syzbot


BUG: unable to handle kernel paging request in bpf_probe_read_compat_str

Status: upstream: reported C repro on 2024/01/22 23:41
Bug presence: origin:upstream
Labels: missing-backport
[Documentation on labels]
Reported-by: syzbot+3b4268501e3bacda8434@syzkaller.appspotmail.com
First crash: 121d, last: 76d
Fix commit to backport (bisect log) :
tree: upstream
commit 32019c659ecfe1d92e3bf9fcdfbb11a7c70acd58
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()

  
Fix bisection: the issue occurs on the latest tested release (bisect log)
Crash: BUG: unable to handle kernel paging request in bpf_probe_read_compat_str (log)
Repro: C syz .config
  
Bug presence (3)
Date Name Commit Repro Result
2024/03/08 linux-5.15.y (ToT) 574362648507 C [report] BUG: unable to handle kernel paging request in bpf_probe_read_compat_str
2024/01/23 upstream (ToT) 7ed2632ec7d7 C [report] BUG: unable to handle kernel paging request in bpf_probe_read_compat_str
2024/03/08 upstream (ToT) 3aaa8ce7a335 C Didn't crash
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream BUG: unable to handle kernel paging request in bpf_probe_read_compat_str mm C done 4 93d 117d 0/26 upstream: reported C repro on 2024/01/27 00:25
android-5-15 BUG: unable to handle kernel paging request in bpf_probe_read_compat_str origin:upstream missing-backport C 2 11d 121d 0/2 upstream: reported C repro on 2024/01/23 03:08
android-6-1 BUG: unable to handle kernel paging request in bpf_probe_read_compat_str origin:upstream missing-backport C error 3 31d 122d 0/2 upstream: reported C repro on 2024/01/22 23:16
linux-6.1 BUG: unable to handle kernel paging request in bpf_probe_read_compat_str origin:upstream missing-backport C done 1 76d 121d 0/3 upstream: reported C repro on 2024/01/23 14:36
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2024/03/18 03:38 4h11m fix candidate upstream job log (1)
2024/02/22 00:16 1h08m bisect fix linux-5.15.y job log (0) 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 c691067 P4D c691067 PUD c693067 PMD c6b6067 PTE 800000000c609165
Oops: 0001 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 3501 Comm: syz-executor352 Not tainted 5.15.147-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
RIP: 0010:strncpy_from_kernel_nofault+0x89/0x1c0 mm/maccess.c:92
Code: 00 48 89 d0 48 c1 e8 03 48 89 44 24 10 0f b6 04 28 84 c0 48 89 14 24 0f 85 d5 00 00 00 ff 02 45 31 f6 49 89 df 48 8b 54 24 08 <42> 8a 1c 33 4a 8d 3c 32 48 89 f8 48 c1 e8 03 49 89 ec 0f b6 04 28
RSP: 0018:ffffc90002de7898 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffffffffff600000 RCX: ffff88807d679dc0
RDX: ffffc90002de7928 RSI: ffffffffff600000 RDI: ffffffffff600000
RBP: dffffc0000000000 R08: ffffffff8139a0b9 R09: ffffed100facf3b9
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffffff600000
R13: 0000000000000008 R14: 0000000000000000 R15: ffffffffff600000
FS:  00005555571a3380(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600000 CR3: 000000001952b000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 bpf_probe_read_kernel_str_common kernel/trace/bpf_trace.c:255 [inline]
 ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:303 [inline]
 bpf_probe_read_compat_str+0x10a/0x180 kernel/trace/bpf_trace.c:296
 bpf_prog_f17ebaf3f5f7baf8+0x3a/0x624
 bpf_dispatcher_nop_func include/linux/bpf.h:776 [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_run3+0x1d1/0x380 kernel/trace/bpf_trace.c:1921
 trace_sched_switch include/trace/events/sched.h:220 [inline]
 __schedule+0x1e8d/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6459
 freezable_schedule include/linux/freezer.h:172 [inline]
 do_nanosleep+0x1bc/0x7b0 kernel/time/hrtimer.c:2044
 hrtimer_nanosleep+0x24d/0x490 kernel/time/hrtimer.c:2097
 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1308 [inline]
 __se_sys_clock_nanosleep+0x323/0x3b0 kernel/time/posix-timers.c:1285
 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: 0033:0x7f5f564a1473
Code: 00 00 00 00 0f 1f 00 83 ff 03 74 7b 83 ff 02 b8 fa ff ff ff 49 89 ca 0f 44 f8 80 3d ee db 03 00 00 74 14 b8 e6 00 00 00 0f 05 <f7> d8 c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec 28 48 89 54 24 10
RSP: 002b:00007fff1abcc248 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 0000000000000dae RCX: 00007f5f564a1473
RDX: 00007fff1abcc260 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 000000000000a11e R08: 00007fff1abeb0b0 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff1abcc29c
R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001
 </TASK>
Modules linked in:
CR2: ffffffffff600000
---[ end trace d0f7278ca5dae17e ]---
RIP: 0010:strncpy_from_kernel_nofault+0x89/0x1c0 mm/maccess.c:92
Code: 00 48 89 d0 48 c1 e8 03 48 89 44 24 10 0f b6 04 28 84 c0 48 89 14 24 0f 85 d5 00 00 00 ff 02 45 31 f6 49 89 df 48 8b 54 24 08 <42> 8a 1c 33 4a 8d 3c 32 48 89 f8 48 c1 e8 03 49 89 ec 0f b6 04 28
RSP: 0018:ffffc90002de7898 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffffffffff600000 RCX: ffff88807d679dc0
RDX: ffffc90002de7928 RSI: ffffffffff600000 RDI: ffffffffff600000
RBP: dffffc0000000000 R08: ffffffff8139a0b9 R09: ffffed100facf3b9
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffffff600000
R13: 0000000000000008 R14: 0000000000000000 R15: ffffffffff600000
FS:  00005555571a3380(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600000 CR3: 000000001952b000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	00 48 89             	add    %cl,-0x77(%rax)
   3:	d0 48 c1             	rorb   -0x3f(%rax)
   6:	e8 03 48 89 44       	call   0x4489480e
   b:	24 10                	and    $0x10,%al
   d:	0f b6 04 28          	movzbl (%rax,%rbp,1),%eax
  11:	84 c0                	test   %al,%al
  13:	48 89 14 24          	mov    %rdx,(%rsp)
  17:	0f 85 d5 00 00 00    	jne    0xf2
  1d:	ff 02                	incl   (%rdx)
  1f:	45 31 f6             	xor    %r14d,%r14d
  22:	49 89 df             	mov    %rbx,%r15
  25:	48 8b 54 24 08       	mov    0x8(%rsp),%rdx
* 2a:	42 8a 1c 33          	mov    (%rbx,%r14,1),%bl <-- trapping instruction
  2e:	4a 8d 3c 32          	lea    (%rdx,%r14,1),%rdi
  32:	48 89 f8             	mov    %rdi,%rax
  35:	48 c1 e8 03          	shr    $0x3,%rax
  39:	49 89 ec             	mov    %rbp,%r12
  3c:	0f b6 04 28          	movzbl (%rax,%rbp,1),%eax

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/01/22 23:40 linux-5.15.y ddcaf4999061 9bd8dcda .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf BUG: unable to handle kernel paging request in bpf_probe_read_compat_str
* Struck through repros no longer work on HEAD.