================================================================== BUG: KASAN: slab-use-after-free in skb_dst_drop include/net/dst.h:274 [inline] BUG: KASAN: slab-use-after-free in skb_release_head_state+0x283/0x2b0 net/core/skbuff.c:1157 Read of size 8 at addr ffff888026e28a58 by task syz.0.12246/15743 CPU: 1 PID: 15743 Comm: syz.0.12246 Not tainted 6.10.0-rc7-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc3/0x620 mm/kasan/report.c:488 kasan_report+0xd9/0x110 mm/kasan/report.c:601 skb_dst_drop include/net/dst.h:274 [inline] skb_release_head_state+0x283/0x2b0 net/core/skbuff.c:1157 skb_release_all net/core/skbuff.c:1171 [inline] __kfree_skb net/core/skbuff.c:1187 [inline] kfree_skb_reason+0xed/0x210 net/core/skbuff.c:1223 kfree_skb include/linux/skbuff.h:1257 [inline] __hci_req_sync+0x61d/0x980 net/bluetooth/hci_request.c:184 hci_req_sync+0x97/0xd0 net/bluetooth/hci_request.c:206 hci_inquiry+0x3f7/0x970 net/bluetooth/hci_core.c:383 hci_sock_ioctl+0x2bb/0x880 net/bluetooth/hci_sock.c:1153 hci_sock_compat_ioctl net/bluetooth/hci_sock.c:1177 [inline] hci_sock_compat_ioctl+0x68/0x80 net/bluetooth/hci_sock.c:1166 compat_sock_ioctl+0x181/0x7f0 net/socket.c:3522 __do_compat_sys_ioctl+0x2c3/0x330 fs/ioctl.c:1007 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf73e9579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f5cbf57c EFLAGS: 00000292 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 000000000000000b RCX: 00000000800448f0 RDX: 0000000020000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 3522: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:312 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:338 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3940 [inline] slab_alloc_node mm/slub.c:4002 [inline] kmem_cache_alloc_noprof+0x121/0x2f0 mm/slub.c:4009 skb_clone+0x190/0x3f0 net/core/skbuff.c:2052 hci_send_cmd_sync net/bluetooth/hci_core.c:4091 [inline] hci_cmd_work+0x66a/0x710 net/bluetooth/hci_core.c:4111 process_one_work+0x958/0x1ad0 kernel/workqueue.c:3248 process_scheduled_works kernel/workqueue.c:3329 [inline] worker_thread+0x6c8/0xf30 kernel/workqueue.c:3409 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Freed by task 8024: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240 __kasan_slab_free+0x32/0x50 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2196 [inline] slab_free mm/slub.c:4438 [inline] kmem_cache_free+0x12f/0x3a0 mm/slub.c:4513 kfree_skbmem+0x10e/0x200 net/core/skbuff.c:1131 __kfree_skb net/core/skbuff.c:1188 [inline] kfree_skb_reason+0x138/0x210 net/core/skbuff.c:1223 kfree_skb include/linux/skbuff.h:1257 [inline] hci_send_cmd_sync net/bluetooth/hci_core.c:4090 [inline] hci_cmd_work+0x63e/0x710 net/bluetooth/hci_core.c:4111 process_one_work+0x958/0x1ad0 kernel/workqueue.c:3248 process_scheduled_works kernel/workqueue.c:3329 [inline] worker_thread+0x6c8/0xf30 kernel/workqueue.c:3409 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 The buggy address belongs to the object at ffff888026e28a00 which belongs to the cache skbuff_head_cache of size 240 The buggy address is located 88 bytes inside of freed 240-byte region [ffff888026e28a00, ffff888026e28af0) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888026e283c0 pfn:0x26e28 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888011b64401 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffefff(slab) raw: 00fff00000000240 ffff888016f66780 ffffea0000a1d290 ffffea000084ce10 raw: ffff888026e283c0 000000000019000d 00000001ffffefff ffff888011b64401 head: 00fff00000000240 ffff888016f66780 ffffea0000a1d290 ffffea000084ce10 head: ffff888026e283c0 000000000019000d 00000001ffffefff ffff888011b64401 head: 00fff00000000001 ffffea00009b8a01 ffffffffffffffff 0000000000000000 head: 0000000000000002 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0x152820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 6395, tgid 6395 (syz-executor), ts 2674685120275, free_ts 2674677081297 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1473 prep_new_page mm/page_alloc.c:1481 [inline] get_page_from_freelist+0x1353/0x2e50 mm/page_alloc.c:3425 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4683 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] alloc_slab_page+0x56/0x110 mm/slub.c:2265 allocate_slab mm/slub.c:2428 [inline] new_slab+0x84/0x260 mm/slub.c:2481 ___slab_alloc+0xdac/0x1870 mm/slub.c:3667 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3757 __slab_alloc_node mm/slub.c:3810 [inline] slab_alloc_node mm/slub.c:3990 [inline] kmem_cache_alloc_node_noprof+0xed/0x310 mm/slub.c:4045 __alloc_skb+0x2b3/0x380 net/core/skbuff.c:656 alloc_skb include/linux/skbuff.h:1308 [inline] __tcp_send_ack.part.0+0x64/0x720 net/ipv4/tcp_output.c:4247 __tcp_send_ack net/ipv4/tcp_output.c:4279 [inline] tcp_send_ack+0x82/0xa0 net/ipv4/tcp_output.c:4279 __tcp_ack_snd_check+0x188/0xc30 net/ipv4/tcp_input.c:5718 tcp_ack_snd_check net/ipv4/tcp_input.c:5764 [inline] tcp_ack_snd_check net/ipv4/tcp_input.c:5758 [inline] tcp_rcv_established+0x9d4/0x21b0 net/ipv4/tcp_input.c:6204 tcp_v4_do_rcv+0x707/0xab0 net/ipv4/tcp_ipv4.c:1909 tcp_v4_rcv+0x2eb4/0x3c00 net/ipv4/tcp_ipv4.c:2345 ip_protocol_deliver_rcu+0xba/0x4e0 net/ipv4/ip_input.c:205 page last free pid 6395 tgid 6395 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1093 [inline] free_unref_page+0x64a/0xe40 mm/page_alloc.c:2588 mm_free_pgd kernel/fork.c:804 [inline] __mmdrop+0xd5/0x470 kernel/fork.c:920 mmdrop include/linux/sched/mm.h:55 [inline] mmdrop_sched include/linux/sched/mm.h:83 [inline] mmdrop_lazy_tlb_sched include/linux/sched/mm.h:110 [inline] finish_task_switch.isra.0+0x7af/0xcc0 kernel/sched/core.c:5307 context_switch kernel/sched/core.c:5411 [inline] __schedule+0xf1d/0x5d00 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6837 do_nanosleep+0x216/0x510 kernel/time/hrtimer.c:2030 hrtimer_nanosleep+0x1ab/0x440 kernel/time/hrtimer.c:2083 common_nsleep+0xa1/0xd0 kernel/time/posix-timers.c:1350 __do_sys_clock_nanosleep_time32 kernel/time/posix-timers.c:1424 [inline] __se_sys_clock_nanosleep_time32 kernel/time/posix-timers.c:1401 [inline] __ia32_sys_clock_nanosleep_time32+0x334/0x4d0 kernel/time/posix-timers.c:1401 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Memory state around the buggy address: ffff888026e28900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888026e28980: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc >ffff888026e28a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888026e28a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ffff888026e28b00: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi