================================================================== BUG: KASAN: slab-use-after-free in skb_dst_drop include/net/dst.h:281 [inline] BUG: KASAN: slab-use-after-free in skb_release_head_state+0x3b/0x240 net/core/skbuff.c:1040 Read of size 8 at addr ffff88802f6f8198 by task syz.1.10298/29076 CPU: 0 PID: 29076 Comm: syz.1.10298 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xa8/0x210 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 skb_dst_drop include/net/dst.h:281 [inline] skb_release_head_state+0x3b/0x240 net/core/skbuff.c:1040 skb_release_all net/core/skbuff.c:1055 [inline] __kfree_skb net/core/skbuff.c:1071 [inline] kfree_skb_reason+0xd7/0x170 net/core/skbuff.c:1107 kfree_skb include/linux/skbuff.h:1264 [inline] __hci_req_sync+0x613/0x910 net/bluetooth/hci_request.c:184 hci_req_sync+0xa2/0xc0 net/bluetooth/hci_request.c:206 hci_inquiry+0x38f/0x600 net/bluetooth/hci_core.c:394 sock_do_ioctl+0xfc/0x310 net/socket.c:1219 sock_ioctl+0x5ba/0x7e0 net/socket.c:1340 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f2ed179c799 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:00007f2ed25ba028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f2ed1a15fa0 RCX: 00007f2ed179c799 RDX: 0000200000000280 RSI: 00000000800448f0 RDI: 0000000000000004 RBP: 00007f2ed1832c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2ed1a16038 R14: 00007f2ed1a15fa0 R15: 00007ffe4ff95628 Allocated by task 6224: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x11a/0x2d0 mm/slub.c:3519 skb_clone+0x1eb/0x370 net/core/skbuff.c:1915 hci_send_cmd_sync net/bluetooth/hci_core.c:4067 [inline] hci_cmd_work+0x283/0x650 net/bluetooth/hci_core.c:4087 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Freed by task 6214: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] kmem_cache_free+0xf8/0x270 mm/slub.c:3852 kfree_skb include/linux/skbuff.h:1264 [inline] hci_send_cmd_sync net/bluetooth/hci_core.c:4066 [inline] hci_cmd_work+0x25d/0x650 net/bluetooth/hci_core.c:4087 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 The buggy address belongs to the object at ffff88802f6f8140 which belongs to the cache skbuff_head_cache of size 240 The buggy address is located 88 bytes inside of freed 240-byte region [ffff88802f6f8140, ffff88802f6f8230) The buggy address belongs to the physical page: page:ffffea0000bdbe00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2f6f8 flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000800 ffff888141a65000 ffffea0001638b80 dead000000000004 raw: 0000000000000000 00000000000c000c 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 5143, tgid 5143 (udevd), ts 23052870310, free_ts 23041485268 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1581 prep_new_page mm/page_alloc.c:1588 [inline] get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3220 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4500 alloc_slab_page+0x5d/0x160 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2d0 mm/slub.c:2081 ___slab_alloc+0xc5d/0x12f0 mm/slub.c:3253 __slab_alloc mm/slub.c:3339 [inline] __slab_alloc_node mm/slub.c:3392 [inline] slab_alloc_node mm/slub.c:3485 [inline] kmem_cache_alloc_node+0x1e6/0x320 mm/slub.c:3540 __alloc_skb+0x103/0x2c0 net/core/skbuff.c:643 alloc_skb include/linux/skbuff.h:1316 [inline] alloc_skb_with_frags+0xca/0x7b0 net/core/skbuff.c:6334 sock_alloc_send_pskb+0x883/0x9a0 net/core/sock.c:2821 unix_dgram_sendmsg+0x5a2/0x16d0 net/unix/af_unix.c:2001 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] sock_write_iter+0x2df/0x420 net/socket.c:1160 call_write_iter include/linux/fs.h:2018 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x46c/0x990 fs/read_write.c:584 ksys_write+0x150/0x260 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1181 [inline] free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2365 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458 discard_slab mm/slub.c:2127 [inline] __unfreeze_partials+0x1cf/0x210 mm/slub.c:2667 put_cpu_partial+0x17c/0x250 mm/slub.c:2743 __slab_free+0x319/0x400 mm/slub.c:3700 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc_lru+0x111/0x2d0 mm/slub.c:3526 __d_alloc+0x31/0x730 fs/dcache.c:1773 d_alloc fs/dcache.c:1853 [inline] d_alloc_parallel+0xe0/0x1530 fs/dcache.c:2646 lookup_open fs/namei.c:3421 [inline] open_last_lookups fs/namei.c:3564 [inline] path_openat+0x933/0x3230 fs/namei.c:3794 do_filp_open+0x1f5/0x430 fs/namei.c:3824 do_sys_openat2+0x134/0x1d0 fs/open.c:1421 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x139/0x160 fs/open.c:1447 Memory state around the buggy address: ffff88802f6f8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ffff88802f6f8100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff88802f6f8180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802f6f8200: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc ffff88802f6f8280: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================