Hello, syzbot found the following issue on: HEAD commit: 8568bb2ccc27 Add linux-next specific files for 20240405 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=1344efc5180000 kernel config: https://syzkaller.appspot.com/x/.config?x=48ca5acf8d2eb3bc dashboard link: https://syzkaller.appspot.com/bug?extid=27209997e4015fb4702e compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/1d120b5e779c/disk-8568bb2c.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/a89e3589a585/vmlinux-8568bb2c.xz kernel image: https://storage.googleapis.com/syzbot-assets/045e657c0e0d/bzImage-8568bb2c.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+27209997e4015fb4702e@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: slab-use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] BUG: KASAN: slab-use-after-free in refcount_read include/linux/refcount.h:136 [inline] BUG: KASAN: slab-use-after-free in skb_unref include/linux/skbuff.h:1227 [inline] BUG: KASAN: slab-use-after-free in __kfree_skb_reason net/core/skbuff.c:1197 [inline] BUG: KASAN: slab-use-after-free in kfree_skb_reason+0x41/0x3b0 net/core/skbuff.c:1224 Read of size 4 at addr ffff8880645c9864 by task syz-executor.1/5107 CPU: 1 PID: 5107 Comm: syz-executor.1 Not tainted 6.9.0-rc2-next-20240405-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189 instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] refcount_read include/linux/refcount.h:136 [inline] skb_unref include/linux/skbuff.h:1227 [inline] __kfree_skb_reason net/core/skbuff.c:1197 [inline] kfree_skb_reason+0x41/0x3b0 net/core/skbuff.c:1224 kfree_skb include/linux/skbuff.h:1262 [inline] __hci_req_sync+0x62f/0x950 net/bluetooth/hci_request.c:184 hci_req_sync+0xa9/0xd0 net/bluetooth/hci_request.c:206 hci_dev_cmd+0x518/0xa90 net/bluetooth/hci_core.c:797 sock_do_ioctl+0x158/0x460 net/socket.c:1222 sock_ioctl+0x629/0x8e0 net/socket.c:1341 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x72/0x7a RIP: 0033:0x7fd8f7e7dbcb Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00 RSP: 002b:00007ffc3d1858e0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fd8f7e7dbcb RDX: 00007ffc3d185958 RSI: 00000000400448dd RDI: 0000000000000003 RBP: 00005555747dc430 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000003 R14: 00007fd8f7fac9d8 R15: 000000000000000c </TASK> Allocated by task 5105: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:312 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3897 [inline] slab_alloc_node mm/slub.c:3957 [inline] kmem_cache_alloc_noprof+0x135/0x290 mm/slub.c:3964 skb_clone+0x20c/0x390 net/core/skbuff.c:2036 hci_send_cmd_sync net/bluetooth/hci_core.c:4234 [inline] hci_cmd_work+0x29e/0x670 net/bluetooth/hci_core.c:4254 process_one_work kernel/workqueue.c:3218 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299 worker_thread+0x86d/0xd70 kernel/workqueue.c:3380 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 Freed by task 5109: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2190 [inline] slab_free mm/slub.c:4393 [inline] kmem_cache_free+0x145/0x340 mm/slub.c:4468 kfree_skb include/linux/skbuff.h:1262 [inline] hci_req_sync_complete+0xe7/0x290 net/bluetooth/hci_request.c:109 hci_event_packet+0xc71/0x1540 net/bluetooth/hci_event.c:7620 hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4185 process_one_work kernel/workqueue.c:3218 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299 worker_thread+0x86d/0xd70 kernel/workqueue.c:3380 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 The buggy address belongs to the object at ffff8880645c9780 which belongs to the cache skbuff_head_cache of size 240 The buggy address is located 228 bytes inside of freed 240-byte region [ffff8880645c9780, ffff8880645c9870) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x645c9 flags: 0xfff80000000000(node=0|zone=1|lastcpupid=0xfff) page_type: 0xffffefff(slab) raw: 00fff80000000000 ffff888018ec2780 dead000000000122 0000000000000000 raw: 0000000000000000 00000000800c000c 00000001ffffefff 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 0x12820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY), pid 5106, tgid 1501860599 (kworker/u9:4), ts 5106, free_ts 23287202140 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1490 prep_new_page mm/page_alloc.c:1498 [inline] get_page_from_freelist+0x2e7e/0x2f40 mm/page_alloc.c:3454 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4712 __alloc_pages_node_noprof include/linux/gfp.h:244 [inline] alloc_pages_node_noprof include/linux/gfp.h:271 [inline] alloc_slab_page+0x5f/0x120 mm/slub.c:2259 allocate_slab+0x5a/0x2e0 mm/slub.c:2422 new_slab mm/slub.c:2475 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3624 __slab_alloc+0x58/0xa0 mm/slub.c:3714 __slab_alloc_node mm/slub.c:3767 [inline] slab_alloc_node mm/slub.c:3945 [inline] kmem_cache_alloc_node_noprof+0x1fe/0x310 mm/slub.c:4000 __alloc_skb+0x1c3/0x440 net/core/skbuff.c:658 alloc_skb include/linux/skbuff.h:1313 [inline] bt_skb_alloc include/net/bluetooth/bluetooth.h:490 [inline] hci_si_event net/bluetooth/hci_sock.c:784 [inline] hci_sock_dev_event+0x100/0x5f0 net/bluetooth/hci_sock.c:826 hci_dev_open_sync+0xfbe/0x33d0 net/bluetooth/hci_sync.c:5000 hci_dev_do_open net/bluetooth/hci_core.c:490 [inline] hci_power_on+0x1c8/0x700 net/bluetooth/hci_core.c:1022 process_one_work kernel/workqueue.c:3218 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299 worker_thread+0x86d/0xd70 kernel/workqueue.c:3380 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1110 [inline] free_unref_page+0xd3c/0xec0 mm/page_alloc.c:2617 free_contig_range+0x9e/0x160 mm/page_alloc.c:6667 destroy_args+0x8a/0x890 mm/debug_vm_pgtable.c:1037 debug_vm_pgtable+0x4be/0x550 mm/debug_vm_pgtable.c:1417 do_one_initcall+0x248/0x880 init/main.c:1258 do_initcall_level+0x157/0x210 init/main.c:1320 do_initcalls+0x3f/0x80 init/main.c:1336 kernel_init_freeable+0x435/0x5d0 init/main.c:1569 kernel_init+0x1d/0x2b0 init/main.c:1458 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 Memory state around the buggy address: ffff8880645c9700: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc ffff8880645c9780: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880645c9800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ^ ffff8880645c9880: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ffff8880645c9900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup