Hello,
syzbot found the following issue on:
HEAD commit: 596764183be8 Add linux-next specific files for 20240129
git tree: linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=142042f3e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=584144ad19f381aa
dashboard link: https://syzkaller.appspot.com/bug?extid=39a72b995ba73633c1a7
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11844ba7e80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15bd01efe80000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b647c038857b/disk-59676418.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/729e26c3ac55/vmlinux-59676418.xz
kernel image: https://storage.googleapis.com/syzbot-assets/15aa5e287059/bzImage-59676418.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]
arg_start 7fffd9277efb arg_end 7fffd9277f14 env_start 7fffd9277f14 env_end 7fffd9277fdf
binfmt ffffffff8d9c5c00 flags 80007fd
ioctx_table 0000000000000000
owner ffff88802c0cda00 exe_file ffff88801ff60500
notifier_subscriptions 0000000000000000
numa_next_scan 0 numa_scan_offset 0 numa_scan_seq 0
tlb_flush_pending 0
def_flags: 0x0()
------------[ cut here ]------------
kernel BUG at mm/mmap.c:328!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 PID: 5058 Comm: syz-executor310 Not tainted 6.8.0-rc1-next-20240129-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
RIP: 0010:validate_mm+0x3f3/0x4b0 mm/mmap.c:328
Code: 0f 84 a4 fd ff ff e9 47 ff ff ff e8 77 91 b9 ff 44 89 f2 89 de 48 c7 c7 e0 af 19 8b e8 56 69 9b ff 4c 89 ff e8 ce c4 fa ff 90 <0f> 0b e8 56 91 b9 ff 0f b6 15 1f dd b1 0d 31 ff 89 d6 88 14 24 e8
RSP: 0018:ffffc900035df958 EFLAGS: 00010282
RAX: 000000000000032a RBX: 000000000000000d RCX: ffffffff816e2f59
RDX: 0000000000000000 RSI: ffffffff816eb7e6 RDI: 0000000000000005
RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000001 R12: 00007fffd92ff000
R13: 0000000000000000 R14: 000000000000000e R15: ffff88802c6b8000
FS: 0000555557046380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f10ada208a0 CR3: 000000007b434000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
vma_merge+0x16a9/0x3d70 mm/mmap.c:1033
vma_merge_new_vma mm/mmap.c:2465 [inline]
mmap_region+0x206b/0x2760 mm/mmap.c:2841
do_mmap+0x8ae/0xf10 mm/mmap.c:1380
vm_mmap_pgoff+0x1ab/0x3c0 mm/util.c:573
ksys_mmap_pgoff+0x425/0x5b0 mm/mmap.c:1426
__do_sys_mmap arch/x86/kernel/sys_x86_64.c:93 [inline]
__se_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline]
__x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:86
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f10ad9e52a9
Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffd9276338 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fffd9276518 RCX: 00007f10ad9e52a9
RDX: 0000000000000001 RSI: 0000000000002000 RDI: 0000000020ffc000
RBP: 00007f10ada58610 R08: 0000000000000003 R09: 0000000000000000
R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fffd9276508 R14: 0000000000000001 R15: 0000000000000001
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:validate_mm+0x3f3/0x4b0 mm/mmap.c:328
Code: 0f 84 a4 fd ff ff e9 47 ff ff ff e8 77 91 b9 ff 44 89 f2 89 de 48 c7 c7 e0 af 19 8b e8 56 69 9b ff 4c 89 ff e8 ce c4 fa ff 90 <0f> 0b e8 56 91 b9 ff 0f b6 15 1f dd b1 0d 31 ff 89 d6 88 14 24 e8
RSP: 0018:ffffc900035df958 EFLAGS: 00010282
RAX: 000000000000032a RBX: 000000000000000d RCX: ffffffff816e2f59
RDX: 0000000000000000 RSI: ffffffff816eb7e6 RDI: 0000000000000005
RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000001 R12: 00007fffd92ff000
R13: 0000000000000000 R14: 000000000000000e R15: ffff88802c6b8000
FS: 0000555557046380(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000664740 CR3: 000000007b434000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
---
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 [email protected].
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
Yajun,
* syzbot <[email protected]> [240129 06:15]:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 596764183be8 Add linux-next specific files for 20240129
> git tree: linux-next
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=142042f3e80000
> kernel config: https://syzkaller.appspot.com/x/.config?x=584144ad19f381aa
> dashboard link: https://syzkaller.appspot.com/bug?extid=39a72b995ba73633c1a7
> compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11844ba7e80000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15bd01efe80000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/b647c038857b/disk-59676418.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/729e26c3ac55/vmlinux-59676418.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/15aa5e287059/bzImage-59676418.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: [email protected]
>
> arg_start 7fffd9277efb arg_end 7fffd9277f14 env_start 7fffd9277f14 env_end 7fffd9277fdf
> binfmt ffffffff8d9c5c00 flags 80007fd
> ioctx_table 0000000000000000
> owner ffff88802c0cda00 exe_file ffff88801ff60500
> notifier_subscriptions 0000000000000000
> numa_next_scan 0 numa_scan_offset 0 numa_scan_seq 0
> tlb_flush_pending 0
> def_flags: 0x0()
> ------------[ cut here ]------------
> kernel BUG at mm/mmap.c:328!
> invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
> CPU: 1 PID: 5058 Comm: syz-executor310 Not tainted 6.8.0-rc1-next-20240129-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
> RIP: 0010:validate_mm+0x3f3/0x4b0 mm/mmap.c:328
> Code: 0f 84 a4 fd ff ff e9 47 ff ff ff e8 77 91 b9 ff 44 89 f2 89 de 48 c7 c7 e0 af 19 8b e8 56 69 9b ff 4c 89 ff e8 ce c4 fa ff 90 <0f> 0b e8 56 91 b9 ff 0f b6 15 1f dd b1 0d 31 ff 89 d6 88 14 24 e8
> RSP: 0018:ffffc900035df958 EFLAGS: 00010282
> RAX: 000000000000032a RBX: 000000000000000d RCX: ffffffff816e2f59
> RDX: 0000000000000000 RSI: ffffffff816eb7e6 RDI: 0000000000000005
> RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000000
> R10: 0000000080000000 R11: 0000000000000001 R12: 00007fffd92ff000
> R13: 0000000000000000 R14: 000000000000000e R15: ffff88802c6b8000
> FS: 0000555557046380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f10ada208a0 CR3: 000000007b434000 CR4: 00000000003506f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> <TASK>
> vma_merge+0x16a9/0x3d70 mm/mmap.c:1033
> vma_merge_new_vma mm/mmap.c:2465 [inline]
> mmap_region+0x206b/0x2760 mm/mmap.c:2841
> do_mmap+0x8ae/0xf10 mm/mmap.c:1380
> vm_mmap_pgoff+0x1ab/0x3c0 mm/util.c:573
> ksys_mmap_pgoff+0x425/0x5b0 mm/mmap.c:1426
> __do_sys_mmap arch/x86/kernel/sys_x86_64.c:93 [inline]
> __se_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline]
> __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:86
> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83
> entry_SYSCALL_64_after_hwframe+0x6d/0x75
I just tested the reproducer against linux-next with and without your
patch [1], and confirmed that is the cause of this validation failure.
The validation code is seeing an extra vma in the tree compared to the
vma count:
[ 57.065418] mmap: map_count 24 vma iterator 25
There is a C reproducer from the bot. Can you please have a look to
figure out what is missing?
It would really help if you had that complicated if statement expanded
with comments:
if (prev == curr || /* ??? */
addr != curr->vm_start.......
Thanks,
Liam
[1]. https://lore.kernel.org/linux-mm/[email protected]/
On 2024/1/29 23:22, Liam R. Howlett wrote:
> Yajun,
>
>
> * syzbot <[email protected]> [240129 06:15]:
>> Hello,
>>
>> syzbot found the following issue on:
>>
>> HEAD commit: 596764183be8 Add linux-next specific files for 20240129
>> git tree: linux-next
>> console+strace: https://syzkaller.appspot.com/x/log.txt?x=142042f3e80000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=584144ad19f381aa
>> dashboard link: https://syzkaller.appspot.com/bug?extid=39a72b995ba73633c1a7
>> compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11844ba7e80000
>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15bd01efe80000
>>
>> Downloadable assets:
>> disk image: https://storage.googleapis.com/syzbot-assets/b647c038857b/disk-59676418.raw.xz
>> vmlinux: https://storage.googleapis.com/syzbot-assets/729e26c3ac55/vmlinux-59676418.xz
>> kernel image: https://storage.googleapis.com/syzbot-assets/15aa5e287059/bzImage-59676418.xz
>>
>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>> Reported-by: [email protected]
>>
>> arg_start 7fffd9277efb arg_end 7fffd9277f14 env_start 7fffd9277f14 env_end 7fffd9277fdf
>> binfmt ffffffff8d9c5c00 flags 80007fd
>> ioctx_table 0000000000000000
>> owner ffff88802c0cda00 exe_file ffff88801ff60500
>> notifier_subscriptions 0000000000000000
>> numa_next_scan 0 numa_scan_offset 0 numa_scan_seq 0
>> tlb_flush_pending 0
>> def_flags: 0x0()
>> ------------[ cut here ]------------
>> kernel BUG at mm/mmap.c:328!
>> invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
>> CPU: 1 PID: 5058 Comm: syz-executor310 Not tainted 6.8.0-rc1-next-20240129-syzkaller #0
>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
>> RIP: 0010:validate_mm+0x3f3/0x4b0 mm/mmap.c:328
>> Code: 0f 84 a4 fd ff ff e9 47 ff ff ff e8 77 91 b9 ff 44 89 f2 89 de 48 c7 c7 e0 af 19 8b e8 56 69 9b ff 4c 89 ff e8 ce c4 fa ff 90 <0f> 0b e8 56 91 b9 ff 0f b6 15 1f dd b1 0d 31 ff 89 d6 88 14 24 e8
>> RSP: 0018:ffffc900035df958 EFLAGS: 00010282
>> RAX: 000000000000032a RBX: 000000000000000d RCX: ffffffff816e2f59
>> RDX: 0000000000000000 RSI: ffffffff816eb7e6 RDI: 0000000000000005
>> RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000000
>> R10: 0000000080000000 R11: 0000000000000001 R12: 00007fffd92ff000
>> R13: 0000000000000000 R14: 000000000000000e R15: ffff88802c6b8000
>> FS: 0000555557046380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> CR2: 00007f10ada208a0 CR3: 000000007b434000 CR4: 00000000003506f0
>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>> Call Trace:
>> <TASK>
>> vma_merge+0x16a9/0x3d70 mm/mmap.c:1033
>> vma_merge_new_vma mm/mmap.c:2465 [inline]
>> mmap_region+0x206b/0x2760 mm/mmap.c:2841
>> do_mmap+0x8ae/0xf10 mm/mmap.c:1380
>> vm_mmap_pgoff+0x1ab/0x3c0 mm/util.c:573
>> ksys_mmap_pgoff+0x425/0x5b0 mm/mmap.c:1426
>> __do_sys_mmap arch/x86/kernel/sys_x86_64.c:93 [inline]
>> __se_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline]
>> __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:86
>> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>> do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83
>> entry_SYSCALL_64_after_hwframe+0x6d/0x75
> I just tested the reproducer against linux-next with and without your
> patch [1], and confirmed that is the cause of this validation failure.
>
> The validation code is seeing an extra vma in the tree compared to the
> vma count:
>
> [ 57.065418] mmap: map_count 24 vma iterator 25
>
> There is a C reproducer from the bot. Can you please have a look to
> figure out what is missing?
It shoud be like this:
******
PPPPP NNNNN
But it was treated as:
******
PPPPPCCCCCNNNNN
I haven't found something that should be added to the check yet. I'll
continue tomorrow.
>
> It would really help if you had that complicated if statement expanded
> with comments:
>
> if (prev == curr || /* ??? */
> addr != curr->vm_start.......
>
>
> Thanks,
> Liam
>
> [1]. https://lore.kernel.org/linux-mm/[email protected]/