2023-01-27 23:50:15

by Sanan Hasanov

[permalink] [raw]
Subject: general protection fault in efivar_lock

Good day, dear maintainers,

We found a bug using a modified kernel configuration file used by syzbot.

We enhanced the coverage of the configuration file using our tool, klocalizer.

Kernel Branch: 6.2.0-rc5-next-20230125
Kernel config: https://drive.google.com/file/d/1qDN6q_k12wcgp6dt4jfF4hpk3Ix5FaKX/view?usp=sharing
Reproducer: https://drive.google.com/file/d/11bfgp5hzObE2om0k0bNfeSIEf_SciGY1/view?usp=sharing

Thank you!

Best regards,
Sanan Hasanov

general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 4 PID: 27585 Comm: syz-executor.5 Not tainted 6.2.0-rc5-next-20230125 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:efivar_lock+0x4e/0xa0
Code: a8 28 0f fc 45 85 e4 75 3f e8 ee 2c 0f fc 48 8b 1d b7 aa c5 05 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 08 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 39 48 83 7b 08 00 74 19 e8 c0 2c 0f fc 44 89 e0 5b
RSP: 0018:ffff88802549fca8 EFLAGS: 00010212
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc90003cb0000
RDX: 0000000000000001 RSI: ffffffff85792a42 RDI: 0000000000000008
RBP: ffff88802549fcb8 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff82595920 R15: 0000000000000000
FS: 00007fafd9f83700(0000) GS:ffff88811a800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9e23270d78 CR3: 00000000233bb000 CR4: 0000000000350ee0
Call Trace:
<TASK>
efivar_entry_iter+0x29/0x150
efivarfs_kill_sb+0x2f/0x40
deactivate_locked_super+0xa6/0x190
vfs_get_super+0x235/0x2b0
get_tree_single+0x2b/0x40
efivarfs_get_tree+0x21/0x30
vfs_get_tree+0x97/0x370
__do_sys_fsconfig+0x981/0xd20
__x64_sys_fsconfig+0xc1/0x150
do_syscall_64+0x3f/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7fafd8e8edcd
Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 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:00007fafd9f82bf8 EFLAGS: 00000246 ORIG_RAX: 00000000000001af
RAX: ffffffffffffffda RBX: 00007fafd8fbbf80 RCX: 00007fafd8e8edcd
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000004
RBP: 00007fafd8efc59c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff23221a7f R14: 00007fff23221c20 R15: 00007fafd9f82d80
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:efivar_lock+0x4e/0xa0
Code: a8 28 0f fc 45 85 e4 75 3f e8 ee 2c 0f fc 48 8b 1d b7 aa c5 05 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 08 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 39 48 83 7b 08 00 74 19 e8 c0 2c 0f fc 44 89 e0 5b
RSP: 0018:ffff88802549fca8 EFLAGS: 00010212
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc90003cb0000
RDX: 0000000000000001 RSI: ffffffff85792a42 RDI: 0000000000000008
RBP: ffff88802549fcb8 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff82595920 R15: 0000000000000000
FS: 00007fafd9f83700(0000) GS:ffff88811a800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9e23270d78 CR3: 00000000233bb000 CR4: 0000000000350ee0
----------------
Code disassembly (best guess), 1 bytes skipped:
0: 28 0f sub %cl,(%rdi)
2: fc cld
3: 45 85 e4 test %r12d,%r12d
6: 75 3f jne 0x47
8: e8 ee 2c 0f fc call 0xfc0f2cfb
d: 48 8b 1d b7 aa c5 05 mov 0x5c5aab7(%rip),%rbx # 0x5c5aacb
14: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
1b: fc ff df
1e: 48 8d 7b 08 lea 0x8(%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: 75 39 jne 0x68
2f: 48 83 7b 08 00 cmpq $0x0,0x8(%rbx)
34: 74 19 je 0x4f
36: e8 c0 2c 0f fc call 0xfc0f2cfb
3b: 44 89 e0 mov %r12d,%eax
3e: 5b pop %rbx


2023-01-28 16:03:04

by Pedro Falcato

[permalink] [raw]
Subject: Re: general protection fault in efivar_lock

On Fri, Jan 27, 2023 at 11:55 PM Sanan Hasanov
<[email protected]> wrote:
>
> Good day, dear maintainers,
>
> We found a bug using a modified kernel configuration file used by syzbot.
>
> We enhanced the coverage of the configuration file using our tool, klocalizer.
>
> Kernel Branch: 6.2.0-rc5-next-20230125
> Kernel config: https://drive.google.com/file/d/1qDN6q_k12wcgp6dt4jfF4hpk3Ix5FaKX/view?usp=sharing
> Reproducer: https://drive.google.com/file/d/11bfgp5hzObE2om0k0bNfeSIEf_SciGY1/view?usp=sharing
>
> Thank you!
>
> Best regards,
> Sanan Hasanov
>
> general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
> KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
> CPU: 4 PID: 27585 Comm: syz-executor.5 Not tainted 6.2.0-rc5-next-20230125 #1
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
> RIP: 0010:efivar_lock+0x4e/0xa0
> Code: a8 28 0f fc 45 85 e4 75 3f e8 ee 2c 0f fc 48 8b 1d b7 aa c5 05 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 08 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 39 48 83 7b 08 00 74 19 e8 c0 2c 0f fc 44 89 e0 5b
> RSP: 0018:ffff88802549fca8 EFLAGS: 00010212
> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc90003cb0000
> RDX: 0000000000000001 RSI: ffffffff85792a42 RDI: 0000000000000008
> RBP: ffff88802549fcb8 R08: 0000000000000005 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
> R13: 0000000000000000 R14: ffffffff82595920 R15: 0000000000000000
> FS: 00007fafd9f83700(0000) GS:ffff88811a800000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f9e23270d78 CR3: 00000000233bb000 CR4: 0000000000350ee0
> Call Trace:
> <TASK>
> efivar_entry_iter+0x29/0x150
> efivarfs_kill_sb+0x2f/0x40
> deactivate_locked_super+0xa6/0x190
> vfs_get_super+0x235/0x2b0
> get_tree_single+0x2b/0x40
> efivarfs_get_tree+0x21/0x30
> vfs_get_tree+0x97/0x370
> __do_sys_fsconfig+0x981/0xd20
> __x64_sys_fsconfig+0xc1/0x150
> do_syscall_64+0x3f/0x90
> entry_SYSCALL_64_after_hwframe+0x72/0xdc
> RIP: 0033:0x7fafd8e8edcd
> Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 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:00007fafd9f82bf8 EFLAGS: 00000246 ORIG_RAX: 00000000000001af
> RAX: ffffffffffffffda RBX: 00007fafd8fbbf80 RCX: 00007fafd8e8edcd
> RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000004
> RBP: 00007fafd8efc59c R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007fff23221a7f R14: 00007fff23221c20 R15: 00007fafd9f82d80
> </TASK>
> Modules linked in:
> ---[ end trace 0000000000000000 ]---
> RIP: 0010:efivar_lock+0x4e/0xa0
> Code: a8 28 0f fc 45 85 e4 75 3f e8 ee 2c 0f fc 48 8b 1d b7 aa c5 05 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 08 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 39 48 83 7b 08 00 74 19 e8 c0 2c 0f fc 44 89 e0 5b
> RSP: 0018:ffff88802549fca8 EFLAGS: 00010212
> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc90003cb0000
> RDX: 0000000000000001 RSI: ffffffff85792a42 RDI: 0000000000000008
> RBP: ffff88802549fcb8 R08: 0000000000000005 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
> R13: 0000000000000000 R14: ffffffff82595920 R15: 0000000000000000
> FS: 00007fafd9f83700(0000) GS:ffff88811a800000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f9e23270d78 CR3: 00000000233bb000 CR4: 0000000000350ee0
> ----------------
> Code disassembly (best guess), 1 bytes skipped:
> 0: 28 0f sub %cl,(%rdi)
> 2: fc cld
> 3: 45 85 e4 test %r12d,%r12d
> 6: 75 3f jne 0x47
> 8: e8 ee 2c 0f fc call 0xfc0f2cfb
> d: 48 8b 1d b7 aa c5 05 mov 0x5c5aab7(%rip),%rbx # 0x5c5aacb
> 14: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
> 1b: fc ff df
> 1e: 48 8d 7b 08 lea 0x8(%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: 75 39 jne 0x68
> 2f: 48 83 7b 08 00 cmpq $0x0,0x8(%rbx)
> 34: 74 19 je 0x4f
> 36: e8 c0 2c 0f fc call 0xfc0f2cfb
> 3b: 44 89 e0 mov %r12d,%eax
> 3e: 5b pop %rbx
Hi,

Should be fixed by
https://lore.kernel.org/linux-efi/[email protected]/
(squashed into c3fd71b428b8fa on Ard's tree). Also in linux-next.git
301de9a205535737.

Can you see if that fixes your crash?

--
Pedro