Hello, syzbot found the following issue on: HEAD commit: 33f339a1ba54 bpf, net: Fix a potential race in do_sock_get.. git tree: net console output: https://syzkaller.appspot.com/x/log.txt?x=13f046fb980000 kernel config: https://syzkaller.appspot.com/x/.config?x=996585887acdadb3 dashboard link: https://syzkaller.appspot.com/bug?extid=b4bc25bfaad44df51f05 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/05db6c7e2db6/disk-33f339a1.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/236ebb3d5e01/vmlinux-33f339a1.xz kernel image: https://storage.googleapis.com/syzbot-assets/97dd5f4e883e/bzImage-33f339a1.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+b4bc25bfaad44df51f05@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: slab-use-after-free in sk_filter_trim_cap+0x270/0xa80 net/core/filter.c:155 Read of size 8 at addr ffff888062a0a178 by task syz.3.1323/10208 CPU: 0 UID: 0 PID: 10208 Comm: syz.3.1323 Not tainted 6.11.0-rc5-syzkaller-00191-g33f339a1ba54 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 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 sk_filter_trim_cap+0x270/0xa80 net/core/filter.c:155 sk_filter include/linux/filter.h:1052 [inline] sock_queue_rcv_skb_reason+0x28/0xf0 net/core/sock.c:521 sock_queue_rcv_skb include/net/sock.h:2376 [inline] mgmt_cmd_status+0x28d/0x4d0 net/bluetooth/mgmt_util.c:156 cmd_status_rsp net/bluetooth/mgmt.c:1450 [inline] cmd_complete_rsp+0xe7/0x150 net/bluetooth/mgmt.c:1465 mgmt_pending_foreach+0xd1/0x130 net/bluetooth/mgmt_util.c:259 __mgmt_power_off+0x187/0x420 net/bluetooth/mgmt.c:9469 hci_dev_close_sync+0x665/0x11a0 net/bluetooth/hci_sync.c:5191 hci_dev_do_close net/bluetooth/hci_core.c:483 [inline] hci_dev_close+0x112/0x210 net/bluetooth/hci_core.c:508 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_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4ef0d7cef9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4ef1b48038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f4ef0f35f80 RCX: 00007f4ef0d7cef9 RDX: 0000000000000000 RSI: 00000000400448ca RDI: 0000000000000005 RBP: 00007f4ef0def01e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f4ef0f35f80 R15: 00007ffef1e33f48 </TASK> Allocated by task 6202: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slub.c:4158 [inline] __kmalloc_noprof+0x1fc/0x400 mm/slub.c:4170 kmalloc_noprof include/linux/slab.h:685 [inline] sk_prot_alloc+0xe0/0x210 net/core/sock.c:2096 sk_alloc+0x38/0x370 net/core/sock.c:2149 bt_sock_alloc+0x3c/0x340 net/bluetooth/af_bluetooth.c:148 hci_sock_create+0xa1/0x190 net/bluetooth/hci_sock.c:2202 bt_sock_create+0x161/0x230 net/bluetooth/af_bluetooth.c:132 __sock_create+0x490/0x920 net/socket.c:1571 sock_create net/socket.c:1622 [inline] __sys_socket_create net/socket.c:1659 [inline] __sys_socket+0x150/0x3c0 net/socket.c:1706 __do_sys_socket net/socket.c:1720 [inline] __se_sys_socket net/socket.c:1718 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1718 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 10210: 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:2252 [inline] slab_free mm/slub.c:4473 [inline] kfree+0x149/0x360 mm/slub.c:4594 sk_prot_free net/core/sock.c:2132 [inline] __sk_destruct+0x479/0x5f0 net/core/sock.c:2224 sock_put include/net/sock.h:1884 [inline] mgmt_pending_free net/bluetooth/mgmt_util.c:307 [inline] mgmt_pending_remove+0x13e/0x1a0 net/bluetooth/mgmt_util.c:315 mgmt_pending_foreach+0xd1/0x130 net/bluetooth/mgmt_util.c:259 mgmt_index_removed+0xe6/0x340 net/bluetooth/mgmt.c:9402 hci_sock_bind+0xcce/0x1150 net/bluetooth/hci_sock.c:1307 __sys_bind_socket net/socket.c:1833 [inline] __sys_bind+0x23d/0x2f0 net/socket.c:1857 __do_sys_bind net/socket.c:1865 [inline] __se_sys_bind net/socket.c:1863 [inline] __x64_sys_bind+0x7a/0x90 net/socket.c:1863 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888062a0a000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 376 bytes inside of freed 2048-byte region [ffff888062a0a000, ffff888062a0a800) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x62a08 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xfdffffff(slab) raw: 00fff00000000040 ffff88801ac42000 ffffea0000a95600 dead000000000002 raw: 0000000000000000 0000000000080008 00000001fdffffff 0000000000000000 head: 00fff00000000040 ffff88801ac42000 ffffea0000a95600 dead000000000002 head: 0000000000000000 0000000000080008 00000001fdffffff 0000000000000000 head: 00fff00000000003 ffffea00018a8201 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5235, tgid 5235 (syz-executor), ts 58768438859, free_ts 15148990809 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1493 prep_new_page mm/page_alloc.c:1501 [inline] get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3439 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4695 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] alloc_slab_page+0x5f/0x120 mm/slub.c:2321 allocate_slab+0x5a/0x2f0 mm/slub.c:2484 new_slab mm/slub.c:2537 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3723 __slab_alloc+0x58/0xa0 mm/slub.c:3813 __slab_alloc_node mm/slub.c:3866 [inline] slab_alloc_node mm/slub.c:4025 [inline] __do_kmalloc_node mm/slub.c:4157 [inline] __kmalloc_node_track_caller_noprof+0x281/0x440 mm/slub.c:4177 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:605 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:674 alloc_skb include/linux/skbuff.h:1320 [inline] nlmsg_new include/net/netlink.h:1015 [inline] inet6_ifinfo_notify+0x72/0x120 net/ipv6/addrconf.c:6162 addrconf_notify+0xc6b/0x1020 net/ipv6/addrconf.c:3763 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93 __dev_notify_flags+0x207/0x400 dev_change_flags+0xf0/0x1a0 net/core/dev.c:8915 do_setlink+0xcd0/0x41f0 net/core/rtnetlink.c:2900 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:1094 [inline] free_unref_page+0xd22/0xea0 mm/page_alloc.c:2612 free_contig_range+0x9e/0x160 mm/page_alloc.c:6660 destroy_args+0x8a/0x890 mm/debug_vm_pgtable.c:1017 debug_vm_pgtable+0x4be/0x550 mm/debug_vm_pgtable.c:1397 do_one_initcall+0x248/0x880 init/main.c:1267 do_initcall_level+0x157/0x210 init/main.c:1329 do_initcalls+0x3f/0x80 init/main.c:1345 kernel_init_freeable+0x435/0x5d0 init/main.c:1578 kernel_init+0x1d/0x2b0 init/main.c:1467 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Memory state around the buggy address: ffff888062a0a000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888062a0a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888062a0a100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888062a0a180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888062a0a200: 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
