[syzbot] general protection fault in vma_interval_tree_remove

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: bdc61aad77fa Add linux-next specific files for 20220428
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1196c4bcf00000
kernel config: https://syzkaller.appspot.com/x/.config?x=87767e89da13a759
dashboard link: https://syzkaller.appspot.com/bug?extid=ee1fdd8dcc770a3a169a
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ee1fdd...@syzkaller.appspotmail.com

RBP: 0000000020000000 R08: 0000000000000004 R09: 0000000000000000
R10: 0000000000008011 R11: 0000000000000206 R12: 0000000020000800
R13: 0000000020000000 R14: 00000000200007c0 R15: 0000000020000000
</TASK>
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 32272 Comm: syz-executor.4 Not tainted 5.18.0-rc4-next-20220428-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:rb_set_parent_color include/linux/rbtree_augmented.h:165 [inline]
RIP: 0010:____rb_erase_color lib/rbtree.c:359 [inline]
RIP: 0010:__rb_erase_color+0x2fd/0xdb0 lib/rbtree.c:413
Code: 00 4d 89 ec 4d 8b 6d 10 e9 ac fd ff ff 4c 89 60 10 eb be 4c 89 e9 48 89 e8 4c 89 6d 10 48 c1 e9 03 49 89 6c 24 08 48 83 c8 01 <80> 3c 19 00 0f 85 1d 08 00 00 49 89 45 00 48 89 e8 48 c1 e8 03 80
RSP: 0018:ffffc900149ffa48 EFLAGS: 00010286
RAX: ffff88801f3fbb21 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffffed1002fe1617 RSI: ffff888017f0b0b8 RDI: ffff8880790928a0
RBP: ffff88801f3fbb20 R08: ffff88801f3fbb30 R09: ffff888017f0b0af
R10: ffffffff81b01168 R11: 0000000000000001 R12: ffff888079092898
R13: 0000000000000000 R14: ffff888017f0b0b8 R15: ffffffff81afff50
FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000001da88000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
rb_erase_augmented include/linux/rbtree_augmented.h:305 [inline]
rb_erase_augmented_cached include/linux/rbtree_augmented.h:314 [inline]
vma_interval_tree_remove+0x694/0xed0 mm/interval_tree.c:23
__remove_shared_vm_struct mm/mmap.c:160 [inline]
unlink_file_vma+0xbd/0x110 mm/mmap.c:175
free_pgtables+0x255/0x420 mm/memory.c:440
exit_mmap+0x1ff/0x740 mm/mmap.c:3148
__mmput+0xe4/0x460 kernel/fork.c:1175
mmput+0x5c/0x70 kernel/fork.c:1197
exit_mm kernel/exit.c:510 [inline]
do_exit+0xa18/0x2a00 kernel/exit.c:782
do_group_exit+0xd2/0x2f0 kernel/exit.c:925
__do_sys_exit_group kernel/exit.c:936 [inline]
__se_sys_exit_group kernel/exit.c:934 [inline]
__x64_sys_exit_group+0x3a/0x50 kernel/exit.c:934
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: 0033:0x7f858fe890e9
Code: Unable to access opcode bytes at RIP 0x7f858fe890bf.
RSP: 002b:00007f85910bbaf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f858fe890e9
RDX: 00007f858fe89132 RSI: 0000000000000000 RDI: 000000000000000b
RBP: 000000000000000b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000004 R11: 0000000000000246 R12: 0000000020000800
R13: 0000000020000000 R14: 00000000200007c0 R15: 0000000020000000
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:rb_set_parent_color include/linux/rbtree_augmented.h:165 [inline]
RIP: 0010:____rb_erase_color lib/rbtree.c:359 [inline]
RIP: 0010:__rb_erase_color+0x2fd/0xdb0 lib/rbtree.c:413
Code: 00 4d 89 ec 4d 8b 6d 10 e9 ac fd ff ff 4c 89 60 10 eb be 4c 89 e9 48 89 e8 4c 89 6d 10 48 c1 e9 03 49 89 6c 24 08 48 83 c8 01 <80> 3c 19 00 0f 85 1d 08 00 00 49 89 45 00 48 89 e8 48 c1 e8 03 80
RSP: 0018:ffffc900149ffa48 EFLAGS: 00010286
RAX: ffff88801f3fbb21 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffffed1002fe1617 RSI: ffff888017f0b0b8 RDI: ffff8880790928a0
RBP: ffff88801f3fbb20 R08: ffff88801f3fbb30 R09: ffff888017f0b0af
R10: ffffffff81b01168 R11: 0000000000000001 R12: ffff888079092898
R13: 0000000000000000 R14: ffff888017f0b0b8 R15: ffffffff81afff50
FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000001da88000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 00 4d 89 add %cl,-0x77(%rbp)
3: ec in (%dx),%al
4: 4d 8b 6d 10 mov 0x10(%r13),%r13
8: e9 ac fd ff ff jmpq 0xfffffdb9
d: 4c 89 60 10 mov %r12,0x10(%rax)
11: eb be jmp 0xffffffd1
13: 4c 89 e9 mov %r13,%rcx
16: 48 89 e8 mov %rbp,%rax
19: 4c 89 6d 10 mov %r13,0x10(%rbp)
1d: 48 c1 e9 03 shr $0x3,%rcx
21: 49 89 6c 24 08 mov %rbp,0x8(%r12)
26: 48 83 c8 01 or $0x1,%rax
* 2a: 80 3c 19 00 cmpb $0x0,(%rcx,%rbx,1) <-- trapping instruction
2e: 0f 85 1d 08 00 00 jne 0x851
34: 49 89 45 00 mov %rax,0x0(%r13)
38: 48 89 e8 mov %rbp,%rax
3b: 48 c1 e8 03 shr $0x3,%rax
3f: 80 .byte 0x80


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 1e1b28b936ae Add linux-next specific files for 20220513
git tree: linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=11da21b9f00000
kernel config: https://syzkaller.appspot.com/x/.config?x=e4eb3c0c4b289571

dashboard link: https://syzkaller.appspot.com/bug?extid=ee1fdd8dcc770a3a169a
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=142757f1f00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17cf0966f00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ee1fdd...@syzkaller.appspotmail.com

general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]

CPU: 1 PID: 3612 Comm: syz-executor255 Not tainted 5.18.0-rc6-next-20220513-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

RIP: 0010:____rb_erase_color lib/rbtree.c:354 [inline]
RIP: 0010:__rb_erase_color+0x159/0xdb0 lib/rbtree.c:413
Code: 89 ed 48 89 c5 e9 f5 fe ff ff 4c 8d 45 10 4c 89 c0 48 c1 e8 03 80 3c 18 00 0f 85 3a 08 00 00 4c 8b 65 10 4c 89 e0 48 c1 e8 03 <80> 3c 18 00 0f 85 6a 08 00 00 49 8b 04 24 49 8d 7c 24 08 48 89 f9
RSP: 0018:ffffc90002e877a8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffffed100e8d3aed RSI: ffff88807469d768 RDI: ffff8880202132b0
RBP: ffff8880202132b0 R08: ffff8880202132c0 R09: ffff88807469d75f
R10: ffffffff81b02518 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88807469d768 R15: ffffffff81b01300

FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00007ffe92002ff8 CR3: 00000000764a0000 CR4: 00000000003506e0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
rb_erase_augmented include/linux/rbtree_augmented.h:305 [inline]
rb_erase_augmented_cached include/linux/rbtree_augmented.h:314 [inline]
vma_interval_tree_remove+0x694/0xed0 mm/interval_tree.c:23
__remove_shared_vm_struct mm/mmap.c:160 [inline]
unlink_file_vma+0xbd/0x110 mm/mmap.c:175
free_pgtables+0x255/0x420 mm/memory.c:440

exit_mmap+0x1ff/0x740 mm/mmap.c:3219
__mmput+0x128/0x4c0 kernel/fork.c:1180
mmput+0x5c/0x70 kernel/fork.c:1201

exit_mm kernel/exit.c:510 [inline]
do_exit+0xa18/0x2a00 kernel/exit.c:782
do_group_exit+0xd2/0x2f0 kernel/exit.c:925

get_signal+0x2542/0x2600 kernel/signal.c:2857
arch_do_signal_or_restart+0x82/0x20f0 arch/x86/kernel/signal.c:869
exit_to_user_mode_loop kernel/entry/common.c:166 [inline]
exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:201
irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:307
exc_page_fault+0xc6/0x180 arch/x86/mm/fault.c:1543
asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0033:0x7f1771dc98cf
Code: Unable to access opcode bytes at RIP 0x7f1771dc98a5.
RSP: 002b:00007ffe920035a0 EFLAGS: 00010206
RAX: 0000000000000001 RBX: 00007f1771e78138 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 00007f1771e78138 RDI: 000000000000000b
RBP: 000000000000000b R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000008011 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000001 R14: 00000000000c3ec0 R15: 0000000000000001

</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---

RIP: 0010:____rb_erase_color lib/rbtree.c:354 [inline]
RIP: 0010:__rb_erase_color+0x159/0xdb0 lib/rbtree.c:413
Code: 89 ed 48 89 c5 e9 f5 fe ff ff 4c 8d 45 10 4c 89 c0 48 c1 e8 03 80 3c 18 00 0f 85 3a 08 00 00 4c 8b 65 10 4c 89 e0 48 c1 e8 03 <80> 3c 18 00 0f 85 6a 08 00 00 49 8b 04 24 49 8d 7c 24 08 48 89 f9
RSP: 0018:ffffc90002e877a8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffffed100e8d3aed RSI: ffff88807469d768 RDI: ffff8880202132b0
RBP: ffff8880202132b0 R08: ffff8880202132c0 R09: ffff88807469d75f
R10: ffffffff81b02518 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88807469d768 R15: ffffffff81b01300
FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000

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

CR2: 00000000000c3ec8 CR3: 0000000023516000 CR4: 00000000003506f0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):

0: 89 ed mov %ebp,%ebp
2: 48 89 c5 mov %rax,%rbp
5: e9 f5 fe ff ff jmpq 0xfffffeff
a: 4c 8d 45 10 lea 0x10(%rbp),%r8
e: 4c 89 c0 mov %r8,%rax
11: 48 c1 e8 03 shr $0x3,%rax
15: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1)
19: 0f 85 3a 08 00 00 jne 0x859
1f: 4c 8b 65 10 mov 0x10(%rbp),%r12
23: 4c 89 e0 mov %r12,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1) <-- trapping instruction
2e: 0f 85 6a 08 00 00 jne 0x89e
34: 49 8b 04 24 mov (%r12),%rax
38: 49 8d 7c 24 08 lea 0x8(%r12),%rdi
3d: 48 89 f9 mov %rdi,%rcx

[Andrew Morton]

On Sat, 14 May 2022 13:18:26 -0700 syzbot <syzbot+ee1fdd...@syzkaller.appspotmail.com> wrote:

> syzbot has found a reproducer for the following issue on:
>
> HEAD commit: 1e1b28b936ae Add linux-next specific files for 20220513
> git tree: linux-next
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=11da21b9f00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=e4eb3c0c4b289571
> dashboard link: https://syzkaller.appspot.com/bug?extid=ee1fdd8dcc770a3a169a
> 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=142757f1f00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17cf0966f00000

Thanks.

So it was there on April 28 and it's there now. Liam, do you think
anything in the mapletree changes could have perturbed the interval
tree handling?

[syzbot]

syzbot has bisected this issue to:

commit b7d0f898f5ce328ad809417f2e728b58153d52d1
Author: Liam R. Howlett <Liam.H...@Oracle.com>
Date: Fri May 13 04:15:44 2022 +0000

mm: remove the vma linked list

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=12fefe69f00000
start commit: 1e1b28b936ae Add linux-next specific files for 20220513
git tree: linux-next
final oops: https://syzkaller.appspot.com/x/report.txt?x=11fefe69f00000
console output: https://syzkaller.appspot.com/x/log.txt?x=16fefe69f00000

kernel config: https://syzkaller.appspot.com/x/.config?x=e4eb3c0c4b289571
dashboard link: https://syzkaller.appspot.com/bug?extid=ee1fdd8dcc770a3a169a

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=142757f1f00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17cf0966f00000

Reported-by: syzbot+ee1fdd...@syzkaller.appspotmail.com
Fixes: b7d0f898f5ce ("mm: remove the vma linked list")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

[Liam Howlett]

* Andrew Morton <ak...@linux-foundation.org> [220514 16:50]:

> On Sat, 14 May 2022 13:18:26 -0700 syzbot <syzbot+ee1fdd...@syzkaller.appspotmail.com> wrote:
>
> > syzbot has found a reproducer for the following issue on:
> >
> > HEAD commit: 1e1b28b936ae Add linux-next specific files for 20220513
> > git tree: linux-next
> > console+strace: https://syzkaller.appspot.com/x/log.txt?x=11da21b9f00000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=e4eb3c0c4b289571
> > dashboard link: https://syzkaller.appspot.com/bug?extid=ee1fdd8dcc770a3a169a
> > 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=142757f1f00000
> > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17cf0966f00000
>
> Thanks.
>
> So it was there on April 28 and it's there now. Liam, do you think
> anything in the mapletree changes could have perturbed the interval
> tree handling?

It is certainly possible, these two trees are intertwined so much. One
area that sticks out as a possibility is vma_expand(). I created a
vma_expand() function to handle growing a vma and potentially removing
the next vma. I do some interval tree modifications in there.

I'll add it to my list of items to look at.

[Liam Howlett]

* Liam R. Howlett <Liam.H...@Oracle.com> [220516 13:59]:

> * Andrew Morton <ak...@linux-foundation.org> [220514 16:50]:
> > On Sat, 14 May 2022 13:18:26 -0700 syzbot <syzbot+ee1fdd...@syzkaller.appspotmail.com> wrote:
> >
> > > syzbot has found a reproducer for the following issue on:
> > >
> > > HEAD commit: 1e1b28b936ae Add linux-next specific files for 20220513
> > > git tree: linux-next
> > > console+strace: https://syzkaller.appspot.com/x/log.txt?x=11da21b9f00000
> > > kernel config: https://syzkaller.appspot.com/x/.config?x=e4eb3c0c4b289571
> > > dashboard link: https://syzkaller.appspot.com/bug?extid=ee1fdd8dcc770a3a169a
> > > 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=142757f1f00000
> > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17cf0966f00000
> >
> > Thanks.
> >
> > So it was there on April 28 and it's there now. Liam, do you think
> > anything in the mapletree changes could have perturbed the interval
> > tree handling?
>
> It is certainly possible, these two trees are intertwined so much. One
> area that sticks out as a possibility is vma_expand(). I created a
> vma_expand() function to handle growing a vma and potentially removing
> the next vma. I do some interval tree modifications in there.
>
> I'll add it to my list of items to look at.

This was my bug. I reused a pointer that wasn't reused in this function
until I altered the error path in this commit.

Please apply this patch to the maple tree series to fix "mm/mmap: use
advanced maple tree API for mmap_region()"

Thanks,
Liam

[Dmitry Vyukov]

Please add this tag to the fix: