev_trap_report_work+0xd2/0xb80 drivers/net/netdevsim/dev.c:848
Read of size 8 at addr ffff8880581185e0 by task kworker/u8:8/3025

CPU: 1 UID: 0 PID: 3025 Comm: kworker/u8:8 Not tainted 6.15.0-rc7-syzkaller-00142-g4856ebd99715 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound nsim_dev_trap_report_work
Call Trace:
 <TASK>
 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
 nsim_dev_trap_report_work+0xd2/0xb80 drivers/net/netdevsim/dev.c:848
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xade/0x17a0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 63:
 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]
 fib6_info_alloc+0x30/0xf0 net/ipv6/ip6_fib.c:155
 ip6_route_info_create+0x4b3/0x1360 net/ipv6/route.c:3802
 ip6_route_add+0x28/0x160 net/ipv6/route.c:3896
 addrconf_add_mroute net/ipv6/addrconf.c:2551 [inline]
 addrconf_add_dev+0x24f/0x340 net/ipv6/addrconf.c:2569
 addrconf_dev_config net/ipv6/addrconf.c:3477 [inline]
 addrconf_init_auto_addrs+0x5cf/0xb50 net/ipv6/addrconf.c:3571
 addrconf_notify+0xacc/0x1010 net/ipv6/addrconf.c:3744
 notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85
 netif_state_change+0x284/0x3a0 net/core/dev.c:1530
 linkwatch_do_dev+0x117/0x170 net/core/link_watch.c:186
 __linkwatch_run_queue+0x56d/0x7e0 net/core/link_watch.c:244
 linkwatch_event+0x4c/0x60 net/core/link_watch.c:304
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xade/0x17a0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff888058118400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 192 bytes to the right of
 allocated 288-byte region [ffff888058118400, ffff888058118520)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88805811bc00 pfn:0x58118
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 ffffea0000cd7610 ffffea0000a5d710
raw: ffff88805811bc00 0000000000100009 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88801a041c80 ffffea0000cd7610 ffffea0000a5d710
head: ffff88805811bc00 0000000000100009 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0001604601 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 5204, tgid 5204 (udevadm), ts 38406183192, free_ts 38178327026
 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+0x21c7/0x22a0 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]
 __kmalloc_cache_noprof+0x296/0x3d0 mm/slub.c:4353
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 kernfs_fop_open+0x397/0xca0 fs/kernfs/file.c:623
 do_dentry_open+0xdf3/0x1970 fs/open.c:956
 vfs_open+0x3b/0x340 fs/open.c:1086
 do_open fs/namei.c:3880 [inline]
 path_openat+0x2ee5/0x3830 fs/namei.c:4039
 do_filp_open+0x1fa/0x410 fs/namei.c:4066
 do_sys_openat2+0x121/0x1c0 fs/open.c:1429
 do_sys_open fs/open.c:1444 [inline]
 __do_sys_openat fs/open.c:1460 [inline]
 __se_sys_openat fs/open.c:1455 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1455
 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
page last free pid 5196 tgid 5196 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1258 [inline]
 __free_frozen_pages+0xb05/0xcd0 mm/page_alloc.c:2721
 discard_slab mm/slub.c:2716 [inline]
 __put_partials+0x161/0x1c0 mm/slub.c:3185
 put_cpu_partial+0x17c/0x250 mm/slub.c:3260
 __slab_free+0x2f7/0x400 mm/slub.c:4512
 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
 getname_flags+0xb8/0x540 fs/namei.c:146
 getname include/linux/fs.h:2852 [inline]
 do_sys_openat2+0xbc/0x1c0 fs/open.c:1423
 do_sys_open fs/open.c:1444 [inline]
 __do_sys_openat fs/open.c:1460 [inline]
 __se_sys_openat fs/open.c:1455 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1455
 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

Memory state around the buggy address:
 ffff888058118480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888058118500: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888058118580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                       ^
 ffff888058118600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888058118680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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