syzbot


KASAN: use-after-free Read in receive_buf (2)

Status: auto-obsoleted due to no activity on 2023/09/20 11:49
Subsystems: net virt
[Documentation on labels]
First crash: 368d, last: 368d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in receive_buf kernel 1 452d 452d 0/26 closed as invalid on 2023/02/08 20:19
upstream general protection fault in receive_buf net virt 2 1098d 1105d 0/26 auto-closed as invalid on 2021/07/03 00:24

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in receive_mergeable drivers/net/virtio_net.c:1179 [inline]
BUG: KASAN: use-after-free in receive_buf+0x3bc1/0x53c0 drivers/net/virtio_net.c:1479
Read of size 2 at addr ffff888078e7f80a by task syz-executor.5/5026

CPU: 1 PID: 5026 Comm: syz-executor.5 Not tainted 6.3.0-syzkaller-12570-g7df047b3f0aa #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:351 [inline]
 print_report+0x163/0x540 mm/kasan/report.c:462
 kasan_report+0x176/0x1b0 mm/kasan/report.c:572
 receive_mergeable drivers/net/virtio_net.c:1179 [inline]
 receive_buf+0x3bc1/0x53c0 drivers/net/virtio_net.c:1479
 virtnet_receive drivers/net/virtio_net.c:1777 [inline]
 virtnet_poll+0x6d7/0x1470 drivers/net/virtio_net.c:1849
 __napi_poll+0xc7/0x470 net/core/dev.c:6496
 napi_poll net/core/dev.c:6563 [inline]
 net_rx_action+0x78b/0x1010 net/core/dev.c:6696
 __do_softirq+0x2ab/0x908 kernel/softirq.c:571
 invoke_softirq kernel/softirq.c:445 [inline]
 __irq_exit_rcu+0x159/0x240 kernel/softirq.c:650
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:662
 common_interrupt+0xa8/0xc0 arch/x86/kernel/irq.c:240
 </IRQ>
 <TASK>
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:636
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194
Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 ce 9f 2a f7 f6 44 24 21 02 75 4e 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 03 57 a6 f6 65 8b 05 e4 fc 4a 75 85 c0 74 3f 48 c7 04 24 0e 36
RSP: 0018:ffffc90003c3fba0 EFLAGS: 00000206
RAX: 19dc682d1134ec00 RBX: 1ffff92000787f78 RCX: ffffffff91b21103
RDX: dffffc0000000000 RSI: ffffffff8aea8ea0 RDI: 0000000000000001
RBP: ffffc90003c3fc30 R08: dffffc0000000000 R09: fffffbfff1cab886
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff92000787f74 R14: ffffc90003c3fbc0 R15: 0000000000000246
 hrtimer_start_expires include/linux/hrtimer.h:432 [inline]
 hrtimer_sleeper_start_expires kernel/time/hrtimer.c:1965 [inline]
 do_nanosleep+0x14c/0x610 kernel/time/hrtimer.c:2041
 hrtimer_nanosleep+0x226/0x460 kernel/time/hrtimer.c:2097
 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1281 [inline]
 __se_sys_clock_nanosleep+0x327/0x3b0 kernel/time/posix-timers.c:1258
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f95772b0e91
Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 aa e7 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 e3 e7 ff ff 48 8b 04 24 eb 97 66 2e 0f 1f
RSP: 002b:00007ffc89876e40 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 0000000000000949 RCX: 00007f95772b0e91
RDX: 00007ffc89876e80 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffc89876f0c R08: 0000000000000000 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032
R13: 0000000000188bab R14: 0000000000000000 R15: 00007ffc89876f70
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0001e39fc0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x78e7f
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x152820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 32016, tgid 32015 (syz-executor.4), ts 1418479499659, free_ts 1609310758961
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1722
 prep_new_page mm/page_alloc.c:1729 [inline]
 get_page_from_freelist+0x321c/0x33a0 mm/page_alloc.c:3493
 __alloc_pages+0x255/0x670 mm/page_alloc.c:4759
 skb_page_frag_refill+0x158/0x2f0 net/core/sock.c:2854
 add_recvbuf_mergeable drivers/net/virtio_net.c:1631 [inline]
 try_fill_recv+0x550/0x1880 drivers/net/virtio_net.c:1675
 virtnet_receive drivers/net/virtio_net.c:1789 [inline]
 virtnet_poll+0x8fb/0x1470 drivers/net/virtio_net.c:1849
 __napi_poll+0xc7/0x470 net/core/dev.c:6496
 napi_poll net/core/dev.c:6563 [inline]
 net_rx_action+0x78b/0x1010 net/core/dev.c:6696
 __do_softirq+0x2ab/0x908 kernel/softirq.c:571
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1302 [inline]
 free_unref_page_prepare+0x903/0xa30 mm/page_alloc.c:2555
 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2650
 page_to_skb+0x3dc/0x9a0 drivers/net/virtio_net.c:545
 receive_mergeable drivers/net/virtio_net.c:1344 [inline]
 receive_buf+0x465/0x53c0 drivers/net/virtio_net.c:1479
 virtnet_receive drivers/net/virtio_net.c:1777 [inline]
 virtnet_poll+0x6d7/0x1470 drivers/net/virtio_net.c:1849
 __napi_poll+0xc7/0x470 net/core/dev.c:6496
 napi_poll net/core/dev.c:6563 [inline]
 net_rx_action+0x78b/0x1010 net/core/dev.c:6696
 __do_softirq+0x2ab/0x908 kernel/softirq.c:571

Memory state around the buggy address:
 ffff888078e7f700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888078e7f780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888078e7f800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                      ^
 ffff888078e7f880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888078e7f900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
----------------
Code disassembly (best guess):
   0:	9c                   	pushfq
   1:	8f 44 24 20          	popq   0x20(%rsp)
   5:	42 80 3c 23 00       	cmpb   $0x0,(%rbx,%r12,1)
   a:	74 08                	je     0x14
   c:	4c 89 f7             	mov    %r14,%rdi
   f:	e8 ce 9f 2a f7       	callq  0xf72a9fe2
  14:	f6 44 24 21 02       	testb  $0x2,0x21(%rsp)
  19:	75 4e                	jne    0x69
  1b:	41 f7 c7 00 02 00 00 	test   $0x200,%r15d
  22:	74 01                	je     0x25
  24:	fb                   	sti
  25:	bf 01 00 00 00       	mov    $0x1,%edi
* 2a:	e8 03 57 a6 f6       	callq  0xf6a65732 <-- trapping instruction
  2f:	65 8b 05 e4 fc 4a 75 	mov    %gs:0x754afce4(%rip),%eax        # 0x754afd1a
  36:	85 c0                	test   %eax,%eax
  38:	74 3f                	je     0x79
  3a:	48                   	rex.W
  3b:	c7                   	.byte 0xc7
  3c:	04 24                	add    $0x24,%al
  3e:	0e                   	(bad)
  3f:	36                   	ss

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/05/03 10:33 upstream 7df047b3f0aa 48e0a81d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: use-after-free Read in receive_buf
* Struck through repros no longer work on HEAD.