KASAN: slab-out-of-bounds Write in sha1_final

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syzbot

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Jun 7, 2018, 5:27:04 PM6/7/18

to syzkaller-upst...@googlegroups.com

Hello,

syzbot found the following crash on:

HEAD commit: 1c8c5a9d38f6 Merge git://git.kernel.org/pub/scm/linux/kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11da316f800000
kernel config: https://syzkaller.appspot.com/x/.config?x=4f1acdf888c9d4e9
dashboard link: https://syzkaller.appspot.com/bug?extid=db8b846f704a6c3c9bcc
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
userspace arch: i386
CC: [da...@davemloft.net her...@gondor.apana.org.au
linux-...@vger.kernel.org linux-...@vger.kernel.org]

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+db8b84...@syzkaller.appspotmail.com

==================================================================
netlink: 4 bytes leftover after parsing attributes in process
`syz-executor2'.
BUG: KASAN: slab-out-of-bounds in put_unaligned_be32
include/linux/unaligned/access_ok.h:60 [inline]
BUG: KASAN: slab-out-of-bounds in sha1_base_finish
include/crypto/sha1_base.h:102 [inline]
BUG: KASAN: slab-out-of-bounds in sha1_final+0x283/0x2e0
crypto/sha1_generic.c:58
Write of size 4 at addr ffff8801ac91b3d8 by task syz-executor4/2071

CPU: 0 PID: 2071 Comm: syz-executor4 Not tainted 4.17.0+ #114
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
netlink: 4 bytes leftover after parsing attributes in process
`syz-executor2'.
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1b9/0x294 lib/dump_stack.c:113
print_address_description+0x6c/0x20b mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
__asan_report_store4_noabort+0x17/0x20 mm/kasan/report.c:437
put_unaligned_be32 include/linux/unaligned/access_ok.h:60 [inline]
sha1_base_finish include/crypto/sha1_base.h:102 [inline]
sha1_final+0x283/0x2e0 crypto/sha1_generic.c:58
crypto_shash_final+0x104/0x260 crypto/shash.c:152
kdf_ctr security/keys/dh.c:186 [inline]
keyctl_dh_compute_kdf security/keys/dh.c:217 [inline]
__keyctl_dh_compute+0x1184/0x1bc0 security/keys/dh.c:389
compat_keyctl_dh_compute+0x2c8/0x3e0 security/keys/compat_dh.c:39
__do_compat_sys_keyctl security/keys/compat.c:136 [inline]
__se_compat_sys_keyctl security/keys/compat.c:59 [inline]
__ia32_compat_sys_keyctl+0x137/0x3b0 security/keys/compat.c:59
do_syscall_32_irqs_on arch/x86/entry/common.c:323 [inline]
do_fast_syscall_32+0x345/0xf9b arch/x86/entry/common.c:394
entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7fd9cb9
Code: 55 08 8b 88 64 cd ff ff 8b 98 68 cd ff ff 89 c8 85 d2 74 02 89 0a 5b
5d c3 8b 04 24 c3 8b 1c 24 c3 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90
90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f5fd50ac EFLAGS: 00000282 ORIG_RAX: 0000000000000120
RAX: ffffffffffffffda RBX: 0000000000000017 RCX: 0000000020000100
RDX: 0000000020a53ffb RSI: 0000000000000005 RDI: 0000000020000140
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 2071:
save_stack+0x43/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
__do_kmalloc mm/slab.c:3718 [inline]
__kmalloc+0x14e/0x760 mm/slab.c:3727
kmalloc include/linux/slab.h:518 [inline]
keyctl_dh_compute_kdf security/keys/dh.c:211 [inline]
__keyctl_dh_compute+0xfe9/0x1bc0 security/keys/dh.c:389
compat_keyctl_dh_compute+0x2c8/0x3e0 security/keys/compat_dh.c:39
__do_compat_sys_keyctl security/keys/compat.c:136 [inline]
__se_compat_sys_keyctl security/keys/compat.c:59 [inline]
__ia32_compat_sys_keyctl+0x137/0x3b0 security/keys/compat.c:59
do_syscall_32_irqs_on arch/x86/entry/common.c:323 [inline]
do_fast_syscall_32+0x345/0xf9b arch/x86/entry/common.c:394
entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

Freed by task 4589:
save_stack+0x43/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
__kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
__cache_free mm/slab.c:3498 [inline]
kfree+0xd9/0x260 mm/slab.c:3813
kvfree+0x61/0x70 mm/util.c:440
__vunmap+0x2c5/0x3c0 mm/vmalloc.c:1542
vfree+0x68/0x100 mm/vmalloc.c:1606
xt_compat_flush_offsets+0x14e/0x270 net/netfilter/x_tables.c:674
compat_get_entries net/ipv4/netfilter/arp_tables.c:1412 [inline]
compat_do_arpt_get_ctl+0x4ab/0xba0 net/ipv4/netfilter/arp_tables.c:1437
compat_nf_sockopt net/netfilter/nf_sockopt.c:139 [inline]
compat_nf_getsockopt+0x9e/0x140 net/netfilter/nf_sockopt.c:163
compat_ip_getsockopt+0x209/0x2f0 net/ipv4/ip_sockglue.c:1611
inet_csk_compat_getsockopt+0x97/0x120 net/ipv4/inet_connection_sock.c:1023
compat_tcp_getsockopt+0x49/0x80 net/ipv4/tcp.c:3543
compat_sock_common_getsockopt+0xb4/0x150 net/core/sock.c:3023
__compat_sys_getsockopt+0x1ae/0x880 net/compat.c:532
__do_compat_sys_socketcall net/compat.c:916 [inline]
__se_compat_sys_socketcall net/compat.c:844 [inline]
__ia32_compat_sys_socketcall+0xcd1/0x1070 net/compat.c:844
do_syscall_32_irqs_on arch/x86/entry/common.c:323 [inline]
do_fast_syscall_32+0x345/0xf9b arch/x86/entry/common.c:394
entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

The buggy address belongs to the object at ffff8801ac91b3c0
which belongs to the cache kmalloc-32 of size 32
The buggy address is located 24 bytes inside of
32-byte region [ffff8801ac91b3c0, ffff8801ac91b3e0)
The buggy address belongs to the page:
page:ffffea0006b246c0 count:1 mapcount:0 mapping:ffff8801ac91b000
index:0xffff8801ac91bfc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801ac91b000 ffff8801ac91bfc1 0000000100000023
raw: ffffea0006bb67a0 ffffea00073b6960 ffff8801da8001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff8801ac91b280: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
ffff8801ac91b300: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
> ffff8801ac91b380: fb fb fb fb fc fc fc fc 00 00 00 fc fc fc fc fc
^
ffff8801ac91b400: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
ffff8801ac91b480: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
==================================================================

---
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 syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
syzbot.

Eric Biggers

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Jun 7, 2018, 5:29:59 PM6/7/18

to syzbot, syzkaller-upst...@googlegroups.com

Duplicate:

#syz dup: KASAN: slab-out-of-bounds Write in sha1_finup

Tentative fix is "[PATCH] dh key: fix rounding up KDF output length".

syzbot

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Jun 7, 2018, 5:30:00 PM6/7/18

to Eric Biggers, ebig...@google.com, syzkaller-upst...@googlegroups.com

Dup bug is already upstreamed.

syzbot

unread,

Jun 7, 2018, 6:17:03 PM6/7/18

to ebig...@google.com, syzkaller-upst...@googlegroups.com

syzbot has found a reproducer for the following crash on:

HEAD commit: 1c8c5a9d38f6 Merge git://git.kernel.org/pub/scm/linux/kern..
git tree: upstream

console output: https://syzkaller.appspot.com/x/log.txt?x=1479841f800000

kernel config: https://syzkaller.appspot.com/x/.config?x=4f1acdf888c9d4e9
dashboard link: https://syzkaller.appspot.com/bug?extid=db8b846f704a6c3c9bcc
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
userspace arch: i386

syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=165b47d7800000

CC: [da...@davemloft.net her...@gondor.apana.org.au
linux-...@vger.kernel.org linux-...@vger.kernel.org]

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+db8b84...@syzkaller.appspotmail.com

IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): team0: link is not ready
8021q: adding VLAN 0 to HW filter on device team0
IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready
==================================================================

BUG: KASAN: slab-out-of-bounds in put_unaligned_be32
include/linux/unaligned/access_ok.h:60 [inline]
BUG: KASAN: slab-out-of-bounds in sha1_base_finish
include/crypto/sha1_base.h:102 [inline]
BUG: KASAN: slab-out-of-bounds in sha1_final+0x283/0x2e0
crypto/sha1_generic.c:58

Write of size 4 at addr ffff8801d0866f98 by task syz-executor0/4773

CPU: 0 PID: 4773 Comm: syz-executor0 Not tainted 4.17.0+ #114

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+0x1b9/0x294 lib/dump_stack.c:113
print_address_description+0x6c/0x20b mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
__asan_report_store4_noabort+0x17/0x20 mm/kasan/report.c:437
put_unaligned_be32 include/linux/unaligned/access_ok.h:60 [inline]
sha1_base_finish include/crypto/sha1_base.h:102 [inline]
sha1_final+0x283/0x2e0 crypto/sha1_generic.c:58
crypto_shash_final+0x104/0x260 crypto/shash.c:152
kdf_ctr security/keys/dh.c:186 [inline]
keyctl_dh_compute_kdf security/keys/dh.c:217 [inline]
__keyctl_dh_compute+0x1184/0x1bc0 security/keys/dh.c:389
compat_keyctl_dh_compute+0x2c8/0x3e0 security/keys/compat_dh.c:39
__do_compat_sys_keyctl security/keys/compat.c:136 [inline]
__se_compat_sys_keyctl security/keys/compat.c:59 [inline]
__ia32_compat_sys_keyctl+0x137/0x3b0 security/keys/compat.c:59
do_syscall_32_irqs_on arch/x86/entry/common.c:323 [inline]
do_fast_syscall_32+0x345/0xf9b arch/x86/entry/common.c:394
entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

RIP: 0023:0xf7fcdcb9

Code: 55 08 8b 88 64 cd ff ff 8b 98 68 cd ff ff 89 c8 85 d2 74 02 89 0a 5b
5d c3 8b 04 24 c3 8b 1c 24 c3 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90
90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90

RSP: 002b:00000000ff9b8dac EFLAGS: 00000282 ORIG_RAX: 0000000000000120

RAX: ffffffffffffffda RBX: 0000000000000017 RCX: 0000000020000100
RDX: 0000000020a53ffb RSI: 0000000000000005 RDI: 0000000020000140
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000

R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 4773:

save_stack+0x43/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
__do_kmalloc mm/slab.c:3718 [inline]
__kmalloc+0x14e/0x760 mm/slab.c:3727
kmalloc include/linux/slab.h:518 [inline]
keyctl_dh_compute_kdf security/keys/dh.c:211 [inline]
__keyctl_dh_compute+0xfe9/0x1bc0 security/keys/dh.c:389
compat_keyctl_dh_compute+0x2c8/0x3e0 security/keys/compat_dh.c:39
__do_compat_sys_keyctl security/keys/compat.c:136 [inline]
__se_compat_sys_keyctl security/keys/compat.c:59 [inline]
__ia32_compat_sys_keyctl+0x137/0x3b0 security/keys/compat.c:59
do_syscall_32_irqs_on arch/x86/entry/common.c:323 [inline]
do_fast_syscall_32+0x345/0xf9b arch/x86/entry/common.c:394
entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

Freed by task 2311:

save_stack+0x43/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
__kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
__cache_free mm/slab.c:3498 [inline]
kfree+0xd9/0x260 mm/slab.c:3813

tty_ldisc_put+0x4c/0x70 drivers/tty/tty_ldisc.c:201
tty_ldisc_kill+0x6e/0xc0 drivers/tty/tty_ldisc.c:624
tty_ldisc_hangup+0x2dd/0x640 drivers/tty/tty_ldisc.c:741
__tty_hangup.part.21+0x2da/0x6e0 drivers/tty/tty_io.c:621
__tty_hangup drivers/tty/tty_io.c:571 [inline]
tty_vhangup+0x21/0x30 drivers/tty/tty_io.c:694
pty_close+0x3bd/0x510 drivers/tty/pty.c:78
tty_release+0x494/0x12e0 drivers/tty/tty_io.c:1656
__fput+0x353/0x890 fs/file_table.c:209
____fput+0x15/0x20 fs/file_table.c:243
task_work_run+0x1e4/0x290 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:192 [inline]
exit_to_usermode_loop+0x2bd/0x310 arch/x86/entry/common.c:166
prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
do_syscall_64+0x6ac/0x800 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801d0866f80

which belongs to the cache kmalloc-32 of size 32
The buggy address is located 24 bytes inside of

32-byte region [ffff8801d0866f80, ffff8801d0866fa0)

The buggy address belongs to the page:

page:ffffea0007421980 count:1 mapcount:0 mapping:ffff8801d0866000
index:0xffff8801d0866fc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801d0866000 ffff8801d0866fc1 0000000100000008
raw: ffffea00074264e0 ffffea000743d320 ffff8801da8001c0 0000000000000000

page dumped because: kasan: bad access detected

Memory state around the buggy address:

ffff8801d0866e80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
ffff8801d0866f00: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc
> ffff8801d0866f80: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff8801d0867000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8801d0867080: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc
==================================================================

syzbot

unread,

Jun 7, 2018, 8:22:03 PM6/7/18

to ebig...@google.com, syzkaller-upst...@googlegroups.com

syzbot has found a reproducer for the following crash on:

HEAD commit: 1c8c5a9d38f6 Merge git://git.kernel.org/pub/scm/linux/kern..
git tree: upstream

console output: https://syzkaller.appspot.com/x/log.txt?x=10f9841f800000

syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=12e1756f800000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1744005f800000

CC: [da...@davemloft.net her...@gondor.apana.org.au
linux-...@vger.kernel.org linux-...@vger.kernel.org]

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+db8b84...@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)
==================================================================

Write of size 4 at addr ffff8801d708f958 by task syz-executor062/4535

CPU: 1 PID: 4535 Comm: syz-executor062 Not tainted 4.17.0+ #89

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011

keyctl_dh_compute+0xb9/0x100 security/keys/dh.c:425
__do_sys_keyctl security/keys/keyctl.c:1741 [inline]
__se_sys_keyctl security/keys/keyctl.c:1637 [inline]
__x64_sys_keyctl+0x12a/0x3b0 security/keys/keyctl.c:1637
do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x43ffa9
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 6b 45 00 00 c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffea3065eb8 EFLAGS: 00000217 ORIG_RAX: 00000000000000fa
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043ffa9
RDX: 0000000020a53ffb RSI: 0000000020000100 RDI: 0000000000000017
RBP: 00000000006ca018 R08: 0000000020000140 R09: 00000000004002c8
R10: 0000000000000005 R11: 0000000000000217 R12: 00000000004018d0
R13: 0000000000401960 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 4535:

single_release+0x8f/0xb0 fs/seq_file.c:609

__fput+0x353/0x890 fs/file_table.c:209
____fput+0x15/0x20 fs/file_table.c:243
task_work_run+0x1e4/0x290 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:192 [inline]
exit_to_usermode_loop+0x2bd/0x310 arch/x86/entry/common.c:166
prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
do_syscall_64+0x6ac/0x800 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801d708f940

which belongs to the cache kmalloc-32 of size 32
The buggy address is located 24 bytes inside of

32-byte region [ffff8801d708f940, ffff8801d708f960)

The buggy address belongs to the page:

page:ffffea00075c23c0 count:1 mapcount:0 mapping:ffff8801d708f000
index:0xffff8801d708ffc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801d708f000 ffff8801d708ffc1 0000000100000034
raw: ffffea00075c1420 ffffea00075c1520 ffff8801da8001c0 0000000000000000

page dumped because: kasan: bad access detected

Memory state around the buggy address:

ffff8801d708f800: 00 00 00 00 fc fc fc fc 00 fc fc fc fc fc fc fc
ffff8801d708f880: 00 00 00 00 fc fc fc fc 00 00 00 fc fc fc fc fc
> ffff8801d708f900: fb fb fb fb fc fc fc fc 00 00 00 fc fc fc fc fc
^
ffff8801d708f980: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
ffff8801d708fa00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
==================================================================

Dmitry Vyukov

unread,

Jun 8, 2018, 3:45:39 AM6/8/18

to syzbot, Eric Biggers, 'Dmitry Vyukov' via syzkaller-upstream-moderation

On Thu, Jun 7, 2018 at 11:29 PM, syzbot
<syzbot+db8b84...@syzkaller.appspotmail.com> wrote:
> Dup bug is already upstreamed.

Cross-reporting dups are still not supported:
https://github.com/google/syzkaller/issues/569

let's do:

#syz fix: dh key: fix rounding up KDF output length

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