KASAN: slab-out-of-bounds Write in rmd160_final

syzbot
2018-06-07T13:12:08Z

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=17f025df800000
kernel config: https://syzkaller.appspot.com/x/.config?x=2e1a31e8576e013a
dashboard link: https://syzkaller.appspot.com/bug?extid=d04e58bd384f1fe0b112
compiler: gcc (GCC) 8.0.1 20180413 (experimental)

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+d04e58bd384f1fe0b112@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-out-of-bounds in rmd160_final+0x201/0x240
crypto/rmd160.c:334
Write of size 4 at addr ffff8801b00585d8 by task syz-executor1/15928

CPU: 0 PID: 15928 Comm: syz-executor1 Not tainted 4.17.0+ #88
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
rmd160_final+0x201/0x240 crypto/rmd160.c:334
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
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: 0033:0x455a09
Code: 1d ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f2e9de49c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000fa
RAX: ffffffffffffffda RBX: 00007f2e9de4a6d4 RCX: 0000000000455a09
RDX: 0000000020a53ffb RSI: 0000000020000140 RDI: 0000000000000017
RBP: 000000000072bea0 R08: 0000000020c61fc8 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000499 R14: 00000000006fbef8 R15: 0000000000000000

Allocated by task 15928:
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
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

Freed by task 4605:
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
translate_table+0xc24/0x1780 net/ipv4/netfilter/ip_tables.c:714
do_replace net/ipv4/netfilter/ip_tables.c:1138 [inline]
do_ipt_set_ctl+0x3c7/0x645 net/ipv4/netfilter/ip_tables.c:1674
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x7d/0xd0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0xd8/0xf0 net/ipv4/ip_sockglue.c:1258
tcp_setsockopt+0x93/0xe0 net/ipv4/tcp.c:3047
sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3053
__sys_setsockopt+0x1bd/0x390 net/socket.c:1935
__do_sys_setsockopt net/socket.c:1946 [inline]
__se_sys_setsockopt net/socket.c:1943 [inline]
__x64_sys_setsockopt+0xbe/0x150 net/socket.c:1943
do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801b00585c0
which belongs to the cache kmalloc-32 of size 32
The buggy address is located 24 bytes inside of
32-byte region [ffff8801b00585c0, ffff8801b00585e0)
The buggy address belongs to the page:
page:ffffea0006c01600 count:1 mapcount:0 mapping:ffff8801b0058000
index:0xffff8801b0058fc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801b0058000 ffff8801b0058fc1 0000000100000031
raw: ffffea00073f66a0 ffffea0007209620 ffff8801da8001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff8801b0058480: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
ffff8801b0058500: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
> ffff8801b0058580: 05 fc fc fc fc fc fc fc 00 00 00 fc fc fc fc fc
^
ffff8801b0058600: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
ffff8801b0058680: 00 00 01 fc fc fc fc fc 00 00 03 fc fc fc fc fc
==================================================================

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