================================================================== 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 ffff88823bd9ec79 by task syz-executor.0/17110 CPU: 0 PID: 17110 Comm: syz-executor.0 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 skb_queue_purge+0x14/0x30 net/core/skbuff.c:3086 packet_release+0x75f/0xc90 net/packet/af_packet.c:3102 __sock_release+0xcd/0x280 net/socket.c:597 sock_close+0x18/0x20 net/socket.c:1256 __fput+0x283/0x920 fs/file_table.c:280 task_work_run+0xdd/0x190 kernel/task_work.c:140 exit_task_work include/linux/task_work.h:30 [inline] do_exit+0xb89/0x29e0 kernel/exit.c:823 do_group_exit+0x125/0x310 kernel/exit.c:920 get_signal+0x3ec/0x2010 kernel/signal.c:2770 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811 handle_signal_work kernel/entry/common.c:147 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:201 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:315 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628 RIP: 0033:0x412dbe Code: Unable to access opcode bytes at RIP 0x412d94. RSP: 002b:00007fff73e5b520 EFLAGS: 00000246 RAX: ffffffff81784541 RBX: 0000000000000001 RCX: 0000001b2ce20000 RDX: 000000000003d3ff RSI: 0000000080000000 RDI: 00000000bad16b48 RBP: 000000000119c008 R08: 0000000000000b48 R09: 00000000bad16b4c R10: 00007fff73e5b6c0 R11: 0000000000000000 R12: 00007fe633ade008 R13: 000000000003d3ff R14: 00007fe633ade000 R15: ffffffff81784551 Allocated by task 0: (stack is not available) The buggy address belongs to the object at ffff88823bd9e000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1145 bytes to the right of 2048-byte region [ffff88823bd9e000, ffff88823bd9e800) The buggy address belongs to the page: page:000000002620cd79 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x23bd9e flags: 0x57ff00000001200(slab|reserved) raw: 057ff00000001200 ffffea0008ef6788 ffffea0008ef6788 ffff888010042000 raw: 0000000000000000 0000000000010000 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88823bd9eb00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88823bd9eb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88823bd9ec00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 ^ ffff88823bd9ec80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88823bd9ed00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================