================================================================== BUG: KASAN: out-of-bounds in check_canary_byte mm/kfence/core.c:211 [inline] BUG: KASAN: out-of-bounds in for_each_canary mm/kfence/core.c:245 [inline] BUG: KASAN: out-of-bounds in kfence_guarded_free+0x7f1/0x8f0 mm/kfence/core.c:374 Read of size 1 at addr ffff88823bc10c51 by task syz-executor.3/28409 CPU: 0 PID: 28409 Comm: syz-executor.3 Not tainted 5.10.0-next-20201223-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:230 __kasan_report mm/kasan/report.c:396 [inline] kasan_report.cold+0x79/0xd5 mm/kasan/report.c:413 check_canary_byte mm/kfence/core.c:211 [inline] for_each_canary mm/kfence/core.c:245 [inline] kfence_guarded_free+0x7f1/0x8f0 mm/kfence/core.c:374 __kfence_free+0x70/0x150 mm/kfence/core.c:756 do_slab_free mm/slub.c:3145 [inline] slab_free mm/slub.c:3158 [inline] kfree+0x57c/0x5c0 mm/slub.c:4156 skb_free_head net/core/skbuff.c:595 [inline] skb_release_data+0x6d9/0x910 net/core/skbuff.c:615 skb_release_all net/core/skbuff.c:669 [inline] __kfree_skb net/core/skbuff.c:683 [inline] kfree_skb net/core/skbuff.c:701 [inline] kfree_skb+0x133/0x3f0 net/core/skbuff.c:695 vti6_tnl_xmit+0xbb9/0x1cd0 net/ipv6/ip6_vti.c:595 __netdev_start_xmit include/linux/netdevice.h:4776 [inline] netdev_start_xmit include/linux/netdevice.h:4790 [inline] xmit_one net/core/dev.c:3574 [inline] dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3590 __dev_queue_xmit+0x21db/0x2dd0 net/core/dev.c:4151 __bpf_tx_skb net/core/filter.c:2116 [inline] __bpf_redirect_no_mac net/core/filter.c:2141 [inline] __bpf_redirect+0x52e/0xc60 net/core/filter.c:2164 ____bpf_clone_redirect net/core/filter.c:2448 [inline] bpf_clone_redirect+0x2ae/0x420 net/core/filter.c:2420 bpf_prog_5e3b4e18def6d727+0x56/0x4c0 bpf_dispatcher_nop_func include/linux/bpf.h:651 [inline] bpf_test_run+0x3f2/0xcc0 net/bpf/test_run.c:50 bpf_prog_test_run_skb+0xabc/0x1c50 net/bpf/test_run.c:581 bpf_prog_test_run kernel/bpf/syscall.c:3120 [inline] __do_sys_bpf+0x1ea9/0x4f10 kernel/bpf/syscall.c:4398 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e229 Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fd7f9145c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045e229 RDX: 0000000000000028 RSI: 0000000020000080 RDI: 000000000000000a RBP: 000000000119bfc0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007ffc9860616f R14: 00007fd7f91469c0 R15: 000000000119bf8c Allocated by task 0: (stack is not available) The buggy address belongs to the object at ffff88823bc10000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1105 bytes to the right of 2048-byte region [ffff88823bc10000, ffff88823bc10800) The buggy address belongs to the page: page:000000006bba1c17 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x23bc10 flags: 0x57ff00000001200(slab|reserved) raw: 057ff00000001200 ffffea0008ef0408 ffffea0008ef0408 ffff888010042000 raw: 0000000000000000 0000000000010000 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88823bc10b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88823bc10b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88823bc10c00: 00 00 00 00 00 00 00 00 00 00 01 00 00 00 00 00 ^ ffff88823bc10c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88823bc10d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================