Hello,
syzkaller hit the following crash on
19d28fbd306e7ae7c1acf05c3e6968b56f0d196b
git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master
compiler: gcc (GCC) 7.1.1 20170620
.config is attached
Raw console output is attached.
C reproducer is attached
syzkaller reproducer is attached. See https://goo.gl/kgGztJ
for information about syzkaller reproducers
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: [email protected]
It will help syzbot understand when the bug is fixed. See footer for
details.
If you forward the report, please keep this part and the footer.
audit: type=1400 audit(1515782899.456:8): avc: denied { sys_admin } for
pid=3501 comm="syzkaller937663" capability=21
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns
permissive=1
audit: type=1400 audit(1515782899.512:9): avc: denied { sys_chroot } for
pid=3502 comm="syzkaller937663" capability=18
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns
permissive=1
==================================================================
BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:344 [inline]
BUG: KASAN: slab-out-of-bounds in map_lookup_elem+0x4dc/0xbd0
kernel/bpf/syscall.c:584
Read of size 2097153 at addr ffff8801bfc7e690 by task syzkaller937663/3502
CPU: 0 PID: 3502 Comm: syzkaller937663 Not tainted 4.15.0-rc7+ #185
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x257 lib/dump_stack.c:53
print_address_description+0x73/0x250 mm/kasan/report.c:252
kasan_report_error mm/kasan/report.c:351 [inline]
kasan_report+0x25b/0x340 mm/kasan/report.c:409
check_memory_region_inline mm/kasan/kasan.c:260 [inline]
check_memory_region+0x137/0x190 mm/kasan/kasan.c:267
memcpy+0x23/0x50 mm/kasan/kasan.c:302
memcpy include/linux/string.h:344 [inline]
map_lookup_elem+0x4dc/0xbd0 kernel/bpf/syscall.c:584
SYSC_bpf kernel/bpf/syscall.c:1808 [inline]
SyS_bpf+0x922/0x4400 kernel/bpf/syscall.c:1782
entry_SYSCALL_64_fastpath+0x23/0x9a
RIP: 0033:0x440ab9
RSP: 002b:00000000007dff68 EFLAGS: 00000203 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fffc494ea60 RCX: 0000000000440ab9
RDX: 0000000000000018 RSI: 0000000020eab000 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000203 R12: 0000000000402290
R13: 0000000000402320 R14: 0000000000000000 R15: 0000000000000000
Allocated by task 3502:
save_stack+0x43/0xd0 mm/kasan/kasan.c:447
set_track mm/kasan/kasan.c:459 [inline]
kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
__do_kmalloc_node mm/slab.c:3672 [inline]
__kmalloc_node+0x47/0x70 mm/slab.c:3679
kmalloc_node include/linux/slab.h:541 [inline]
bpf_map_area_alloc+0x32/0x80 kernel/bpf/syscall.c:123
array_map_alloc+0x351/0xa00 kernel/bpf/arraymap.c:96
find_and_alloc_map kernel/bpf/syscall.c:105 [inline]
map_create kernel/bpf/syscall.c:404 [inline]
SYSC_bpf kernel/bpf/syscall.c:1805 [inline]
SyS_bpf+0x7f8/0x4400 kernel/bpf/syscall.c:1782
entry_SYSCALL_64_fastpath+0x23/0x9a
Freed by task 1966:
save_stack+0x43/0xd0 mm/kasan/kasan.c:447
set_track mm/kasan/kasan.c:459 [inline]
kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
__cache_free mm/slab.c:3488 [inline]
kfree+0xd6/0x260 mm/slab.c:3803
seq_release fs/seq_file.c:366 [inline]
single_release+0x80/0xb0 fs/seq_file.c:602
__fput+0x327/0x7e0 fs/file_table.c:210
____fput+0x15/0x20 fs/file_table.c:244
task_work_run+0x199/0x270 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:191 [inline]
exit_to_usermode_loop+0x296/0x310 arch/x86/entry/common.c:162
prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264
entry_SYSCALL_64_fastpath+0x98/0x9a
The buggy address belongs to the object at ffff8801bfc7e5c0
which belongs to the cache kmalloc-256 of size 256
The buggy address is located 208 bytes inside of
256-byte region [ffff8801bfc7e5c0, ffff8801bfc7e6c0)
The buggy address belongs to the page:
page:ffffea0006ff1f80 count:1 mapcount:0 mapping:ffff8801bfc7e0c0 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801bfc7e0c0 0000000000000000 000000010000000c
raw: ffffea00070149e0 ffffea0006ff2be0 ffff8801dac007c0 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8801bfc7e580: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
ffff8801bfc7e600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ffff8801bfc7e680: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
^
ffff8801bfc7e700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8801bfc7e780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
---
This bug is generated by a dumb bot. It may contain errors.
See https://goo.gl/tpsmEJ for details.
Direct all questions to [email protected].
syzbot will keep track of this bug report.
If you forgot to add the Reported-by tag, once the fix for this bug is
merged
into any tree, please reply to this email with:
#syz fix: exact-commit-title
If you want to test a patch for this bug, please reply with:
#syz test: git://repo/address.git branch
and provide the patch inline or as an attachment.
To mark this as a duplicate of another syzbot report, please reply with:
#syz dup: exact-subject-of-another-report
If it's a one-off invalid bug report, please reply with:
#syz invalid
Note: if the crash happens again, it will cause creation of a new bug
report.
Note: all commands must start from beginning of the line in the email body.
On 01/13/2018 02:58 AM, syzbot wrote:
> Hello,
>
> syzkaller hit the following crash on 19d28fbd306e7ae7c1acf05c3e6968b56f0d196b
> git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master
> compiler: gcc (GCC) 7.1.1 20170620
> .config is attached
> Raw console output is attached.
> C reproducer is attached
> syzkaller reproducer is attached. See https://goo.gl/kgGztJ
> for information about syzkaller reproducers
Fixed here as well:
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=bbeb6e4323dad9b5e0ee9f60c223dd532e2403b1
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: [email protected]
> It will help syzbot understand when the bug is fixed. See footer for details.
> If you forward the report, please keep this part and the footer.
>
> audit: type=1400 audit(1515782899.456:8): avc: denied { sys_admin } for pid=3501 comm="syzkaller937663" capability=21 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
> audit: type=1400 audit(1515782899.512:9): avc: denied { sys_chroot } for pid=3502 comm="syzkaller937663" capability=18 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
> ==================================================================
> BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:344 [inline]
> BUG: KASAN: slab-out-of-bounds in map_lookup_elem+0x4dc/0xbd0 kernel/bpf/syscall.c:584
> Read of size 2097153 at addr ffff8801bfc7e690 by task syzkaller937663/3502
>
> CPU: 0 PID: 3502 Comm: syzkaller937663 Not tainted 4.15.0-rc7+ #185
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Call Trace:
> __dump_stack lib/dump_stack.c:17 [inline]
> dump_stack+0x194/0x257 lib/dump_stack.c:53
> print_address_description+0x73/0x250 mm/kasan/report.c:252
> kasan_report_error mm/kasan/report.c:351 [inline]
> kasan_report+0x25b/0x340 mm/kasan/report.c:409
> check_memory_region_inline mm/kasan/kasan.c:260 [inline]
> check_memory_region+0x137/0x190 mm/kasan/kasan.c:267
> memcpy+0x23/0x50 mm/kasan/kasan.c:302
> memcpy include/linux/string.h:344 [inline]
> map_lookup_elem+0x4dc/0xbd0 kernel/bpf/syscall.c:584
> SYSC_bpf kernel/bpf/syscall.c:1808 [inline]
> SyS_bpf+0x922/0x4400 kernel/bpf/syscall.c:1782
> entry_SYSCALL_64_fastpath+0x23/0x9a
> RIP: 0033:0x440ab9
> RSP: 002b:00000000007dff68 EFLAGS: 00000203 ORIG_RAX: 0000000000000141
> RAX: ffffffffffffffda RBX: 00007fffc494ea60 RCX: 0000000000440ab9
> RDX: 0000000000000018 RSI: 0000000020eab000 RDI: 0000000000000001
> RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000203 R12: 0000000000402290
> R13: 0000000000402320 R14: 0000000000000000 R15: 0000000000000000
>
> Allocated by task 3502:
> save_stack+0x43/0xd0 mm/kasan/kasan.c:447
> set_track mm/kasan/kasan.c:459 [inline]
> kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
> __do_kmalloc_node mm/slab.c:3672 [inline]
> __kmalloc_node+0x47/0x70 mm/slab.c:3679
> kmalloc_node include/linux/slab.h:541 [inline]
> bpf_map_area_alloc+0x32/0x80 kernel/bpf/syscall.c:123
> array_map_alloc+0x351/0xa00 kernel/bpf/arraymap.c:96
> find_and_alloc_map kernel/bpf/syscall.c:105 [inline]
> map_create kernel/bpf/syscall.c:404 [inline]
> SYSC_bpf kernel/bpf/syscall.c:1805 [inline]
> SyS_bpf+0x7f8/0x4400 kernel/bpf/syscall.c:1782
> entry_SYSCALL_64_fastpath+0x23/0x9a
>
> Freed by task 1966:
> save_stack+0x43/0xd0 mm/kasan/kasan.c:447
> set_track mm/kasan/kasan.c:459 [inline]
> kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
> __cache_free mm/slab.c:3488 [inline]
> kfree+0xd6/0x260 mm/slab.c:3803
> seq_release fs/seq_file.c:366 [inline]
> single_release+0x80/0xb0 fs/seq_file.c:602
> __fput+0x327/0x7e0 fs/file_table.c:210
> ____fput+0x15/0x20 fs/file_table.c:244
> task_work_run+0x199/0x270 kernel/task_work.c:113
> tracehook_notify_resume include/linux/tracehook.h:191 [inline]
> exit_to_usermode_loop+0x296/0x310 arch/x86/entry/common.c:162
> prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
> syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264
> entry_SYSCALL_64_fastpath+0x98/0x9a
>
> The buggy address belongs to the object at ffff8801bfc7e5c0
> which belongs to the cache kmalloc-256 of size 256
> The buggy address is located 208 bytes inside of
> 256-byte region [ffff8801bfc7e5c0, ffff8801bfc7e6c0)
> The buggy address belongs to the page:
> page:ffffea0006ff1f80 count:1 mapcount:0 mapping:ffff8801bfc7e0c0 index:0x0
> flags: 0x2fffc0000000100(slab)
> raw: 02fffc0000000100 ffff8801bfc7e0c0 0000000000000000 000000010000000c
> raw: ffffea00070149e0 ffffea0006ff2be0 ffff8801dac007c0 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
> ffff8801bfc7e580: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
> ffff8801bfc7e600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>> ffff8801bfc7e680: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
> ^
> ffff8801bfc7e700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff8801bfc7e780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================
>
>
> ---
> This bug is generated by a dumb bot. It may contain errors.
> See https://goo.gl/tpsmEJ for details.
> Direct all questions to [email protected].
>
> syzbot will keep track of this bug report.
> If you forgot to add the Reported-by tag, once the fix for this bug is merged
> into any tree, please reply to this email with:
> #syz fix: exact-commit-title
> If you want to test a patch for this bug, please reply with:
> #syz test: git://repo/address.git branch
> and provide the patch inline or as an attachment.
> To mark this as a duplicate of another syzbot report, please reply with:
> #syz dup: exact-subject-of-another-report
> If it's a one-off invalid bug report, please reply with:
> #syz invalid
> Note: if the crash happens again, it will cause creation of a new bug report.
> Note: all commands must start from beginning of the line in the email body.
On Sun, Jan 14, 2018 at 1:13 AM, Daniel Borkmann <[email protected]> wrote:
> On 01/13/2018 02:58 AM, syzbot wrote:
>> Hello,
>>
>> syzkaller hit the following crash on 19d28fbd306e7ae7c1acf05c3e6968b56f0d196b
>> git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master
>> compiler: gcc (GCC) 7.1.1 20170620
>> .config is attached
>> Raw console output is attached.
>> C reproducer is attached
>> syzkaller reproducer is attached. See https://goo.gl/kgGztJ
>> for information about syzkaller reproducers
>
> Fixed here as well:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=bbeb6e4323dad9b5e0ee9f60c223dd532e2403b1
Thanks.
Let's tell syzbot about this so that it reports bugs in
map_lookup_elem ever again:
#syz fix:
bpf, array: fix overflow in max_entries and undefined behavior in index_mask
>> IMPORTANT: if you fix the bug, please add the following tag to the commit:
>> Reported-by: [email protected]
>> It will help syzbot understand when the bug is fixed. See footer for details.
>> If you forward the report, please keep this part and the footer.
>>
>> audit: type=1400 audit(1515782899.456:8): avc: denied { sys_admin } for pid=3501 comm="syzkaller937663" capability=21 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
>> audit: type=1400 audit(1515782899.512:9): avc: denied { sys_chroot } for pid=3502 comm="syzkaller937663" capability=18 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
>> ==================================================================
>> BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:344 [inline]
>> BUG: KASAN: slab-out-of-bounds in map_lookup_elem+0x4dc/0xbd0 kernel/bpf/syscall.c:584
>> Read of size 2097153 at addr ffff8801bfc7e690 by task syzkaller937663/3502
>>
>> CPU: 0 PID: 3502 Comm: syzkaller937663 Not tainted 4.15.0-rc7+ #185
>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
>> Call Trace:
>> __dump_stack lib/dump_stack.c:17 [inline]
>> dump_stack+0x194/0x257 lib/dump_stack.c:53
>> print_address_description+0x73/0x250 mm/kasan/report.c:252
>> kasan_report_error mm/kasan/report.c:351 [inline]
>> kasan_report+0x25b/0x340 mm/kasan/report.c:409
>> check_memory_region_inline mm/kasan/kasan.c:260 [inline]
>> check_memory_region+0x137/0x190 mm/kasan/kasan.c:267
>> memcpy+0x23/0x50 mm/kasan/kasan.c:302
>> memcpy include/linux/string.h:344 [inline]
>> map_lookup_elem+0x4dc/0xbd0 kernel/bpf/syscall.c:584
>> SYSC_bpf kernel/bpf/syscall.c:1808 [inline]
>> SyS_bpf+0x922/0x4400 kernel/bpf/syscall.c:1782
>> entry_SYSCALL_64_fastpath+0x23/0x9a
>> RIP: 0033:0x440ab9
>> RSP: 002b:00000000007dff68 EFLAGS: 00000203 ORIG_RAX: 0000000000000141
>> RAX: ffffffffffffffda RBX: 00007fffc494ea60 RCX: 0000000000440ab9
>> RDX: 0000000000000018 RSI: 0000000020eab000 RDI: 0000000000000001
>> RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
>> R10: 0000000000000000 R11: 0000000000000203 R12: 0000000000402290
>> R13: 0000000000402320 R14: 0000000000000000 R15: 0000000000000000
>>
>> Allocated by task 3502:
>> save_stack+0x43/0xd0 mm/kasan/kasan.c:447
>> set_track mm/kasan/kasan.c:459 [inline]
>> kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
>> __do_kmalloc_node mm/slab.c:3672 [inline]
>> __kmalloc_node+0x47/0x70 mm/slab.c:3679
>> kmalloc_node include/linux/slab.h:541 [inline]
>> bpf_map_area_alloc+0x32/0x80 kernel/bpf/syscall.c:123
>> array_map_alloc+0x351/0xa00 kernel/bpf/arraymap.c:96
>> find_and_alloc_map kernel/bpf/syscall.c:105 [inline]
>> map_create kernel/bpf/syscall.c:404 [inline]
>> SYSC_bpf kernel/bpf/syscall.c:1805 [inline]
>> SyS_bpf+0x7f8/0x4400 kernel/bpf/syscall.c:1782
>> entry_SYSCALL_64_fastpath+0x23/0x9a
>>
>> Freed by task 1966:
>> save_stack+0x43/0xd0 mm/kasan/kasan.c:447
>> set_track mm/kasan/kasan.c:459 [inline]
>> kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
>> __cache_free mm/slab.c:3488 [inline]
>> kfree+0xd6/0x260 mm/slab.c:3803
>> seq_release fs/seq_file.c:366 [inline]
>> single_release+0x80/0xb0 fs/seq_file.c:602
>> __fput+0x327/0x7e0 fs/file_table.c:210
>> ____fput+0x15/0x20 fs/file_table.c:244
>> task_work_run+0x199/0x270 kernel/task_work.c:113
>> tracehook_notify_resume include/linux/tracehook.h:191 [inline]
>> exit_to_usermode_loop+0x296/0x310 arch/x86/entry/common.c:162
>> prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
>> syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264
>> entry_SYSCALL_64_fastpath+0x98/0x9a
>>
>> The buggy address belongs to the object at ffff8801bfc7e5c0
>> which belongs to the cache kmalloc-256 of size 256
>> The buggy address is located 208 bytes inside of
>> 256-byte region [ffff8801bfc7e5c0, ffff8801bfc7e6c0)
>> The buggy address belongs to the page:
>> page:ffffea0006ff1f80 count:1 mapcount:0 mapping:ffff8801bfc7e0c0 index:0x0
>> flags: 0x2fffc0000000100(slab)
>> raw: 02fffc0000000100 ffff8801bfc7e0c0 0000000000000000 000000010000000c
>> raw: ffffea00070149e0 ffffea0006ff2be0 ffff8801dac007c0 0000000000000000
>> page dumped because: kasan: bad access detected
>>
>> Memory state around the buggy address:
>> ffff8801bfc7e580: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
>> ffff8801bfc7e600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>>> ffff8801bfc7e680: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>> ^
>> ffff8801bfc7e700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>> ffff8801bfc7e780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>> ==================================================================
>>
>>
>> ---
>> This bug is generated by a dumb bot. It may contain errors.
>> See https://goo.gl/tpsmEJ for details.
>> Direct all questions to [email protected].
>>
>> syzbot will keep track of this bug report.
>> If you forgot to add the Reported-by tag, once the fix for this bug is merged
>> into any tree, please reply to this email with:
>> #syz fix: exact-commit-title
>> If you want to test a patch for this bug, please reply with:
>> #syz test: git://repo/address.git branch
>> and provide the patch inline or as an attachment.
>> To mark this as a duplicate of another syzbot report, please reply with:
>> #syz dup: exact-subject-of-another-report
>> If it's a one-off invalid bug report, please reply with:
>> #syz invalid
>> Note: if the crash happens again, it will cause creation of a new bug report.
>> Note: all commands must start from beginning of the line in the email body.
>
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