* divide error in nbd_ioctl
@ 2018-09-04 7:51 syzbot
2018-09-04 15:07 ` Jens Axboe
0 siblings, 1 reply; 4+ messages in thread
From: syzbot @ 2018-09-04 7:51 UTC (permalink / raw)
To: axboe, josef, linux-block, linux-kernel, nbd, syzkaller-bugs
Hello,
syzbot found the following crash on:
HEAD commit: 217c3e019675 disable stringop truncation warnings for now
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13665da6400000
kernel config: https://syzkaller.appspot.com/x/.config?x=531a917630d2a492
dashboard link: https://syzkaller.appspot.com/bug?extid=25dbecbec1e62c6b0dd4
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=163e910a400000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=169dfe0a400000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+25dbecbec1e62c6b0dd4@syzkaller.appspotmail.com
random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
divide error: 0000 [#1] SMP KASAN
CPU: 0 PID: 4667 Comm: syz-executor024 Not tainted 4.19.0-rc1+ #216
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:div_s64_rem include/linux/math64.h:41 [inline]
RIP: 0010:div_s64 include/linux/math64.h:139 [inline]
RIP: 0010:__nbd_ioctl drivers/block/nbd.c:1242 [inline]
RIP: 0010:nbd_ioctl+0x53c/0xcf0 drivers/block/nbd.c:1303
Code: ea 03 80 3c 02 00 0f 85 1c 07 00 00 48 8b b5 c0 fe ff ff 48 63 8d b8
fe ff ff 48 8b 86 c8 00 00 00 48 8d be c0 00 00 00 48 99 <48> f7 f9 48 ba
00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c
RSP: 0018:ffff8801c90bf828 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff8801ccb23c00 RDI: ffff8801ccb23cc0
RBP: ffff8801c90bf9a0 R08: ffff8801bc502640 R09: ffffed003a62d01d
R10: ffff8801c90bf818 R11: ffff8801d31680ef R12: ffff8801d3168000
R13: 00000000ffffffe7 R14: ffff8801d31680e0 R15: ffff8801d5730840
FS: 00000000015b2880(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000043e560 CR3: 00000001b8034000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__blkdev_driver_ioctl block/ioctl.c:303 [inline]
blkdev_ioctl+0x9cd/0x2030 block/ioctl.c:601
block_ioctl+0xee/0x130 fs/block_dev.c:1883
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685
ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702
__do_sys_ioctl fs/ioctl.c:709 [inline]
__se_sys_ioctl fs/ioctl.c:707 [inline]
__x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x443d29
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 7b d8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffe343644d8 EFLAGS: 00000213 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000443d29
RDX: 0000000000000000 RSI: 000000000000ab01 RDI: 0000000000000003
RBP: 00000000006ce018 R08: 0000000000000000 R09: 00000000004002e0
R10: 000000000000000f R11: 0000000000000213 R12: 0000000000401a30
R13: 0000000000401ac0 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
Dumping ftrace buffer:
(ftrace buffer empty)
---[ end trace 25c60c4714d4e2ee ]---
RIP: 0010:div_s64_rem include/linux/math64.h:41 [inline]
RIP: 0010:div_s64 include/linux/math64.h:139 [inline]
RIP: 0010:__nbd_ioctl drivers/block/nbd.c:1242 [inline]
RIP: 0010:nbd_ioctl+0x53c/0xcf0 drivers/block/nbd.c:1303
Code: ea 03 80 3c 02 00 0f 85 1c 07 00 00 48 8b b5 c0 fe ff ff 48 63 8d b8
fe ff ff 48 8b 86 c8 00 00 00 48 8d be c0 00 00 00 48 99 <48> f7 f9 48 ba
00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c
RSP: 0018:ffff8801c90bf828 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff8801ccb23c00 RDI: ffff8801ccb23cc0
RBP: ffff8801c90bf9a0 R08: ffff8801bc502640 R09: ffffed003a62d01d
R10: ffff8801c90bf818 R11: ffff8801d31680ef R12: ffff8801d3168000
R13: 00000000ffffffe7 R14: ffff8801d31680e0 R15: ffff8801d5730840
FS: 00000000015b2880(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000043e560 CR3: 00000001b8034000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
---
This bug 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 syzkaller@googlegroups.com.
syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: divide error in nbd_ioctl
2018-09-04 7:51 divide error in nbd_ioctl syzbot
@ 2018-09-04 15:07 ` Jens Axboe
2018-09-04 17:48 ` Josef Bacik
0 siblings, 1 reply; 4+ messages in thread
From: Jens Axboe @ 2018-09-04 15:07 UTC (permalink / raw)
To: syzbot, josef, linux-block, linux-kernel, nbd, syzkaller-bugs
On 9/4/18 1:51 AM, syzbot wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: 217c3e019675 disable stringop truncation warnings for now
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=13665da6400000
> kernel config: https://syzkaller.appspot.com/x/.config?x=531a917630d2a492
> dashboard link: https://syzkaller.appspot.com/bug?extid=25dbecbec1e62c6b0dd4
> compiler: gcc (GCC) 8.0.1 20180413 (experimental)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=163e910a400000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=169dfe0a400000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+25dbecbec1e62c6b0dd4@syzkaller.appspotmail.com
>
> random: sshd: uninitialized urandom read (32 bytes read)
> random: sshd: uninitialized urandom read (32 bytes read)
> random: sshd: uninitialized urandom read (32 bytes read)
> random: sshd: uninitialized urandom read (32 bytes read)
> random: sshd: uninitialized urandom read (32 bytes read)
> divide error: 0000 [#1] SMP KASAN
> CPU: 0 PID: 4667 Comm: syz-executor024 Not tainted 4.19.0-rc1+ #216
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> RIP: 0010:div_s64_rem include/linux/math64.h:41 [inline]
> RIP: 0010:div_s64 include/linux/math64.h:139 [inline]
> RIP: 0010:__nbd_ioctl drivers/block/nbd.c:1242 [inline]
> RIP: 0010:nbd_ioctl+0x53c/0xcf0 drivers/block/nbd.c:1303
> Code: ea 03 80 3c 02 00 0f 85 1c 07 00 00 48 8b b5 c0 fe ff ff 48 63 8d b8
> fe ff ff 48 8b 86 c8 00 00 00 48 8d be c0 00 00 00 48 99 <48> f7 f9 48 ba
> 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c
> RSP: 0018:ffff8801c90bf828 EFLAGS: 00010246
> RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: ffff8801ccb23c00 RDI: ffff8801ccb23cc0
> RBP: ffff8801c90bf9a0 R08: ffff8801bc502640 R09: ffffed003a62d01d
> R10: ffff8801c90bf818 R11: ffff8801d31680ef R12: ffff8801d3168000
> R13: 00000000ffffffe7 R14: ffff8801d31680e0 R15: ffff8801d5730840
> FS: 00000000015b2880(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000000000043e560 CR3: 00000001b8034000 CR4: 00000000001406f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> __blkdev_driver_ioctl block/ioctl.c:303 [inline]
> blkdev_ioctl+0x9cd/0x2030 block/ioctl.c:601
> block_ioctl+0xee/0x130 fs/block_dev.c:1883
> vfs_ioctl fs/ioctl.c:46 [inline]
> file_ioctl fs/ioctl.c:501 [inline]
> do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685
> ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702
> __do_sys_ioctl fs/ioctl.c:709 [inline]
> __se_sys_ioctl fs/ioctl.c:707 [inline]
> __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707
> do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x443d29
> Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 7b d8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
> RSP: 002b:00007ffe343644d8 EFLAGS: 00000213 ORIG_RAX: 0000000000000010
> RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000443d29
> RDX: 0000000000000000 RSI: 000000000000ab01 RDI: 0000000000000003
> RBP: 00000000006ce018 R08: 0000000000000000 R09: 00000000004002e0
> R10: 000000000000000f R11: 0000000000000213 R12: 0000000000401a30
> R13: 0000000000401ac0 R14: 0000000000000000 R15: 0000000000000000
> Modules linked in:
> Dumping ftrace buffer:
> (ftrace buffer empty)
> ---[ end trace 25c60c4714d4e2ee ]---
> RIP: 0010:div_s64_rem include/linux/math64.h:41 [inline]
> RIP: 0010:div_s64 include/linux/math64.h:139 [inline]
> RIP: 0010:__nbd_ioctl drivers/block/nbd.c:1242 [inline]
> RIP: 0010:nbd_ioctl+0x53c/0xcf0 drivers/block/nbd.c:1303
> Code: ea 03 80 3c 02 00 0f 85 1c 07 00 00 48 8b b5 c0 fe ff ff 48 63 8d b8
> fe ff ff 48 8b 86 c8 00 00 00 48 8d be c0 00 00 00 48 99 <48> f7 f9 48 ba
> 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c
> RSP: 0018:ffff8801c90bf828 EFLAGS: 00010246
> RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: ffff8801ccb23c00 RDI: ffff8801ccb23cc0
> RBP: ffff8801c90bf9a0 R08: ffff8801bc502640 R09: ffffed003a62d01d
> R10: ffff8801c90bf818 R11: ffff8801d31680ef R12: ffff8801d3168000
> R13: 00000000ffffffe7 R14: ffff8801d31680e0 R15: ffff8801d5730840
> FS: 00000000015b2880(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000000000043e560 CR3: 00000001b8034000 CR4: 00000000001406f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Looks like NBD_SET_BLKSIZE is happy to just take whatever value.
We should ensure that it's a power of 2, not zero, and bigger
or equal than 512, but smaller or equal to PAGE_SIZE. Something
like this?
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 3863c00372bb..14a51254c3db 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -1239,6 +1239,9 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
case NBD_SET_SOCK:
return nbd_add_socket(nbd, arg, false);
case NBD_SET_BLKSIZE:
+ if (!arg || !is_power_of_2(arg) || arg < 512 ||
+ arg > PAGE_SIZE)
+ return -EINVAL;
nbd_size_set(nbd, arg,
div_s64(config->bytesize, arg));
return 0;
--
Jens Axboe
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: divide error in nbd_ioctl
2018-09-04 15:07 ` Jens Axboe
@ 2018-09-04 17:48 ` Josef Bacik
2018-09-04 17:55 ` Jens Axboe
0 siblings, 1 reply; 4+ messages in thread
From: Josef Bacik @ 2018-09-04 17:48 UTC (permalink / raw)
To: Jens Axboe; +Cc: syzbot, josef, linux-block, linux-kernel, nbd, syzkaller-bugs
On Tue, Sep 04, 2018 at 09:07:37AM -0600, Jens Axboe wrote:
> On 9/4/18 1:51 AM, syzbot wrote:
> > Hello,
> >
> > syzbot found the following crash on:
> >
> > HEAD commit: 217c3e019675 disable stringop truncation warnings for now
> > git tree: upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=13665da6400000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=531a917630d2a492
> > dashboard link: https://syzkaller.appspot.com/bug?extid=25dbecbec1e62c6b0dd4
> > compiler: gcc (GCC) 8.0.1 20180413 (experimental)
> > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=163e910a400000
> > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=169dfe0a400000
> >
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+25dbecbec1e62c6b0dd4@syzkaller.appspotmail.com
> >
> > random: sshd: uninitialized urandom read (32 bytes read)
> > random: sshd: uninitialized urandom read (32 bytes read)
> > random: sshd: uninitialized urandom read (32 bytes read)
> > random: sshd: uninitialized urandom read (32 bytes read)
> > random: sshd: uninitialized urandom read (32 bytes read)
> > divide error: 0000 [#1] SMP KASAN
> > CPU: 0 PID: 4667 Comm: syz-executor024 Not tainted 4.19.0-rc1+ #216
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> > Google 01/01/2011
> > RIP: 0010:div_s64_rem include/linux/math64.h:41 [inline]
> > RIP: 0010:div_s64 include/linux/math64.h:139 [inline]
> > RIP: 0010:__nbd_ioctl drivers/block/nbd.c:1242 [inline]
> > RIP: 0010:nbd_ioctl+0x53c/0xcf0 drivers/block/nbd.c:1303
> > Code: ea 03 80 3c 02 00 0f 85 1c 07 00 00 48 8b b5 c0 fe ff ff 48 63 8d b8
> > fe ff ff 48 8b 86 c8 00 00 00 48 8d be c0 00 00 00 48 99 <48> f7 f9 48 ba
> > 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c
> > RSP: 0018:ffff8801c90bf828 EFLAGS: 00010246
> > RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
> > RDX: 0000000000000000 RSI: ffff8801ccb23c00 RDI: ffff8801ccb23cc0
> > RBP: ffff8801c90bf9a0 R08: ffff8801bc502640 R09: ffffed003a62d01d
> > R10: ffff8801c90bf818 R11: ffff8801d31680ef R12: ffff8801d3168000
> > R13: 00000000ffffffe7 R14: ffff8801d31680e0 R15: ffff8801d5730840
> > FS: 00000000015b2880(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000
> > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > CR2: 000000000043e560 CR3: 00000001b8034000 CR4: 00000000001406f0
> > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> > Call Trace:
> > __blkdev_driver_ioctl block/ioctl.c:303 [inline]
> > blkdev_ioctl+0x9cd/0x2030 block/ioctl.c:601
> > block_ioctl+0xee/0x130 fs/block_dev.c:1883
> > vfs_ioctl fs/ioctl.c:46 [inline]
> > file_ioctl fs/ioctl.c:501 [inline]
> > do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685
> > ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702
> > __do_sys_ioctl fs/ioctl.c:709 [inline]
> > __se_sys_ioctl fs/ioctl.c:707 [inline]
> > __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707
> > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
> > entry_SYSCALL_64_after_hwframe+0x49/0xbe
> > RIP: 0033:0x443d29
> > Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 7b d8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
> > RSP: 002b:00007ffe343644d8 EFLAGS: 00000213 ORIG_RAX: 0000000000000010
> > RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000443d29
> > RDX: 0000000000000000 RSI: 000000000000ab01 RDI: 0000000000000003
> > RBP: 00000000006ce018 R08: 0000000000000000 R09: 00000000004002e0
> > R10: 000000000000000f R11: 0000000000000213 R12: 0000000000401a30
> > R13: 0000000000401ac0 R14: 0000000000000000 R15: 0000000000000000
> > Modules linked in:
> > Dumping ftrace buffer:
> > (ftrace buffer empty)
> > ---[ end trace 25c60c4714d4e2ee ]---
> > RIP: 0010:div_s64_rem include/linux/math64.h:41 [inline]
> > RIP: 0010:div_s64 include/linux/math64.h:139 [inline]
> > RIP: 0010:__nbd_ioctl drivers/block/nbd.c:1242 [inline]
> > RIP: 0010:nbd_ioctl+0x53c/0xcf0 drivers/block/nbd.c:1303
> > Code: ea 03 80 3c 02 00 0f 85 1c 07 00 00 48 8b b5 c0 fe ff ff 48 63 8d b8
> > fe ff ff 48 8b 86 c8 00 00 00 48 8d be c0 00 00 00 48 99 <48> f7 f9 48 ba
> > 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c
> > RSP: 0018:ffff8801c90bf828 EFLAGS: 00010246
> > RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
> > RDX: 0000000000000000 RSI: ffff8801ccb23c00 RDI: ffff8801ccb23cc0
> > RBP: ffff8801c90bf9a0 R08: ffff8801bc502640 R09: ffffed003a62d01d
> > R10: ffff8801c90bf818 R11: ffff8801d31680ef R12: ffff8801d3168000
> > R13: 00000000ffffffe7 R14: ffff8801d31680e0 R15: ffff8801d5730840
> > FS: 00000000015b2880(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000
> > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > CR2: 000000000043e560 CR3: 00000001b8034000 CR4: 00000000001406f0
> > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>
> Looks like NBD_SET_BLKSIZE is happy to just take whatever value.
> We should ensure that it's a power of 2, not zero, and bigger
> or equal than 512, but smaller or equal to PAGE_SIZE. Something
> like this?
>
>
> diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
> index 3863c00372bb..14a51254c3db 100644
> --- a/drivers/block/nbd.c
> +++ b/drivers/block/nbd.c
> @@ -1239,6 +1239,9 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
> case NBD_SET_SOCK:
> return nbd_add_socket(nbd, arg, false);
> case NBD_SET_BLKSIZE:
> + if (!arg || !is_power_of_2(arg) || arg < 512 ||
> + arg > PAGE_SIZE)
> + return -EINVAL;
> nbd_size_set(nbd, arg,
> div_s64(config->bytesize, arg));
> return 0;
Thanks Jens, you can add
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Thanks,
Josef
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: divide error in nbd_ioctl
2018-09-04 17:48 ` Josef Bacik
@ 2018-09-04 17:55 ` Jens Axboe
0 siblings, 0 replies; 4+ messages in thread
From: Jens Axboe @ 2018-09-04 17:55 UTC (permalink / raw)
To: Josef Bacik; +Cc: syzbot, linux-block, linux-kernel, nbd, syzkaller-bugs
On 9/4/18 11:48 AM, Josef Bacik wrote:
> On Tue, Sep 04, 2018 at 09:07:37AM -0600, Jens Axboe wrote:
>> On 9/4/18 1:51 AM, syzbot wrote:
>>> Hello,
>>>
>>> syzbot found the following crash on:
>>>
>>> HEAD commit: 217c3e019675 disable stringop truncation warnings for now
>>> git tree: upstream
>>> console output: https://syzkaller.appspot.com/x/log.txt?x=13665da6400000
>>> kernel config: https://syzkaller.appspot.com/x/.config?x=531a917630d2a492
>>> dashboard link: https://syzkaller.appspot.com/bug?extid=25dbecbec1e62c6b0dd4
>>> compiler: gcc (GCC) 8.0.1 20180413 (experimental)
>>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=163e910a400000
>>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=169dfe0a400000
>>>
>>> IMPORTANT: if you fix the bug, please add the following tag to the commit:
>>> Reported-by: syzbot+25dbecbec1e62c6b0dd4@syzkaller.appspotmail.com
>>>
>>> random: sshd: uninitialized urandom read (32 bytes read)
>>> random: sshd: uninitialized urandom read (32 bytes read)
>>> random: sshd: uninitialized urandom read (32 bytes read)
>>> random: sshd: uninitialized urandom read (32 bytes read)
>>> random: sshd: uninitialized urandom read (32 bytes read)
>>> divide error: 0000 [#1] SMP KASAN
>>> CPU: 0 PID: 4667 Comm: syz-executor024 Not tainted 4.19.0-rc1+ #216
>>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
>>> Google 01/01/2011
>>> RIP: 0010:div_s64_rem include/linux/math64.h:41 [inline]
>>> RIP: 0010:div_s64 include/linux/math64.h:139 [inline]
>>> RIP: 0010:__nbd_ioctl drivers/block/nbd.c:1242 [inline]
>>> RIP: 0010:nbd_ioctl+0x53c/0xcf0 drivers/block/nbd.c:1303
>>> Code: ea 03 80 3c 02 00 0f 85 1c 07 00 00 48 8b b5 c0 fe ff ff 48 63 8d b8
>>> fe ff ff 48 8b 86 c8 00 00 00 48 8d be c0 00 00 00 48 99 <48> f7 f9 48 ba
>>> 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c
>>> RSP: 0018:ffff8801c90bf828 EFLAGS: 00010246
>>> RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
>>> RDX: 0000000000000000 RSI: ffff8801ccb23c00 RDI: ffff8801ccb23cc0
>>> RBP: ffff8801c90bf9a0 R08: ffff8801bc502640 R09: ffffed003a62d01d
>>> R10: ffff8801c90bf818 R11: ffff8801d31680ef R12: ffff8801d3168000
>>> R13: 00000000ffffffe7 R14: ffff8801d31680e0 R15: ffff8801d5730840
>>> FS: 00000000015b2880(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000
>>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> CR2: 000000000043e560 CR3: 00000001b8034000 CR4: 00000000001406f0
>>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>>> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>>> Call Trace:
>>> __blkdev_driver_ioctl block/ioctl.c:303 [inline]
>>> blkdev_ioctl+0x9cd/0x2030 block/ioctl.c:601
>>> block_ioctl+0xee/0x130 fs/block_dev.c:1883
>>> vfs_ioctl fs/ioctl.c:46 [inline]
>>> file_ioctl fs/ioctl.c:501 [inline]
>>> do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685
>>> ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702
>>> __do_sys_ioctl fs/ioctl.c:709 [inline]
>>> __se_sys_ioctl fs/ioctl.c:707 [inline]
>>> __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707
>>> do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
>>> entry_SYSCALL_64_after_hwframe+0x49/0xbe
>>> RIP: 0033:0x443d29
>>> Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 7b d8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
>>> RSP: 002b:00007ffe343644d8 EFLAGS: 00000213 ORIG_RAX: 0000000000000010
>>> RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000443d29
>>> RDX: 0000000000000000 RSI: 000000000000ab01 RDI: 0000000000000003
>>> RBP: 00000000006ce018 R08: 0000000000000000 R09: 00000000004002e0
>>> R10: 000000000000000f R11: 0000000000000213 R12: 0000000000401a30
>>> R13: 0000000000401ac0 R14: 0000000000000000 R15: 0000000000000000
>>> Modules linked in:
>>> Dumping ftrace buffer:
>>> (ftrace buffer empty)
>>> ---[ end trace 25c60c4714d4e2ee ]---
>>> RIP: 0010:div_s64_rem include/linux/math64.h:41 [inline]
>>> RIP: 0010:div_s64 include/linux/math64.h:139 [inline]
>>> RIP: 0010:__nbd_ioctl drivers/block/nbd.c:1242 [inline]
>>> RIP: 0010:nbd_ioctl+0x53c/0xcf0 drivers/block/nbd.c:1303
>>> Code: ea 03 80 3c 02 00 0f 85 1c 07 00 00 48 8b b5 c0 fe ff ff 48 63 8d b8
>>> fe ff ff 48 8b 86 c8 00 00 00 48 8d be c0 00 00 00 48 99 <48> f7 f9 48 ba
>>> 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c
>>> RSP: 0018:ffff8801c90bf828 EFLAGS: 00010246
>>> RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
>>> RDX: 0000000000000000 RSI: ffff8801ccb23c00 RDI: ffff8801ccb23cc0
>>> RBP: ffff8801c90bf9a0 R08: ffff8801bc502640 R09: ffffed003a62d01d
>>> R10: ffff8801c90bf818 R11: ffff8801d31680ef R12: ffff8801d3168000
>>> R13: 00000000ffffffe7 R14: ffff8801d31680e0 R15: ffff8801d5730840
>>> FS: 00000000015b2880(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000
>>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> CR2: 000000000043e560 CR3: 00000001b8034000 CR4: 00000000001406f0
>>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>>> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>>
>> Looks like NBD_SET_BLKSIZE is happy to just take whatever value.
>> We should ensure that it's a power of 2, not zero, and bigger
>> or equal than 512, but smaller or equal to PAGE_SIZE. Something
>> like this?
>>
>>
>> diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
>> index 3863c00372bb..14a51254c3db 100644
>> --- a/drivers/block/nbd.c
>> +++ b/drivers/block/nbd.c
>> @@ -1239,6 +1239,9 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
>> case NBD_SET_SOCK:
>> return nbd_add_socket(nbd, arg, false);
>> case NBD_SET_BLKSIZE:
>> + if (!arg || !is_power_of_2(arg) || arg < 512 ||
>> + arg > PAGE_SIZE)
>> + return -EINVAL;
>> nbd_size_set(nbd, arg,
>> div_s64(config->bytesize, arg));
>> return 0;
>
> Thanks Jens, you can add
>
> Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Thanks, applied for 4.19.
--
Jens Axboe
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2018-09-04 17:55 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-09-04 7:51 divide error in nbd_ioctl syzbot
2018-09-04 15:07 ` Jens Axboe
2018-09-04 17:48 ` Josef Bacik
2018-09-04 17:55 ` Jens Axboe
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