* 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 [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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