Subject: Re: [syzbot] [bpf?] [net?] general protection fault in __cpu_map_flush

From: syzbot <[email-masked]>
Date: Wed, 24 Jul 2024 04:45:19 -0700

syzbot has found a reproducer for the following issue on:

HEAD commit:    9ec6ec93f2c1 Add linux-next specific files for 20240724
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=10e71ca1980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=83e9d0906fa0e2bd
dashboard link: https://syzkaller.appspot.com/bug?extid=c226757eb784a9da3e8b
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17c0f8e3980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=151b9919980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c0ab2da24b1f/disk-9ec6ec93.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/da6faf16185f/vmlinux-9ec6ec93.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1ad900571155/bzImage-9ec6ec93.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]

Oops: general protection fault, probably for non-canonical address 0xe3fffb24002e6fe6: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: maybe wild-memory-access in range [0x1ffff92001737f30-0x1ffff92001737f37]
CPU: 1 UID: 0 PID: 11878 Comm: syz-executor412 Not tainted 6.10.0-next-20240724-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
RIP: 0010:__cpu_map_flush+0x42/0xd0
Code: e8 13 8c d6 ff 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 4d 12 3e 00 49 8b 1e 4c 39 f3 74 77 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 2f 12 3e 00 4c 8b 23 48 8d 7b c0
RSP: 0018:ffffc90000a18b10 EFLAGS: 00010202
RAX: 03ffff24002e6fe6 RBX: 1ffff92001737f30 RCX: ffff888074dc8000
RDX: 0000000080000101 RSI: 0000000000000010 RDI: ffffc9000b9bf800
RBP: dffffc0000000000 R08: ffffffff896d3b5a R09: 1ffffffff1f5f375
R10: dffffc0000000000 R11: fffffbfff1f5f376 R12: ffffc9000b9bf800
R13: ffffc9000b9bf820 R14: ffffc9000b9bf800 R15: dffffc0000000000
FS:  0000555592677380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd44da640f0 CR3: 000000001ea68000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 xdp_do_check_flushed+0x136/0x240 net/core/filter.c:4304
 __napi_poll+0xe4/0x490 net/core/dev.c:6774
 napi_poll net/core/dev.c:6840 [inline]
 net_rx_action+0x89b/0x1240 net/core/dev.c:6962
 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
 __do_softirq kernel/softirq.c:588 [inline]
 invoke_softirq kernel/softirq.c:428 [inline]
 __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649
 common_interrupt+0xaa/0xd0 arch/x86/kernel/irq.c:278
 </IRQ>
 <TASK>
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
RIP: 0010:check_kcov_mode kernel/kcov.c:184 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x70 kernel/kcov.c:207
Code: 40 d7 03 00 65 8b 15 10 0c 70 7e f7 c2 00 01 ff 00 74 11 f7 c2 00 01 00 00 74 35 83 b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 <83> fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc
RSP: 0018:ffffc9000b9bf8a0 EFLAGS: 00000246
RAX: ffffffff81410dcc RBX: 0000000000000000 RCX: ffff888074dc8000
RDX: 0000000000000000 RSI: ffffffff8b942412 RDI: ffffffff8b942328
RBP: 1ffff92001737f30 R08: ffffffff81410c60 R09: ffffc9000b9bfa70
R10: 0000000000000003 R11: ffffffff817f7030 R12: ffffffff90294810
R13: dffffc0000000000 R14: 1ffff92001737f30 R15: ffffffff90d0fbd4
 unwind_next_frame+0x67c/0x2a00 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x151/0x1b0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240
 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2252 [inline]
 slab_free mm/slub.c:4473 [inline]
 kmem_cache_free+0x145/0x350 mm/slub.c:4548
 __dentry_kill+0x497/0x630 fs/dcache.c:629
 dput+0x19f/0x2b0 fs/dcache.c:852
 __fput+0x5f8/0x8a0 fs/file_table.c:430
 __do_sys_close fs/open.c:1566 [inline]
 __se_sys_close fs/open.c:1551 [inline]
 __x64_sys_close+0x7f/0x110 fs/open.c:1551
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd44d9ed9c0
Code: ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 80 3d e1 76 07 00 00 74 17 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c
RSP: 002b:00007fff7a1e95b8 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fd44d9ed9c0
RDX: 0000000000000e80 RSI: 0000000020000100 RDI: 0000000000000004
RBP: 00007fff7a1e9600 R08: 00007fff7a1e95e0 R09: 00007fff7a1e95e0
R10: 00007fff7a1e95e0 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__cpu_map_flush+0x42/0xd0
Code: e8 13 8c d6 ff 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 4d 12 3e 00 49 8b 1e 4c 39 f3 74 77 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 2f 12 3e 00 4c 8b 23 48 8d 7b c0
RSP: 0018:ffffc90000a18b10 EFLAGS: 00010202
RAX: 03ffff24002e6fe6 RBX: 1ffff92001737f30 RCX: ffff888074dc8000
RDX: 0000000080000101 RSI: 0000000000000010 RDI: ffffc9000b9bf800
RBP: dffffc0000000000 R08: ffffffff896d3b5a R09: 1ffffffff1f5f375
R10: dffffc0000000000 R11: fffffbfff1f5f376 R12: ffffc9000b9bf800
R13: ffffc9000b9bf820 R14: ffffc9000b9bf800 R15: dffffc0000000000
FS:  0000555592677380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd44da640f0 CR3: 000000001ea68000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	e8 13 8c d6 ff       	call   0xffd68c18
   5:	4c 89 f0             	mov    %r14,%rax
   8:	48 c1 e8 03          	shr    $0x3,%rax
   c:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1)
  11:	74 08                	je     0x1b
  13:	4c 89 f7             	mov    %r14,%rdi
  16:	e8 4d 12 3e 00       	call   0x3e1268
  1b:	49 8b 1e             	mov    (%r14),%rbx
  1e:	4c 39 f3             	cmp    %r14,%rbx
  21:	74 77                	je     0x9a
  23:	48 89 d8             	mov    %rbx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 2f 12 3e 00       	call   0x3e1268
  39:	4c 8b 23             	mov    (%rbx),%r12
  3c:	48 8d 7b c0          	lea    -0x40(%rbx),%rdi

---
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