netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* KMSAN: kernel-infoleak in move_addr_to_user (4)
@ 2021-01-10 10:19 syzbot
  2021-01-11 19:30 ` Jakub Kicinski
  0 siblings, 1 reply; 4+ messages in thread
From: syzbot @ 2021-01-10 10:19 UTC (permalink / raw)
  To: davem, glider, kuba, linux-kernel, netdev, syzkaller-bugs

Hello,

syzbot found the following issue on:

HEAD commit:    73d62e81 kmsan: random: prevent boot-time reports in _mix_..
git tree:       https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=15c8b8c7500000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2cdf4151c9653e32
dashboard link: https://syzkaller.appspot.com/bug?extid=057884e2f453e8afebc8
compiler:       clang version 11.0.0 (https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=101520c7500000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=100b8f4f500000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+057884e2f453e8afebc8@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: kernel-infoleak in kmsan_copy_to_user+0x9c/0xb0 mm/kmsan/kmsan_hooks.c:249
CPU: 0 PID: 8245 Comm: syz-executor868 Not tainted 5.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x21c/0x280 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
 kmsan_internal_check_memory+0x202/0x520 mm/kmsan/kmsan.c:402
 kmsan_copy_to_user+0x9c/0xb0 mm/kmsan/kmsan_hooks.c:249
 instrument_copy_to_user include/linux/instrumented.h:121 [inline]
 _copy_to_user+0x1af/0x270 lib/usercopy.c:33
 copy_to_user include/linux/uaccess.h:209 [inline]
 move_addr_to_user+0x3a2/0x640 net/socket.c:237
 __sys_getsockname+0x407/0x5d0 net/socket.c:1906
 __do_sys_getsockname net/socket.c:1917 [inline]
 __se_sys_getsockname+0x91/0xb0 net/socket.c:1914
 __x64_sys_getsockname+0x4a/0x70 net/socket.c:1914
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x441219
Code: e8 fc ab 02 00 48 83 c4 18 c3 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 0f 83 1b 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffe3c24eaf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000033
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441219
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 0000000000000003
RBP: 00000000006cb018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000401fc0
R13: 0000000000402050 R14: 0000000000000000 R15: 0000000000000000

Local variable ----address@__sys_getsockname created at:
 __sys_getsockname+0x91/0x5d0 net/socket.c:1891
 __sys_getsockname+0x91/0x5d0 net/socket.c:1891

Bytes 2-3 of 20 are uninitialized
Memory access of size 20 starts at ffff888124bbbdf0
Data copied to user address 0000000020000100
=====================================================


---
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 syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: KMSAN: kernel-infoleak in move_addr_to_user (4)
  2021-01-10 10:19 KMSAN: kernel-infoleak in move_addr_to_user (4) syzbot
@ 2021-01-11 19:30 ` Jakub Kicinski
  2021-01-12  0:17   ` Cong Wang
  0 siblings, 1 reply; 4+ messages in thread
From: Jakub Kicinski @ 2021-01-11 19:30 UTC (permalink / raw)
  To: syzbot, Robin van der Gracht, Oleksij Rempel, Marc Kleine-Budde,
	linux-can
  Cc: davem, glider, linux-kernel, netdev, syzkaller-bugs

Looks like a AF_CAN socket:

r0 = socket(0x1d, 0x2, 0x6)
getsockname$packet(r0, &(0x7f0000000100)={0x11, 0x0, 0x0, 0x1, 0x0, 0x6, @broadcast}, &(0x7f0000000000)=0x14)


On Sun, 10 Jan 2021 02:19:15 -0800 syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    73d62e81 kmsan: random: prevent boot-time reports in _mix_..
> git tree:       https://github.com/google/kmsan.git master
> console output: https://syzkaller.appspot.com/x/log.txt?x=15c8b8c7500000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=2cdf4151c9653e32
> dashboard link: https://syzkaller.appspot.com/bug?extid=057884e2f453e8afebc8
> compiler:       clang version 11.0.0 (https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b)
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=101520c7500000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=100b8f4f500000
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+057884e2f453e8afebc8@syzkaller.appspotmail.com
> 
> =====================================================
> BUG: KMSAN: kernel-infoleak in kmsan_copy_to_user+0x9c/0xb0 mm/kmsan/kmsan_hooks.c:249
> CPU: 0 PID: 8245 Comm: syz-executor868 Not tainted 5.10.0-rc4-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Call Trace:
>  __dump_stack lib/dump_stack.c:77 [inline]
>  dump_stack+0x21c/0x280 lib/dump_stack.c:118
>  kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
>  kmsan_internal_check_memory+0x202/0x520 mm/kmsan/kmsan.c:402
>  kmsan_copy_to_user+0x9c/0xb0 mm/kmsan/kmsan_hooks.c:249
>  instrument_copy_to_user include/linux/instrumented.h:121 [inline]
>  _copy_to_user+0x1af/0x270 lib/usercopy.c:33
>  copy_to_user include/linux/uaccess.h:209 [inline]
>  move_addr_to_user+0x3a2/0x640 net/socket.c:237
>  __sys_getsockname+0x407/0x5d0 net/socket.c:1906
>  __do_sys_getsockname net/socket.c:1917 [inline]
>  __se_sys_getsockname+0x91/0xb0 net/socket.c:1914
>  __x64_sys_getsockname+0x4a/0x70 net/socket.c:1914
>  do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
>  entry_SYSCALL_64_after_hwframe+0x44/0xa9
> RIP: 0033:0x441219
> Code: e8 fc ab 02 00 48 83 c4 18 c3 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 0f 83 1b 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00
> RSP: 002b:00007ffe3c24eaf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000033
> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441219
> RDX: 0000000020000000 RSI: 0000000020000100 RDI: 0000000000000003
> RBP: 00000000006cb018 R08: 00000000004002c8 R09: 00000000004002c8
> R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000401fc0
> R13: 0000000000402050 R14: 0000000000000000 R15: 0000000000000000
> 
> Local variable ----address@__sys_getsockname created at:
>  __sys_getsockname+0x91/0x5d0 net/socket.c:1891
>  __sys_getsockname+0x91/0x5d0 net/socket.c:1891
> 
> Bytes 2-3 of 20 are uninitialized
> Memory access of size 20 starts at ffff888124bbbdf0
> Data copied to user address 0000000020000100
> =====================================================
> 
> 
> ---
> 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 syzkaller@googlegroups.com.
> 
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> syzbot can test patches for this issue, for details see:
> https://goo.gl/tpsmEJ#testing-patches


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: KMSAN: kernel-infoleak in move_addr_to_user (4)
  2021-01-11 19:30 ` Jakub Kicinski
@ 2021-01-12  0:17   ` Cong Wang
  2021-01-12  9:12     ` Oliver Hartkopp
  0 siblings, 1 reply; 4+ messages in thread
From: Cong Wang @ 2021-01-12  0:17 UTC (permalink / raw)
  To: Jakub Kicinski
  Cc: syzbot, Robin van der Gracht, Oleksij Rempel, Marc Kleine-Budde,
	linux-can, David Miller, Alexander Potapenko, LKML,
	Linux Kernel Network Developers, syzkaller-bugs

On Mon, Jan 11, 2021 at 11:33 AM Jakub Kicinski <kuba@kernel.org> wrote:
>
> Looks like a AF_CAN socket:
>
> r0 = socket(0x1d, 0x2, 0x6)
> getsockname$packet(r0, &(0x7f0000000100)={0x11, 0x0, 0x0, 0x1, 0x0, 0x6, @broadcast}, &(0x7f0000000000)=0x14)
>

Right, it seems we need a memset(0) in isotp_getname().

Thanks.

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: KMSAN: kernel-infoleak in move_addr_to_user (4)
  2021-01-12  0:17   ` Cong Wang
@ 2021-01-12  9:12     ` Oliver Hartkopp
  0 siblings, 0 replies; 4+ messages in thread
From: Oliver Hartkopp @ 2021-01-12  9:12 UTC (permalink / raw)
  To: Cong Wang, Jakub Kicinski
  Cc: syzbot, Robin van der Gracht, Oleksij Rempel, Marc Kleine-Budde,
	linux-can, David Miller, Alexander Potapenko, LKML,
	Linux Kernel Network Developers, syzkaller-bugs



On 12.01.21 01:17, Cong Wang wrote:
> On Mon, Jan 11, 2021 at 11:33 AM Jakub Kicinski <kuba@kernel.org> wrote:
>>
>> Looks like a AF_CAN socket:
>>
>> r0 = socket(0x1d, 0x2, 0x6)
>> getsockname$packet(r0, &(0x7f0000000100)={0x11, 0x0, 0x0, 0x1, 0x0, 0x6, @broadcast}, &(0x7f0000000000)=0x14)
>>
> 
> Right, it seems we need a memset(0) in isotp_getname().

Yes m(

Sent a patch to fix it:

https://lore.kernel.org/linux-can/20210112090457.11262-1-socketcan@hartkopp.net/T/#u

Many thanks!

Oliver

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2021-01-12  9:15 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-01-10 10:19 KMSAN: kernel-infoleak in move_addr_to_user (4) syzbot
2021-01-11 19:30 ` Jakub Kicinski
2021-01-12  0:17   ` Cong Wang
2021-01-12  9:12     ` Oliver Hartkopp

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).