[syzbot] general protection fault in bpf_skb_cgroup_id

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2865ba82476a Merge git://git.kernel.org/pub/scm/linux/kern..
git tree: bpf
console output: https://syzkaller.appspot.com/x/log.txt?x=15089853300000
kernel config: https://syzkaller.appspot.com/x/.config?x=c31c0936547df9ea
dashboard link: https://syzkaller.appspot.com/bug?extid=33f36d0754d4c5c0e102
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14dbd7ed300000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1586f83b300000

Bisection is inconclusive: the first bad commit could be any of:

0e6491b55970 bpf: Add oversize check before call kvcalloc()
2f1aaf3ea666 bpf, mm: Fix lockdep warning triggered by stack_map_get_build_id_offset()
8520e224f547 bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode
3a029e1f3d6e selftests/bpf: Fix build of task_pt_regs test for arm64
d8079d8026f8 bpf, selftests: Add cgroup v1 net_cls classid helpers
43d2b88c29f2 bpf, selftests: Add test case for mixed cgroup v1/v2
49ca6153208f bpf: Relicense disassembler as GPL-2.0-only OR BSD-2-Clause
2865ba82476a Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=16b5ccdd300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+33f36d...@syzkaller.appspotmail.com

general protection fault, probably for non-canonical address 0xdffffc0000000029: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000148-0x000000000000014f]
CPU: 1 PID: 8436 Comm: syz-executor679 Not tainted 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:cgroup_id include/linux/cgroup.h:312 [inline]
RIP: 0010:__bpf_sk_cgroup_id net/core/filter.c:4468 [inline]
RIP: 0010:____bpf_skb_cgroup_id net/core/filter.c:4473 [inline]
RIP: 0010:bpf_skb_cgroup_id+0x138/0x210 net/core/filter.c:4471
Code: 03 80 3c 02 00 0f 85 cc 00 00 00 48 8b 9b 58 04 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d bb 48 01 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 ad 00 00 00 48 8b 9b 48 01 00 00 48 b8 00 00 00
RSP: 0018:ffffc9000184f9c0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000029 RSI: ffffffff8728f537 RDI: 0000000000000148
RBP: 0000000000000080 R08: 0000000000000000 R09: 0000000000000007
R10: ffffffff8728f52a R11: 000000000000001f R12: 0000000000000007
R13: ffffc90000e6a000 R14: ffffc9000184fc30 R15: ffffc90000e6a048
FS: 0000000000f5e300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200004c0 CR3: 000000001d929000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
bpf_prog_3a33f00dea259162+0x10/0xfa8
bpf_dispatcher_nop_func include/linux/bpf.h:717 [inline]
__bpf_prog_run include/linux/filter.h:624 [inline]
bpf_prog_run include/linux/filter.h:631 [inline]
bpf_test_run+0x381/0xa30 net/bpf/test_run.c:119
bpf_prog_test_run_skb+0xac5/0x1d20 net/bpf/test_run.c:657
bpf_prog_test_run kernel/bpf/syscall.c:3307 [inline]
__sys_bpf+0x2137/0x5df0 kernel/bpf/syscall.c:4605
__do_sys_bpf kernel/bpf/syscall.c:4691 [inline]
__se_sys_bpf kernel/bpf/syscall.c:4689 [inline]
__x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:4689
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x43f009
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcff384d88 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 0000000000400488 RCX: 000000000043f009
RDX: 0000000000000028 RSI: 0000000020000440 RDI: 000000000000000a
RBP: 0000000000402ff0 R08: 0000000000000000 R09: 0000000000400488
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000403080
R13: 0000000000000000 R14: 00000000004ad018 R15: 0000000000400488
Modules linked in:
---[ end trace d161abccc2184019 ]---
RIP: 0010:cgroup_id include/linux/cgroup.h:312 [inline]
RIP: 0010:__bpf_sk_cgroup_id net/core/filter.c:4468 [inline]
RIP: 0010:____bpf_skb_cgroup_id net/core/filter.c:4473 [inline]
RIP: 0010:bpf_skb_cgroup_id+0x138/0x210 net/core/filter.c:4471
Code: 03 80 3c 02 00 0f 85 cc 00 00 00 48 8b 9b 58 04 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d bb 48 01 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 ad 00 00 00 48 8b 9b 48 01 00 00 48 b8 00 00 00
RSP: 0018:ffffc9000184f9c0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000029 RSI: ffffffff8728f537 RDI: 0000000000000148
RBP: 0000000000000080 R08: 0000000000000000 R09: 0000000000000007
R10: ffffffff8728f52a R11: 000000000000001f R12: 0000000000000007
R13: ffffc90000e6a000 R14: ffffc9000184fc30 R15: ffffc90000e6a048
FS: 0000000000f5e300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200004c0 CR3: 000000001d929000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 1 bytes skipped:
0: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
4: 0f 85 cc 00 00 00 jne 0xd6
a: 48 8b 9b 58 04 00 00 mov 0x458(%rbx),%rbx
11: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
18: fc ff df
1b: 48 8d bb 48 01 00 00 lea 0x148(%rbx),%rdi
22: 48 89 fa mov %rdi,%rdx
25: 48 c1 ea 03 shr $0x3,%rdx
* 29: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
2d: 0f 85 ad 00 00 00 jne 0xe0
33: 48 8b 9b 48 01 00 00 mov 0x148(%rbx),%rbx
3a: 48 rex.W
3b: b8 .byte 0xb8
3c: 00 00 add %al,(%rax)


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches

[Daniel Borkmann]

On 9/17/21 11:06 PM, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 2865ba82476a Merge git://git.kernel.org/pub/scm/linux/kern..
> git tree: bpf
> console output: https://syzkaller.appspot.com/x/log.txt?x=15089853300000
> kernel config: https://syzkaller.appspot.com/x/.config?x=c31c0936547df9ea
> dashboard link: https://syzkaller.appspot.com/bug?extid=33f36d0754d4c5c0e102
> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14dbd7ed300000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1586f83b300000
>
> Bisection is inconclusive: the first bad commit could be any of:
>
> 0e6491b55970 bpf: Add oversize check before call kvcalloc()
> 2f1aaf3ea666 bpf, mm: Fix lockdep warning triggered by stack_map_get_build_id_offset()
> 8520e224f547 bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode
> 3a029e1f3d6e selftests/bpf: Fix build of task_pt_regs test for arm64
> d8079d8026f8 bpf, selftests: Add cgroup v1 net_cls classid helpers
> 43d2b88c29f2 bpf, selftests: Add test case for mixed cgroup v1/v2
> 49ca6153208f bpf: Relicense disassembler as GPL-2.0-only OR BSD-2-Clause
> 2865ba82476a Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=16b5ccdd300000

I'll take a look at the report.

Thanks,
Daniel

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+33f36d...@syzkaller.appspotmail.com

Tested on:

commit: f9eec43b bpf, cgroup: test fix
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/dborkman/bpf.git pr/bpf-cgroup-test

kernel config: https://syzkaller.appspot.com/x/.config?x=c31c0936547df9ea
dashboard link: https://syzkaller.appspot.com/bug?extid=33f36d0754d4c5c0e102
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Note: testing is done by a robot and is best-effort only.

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
general protection fault in bpf_skb_cgroup_id

general protection fault, probably for non-canonical address 0xdffffc0000000029: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000148-0x000000000000014f]

CPU: 0 PID: 8919 Comm: syz-executor817 Not tainted 5.14.0-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:cgroup_id include/linux/cgroup.h:312 [inline]
RIP: 0010:__bpf_sk_cgroup_id net/core/filter.c:4468 [inline]
RIP: 0010:____bpf_skb_cgroup_id net/core/filter.c:4473 [inline]
RIP: 0010:bpf_skb_cgroup_id+0x138/0x210 net/core/filter.c:4471
Code: 03 80 3c 02 00 0f 85 cc 00 00 00 48 8b 9b 58 04 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d bb 48 01 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 ad 00 00 00 48 8b 9b 48 01 00 00 48 b8 00 00 00

RSP: 0018:ffffc90000e9f9c0 EFLAGS: 00010202

RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000

RDX: 0000000000000029 RSI: ffffffff8728f677 RDI: 0000000000000148

RBP: 0000000000000080 R08: 0000000000000000 R09: 0000000000000007

R10: ffffffff8728f66a R11: 000000000000001f R12: 0000000000000007
R13: ffffc90000e48000 R14: ffffc90000e9fc30 R15: ffffc90000e48048
FS: 0000555555ed2300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00000000200004c0 CR3: 000000001ca13000 CR4: 00000000001506f0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:

bpf_prog_3a33f00dea259162+0x10/0x27c
bpf_dispatcher_nop_func include/linux/bpf.h:718 [inline]

__bpf_prog_run include/linux/filter.h:624 [inline]
bpf_prog_run include/linux/filter.h:631 [inline]
bpf_test_run+0x381/0xa30 net/bpf/test_run.c:119
bpf_prog_test_run_skb+0xac5/0x1d20 net/bpf/test_run.c:657
bpf_prog_test_run kernel/bpf/syscall.c:3307 [inline]
__sys_bpf+0x2137/0x5df0 kernel/bpf/syscall.c:4605
__do_sys_bpf kernel/bpf/syscall.c:4691 [inline]
__se_sys_bpf kernel/bpf/syscall.c:4689 [inline]
__x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:4689
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

RIP: 0033:0x7fb47b0d0cb9

Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 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 c0 ff ff ff f7 d8 64 89 01 48

RSP: 002b:00007ffe4159b608 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb47b0d0cb9

RDX: 0000000000000028 RSI: 0000000020000440 RDI: 000000000000000a

RBP: 00007fb47b094e60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb47b094ef0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace 463d1c250770ae17 ]---

RIP: 0010:cgroup_id include/linux/cgroup.h:312 [inline]
RIP: 0010:__bpf_sk_cgroup_id net/core/filter.c:4468 [inline]
RIP: 0010:____bpf_skb_cgroup_id net/core/filter.c:4473 [inline]
RIP: 0010:bpf_skb_cgroup_id+0x138/0x210 net/core/filter.c:4471
Code: 03 80 3c 02 00 0f 85 cc 00 00 00 48 8b 9b 58 04 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d bb 48 01 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 ad 00 00 00 48 8b 9b 48 01 00 00 48 b8 00 00 00

RSP: 0018:ffffc90000e9f9c0 EFLAGS: 00010202

RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000

RDX: 0000000000000029 RSI: ffffffff8728f677 RDI: 0000000000000148

RBP: 0000000000000080 R08: 0000000000000000 R09: 0000000000000007

R10: ffffffff8728f66a R11: 000000000000001f R12: 0000000000000007
R13: ffffc90000e48000 R14: ffffc90000e9fc30 R15: ffffc90000e48048
FS: 0000555555ed2300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00007f56cbe37000 CR3: 000000001ca13000 CR4: 00000000001506f0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 1 bytes skipped:
0: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
4: 0f 85 cc 00 00 00 jne 0xd6
a: 48 8b 9b 58 04 00 00 mov 0x458(%rbx),%rbx
11: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
18: fc ff df
1b: 48 8d bb 48 01 00 00 lea 0x148(%rbx),%rdi
22: 48 89 fa mov %rdi,%rdx
25: 48 c1 ea 03 shr $0x3,%rdx
* 29: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
2d: 0f 85 ad 00 00 00 jne 0xe0
33: 48 8b 9b 48 01 00 00 mov 0x148(%rbx),%rbx
3a: 48 rex.W
3b: b8 .byte 0xb8
3c: 00 00 add %al,(%rax)

Tested on:

commit: 39f15afa bpf, cgroup: test fix 2
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/dborkman/bpf.git pr/bpf-cgroup-test2
console output: https://syzkaller.appspot.com/x/log.txt?x=100dce4b300000

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+33f36d...@syzkaller.appspotmail.com

Tested on:

commit: 93f377ac bpf, test, cgroup: Use cgroup_sk_{alloc,free}..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/dborkman/bpf.git pr/bpf-cgroup-test3

kernel config: https://syzkaller.appspot.com/x/.config?x=c31c0936547df9ea
dashboard link: https://syzkaller.appspot.com/bug?extid=33f36d0754d4c5c0e102
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

[syzbot]

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+33f36d...@syzkaller.appspotmail.com

Tested on:

commit: 0a3ead8a bpf, test, cgroup: Use sk_{alloc,free} for te..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/dborkman/bpf.git pr/bpf-cgroup-test4