syzbot


KASAN: use-after-free Read in ieee80211_select_queue_80211

Status: upstream: reported on 2026/06/03 16:30
Reported-by: syzbot+6333b0559dc26d07c6cf@syzkaller.appspotmail.com
First crash: 3d20h, last: 3d20h

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in ieee80211_select_queue_80211+0x278/0x2c0 net/mac80211/wme.c:138
Read of size 1 at addr ffff8880606dda19 by task syz.0.884/7358

CPU: 0 PID: 7358 Comm: syz.0.884 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 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
 ieee80211_select_queue_80211+0x278/0x2c0 net/mac80211/wme.c:138
 netdev_core_pick_tx+0x118/0x2e0 net/core/dev.c:4184
 __dev_queue_xmit+0x756/0x2f80 net/core/dev.c:4261
 packet_snd net/packet/af_packet.c:3089 [inline]
 packet_sendmsg+0x3dba/0x5060 net/packet/af_packet.c:3120
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445
 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2499
 __sys_sendmsg net/socket.c:2528 [inline]
 __do_sys_sendmsg net/socket.c:2537 [inline]
 __se_sys_sendmsg+0x1af/0x290 net/socket.c:2535
 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: 0033:0x7fdcb8a61e59
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:00007fdcb6cbb028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fdcb8cdafa0 RCX: 00007fdcb8a61e59
RDX: 0000000000000000 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007fdcb8af7d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdcb8cdb038 R14: 00007fdcb8cdafa0 R15: 00007ffcb6b989b8
 </TASK>

Allocated by task 4189:
 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_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x100/0x290 mm/slub.c:3238
 kmem_cache_zalloc include/linux/slab.h:728 [inline]
 fill_pool lib/debugobjects.c:172 [inline]
 __debug_object_init+0x9a8/0xc80 lib/debugobjects.c:615
 ipv6_add_addr+0x591/0xe10 net/ipv6/addrconf.c:1137
 addrconf_add_linklocal+0x26a/0x6c0 net/ipv6/addrconf.c:3238
 addrconf_addr_gen+0x559/0x6b0 net/ipv6/addrconf.c:3369
 addrconf_init_auto_addrs+0x747/0xb00 net/ipv6/addrconf.c:-1
 addrconf_notify+0xa6b/0xf00 net/ipv6/addrconf.c:3662
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391
 call_netdevice_notifiers_extack net/core/dev.c:2074 [inline]
 call_netdevice_notifiers net/core/dev.c:2088 [inline]
 __dev_notify_flags+0x194/0x300 net/core/dev.c:8917
 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8955
 do_setlink+0xcdb/0x3d60 net/core/rtnetlink.c:2785
 __rtnl_newlink net/core/rtnetlink.c:3456 [inline]
 rtnl_newlink+0x1658/0x1a50 net/core/rtnetlink.c:3578
 rtnetlink_rcv_msg+0x844/0xf30 net/core/rtnetlink.c:5688
 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2507
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 __sys_sendto+0x46d/0x620 net/socket.c:2072
 __do_sys_sendto net/socket.c:2084 [inline]
 __se_sys_sendto net/socket.c:2080 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2080
 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 ffff8880606dda10
 which belongs to the cache debug_objects_cache of size 40
The buggy address is located 9 bytes inside of
 40-byte region [ffff8880606dda10, ffff8880606dda38)
The buggy address belongs to the page:
page:ffffea000181b740 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880606dd380 pfn:0x606dd
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea00018b2c48 ffffea00018b7a48 ffff888016c4f8c0
raw: ffff8880606dd380 0000000000490033 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12020(__GFP_HIGH|__GFP_NOWARN|__GFP_NORETRY), pid 21, ts 69427143727, free_ts 23647301760
 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+0x195/0x290 mm/slub.c:3238
 kmem_cache_zalloc include/linux/slab.h:728 [inline]
 fill_pool lib/debugobjects.c:172 [inline]
 __debug_object_init+0x7cc/0xc80 lib/debugobjects.c:615
 debug_timer_init kernel/time/timer.c:724 [inline]
 debug_init kernel/time/timer.c:772 [inline]
 init_timer_key+0x3d/0x2a0 kernel/time/timer.c:816
 neigh_alloc net/core/neighbour.c:451 [inline]
 ___neigh_create+0x9e0/0x2250 net/core/neighbour.c:591
 ip6_finish_output2+0x9f6/0x1510 net/ipv6/ip6_output.c:127
 dst_output include/net/dst.h:452 [inline]
 NF_HOOK include/linux/netfilter.h:302 [inline]
 ndisc_send_skb+0xc2a/0x1500 net/ipv6/ndisc.c:513
 ndisc_send_ns+0x648/0x850 net/ipv6/ndisc.c:655
 addrconf_dad_work+0xa63/0x1540 net/ipv6/addrconf.c:4198
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
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+0x8f/0x2a0 mm/page_alloc.c:3396
 free_contig_range+0x96/0xf0 mm/page_alloc.c:9428
 destroy_args+0xf0/0xa00 mm/debug_vm_pgtable.c:1018
 debug_vm_pgtable+0x321/0x380 mm/debug_vm_pgtable.c:1336
 do_one_initcall+0x272/0x730 init/main.c:1316
 do_initcall_level+0x137/0x1f0 init/main.c:1389
 do_initcalls+0x4b/0x90 init/main.c:1405
 kernel_init_freeable+0x3e9/0x570 init/main.c:1629
 kernel_init+0x19/0x1b0 init/main.c:1520
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Memory state around the buggy address:
 ffff8880606dd900: 00 00 00 00 fc fc 00 00 00 00 00 fc fc 00 00 00
 ffff8880606dd980: 00 00 fc fc 00 00 00 00 00 fc fc 00 00 00 00 00
>ffff8880606dda00: fc fc fb fb fb fb fb fc fc 00 00 00 00 00 fc fc
                            ^
 ffff8880606dda80: 00 00 00 00 00 fc fc fb fb fb fb fb fc fc 00 00
 ffff8880606ddb00: 00 00 00 fc fc 00 00 00 00 00 fc fc fb fb fb fb
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/03 16:30 linux-5.15.y dc027a595035 234057e5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ieee80211_select_queue_80211
* Struck through repros no longer work on HEAD.