syzbot


BUG: unable to handle kernel paging request in bpf_probe_read_kernel_str

Status: upstream: reported C repro on 2024/02/05 22:23
Labels: missing-backport
[Documentation on labels]
Reported-by: syzbot+72489cfa4c396c17d343@syzkaller.appspotmail.com
First crash: 215d, last: 39d
Fix bisection: fixed by (bisect log) :
commit e8a67fe34b76a49320b33032228a794f40b0316b
Author: Hou Tao <houtao1@huawei.com>
Date: Fri Feb 2 10:39:34 2024 +0000

  x86/mm: Disallow vsyscall page read for copy_from_kernel_nofault()

  
Bug presence (2)
Date Name Commit Repro Result
2024/08/31 lts (merge base) c52b9710c83d C Didn't crash
2024/08/31 upstream (ToT) 1934261d8974 C Didn't crash
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 BUG: unable to handle kernel paging request in bpf_probe_read_kernel_str origin:upstream C done 1 183d 214d 3/3 fixed on 2024/04/08 12:30
upstream BUG: unable to handle kernel paging request in bpf_probe_read_kernel_str mm C done error 4 197d 213d 0/27 auto-obsoleted due to no activity on 2024/07/13 02:13
android-6-1 BUG: unable to handle kernel paging request in bpf_probe_read_kernel_str missing-backport C inconclusive 3 80d 217d 0/2 upstream: reported C repro on 2024/02/03 06:51
linux-5.15 BUG: unable to handle kernel paging request in bpf_probe_read_kernel_str origin:upstream C done 1 184d 217d 3/3 fixed on 2024/04/08 12:30
Last patch testing requests (3)
Created Duration User Patch Repo Result
2024/08/31 06:29 20m retest repro android13-5.15-lts OK log
2024/06/22 06:17 5m retest repro android13-5.15-lts report log
2024/05/08 01:05 15m retest repro android13-5.15-lts report log
Fix bisection attempts (3)
Created Duration User Patch Repo Result
2024/09/03 12:49 4h07m bisect fix android13-5.15-lts OK (1) job log
2024/07/30 20:09 35m bisect fix android13-5.15-lts OK (0) job log log
2024/06/07 16:05 41m bisect fix android13-5.15-lts OK (0) job log log

Sample crash report:
BUG: unable to handle page fault for address: ffffffffff600000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0001) - permissions violation
PGD 6812067 P4D 6812067 PUD 6814067 PMD 6816067 PTE 8000000006809165
Oops: 0001 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 292 Comm: syz-executor411 Not tainted 5.15.148-syzkaller-00704-g3802b45594e1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
RIP: 0010:strncpy_from_kernel_nofault+0x92/0x1e0 mm/maccess.c:92
Code: d0 48 c1 e8 03 48 89 45 c0 42 0f b6 04 30 84 c0 48 89 55 c8 0f 85 eb 00 00 00 ff 02 45 31 e4 48 8b 55 d0 4c 8b 7d b8 49 89 dd <42> 8a 1c 23 4a 8d 3c 22 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0
RSP: 0018:ffffc900001cf9d8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffffffff600000 RCX: ffff888119814f00
RDX: ffffc900001cfa60 RSI: ffffffffff600000 RDI: ffffffffff600000
RBP: ffffc900001cfa20 R08: ffffffff8135f3ed R09: fffff940008f4b07
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: ffffffffff600000 R14: dffffc0000000000 R15: 0000000000000005
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600000 CR3: 000000011e8c8000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 bpf_probe_read_kernel_str_common kernel/trace/bpf_trace.c:255 [inline]
 ____bpf_probe_read_kernel_str kernel/trace/bpf_trace.c:264 [inline]
 bpf_probe_read_kernel_str+0x2a/0x70 kernel/trace/bpf_trace.c:261
 bpf_prog_ef3a4661c9d1378e+0x42/0xed8
 bpf_dispatcher_nop_func include/linux/bpf.h:785 [inline]
 __bpf_prog_run include/linux/filter.h:625 [inline]
 bpf_prog_run include/linux/filter.h:632 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:1883 [inline]
 bpf_trace_run2+0xec/0x210 kernel/trace/bpf_trace.c:1920
 __bpf_trace_kfree+0x6f/0x90 include/trace/events/kmem.h:118
 trace_kfree include/trace/events/kmem.h:118 [inline]
 kfree+0x1f3/0x220 mm/slub.c:4569
 skb_free_head net/core/skbuff.c:656 [inline]
 skb_release_data+0x8a9/0xa80 net/core/skbuff.c:678
 skb_release_all net/core/skbuff.c:743 [inline]
 __kfree_skb+0x50/0x70 net/core/skbuff.c:757
 sk_wmem_free_skb include/net/sock.h:1634 [inline]
 tcp_rtx_queue_unlink_and_free+0x203/0x720 include/net/tcp.h:1907
 tcp_clean_rtx_queue net/ipv4/tcp_input.c:3343 [inline]
 tcp_ack+0x23e0/0x68a0 net/ipv4/tcp_input.c:3900
 tcp_rcv_established+0xcd6/0x1ac0 net/ipv4/tcp_input.c:5904
 tcp_v4_do_rcv+0x3d7/0xa00 net/ipv4/tcp_ipv4.c:1722
 tcp_v4_rcv+0x23dd/0x2a70 net/ipv4/tcp_ipv4.c:2125
 ip_protocol_deliver_rcu+0x32f/0x710 net/ipv4/ip_input.c:204
 ip_local_deliver_finish net/ipv4/ip_input.c:231 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip_local_deliver+0x2c6/0x590 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:454 [inline]
 ip_sublist_rcv_finish net/ipv4/ip_input.c:577 [inline]
 ip_list_rcv_finish net/ipv4/ip_input.c:628 [inline]
 ip_sublist_rcv+0x7e2/0x980 net/ipv4/ip_input.c:636
 ip_list_rcv+0x422/0x470 net/ipv4/ip_input.c:671
 __netif_receive_skb_list_ptype net/core/dev.c:5535 [inline]
 __netif_receive_skb_list_core+0x6b1/0x890 net/core/dev.c:5583
 __netif_receive_skb_list net/core/dev.c:5635 [inline]
 netif_receive_skb_list_internal+0x967/0xcc0 net/core/dev.c:5726
 gro_normal_list net/core/dev.c:5880 [inline]
 napi_complete_done+0x344/0x770 net/core/dev.c:6618
 virtqueue_napi_complete drivers/net/virtio_net.c:357 [inline]
 virtnet_poll+0xbee/0x1260 drivers/net/virtio_net.c:1592
 __napi_poll+0xc4/0x5a0 net/core/dev.c:7042
 napi_poll net/core/dev.c:7109 [inline]
 net_rx_action+0x47d/0xc50 net/core/dev.c:7196
 __do_softirq+0x26d/0x5bf kernel/softirq.c:565
 invoke_softirq kernel/softirq.c:425 [inline]
 __irq_exit_rcu+0x50/0xf0 kernel/softirq.c:648
 irq_exit_rcu+0x9/0x10 kernel/softirq.c:660
 common_interrupt+0xb4/0xd0 arch/x86/kernel/irq.c:240
 </IRQ>
 <TASK>
 asm_common_interrupt+0x27/0x40 arch/x86/include/asm/idtentry.h:629
RIP: 0010:__tlb_remove_page_size+0x124/0x300 mm/mmu_gather.c:90
Code: ff 74 31 e8 5e 85 c6 ff 43 80 7c 35 00 00 74 08 4c 89 e7 e8 6e 82 08 00 4d 89 3c 24 eb 05 e8 43 85 c6 ff 31 c0 48 83 c4 18 5b <41> 5c 41 5d 41 5e 41 5f 5d c3 48 8b 5d d0 48 83 c3 24 4c 89 f0 49
RSP: 0018:ffffc900009f7830 EFLAGS: 00000286
RAX: 0000000000000000 RBX: ffff88811e4c7970 RCX: ffff888119814f00
RDX: 0000000000000000 RSI: 00000000000001fe RDI: 0000000000000058
RBP: ffffc900009f7850 R08: ffffffff81a98a2e R09: fffff940008c4f6f
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 0000000000000058 R14: dffffc0000000000 R15: ffffea0004627b40
 __tlb_remove_page include/asm-generic/tlb.h:444 [inline]
 zap_pte_range mm/memory.c:1435 [inline]
 zap_pmd_range mm/memory.c:1553 [inline]
 zap_pud_range mm/memory.c:1582 [inline]
 zap_p4d_range mm/memory.c:1603 [inline]
 unmap_page_range+0x120a/0x1ca0 mm/memory.c:1624
 unmap_single_vma mm/memory.c:1669 [inline]
 unmap_vmas+0x389/0x560 mm/memory.c:1701
 exit_mmap+0x3d8/0x6f0 mm/mmap.c:3209
 __mmput+0x95/0x310 kernel/fork.c:1179
 mmput+0x5b/0x170 kernel/fork.c:1202
 exit_mm kernel/exit.c:552 [inline]
 do_exit+0xb9c/0x2ca0 kernel/exit.c:865
 do_group_exit+0x141/0x310 kernel/exit.c:1000
 __do_sys_exit_group kernel/exit.c:1011 [inline]
 __se_sys_exit_group kernel/exit.c:1009 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1009
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f8cebb01c89
Code: Unable to access opcode bytes at RIP 0x7f8cebb01c5f.
RSP: 002b:00007ffddf2c4f58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8cebb01c89
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 00007f8cebb7c290 R08: ffffffffffffffb8 R09: 0000000000000006
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8cebb7c290
R13: 0000000000000000 R14: 00007f8cebb7cce0 R15: 00007f8cebad2ec0
 </TASK>
Modules linked in:
CR2: ffffffffff600000
---[ end trace f24df68aa2dea7ec ]---
RIP: 0010:strncpy_from_kernel_nofault+0x92/0x1e0 mm/maccess.c:92
Code: d0 48 c1 e8 03 48 89 45 c0 42 0f b6 04 30 84 c0 48 89 55 c8 0f 85 eb 00 00 00 ff 02 45 31 e4 48 8b 55 d0 4c 8b 7d b8 49 89 dd <42> 8a 1c 23 4a 8d 3c 22 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0
RSP: 0018:ffffc900001cf9d8 EFLAGS: 00010246

RAX: 0000000000000000 RBX: ffffffffff600000 RCX: ffff888119814f00
RDX: ffffc900001cfa60 RSI: ffffffffff600000 RDI: ffffffffff600000
RBP: ffffc900001cfa20 R08: ffffffff8135f3ed R09: fffff940008f4b07
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: ffffffffff600000 R14: dffffc0000000000 R15: 0000000000000005
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600000 CR3: 000000011e8c8000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	d0 48 c1             	rorb   -0x3f(%rax)
   3:	e8 03 48 89 45       	call   0x4589480b
   8:	c0 42 0f b6          	rolb   $0xb6,0xf(%rdx)
   c:	04 30                	add    $0x30,%al
   e:	84 c0                	test   %al,%al
  10:	48 89 55 c8          	mov    %rdx,-0x38(%rbp)
  14:	0f 85 eb 00 00 00    	jne    0x105
  1a:	ff 02                	incl   (%rdx)
  1c:	45 31 e4             	xor    %r12d,%r12d
  1f:	48 8b 55 d0          	mov    -0x30(%rbp),%rdx
  23:	4c 8b 7d b8          	mov    -0x48(%rbp),%r15
  27:	49 89 dd             	mov    %rbx,%r13
* 2a:	42 8a 1c 23          	mov    (%rbx,%r12,1),%bl <-- trapping instruction
  2e:	4a 8d 3c 22          	lea    (%rdx,%r12,1),%rdi
  32:	48 89 f8             	mov    %rdi,%rax
  35:	48 c1 e8 03          	shr    $0x3,%rax
  39:	42 0f b6 04 30       	movzbl (%rax,%r14,1),%eax
  3e:	84 c0                	test   %al,%al

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/02/13 23:54 android13-5.15-lts 3802b45594e1 e66542d7 .config strace log report syz C [disk image] [vmlinux] [kernel image] ci2-android-5-15 BUG: unable to handle kernel paging request in bpf_probe_read_kernel_str
2024/02/05 22:22 android13-5.15-lts 3802b45594e1 e23e8c20 .config strace log report syz C [disk image] [vmlinux] [kernel image] ci2-android-5-15-perf BUG: unable to handle kernel paging request in bpf_probe_read_kernel_str
* Struck through repros no longer work on HEAD.