Hello,
syzbot found the following issue on:
HEAD commit: 9ae1fbdeabd3 Add linux-next specific files for 20211025
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1331363cb00000
kernel config: https://syzkaller.appspot.com/x/.config?x=aeb17e42bc109064
dashboard link: https://syzkaller.appspot.com/bug?extid=b86736b5935e0d25b446
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=116ce954b00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=132fcf62b00000
The issue was bisected to:
commit 22849b5ea5952d853547cc5e0651f34a246b2a4f
Author: Leon Romanovsky <[email protected]>
Date: Thu Oct 21 14:16:14 2021 +0000
devlink: Remove not-executed trap policer notifications
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=137d8bfcb00000
final oops: https://syzkaller.appspot.com/x/report.txt?x=10fd8bfcb00000
console output: https://syzkaller.appspot.com/x/log.txt?x=177d8bfcb00000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]
Fixes: 22849b5ea595 ("devlink: Remove not-executed trap policer notifications")
==================================================================
BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:225 [inline]
BUG: KASAN: slab-out-of-bounds in copy_data+0xf3/0x2e0 drivers/char/hw_random/virtio-rng.c:68
Read of size 64 at addr ffff88801a7a1580 by task syz-executor989/6542
CPU: 1 PID: 6542 Comm: syz-executor989 Not tainted 5.15.0-rc6-next-20211025-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description.constprop.0.cold+0x8d/0x320 mm/kasan/report.c:247
__kasan_report mm/kasan/report.c:433 [inline]
kasan_report.cold+0x83/0xdf mm/kasan/report.c:450
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
memcpy+0x20/0x60 mm/kasan/shadow.c:65
memcpy include/linux/fortify-string.h:225 [inline]
copy_data+0xf3/0x2e0 drivers/char/hw_random/virtio-rng.c:68
virtio_read+0x1e0/0x230 drivers/char/hw_random/virtio-rng.c:90
rng_get_data drivers/char/hw_random/core.c:192 [inline]
rng_dev_read+0x400/0x660 drivers/char/hw_random/core.c:229
vfs_read+0x1b5/0x600 fs/read_write.c:483
ksys_read+0x12d/0x250 fs/read_write.c:623
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: 0033:0x7f05696617e9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 14 00 00 90 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 c4 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd06461948 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 000000000001294d RCX: 00007f05696617e9
RDX: 00000000fffffff1 RSI: 0000000020000180 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffd064619b0 R09: 00007ffd064619b0
R10: 00007ffd064613d0 R11: 0000000000000246 R12: 00007ffd0646197c
R13: 00007ffd064619b0 R14: 00007ffd06461990 R15: 0000000000000002
</TASK>
Allocated by task 1:
kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
____kasan_kmalloc mm/kasan/common.c:513 [inline]
____kasan_kmalloc mm/kasan/common.c:472 [inline]
__kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:522
kmalloc include/linux/slab.h:590 [inline]
kzalloc include/linux/slab.h:724 [inline]
probe_common+0xaa/0x5b0 drivers/char/hw_random/virtio-rng.c:132
virtio_dev_probe+0x44e/0x760 drivers/virtio/virtio.c:273
call_driver_probe drivers/base/dd.c:517 [inline]
really_probe+0x245/0xcc0 drivers/base/dd.c:596
__driver_probe_device+0x338/0x4d0 drivers/base/dd.c:751
driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:781
__driver_attach+0x22d/0x4e0 drivers/base/dd.c:1140
bus_for_each_dev+0x147/0x1d0 drivers/base/bus.c:301
bus_add_driver+0x41d/0x630 drivers/base/bus.c:618
driver_register+0x220/0x3a0 drivers/base/driver.c:171
do_one_initcall+0x103/0x650 init/main.c:1303
do_initcall_level init/main.c:1378 [inline]
do_initcalls init/main.c:1394 [inline]
do_basic_setup init/main.c:1413 [inline]
kernel_init_freeable+0x6b1/0x73a init/main.c:1618
kernel_init+0x1a/0x1d0 init/main.c:1507
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
The buggy address belongs to the object at ffff88801a7a1400
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 384 bytes inside of
512-byte region [ffff88801a7a1400, ffff88801a7a1600)
The buggy address belongs to the page:
page:ffffea000069e800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1a7a0
head:ffffea000069e800 order:2 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888010c41c80
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, ts 7709676886, free_ts 0
prep_new_page mm/page_alloc.c:2418 [inline]
get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4149
__alloc_pages+0x1b2/0x500 mm/page_alloc.c:5369
alloc_page_interleave+0x1e/0x200 mm/mempolicy.c:2036
alloc_pages+0x29f/0x300 mm/mempolicy.c:2186
alloc_slab_page mm/slub.c:1793 [inline]
allocate_slab mm/slub.c:1930 [inline]
new_slab+0x32d/0x4a0 mm/slub.c:1993
___slab_alloc+0x918/0xfe0 mm/slub.c:3022
__slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3109
slab_alloc_node mm/slub.c:3200 [inline]
slab_alloc mm/slub.c:3242 [inline]
kmem_cache_alloc_trace+0x289/0x2c0 mm/slub.c:3259
kmalloc include/linux/slab.h:590 [inline]
kzalloc include/linux/slab.h:724 [inline]
device_private_init drivers/base/core.c:3238 [inline]
device_add+0x11a7/0x1ee0 drivers/base/core.c:3288
device_create_groups_vargs+0x203/0x280 drivers/base/core.c:4052
device_create_with_groups+0xe3/0x120 drivers/base/core.c:4138
misc_register+0x20a/0x690 drivers/char/misc.c:206
register_miscdev drivers/char/hw_random/core.c:422 [inline]
hwrng_modinit+0xd0/0x109 drivers/char/hw_random/core.c:621
do_one_initcall+0x103/0x650 init/main.c:1303
do_initcall_level init/main.c:1378 [inline]
do_initcalls init/main.c:1394 [inline]
do_basic_setup init/main.c:1413 [inline]
kernel_init_freeable+0x6b1/0x73a init/main.c:1618
kernel_init+0x1a/0x1d0 init/main.c:1507
page_owner free stack trace missing
Memory state around the buggy address:
ffff88801a7a1480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88801a7a1500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88801a7a1580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff88801a7a1600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88801a7a1680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
---
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.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches
On 10/26/21 9:39 AM, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 9ae1fbdeabd3 Add linux-next specific files for 20211025
> git tree: linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=1331363cb00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=aeb17e42bc109064
> dashboard link: https://syzkaller.appspot.com/bug?extid=b86736b5935e0d25b446
> 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=116ce954b00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=132fcf62b00000
>
> The issue was bisected to:
>
> commit 22849b5ea5952d853547cc5e0651f34a246b2a4f
> Author: Leon Romanovsky <[email protected]>
> Date: Thu Oct 21 14:16:14 2021 +0000
>
> devlink: Remove not-executed trap policer notifications
More likely this came with
caaf2874ba27b92bca6f0298bf88bad94067ec37 hwrng: virtio - don't waste entropy
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=137d8bfcb00000
> final oops: https://syzkaller.appspot.com/x/report.txt?x=10fd8bfcb00000
> console output: https://syzkaller.appspot.com/x/log.txt?x=177d8bfcb00000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: [email protected]
> Fixes: 22849b5ea595 ("devlink: Remove not-executed trap policer notifications")
>
> ==================================================================
> BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:225 [inline]
> BUG: KASAN: slab-out-of-bounds in copy_data+0xf3/0x2e0 drivers/char/hw_random/virtio-rng.c:68
> Read of size 64 at addr ffff88801a7a1580 by task syz-executor989/6542
>
> CPU: 1 PID: 6542 Comm: syz-executor989 Not tainted 5.15.0-rc6-next-20211025-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Call Trace:
> <TASK>
> __dump_stack lib/dump_stack.c:88 [inline]
> dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
> print_address_description.constprop.0.cold+0x8d/0x320 mm/kasan/report.c:247
> __kasan_report mm/kasan/report.c:433 [inline]
> kasan_report.cold+0x83/0xdf mm/kasan/report.c:450
> check_region_inline mm/kasan/generic.c:183 [inline]
> kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
> memcpy+0x20/0x60 mm/kasan/shadow.c:65
> memcpy include/linux/fortify-string.h:225 [inline]
> copy_data+0xf3/0x2e0 drivers/char/hw_random/virtio-rng.c:68
> virtio_read+0x1e0/0x230 drivers/char/hw_random/virtio-rng.c:90
> rng_get_data drivers/char/hw_random/core.c:192 [inline]
> rng_dev_read+0x400/0x660 drivers/char/hw_random/core.c:229
> vfs_read+0x1b5/0x600 fs/read_write.c:483
> ksys_read+0x12d/0x250 fs/read_write.c:623
> 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: 0033:0x7f05696617e9
> Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 14 00 00 90 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 c4 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007ffd06461948 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
> RAX: ffffffffffffffda RBX: 000000000001294d RCX: 00007f05696617e9
> RDX: 00000000fffffff1 RSI: 0000000020000180 RDI: 0000000000000003
> RBP: 0000000000000000 R08: 00007ffd064619b0 R09: 00007ffd064619b0
> R10: 00007ffd064613d0 R11: 0000000000000246 R12: 00007ffd0646197c
> R13: 00007ffd064619b0 R14: 00007ffd06461990 R15: 0000000000000002
> </TASK>
>
> Allocated by task 1:
> kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
> kasan_set_track mm/kasan/common.c:46 [inline]
> set_alloc_info mm/kasan/common.c:434 [inline]
> ____kasan_kmalloc mm/kasan/common.c:513 [inline]
> ____kasan_kmalloc mm/kasan/common.c:472 [inline]
> __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:522
> kmalloc include/linux/slab.h:590 [inline]
> kzalloc include/linux/slab.h:724 [inline]
> probe_common+0xaa/0x5b0 drivers/char/hw_random/virtio-rng.c:132
> virtio_dev_probe+0x44e/0x760 drivers/virtio/virtio.c:273
> call_driver_probe drivers/base/dd.c:517 [inline]
> really_probe+0x245/0xcc0 drivers/base/dd.c:596
> __driver_probe_device+0x338/0x4d0 drivers/base/dd.c:751
> driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:781
> __driver_attach+0x22d/0x4e0 drivers/base/dd.c:1140
> bus_for_each_dev+0x147/0x1d0 drivers/base/bus.c:301
> bus_add_driver+0x41d/0x630 drivers/base/bus.c:618
> driver_register+0x220/0x3a0 drivers/base/driver.c:171
> do_one_initcall+0x103/0x650 init/main.c:1303
> do_initcall_level init/main.c:1378 [inline]
> do_initcalls init/main.c:1394 [inline]
> do_basic_setup init/main.c:1413 [inline]
> kernel_init_freeable+0x6b1/0x73a init/main.c:1618
> kernel_init+0x1a/0x1d0 init/main.c:1507
> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
>
> The buggy address belongs to the object at ffff88801a7a1400
> which belongs to the cache kmalloc-512 of size 512
> The buggy address is located 384 bytes inside of
> 512-byte region [ffff88801a7a1400, ffff88801a7a1600)
> The buggy address belongs to the page:
> page:ffffea000069e800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1a7a0
> head:ffffea000069e800 order:2 compound_mapcount:0 compound_pincount:0
> flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
> raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888010c41c80
> raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
> page dumped because: kasan: bad access detected
> page_owner tracks the page as allocated
> page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, ts 7709676886, free_ts 0
> prep_new_page mm/page_alloc.c:2418 [inline]
> get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4149
> __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5369
> alloc_page_interleave+0x1e/0x200 mm/mempolicy.c:2036
> alloc_pages+0x29f/0x300 mm/mempolicy.c:2186
> alloc_slab_page mm/slub.c:1793 [inline]
> allocate_slab mm/slub.c:1930 [inline]
> new_slab+0x32d/0x4a0 mm/slub.c:1993
> ___slab_alloc+0x918/0xfe0 mm/slub.c:3022
> __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3109
> slab_alloc_node mm/slub.c:3200 [inline]
> slab_alloc mm/slub.c:3242 [inline]
> kmem_cache_alloc_trace+0x289/0x2c0 mm/slub.c:3259
> kmalloc include/linux/slab.h:590 [inline]
> kzalloc include/linux/slab.h:724 [inline]
> device_private_init drivers/base/core.c:3238 [inline]
> device_add+0x11a7/0x1ee0 drivers/base/core.c:3288
> device_create_groups_vargs+0x203/0x280 drivers/base/core.c:4052
> device_create_with_groups+0xe3/0x120 drivers/base/core.c:4138
> misc_register+0x20a/0x690 drivers/char/misc.c:206
> register_miscdev drivers/char/hw_random/core.c:422 [inline]
> hwrng_modinit+0xd0/0x109 drivers/char/hw_random/core.c:621
> do_one_initcall+0x103/0x650 init/main.c:1303
> do_initcall_level init/main.c:1378 [inline]
> do_initcalls init/main.c:1394 [inline]
> do_basic_setup init/main.c:1413 [inline]
> kernel_init_freeable+0x6b1/0x73a init/main.c:1618
> kernel_init+0x1a/0x1d0 init/main.c:1507
> page_owner free stack trace missing
>
> Memory state around the buggy address:
> ffff88801a7a1480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ffff88801a7a1500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>> ffff88801a7a1580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> ^
> ffff88801a7a1600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> ffff88801a7a1680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> ==================================================================
>
>
> ---
> 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.
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection
> syzbot can test patches for this issue, for details see:
> https://goo.gl/tpsmEJ#testing-patches
>
On 27/10/2021 00:34, Eric Dumazet wrote:
>
>
> On 10/26/21 9:39 AM, syzbot wrote:
>> Hello,
>>
>> syzbot found the following issue on:
>>
>> HEAD commit: 9ae1fbdeabd3 Add linux-next specific files for 20211025
>> git tree: linux-next
>> console output: https://syzkaller.appspot.com/x/log.txt?x=1331363cb00000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=aeb17e42bc109064
>> dashboard link: https://syzkaller.appspot.com/bug?extid=b86736b5935e0d25b446
>> 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=116ce954b00000
>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=132fcf62b00000
>>
>> The issue was bisected to:
>>
>> commit 22849b5ea5952d853547cc5e0651f34a246b2a4f
>> Author: Leon Romanovsky <[email protected]>
>> Date: Thu Oct 21 14:16:14 2021 +0000
>>
>> devlink: Remove not-executed trap policer notifications
>
> More likely this came with
>
> caaf2874ba27b92bca6f0298bf88bad94067ec37 hwrng: virtio - don't waste entropy
>
I'm going to have a look.
Thanks,
Laurent
On Wed, Oct 27, 2021 at 09:08:04AM +0200, Laurent Vivier wrote:
> On 27/10/2021 00:34, Eric Dumazet wrote:
> >
> >
> > On 10/26/21 9:39 AM, syzbot wrote:
> > > Hello,
> > >
> > > syzbot found the following issue on:
> > >
> > > HEAD commit: 9ae1fbdeabd3 Add linux-next specific files for 20211025
> > > git tree: linux-next
> > > console output: https://syzkaller.appspot.com/x/log.txt?x=1331363cb00000
> > > kernel config: https://syzkaller.appspot.com/x/.config?x=aeb17e42bc109064
> > > dashboard link: https://syzkaller.appspot.com/bug?extid=b86736b5935e0d25b446
> > > 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=116ce954b00000
> > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=132fcf62b00000
> > >
> > > The issue was bisected to:
> > >
> > > commit 22849b5ea5952d853547cc5e0651f34a246b2a4f
> > > Author: Leon Romanovsky <[email protected]>
> > > Date: Thu Oct 21 14:16:14 2021 +0000
> > >
> > > devlink: Remove not-executed trap policer notifications
> >
> > More likely this came with
> >
> > caaf2874ba27b92bca6f0298bf88bad94067ec37 hwrng: virtio - don't waste entropy
> >
>
> I'm going to have a look.
>
> Thanks,
> Laurent
How bad is it if we just drop this and waste some bytes of entropy?
--
MST
On 27/10/2021 09:20, Michael S. Tsirkin wrote:
> On Wed, Oct 27, 2021 at 09:08:04AM +0200, Laurent Vivier wrote:
>> On 27/10/2021 00:34, Eric Dumazet wrote:
>>>
>>>
>>> On 10/26/21 9:39 AM, syzbot wrote:
>>>> Hello,
>>>>
>>>> syzbot found the following issue on:
>>>>
>>>> HEAD commit: 9ae1fbdeabd3 Add linux-next specific files for 20211025
>>>> git tree: linux-next
>>>> console output: https://syzkaller.appspot.com/x/log.txt?x=1331363cb00000
>>>> kernel config: https://syzkaller.appspot.com/x/.config?x=aeb17e42bc109064
>>>> dashboard link: https://syzkaller.appspot.com/bug?extid=b86736b5935e0d25b446
>>>> 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=116ce954b00000
>>>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=132fcf62b00000
>>>>
>>>> The issue was bisected to:
>>>>
>>>> commit 22849b5ea5952d853547cc5e0651f34a246b2a4f
>>>> Author: Leon Romanovsky <[email protected]>
>>>> Date: Thu Oct 21 14:16:14 2021 +0000
>>>>
>>>> devlink: Remove not-executed trap policer notifications
>>>
>>> More likely this came with
>>>
>>> caaf2874ba27b92bca6f0298bf88bad94067ec37 hwrng: virtio - don't waste entropy
>>>
>>
>> I'm going to have a look.
>>
>> Thanks,
>> Laurent
>
> How bad is it if we just drop this and waste some bytes of entropy?
>
I don't think it's bad at all. In most of the cases we should use the full buffer.
So, you can drop, I will re-submit them later with a fix.
Thanks,
Laurent
On 26/10/2021 18:39, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 9ae1fbdeabd3 Add linux-next specific files for 20211025
> git tree: linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=1331363cb00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=aeb17e42bc109064
> dashboard link: https://syzkaller.appspot.com/bug?extid=b86736b5935e0d25b446
> 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=116ce954b00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=132fcf62b00000
>
> The issue was bisected to:
>
> commit 22849b5ea5952d853547cc5e0651f34a246b2a4f
> Author: Leon Romanovsky <[email protected]>
> Date: Thu Oct 21 14:16:14 2021 +0000
>
> devlink: Remove not-executed trap policer notifications
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=137d8bfcb00000
> final oops: https://syzkaller.appspot.com/x/report.txt?x=10fd8bfcb00000
> console output: https://syzkaller.appspot.com/x/log.txt?x=177d8bfcb00000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: [email protected]
> Fixes: 22849b5ea595 ("devlink: Remove not-executed trap policer notifications")
>
> ==================================================================
> BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:225 [inline]
> BUG: KASAN: slab-out-of-bounds in copy_data+0xf3/0x2e0 drivers/char/hw_random/virtio-rng.c:68
> Read of size 64 at addr ffff88801a7a1580 by task syz-executor989/6542
>
I'm not able to reproduce the problem with next-20211026 and the C reproducer.
And reviewing the code in copy_data() I don't see any issue.
Is it possible to know what it the VM configuration used to test it?
Thanks,
Laurent
On Wed, 27 Oct 2021 at 15:11, Laurent Vivier <[email protected]> wrote:
>
> On 26/10/2021 18:39, syzbot wrote:
> > Hello,
> >
> > syzbot found the following issue on:
> >
> > HEAD commit: 9ae1fbdeabd3 Add linux-next specific files for 20211025
> > git tree: linux-next
> > console output: https://syzkaller.appspot.com/x/log.txt?x=1331363cb00000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=aeb17e42bc109064
> > dashboard link: https://syzkaller.appspot.com/bug?extid=b86736b5935e0d25b446
> > 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=116ce954b00000
> > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=132fcf62b00000
> >
> > The issue was bisected to:
> >
> > commit 22849b5ea5952d853547cc5e0651f34a246b2a4f
> > Author: Leon Romanovsky <[email protected]>
> > Date: Thu Oct 21 14:16:14 2021 +0000
> >
> > devlink: Remove not-executed trap policer notifications
> >
> > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=137d8bfcb00000
> > final oops: https://syzkaller.appspot.com/x/report.txt?x=10fd8bfcb00000
> > console output: https://syzkaller.appspot.com/x/log.txt?x=177d8bfcb00000
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: [email protected]
> > Fixes: 22849b5ea595 ("devlink: Remove not-executed trap policer notifications")
> >
> > ==================================================================
> > BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:225 [inline]
> > BUG: KASAN: slab-out-of-bounds in copy_data+0xf3/0x2e0 drivers/char/hw_random/virtio-rng.c:68
> > Read of size 64 at addr ffff88801a7a1580 by task syz-executor989/6542
> >
>
> I'm not able to reproduce the problem with next-20211026 and the C reproducer.
>
> And reviewing the code in copy_data() I don't see any issue.
>
> Is it possible to know what it the VM configuration used to test it?
Hi Laurent,
syzbot used e2-standard-2 GCE VM when that happened.
You can see some info about these VMs under the "VM info" link on the dashboard.
On Wed, Oct 27, 2021 at 03:36:19PM +0200, Dmitry Vyukov wrote:
> On Wed, 27 Oct 2021 at 15:11, Laurent Vivier <[email protected]> wrote:
> >
> > On 26/10/2021 18:39, syzbot wrote:
> > > Hello,
> > >
> > > syzbot found the following issue on:
> > >
> > > HEAD commit: 9ae1fbdeabd3 Add linux-next specific files for 20211025
> > > git tree: linux-next
> > > console output: https://syzkaller.appspot.com/x/log.txt?x=1331363cb00000
> > > kernel config: https://syzkaller.appspot.com/x/.config?x=aeb17e42bc109064
> > > dashboard link: https://syzkaller.appspot.com/bug?extid=b86736b5935e0d25b446
> > > 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=116ce954b00000
> > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=132fcf62b00000
> > >
> > > The issue was bisected to:
> > >
> > > commit 22849b5ea5952d853547cc5e0651f34a246b2a4f
> > > Author: Leon Romanovsky <[email protected]>
> > > Date: Thu Oct 21 14:16:14 2021 +0000
> > >
> > > devlink: Remove not-executed trap policer notifications
> > >
> > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=137d8bfcb00000
> > > final oops: https://syzkaller.appspot.com/x/report.txt?x=10fd8bfcb00000
> > > console output: https://syzkaller.appspot.com/x/log.txt?x=177d8bfcb00000
> > >
> > > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > > Reported-by: [email protected]
> > > Fixes: 22849b5ea595 ("devlink: Remove not-executed trap policer notifications")
> > >
> > > ==================================================================
> > > BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:225 [inline]
> > > BUG: KASAN: slab-out-of-bounds in copy_data+0xf3/0x2e0 drivers/char/hw_random/virtio-rng.c:68
> > > Read of size 64 at addr ffff88801a7a1580 by task syz-executor989/6542
> > >
> >
> > I'm not able to reproduce the problem with next-20211026 and the C reproducer.
> >
> > And reviewing the code in copy_data() I don't see any issue.
> >
> > Is it possible to know what it the VM configuration used to test it?
>
> Hi Laurent,
>
> syzbot used e2-standard-2 GCE VM when that happened.
> You can see some info about these VMs under the "VM info" link on the dashboard.
Could you pls confirm whether reverting
caaf2874ba27b92bca6f0298bf88bad94067ec37 addresses this?
On 27/10/2021 18:25, Laurent Vivier wrote:
> On 27/10/2021 17:28, Michael S. Tsirkin wrote:
>> On Wed, Oct 27, 2021 at 03:36:19PM +0200, Dmitry Vyukov wrote:
>>> On Wed, 27 Oct 2021 at 15:11, Laurent Vivier <[email protected]> wrote:
>>>>
>>>> On 26/10/2021 18:39, syzbot wrote:
>>>>> Hello,
>>>>>
>>>>> syzbot found the following issue on:
>>>>>
>>>>> HEAD commit: 9ae1fbdeabd3 Add linux-next specific files for 20211025
>>>>> git tree: linux-next
>>>>> console output: https://syzkaller.appspot.com/x/log.txt?x=1331363cb00000
>>>>> kernel config: https://syzkaller.appspot.com/x/.config?x=aeb17e42bc109064
>>>>> dashboard link: https://syzkaller.appspot.com/bug?extid=b86736b5935e0d25b446
>>>>> 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=116ce954b00000
>>>>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=132fcf62b00000
>>>>>
>>>>> The issue was bisected to:
>>>>>
>>>>> commit 22849b5ea5952d853547cc5e0651f34a246b2a4f
>>>>> Author: Leon Romanovsky <[email protected]>
>>>>> Date: Thu Oct 21 14:16:14 2021 +0000
>>>>>
>>>>> devlink: Remove not-executed trap policer notifications
>>>>>
>>>>> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=137d8bfcb00000
>>>>> final oops: https://syzkaller.appspot.com/x/report.txt?x=10fd8bfcb00000
>>>>> console output: https://syzkaller.appspot.com/x/log.txt?x=177d8bfcb00000
>>>>>
>>>>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>>>>> Reported-by: [email protected]
>>>>> Fixes: 22849b5ea595 ("devlink: Remove not-executed trap policer notifications")
>>>>>
>>>>> ==================================================================
>>>>> BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:225 [inline]
>>>>> BUG: KASAN: slab-out-of-bounds in copy_data+0xf3/0x2e0
>>>>> drivers/char/hw_random/virtio-rng.c:68
>>>>> Read of size 64 at addr ffff88801a7a1580 by task syz-executor989/6542
>>>>>
>>>>
>>>> I'm not able to reproduce the problem with next-20211026 and the C reproducer.
>>>>
>>>> And reviewing the code in copy_data() I don't see any issue.
>>>>
>>>> Is it possible to know what it the VM configuration used to test it?
>>>
>>> Hi Laurent,
>>>
>>> syzbot used e2-standard-2 GCE VM when that happened.
>>> You can see some info about these VMs under the "VM info" link on the dashboard.
>>
>> Could you pls confirm whether reverting
>> caaf2874ba27b92bca6f0298bf88bad94067ec37 addresses this?
>>
>
> I've restarted the syzbot on top of "hwrng: virtio - don't wait on cleanup" [1] and the
> problem has not been triggered.
>
> See https://syzkaller.appspot.com/bug?extid=b86736b5935e0d25b446
The problem seems to be introduced by the last patch:
"hwrng: virtio - always add a pending request"
not
"hwrng: virtio - don't waste entropy"
Thanks,
Laurent
>
> Thanks,
> Laurent
>
> [1]
> d721abbeb145 hwrng: virtio - don't wait on cleanup
> bb768beb0a5f hwrng: virtio - add an internal buffer
> d25f27432f80 (origin/master, origin/HEAD, master) Merge tag 'arm-soc-fixes-5.15-3' of
> git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
>
On 27/10/2021 17:28, Michael S. Tsirkin wrote:
> On Wed, Oct 27, 2021 at 03:36:19PM +0200, Dmitry Vyukov wrote:
>> On Wed, 27 Oct 2021 at 15:11, Laurent Vivier <[email protected]> wrote:
>>>
>>> On 26/10/2021 18:39, syzbot wrote:
>>>> Hello,
>>>>
>>>> syzbot found the following issue on:
>>>>
>>>> HEAD commit: 9ae1fbdeabd3 Add linux-next specific files for 20211025
>>>> git tree: linux-next
>>>> console output: https://syzkaller.appspot.com/x/log.txt?x=1331363cb00000
>>>> kernel config: https://syzkaller.appspot.com/x/.config?x=aeb17e42bc109064
>>>> dashboard link: https://syzkaller.appspot.com/bug?extid=b86736b5935e0d25b446
>>>> 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=116ce954b00000
>>>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=132fcf62b00000
>>>>
>>>> The issue was bisected to:
>>>>
>>>> commit 22849b5ea5952d853547cc5e0651f34a246b2a4f
>>>> Author: Leon Romanovsky <[email protected]>
>>>> Date: Thu Oct 21 14:16:14 2021 +0000
>>>>
>>>> devlink: Remove not-executed trap policer notifications
>>>>
>>>> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=137d8bfcb00000
>>>> final oops: https://syzkaller.appspot.com/x/report.txt?x=10fd8bfcb00000
>>>> console output: https://syzkaller.appspot.com/x/log.txt?x=177d8bfcb00000
>>>>
>>>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>>>> Reported-by: [email protected]
>>>> Fixes: 22849b5ea595 ("devlink: Remove not-executed trap policer notifications")
>>>>
>>>> ==================================================================
>>>> BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:225 [inline]
>>>> BUG: KASAN: slab-out-of-bounds in copy_data+0xf3/0x2e0 drivers/char/hw_random/virtio-rng.c:68
>>>> Read of size 64 at addr ffff88801a7a1580 by task syz-executor989/6542
>>>>
>>>
>>> I'm not able to reproduce the problem with next-20211026 and the C reproducer.
>>>
>>> And reviewing the code in copy_data() I don't see any issue.
>>>
>>> Is it possible to know what it the VM configuration used to test it?
>>
>> Hi Laurent,
>>
>> syzbot used e2-standard-2 GCE VM when that happened.
>> You can see some info about these VMs under the "VM info" link on the dashboard.
>
> Could you pls confirm whether reverting
> caaf2874ba27b92bca6f0298bf88bad94067ec37 addresses this?
>
I've restarted the syzbot on top of "hwrng: virtio - don't wait on cleanup" [1] and the
problem has not been triggered.
See https://syzkaller.appspot.com/bug?extid=b86736b5935e0d25b446
Thanks,
Laurent
[1]
d721abbeb145 hwrng: virtio - don't wait on cleanup
bb768beb0a5f hwrng: virtio - add an internal buffer
d25f27432f80 (origin/master, origin/HEAD, master) Merge tag 'arm-soc-fixes-5.15-3' of
git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
On Wed, Oct 27, 2021 at 08:20:08PM +0200, Laurent Vivier wrote:
> On 27/10/2021 19:03, Laurent Vivier wrote:
> > On 27/10/2021 18:25, Laurent Vivier wrote:
> > > On 27/10/2021 17:28, Michael S. Tsirkin wrote:
> > > > On Wed, Oct 27, 2021 at 03:36:19PM +0200, Dmitry Vyukov wrote:
> > > > > On Wed, 27 Oct 2021 at 15:11, Laurent Vivier <[email protected]> wrote:
> > > > > >
> > > > > > On 26/10/2021 18:39, syzbot wrote:
> > > > > > > Hello,
> > > > > > >
> > > > > > > syzbot found the following issue on:
> > > > > > >
> > > > > > > HEAD commit:??? 9ae1fbdeabd3 Add linux-next specific files for 20211025
> > > > > > > git tree:?????? linux-next
> > > > > > > console output: https://syzkaller.appspot.com/x/log.txt?x=1331363cb00000
> > > > > > > kernel config:? https://syzkaller.appspot.com/x/.config?x=aeb17e42bc109064
> > > > > > > dashboard link: https://syzkaller.appspot.com/bug?extid=b86736b5935e0d25b446
> > > > > > > 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=116ce954b00000
> > > > > > > C reproducer:?? https://syzkaller.appspot.com/x/repro.c?x=132fcf62b00000
> > > > > > >
> > > > > > > The issue was bisected to:
> > > > > > >
> > > > > > > commit 22849b5ea5952d853547cc5e0651f34a246b2a4f
> > > > > > > Author: Leon Romanovsky <[email protected]>
> > > > > > > Date:?? Thu Oct 21 14:16:14 2021 +0000
> > > > > > >
> > > > > > > ????? devlink: Remove not-executed trap policer notifications
> > > > > > >
> > > > > > > bisection log:? https://syzkaller.appspot.com/x/bisect.txt?x=137d8bfcb00000
> > > > > > > final oops:???? https://syzkaller.appspot.com/x/report.txt?x=10fd8bfcb00000
> > > > > > > console output: https://syzkaller.appspot.com/x/log.txt?x=177d8bfcb00000
> > > > > > >
> > > > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > > > > > > Reported-by: [email protected]
> > > > > > > Fixes: 22849b5ea595 ("devlink: Remove not-executed trap policer notifications")
> > > > > > >
> > > > > > > ==================================================================
> > > > > > > BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:225 [inline]
> > > > > > > BUG: KASAN: slab-out-of-bounds in
> > > > > > > copy_data+0xf3/0x2e0
> > > > > > > drivers/char/hw_random/virtio-rng.c:68
> > > > > > > Read of size 64 at addr ffff88801a7a1580 by task syz-executor989/6542
> > > > > > >
> > > > > >
> > > > > > I'm not able to reproduce the problem with next-20211026 and the C reproducer.
> > > > > >
> > > > > > And reviewing the code in copy_data() I don't see any issue.
> > > > > >
> > > > > > Is it possible to know what it the VM configuration used to test it?
> > > > >
> > > > > Hi Laurent,
> > > > >
> > > > > syzbot used e2-standard-2 GCE VM when that happened.
> > > > > You can see some info about these VMs under the "VM info" link on the dashboard.
> > > >
> > > > Could you pls confirm whether reverting
> > > > caaf2874ba27b92bca6f0298bf88bad94067ec37 addresses this?
> > > >
> > >
> > > I've restarted the syzbot on top of "hwrng: virtio - don't wait on
> > > cleanup" [1] and the problem has not been triggered.
> > >
> > > See https://syzkaller.appspot.com/bug?extid=b86736b5935e0d25b446
> >
> > The problem seems to be introduced by the last patch:
> >
> > "hwrng: virtio - always add a pending request"
>
> I think I understand the problem.
>
> As we check data_avail != 0 before waiting on the completion, we can have a data_idx != 0.
>
> The following change fixes the problem for me:
>
> --- a/drivers/char/hw_random/virtio-rng.c
> +++ b/drivers/char/hw_random/virtio-rng.c
> @@ -52,6 +52,8 @@ static void request_entropy(struct virtrng_info *vi)
> struct scatterlist sg;
>
> reinit_completion(&vi->have_data);
> + vi->data_avail = 0;
> + vi->data_idx = 0;
>
> sg_init_one(&sg, vi->data, sizeof(vi->data));
>
>
> MST, do you update the patch or do you want I send a new version?
>
> Thanks,
> Laurent
New version of the patchset pls, and note in the changelog
that just this patch changed.
--
MST