Re: [syzbot] [bpf?] [net?] general protection fault in dev_map_enqueue (2)

From: syzbot
Date: Sun Jun 09 2024 - 07:34:43 EST


syzbot has found a reproducer for the following issue on:

HEAD commit: c44711b78608 liquidio: Adjust a NULL pointer handling path..
git tree: net
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1175e6f6980000
kernel config: https://syzkaller.appspot.com/x/.config?x=333ebe38d43c42e2
dashboard link: https://syzkaller.appspot.com/bug?extid=cca39e6e84a367a7e6f6
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=172b3126980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17caa30a980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/47ff53e982e7/disk-c44711b7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7b10dcb52f35/vmlinux-c44711b7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b4a6bf6f87c5/bzImage-c44711b7.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+cca39e6e84a367a7e6f6@xxxxxxxxxxxxxxxxxxxxxxxxx

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 5098 Comm: syz-executor784 Not tainted 6.10.0-rc2-syzkaller-00228-gc44711b78608 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:dev_map_enqueue+0x31/0x3e0 kernel/bpf/devmap.c:539
Code: 41 56 41 55 41 54 53 48 83 ec 18 49 89 d4 49 89 f5 48 89 fd 49 be 00 00 00 00 00 fc ff df e8 46 9c d7 ff 48 89 e8 48 c1 e8 03 <42> 80 3c 30 00 74 08 48 89 ef e8 a0 5e 3d 00 4c 8b 7d 00 48 83 c5
RSP: 0018:ffffc9000343f678 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88807eb31e00
RDX: 0000000000000000 RSI: ffff88802224a070 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff89625806 R09: ffffffff896257c3
R10: 0000000000000004 R11: ffff88807eb31e00 R12: ffff8880151d8000
R13: ffff88802224a070 R14: dffffc0000000000 R15: 0000000000000000
FS: 00005555867d5380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdc79c59303 CR3: 0000000022bc8000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__xdp_do_redirect_frame net/core/filter.c:4397 [inline]
xdp_do_redirect_frame+0x2a6/0x660 net/core/filter.c:4451
xdp_test_run_batch net/bpf/test_run.c:336 [inline]
bpf_test_run_xdp_live+0xe60/0x1e60 net/bpf/test_run.c:384
bpf_prog_test_run_xdp+0x80e/0x11b0 net/bpf/test_run.c:1281
bpf_prog_test_run+0x33a/0x3b0 kernel/bpf/syscall.c:4292
__sys_bpf+0x48d/0x810 kernel/bpf/syscall.c:5706
__do_sys_bpf kernel/bpf/syscall.c:5795 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5793 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5793
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: 0033:0x7fdc79c5b239
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff5780f908 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fdc79c5b239
RDX: 0000000000000050 RSI: 0000000020000240 RDI: 000000000000000a
RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000006
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dev_map_enqueue+0x31/0x3e0 kernel/bpf/devmap.c:539
Code: 41 56 41 55 41 54 53 48 83 ec 18 49 89 d4 49 89 f5 48 89 fd 49 be 00 00 00 00 00 fc ff df e8 46 9c d7 ff 48 89 e8 48 c1 e8 03 <42> 80 3c 30 00 74 08 48 89 ef e8 a0 5e 3d 00 4c 8b 7d 00 48 83 c5
RSP: 0018:ffffc9000343f678 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88807eb31e00
RDX: 0000000000000000 RSI: ffff88802224a070 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff89625806 R09: ffffffff896257c3
R10: 0000000000000004 R11: ffff88807eb31e00 R12: ffff8880151d8000
R13: ffff88802224a070 R14: dffffc0000000000 R15: 0000000000000000
FS: 00005555867d5380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdc79c59303 CR3: 0000000022bc8000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 41 56 push %r14
2: 41 55 push %r13
4: 41 54 push %r12
6: 53 push %rbx
7: 48 83 ec 18 sub $0x18,%rsp
b: 49 89 d4 mov %rdx,%r12
e: 49 89 f5 mov %rsi,%r13
11: 48 89 fd mov %rdi,%rbp
14: 49 be 00 00 00 00 00 movabs $0xdffffc0000000000,%r14
1b: fc ff df
1e: e8 46 9c d7 ff call 0xffd79c69
23: 48 89 e8 mov %rbp,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 30 00 cmpb $0x0,(%rax,%r14,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 48 89 ef mov %rbp,%rdi
34: e8 a0 5e 3d 00 call 0x3d5ed9
39: 4c 8b 7d 00 mov 0x0(%rbp),%r15
3d: 48 rex.W
3e: 83 .byte 0x83
3f: c5 .byte 0xc5


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