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KASAN: use-after-free Write in enqueue_to_backlog

Status: auto-closed as invalid on 2022/05/13 14:52
Reported-by: syzbot+941415ca86f17e8785c0@syzkaller.appspotmail.com
First crash: 845d, last: 845d
▶ ▼ Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in enqueue_to_backlog net 6 627d 738d 0/26 closed as invalid on 2022/11/15 21:20

Sample crash report:
new mount options do not match the existing superblock, will be ignored
IPVS: ftp: loaded support on port[0] = 21
==================================================================
BUG: KASAN: use-after-free in __write_once_size include/linux/compiler.h:290 [inline]
BUG: KASAN: use-after-free in __skb_insert include/linux/skbuff.h:1763 [inline]
BUG: KASAN: use-after-free in __skb_queue_before include/linux/skbuff.h:1869 [inline]
BUG: KASAN: use-after-free in __skb_queue_tail include/linux/skbuff.h:1903 [inline]
BUG: KASAN: use-after-free in enqueue_to_backlog+0xddc/0xe00 net/core/dev.c:4239
Write of size 8 at addr ffff88802003c080 by task syz-executor.2/7489

CPU: 1 PID: 7489 Comm: syz-executor.2 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_store8_noabort+0x88/0x90 mm/kasan/report.c:438
 __write_once_size include/linux/compiler.h:290 [inline]
 __skb_insert include/linux/skbuff.h:1763 [inline]
 __skb_queue_before include/linux/skbuff.h:1869 [inline]
 __skb_queue_tail include/linux/skbuff.h:1903 [inline]
 enqueue_to_backlog+0xddc/0xe00 net/core/dev.c:4239
 netif_rx_internal+0xfd/0x670 net/core/dev.c:4491
 veth_forward_skb drivers/net/veth.c:176 [inline]
 veth_xmit+0x1eb/0x800 drivers/net/veth.c:203
 __netdev_start_xmit include/linux/netdevice.h:4349 [inline]
 netdev_start_xmit include/linux/netdevice.h:4363 [inline]
 xmit_one net/core/dev.c:3256 [inline]
 dev_hard_start_xmit+0x1a8/0x920 net/core/dev.c:3272
 __dev_queue_xmit+0x269d/0x2e00 net/core/dev.c:3838
 macvlan_queue_xmit drivers/net/macvlan.c:545 [inline]
 macvlan_start_xmit+0x19a/0x7e0 drivers/net/macvlan.c:570
 __netdev_start_xmit include/linux/netdevice.h:4349 [inline]
 netdev_start_xmit include/linux/netdevice.h:4363 [inline]
 xmit_one net/core/dev.c:3256 [inline]
 dev_hard_start_xmit+0x1a8/0x920 net/core/dev.c:3272
 __dev_queue_xmit+0x269d/0x2e00 net/core/dev.c:3838
 neigh_hh_output include/net/neighbour.h:491 [inline]
 neigh_output include/net/neighbour.h:499 [inline]
 ip_finish_output2+0xb6d/0x15a0 net/ipv4/ip_output.c:230
 ip_finish_output+0xae9/0x10b0 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip_mc_output+0x268/0xec0 net/ipv4/ip_output.c:391
 dst_output include/net/dst.h:455 [inline]
 ip_local_out+0xaf/0x170 net/ipv4/ip_output.c:125
 ip_send_skb+0x3e/0xe0 net/ipv4/ip_output.c:1452
 udp_send_skb+0x6a4/0x1170 net/ipv4/udp.c:848
 udp_sendmsg+0x1cb4/0x2550 net/ipv4/udp.c:1135
 inet_sendmsg+0x132/0x5a0 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xc3/0x120 net/socket.c:661
 ___sys_sendmsg+0x3b3/0x8e0 net/socket.c:2227
 __sys_sendmmsg+0x195/0x470 net/socket.c:2322
 __do_sys_sendmmsg net/socket.c:2351 [inline]
 __se_sys_sendmmsg net/socket.c:2348 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2348
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fccaeab5eb9
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fccad40a168 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fccaebc9030 RCX: 00007fccaeab5eb9
RDX: 04000000000000a8 RSI: 00000000200038c0 RDI: 0000000000000004
RBP: 00007fccaeb1008d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff1181411f R14: 00007fccad40a300 R15: 0000000000022000

Allocated by task 7489:
 kmem_cache_alloc+0x122/0x370 mm/slab.c:3559
 skb_clone+0x151/0x3d0 net/core/skbuff.c:1293
 dev_queue_xmit_nit+0x326/0xa20 net/core/dev.c:2018
 xmit_one net/core/dev.c:3252 [inline]
 dev_hard_start_xmit+0xaa/0x920 net/core/dev.c:3272
 __dev_queue_xmit+0x269d/0x2e00 net/core/dev.c:3838
 macvlan_queue_xmit drivers/net/macvlan.c:545 [inline]
 macvlan_start_xmit+0x19a/0x7e0 drivers/net/macvlan.c:570
 __netdev_start_xmit include/linux/netdevice.h:4349 [inline]
 netdev_start_xmit include/linux/netdevice.h:4363 [inline]
 xmit_one net/core/dev.c:3256 [inline]
 dev_hard_start_xmit+0x1a8/0x920 net/core/dev.c:3272
 __dev_queue_xmit+0x269d/0x2e00 net/core/dev.c:3838
 neigh_hh_output include/net/neighbour.h:491 [inline]
 neigh_output include/net/neighbour.h:499 [inline]
 ip_finish_output2+0xb6d/0x15a0 net/ipv4/ip_output.c:230
 ip_finish_output+0xae9/0x10b0 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip_mc_output+0x268/0xec0 net/ipv4/ip_output.c:391
 dst_output include/net/dst.h:455 [inline]
 ip_local_out+0xaf/0x170 net/ipv4/ip_output.c:125
 ip_send_skb+0x3e/0xe0 net/ipv4/ip_output.c:1452
 udp_send_skb+0x6a4/0x1170 net/ipv4/udp.c:848
 udp_sendmsg+0x1cb4/0x2550 net/ipv4/udp.c:1135
 inet_sendmsg+0x132/0x5a0 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xc3/0x120 net/socket.c:661
 ___sys_sendmsg+0x3b3/0x8e0 net/socket.c:2227
 __sys_sendmmsg+0x195/0x470 net/socket.c:2322
 __do_sys_sendmmsg net/socket.c:2351 [inline]
 __se_sys_sendmmsg net/socket.c:2348 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2348
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 7489:
 __cache_free mm/slab.c:3503 [inline]
 kmem_cache_free+0x7f/0x260 mm/slab.c:3765
 kfree_skbmem+0xc1/0x140 net/core/skbuff.c:595
 __kfree_skb net/core/skbuff.c:655 [inline]
 consume_skb+0x120/0x3d0 net/core/skbuff.c:714
 packet_rcv+0xea/0x1490 net/packet/af_packet.c:2148
 dev_queue_xmit_nit+0x756/0xa20 net/core/dev.c:2050
 xmit_one net/core/dev.c:3252 [inline]
 dev_hard_start_xmit+0xaa/0x920 net/core/dev.c:3272
 __dev_queue_xmit+0x269d/0x2e00 net/core/dev.c:3838
 macvlan_queue_xmit drivers/net/macvlan.c:545 [inline]
 macvlan_start_xmit+0x19a/0x7e0 drivers/net/macvlan.c:570
 __netdev_start_xmit include/linux/netdevice.h:4349 [inline]
 netdev_start_xmit include/linux/netdevice.h:4363 [inline]
 xmit_one net/core/dev.c:3256 [inline]
 dev_hard_start_xmit+0x1a8/0x920 net/core/dev.c:3272
 __dev_queue_xmit+0x269d/0x2e00 net/core/dev.c:3838
 neigh_hh_output include/net/neighbour.h:491 [inline]
 neigh_output include/net/neighbour.h:499 [inline]
 ip_finish_output2+0xb6d/0x15a0 net/ipv4/ip_output.c:230
 ip_finish_output+0xae9/0x10b0 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip_mc_output+0x268/0xec0 net/ipv4/ip_output.c:391
 dst_output include/net/dst.h:455 [inline]
 ip_local_out+0xaf/0x170 net/ipv4/ip_output.c:125
 ip_send_skb+0x3e/0xe0 net/ipv4/ip_output.c:1452
 udp_send_skb+0x6a4/0x1170 net/ipv4/udp.c:848
 udp_sendmsg+0x1cb4/0x2550 net/ipv4/udp.c:1135
 inet_sendmsg+0x132/0x5a0 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xc3/0x120 net/socket.c:661
 ___sys_sendmsg+0x3b3/0x8e0 net/socket.c:2227
 __sys_sendmmsg+0x195/0x470 net/socket.c:2322
 __do_sys_sendmmsg net/socket.c:2351 [inline]
 __se_sys_sendmmsg net/socket.c:2348 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2348
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88802003c080
 which belongs to the cache skbuff_head_cache of size 232
The buggy address is located 0 bytes inside of
 232-byte region [ffff88802003c080, ffff88802003c168)
The buggy address belongs to the page:
page:ffffea0000800f00 count:1 mapcount:0 mapping:ffff8880b5b8fd80 index:0x0
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffffea00028cbb08 ffffea00006c9b08 ffff8880b5b8fd80
raw: 0000000000000000 ffff88802003c080 000000010000000c 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88802003bf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88802003c000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802003c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88802003c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc
 ffff88802003c180: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/01/13 14:51 linux-4.19.y 3f8a27f9e27b 44d1319a .config console log report info ci2-linux-4-19 KASAN: use-after-free Write in enqueue_to_backlog
* Struck through repros no longer work on HEAD.