lkml.org 
[lkml]   [2021]   [Jul]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [syzbot] KASAN: use-after-free Write in alloc_ucounts
From
syzbot has found a reproducer for the following issue on:

HEAD commit: 4010a528219e Merge tag 'fixes_for_v5.14-rc4' of git://git...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=133f4a66300000
kernel config: https://syzkaller.appspot.com/x/.config?x=1dee114394f7d2c2
dashboard link: https://syzkaller.appspot.com/bug?extid=59dd63761094a80ad06d
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16b8851a300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+59dd63761094a80ad06d@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: use-after-free in atomic_add_negative include/asm-generic/atomic-instrumented.h:556 [inline]
BUG: KASAN: use-after-free in get_ucounts kernel/ucount.c:152 [inline]
BUG: KASAN: use-after-free in get_ucounts kernel/ucount.c:150 [inline]
BUG: KASAN: use-after-free in alloc_ucounts+0x19b/0x5b0 kernel/ucount.c:188
Write of size 4 at addr ffff888017c0f61c by task syz-executor.0/12089

CPU: 1 PID: 12089 Comm: syz-executor.0 Not tainted 5.14.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105
print_address_description.constprop.0.cold+0x6c/0x2d6 mm/kasan/report.c:233
__kasan_report mm/kasan/report.c:419 [inline]
kasan_report.cold+0x83/0xdf mm/kasan/report.c:436
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
atomic_add_negative include/asm-generic/atomic-instrumented.h:556 [inline]
get_ucounts kernel/ucount.c:152 [inline]
get_ucounts kernel/ucount.c:150 [inline]
alloc_ucounts+0x19b/0x5b0 kernel/ucount.c:188
set_cred_ucounts+0x171/0x3a0 kernel/cred.c:684
__sys_setresuid+0x62c/0x840 kernel/sys.c:702
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: 0033:0x4665e9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f97fb5de188 EFLAGS: 00000246 ORIG_RAX: 0000000000000075
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665e9
RDX: 0000000000000000 RSI: 000000000000ee01 RDI: 000000000000ee01
RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffff4281c7f R14: 00007f97fb5de300 R15: 0000000000022000

Allocated by task 10190:
kasan_save_stack+0x1b/0x40 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+0x98/0xc0 mm/kasan/common.c:522
kasan_kmalloc include/linux/kasan.h:264 [inline]
kmem_cache_alloc_trace+0x1e4/0x480 mm/slab.c:3575
kmalloc include/linux/slab.h:591 [inline]
kzalloc include/linux/slab.h:721 [inline]
alloc_ucounts+0x23d/0x5b0 kernel/ucount.c:169
set_cred_ucounts+0x171/0x3a0 kernel/cred.c:684
__sys_setresuid+0x62c/0x840 kernel/sys.c:702
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

Freed by task 9890:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360
____kasan_slab_free mm/kasan/common.c:366 [inline]
____kasan_slab_free mm/kasan/common.c:328 [inline]
__kasan_slab_free+0xcd/0x100 mm/kasan/common.c:374
kasan_slab_free include/linux/kasan.h:230 [inline]
__cache_free mm/slab.c:3445 [inline]
kfree+0x106/0x2c0 mm/slab.c:3803
put_ucounts kernel/ucount.c:200 [inline]
put_ucounts+0x117/0x150 kernel/ucount.c:192
put_cred_rcu+0x27a/0x520 kernel/cred.c:124
rcu_do_batch kernel/rcu/tree.c:2550 [inline]
rcu_core+0x7ab/0x1380 kernel/rcu/tree.c:2785
__do_softirq+0x29b/0x9c2 kernel/softirq.c:558

Last potentially related work creation:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_record_aux_stack+0xa4/0xd0 mm/kasan/generic.c:348
insert_work+0x48/0x370 kernel/workqueue.c:1332
__queue_work+0x5c1/0xed0 kernel/workqueue.c:1498
queue_work_on+0xee/0x110 kernel/workqueue.c:1525
queue_work include/linux/workqueue.h:507 [inline]
addr_event.part.0+0x31c/0x4d0 drivers/infiniband/core/roce_gid_mgmt.c:853
addr_event drivers/infiniband/core/roce_gid_mgmt.c:824 [inline]
inet6addr_event+0x13e/0x1b0 drivers/infiniband/core/roce_gid_mgmt.c:883
notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
atomic_notifier_call_chain+0x70/0x180 kernel/notifier.c:217
ipv6_add_addr+0x1705/0x1f00 net/ipv6/addrconf.c:1152
addrconf_add_linklocal+0x1ca/0x590 net/ipv6/addrconf.c:3182
addrconf_addr_gen+0x3a4/0x3e0 net/ipv6/addrconf.c:3313
addrconf_dev_config+0x253/0x420 net/ipv6/addrconf.c:3360
addrconf_notify+0x366/0x2400 net/ipv6/addrconf.c:3593
notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2123
netdev_state_change net/core/dev.c:1514 [inline]
netdev_state_change+0x100/0x130 net/core/dev.c:1507
linkwatch_do_dev+0x151/0x1b0 net/core/link_watch.c:167
__linkwatch_run_queue+0x1ea/0x630 net/core/link_watch.c:212
linkwatch_event+0x4a/0x60 net/core/link_watch.c:251
process_one_work+0x98d/0x1630 kernel/workqueue.c:2276
worker_thread+0x658/0x11f0 kernel/workqueue.c:2422
kthread+0x3e5/0x4d0 kernel/kthread.c:319
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

The buggy address belongs to the object at ffff888017c0f600
which belongs to the cache kmalloc-192 of size 192
The buggy address is located 28 bytes inside of
192-byte region [ffff888017c0f600, ffff888017c0f6c0)
The buggy address belongs to the page:
page:ffffea00005f03c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888017c0fb00 pfn:0x17c0f
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea000098a7c8 ffffea0000bcb3c8 ffff888010840000
raw: ffff888017c0fb00 ffff888017c0f000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x242220(__GFP_HIGH|__GFP_ATOMIC|__GFP_NOWARN|__GFP_COMP|__GFP_THISNODE), pid 8466, ts 421925544813, free_ts 416394009964
prep_new_page mm/page_alloc.c:2436 [inline]
get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4169
__alloc_pages+0x1b2/0x500 mm/page_alloc.c:5391
__alloc_pages_node include/linux/gfp.h:570 [inline]
kmem_getpages mm/slab.c:1377 [inline]
cache_grow_begin+0x75/0x460 mm/slab.c:2593
cache_alloc_refill+0x27f/0x380 mm/slab.c:2965
____cache_alloc mm/slab.c:3048 [inline]
____cache_alloc mm/slab.c:3031 [inline]
__do_cache_alloc mm/slab.c:3275 [inline]
slab_alloc mm/slab.c:3316 [inline]
kmem_cache_alloc_trace+0x38c/0x480 mm/slab.c:3573
kmalloc include/linux/slab.h:591 [inline]
addr_event.part.0+0x7b/0x4d0 drivers/infiniband/core/roce_gid_mgmt.c:840
addr_event drivers/infiniband/core/roce_gid_mgmt.c:824 [inline]
inet6addr_event+0x13e/0x1b0 drivers/infiniband/core/roce_gid_mgmt.c:883
notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
atomic_notifier_call_chain+0x70/0x180 kernel/notifier.c:217
ipv6_add_addr+0x1705/0x1f00 net/ipv6/addrconf.c:1152
addrconf_add_linklocal+0x1ca/0x590 net/ipv6/addrconf.c:3182
addrconf_addr_gen+0x3a4/0x3e0 net/ipv6/addrconf.c:3313
addrconf_dev_config+0x253/0x420 net/ipv6/addrconf.c:3360
addrconf_notify+0x366/0x2400 net/ipv6/addrconf.c:3593
notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2123
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1346 [inline]
free_pcp_prepare+0x2c5/0x780 mm/page_alloc.c:1397
free_unref_page_prepare mm/page_alloc.c:3332 [inline]
free_unref_page+0x19/0x690 mm/page_alloc.c:3411
slab_destroy mm/slab.c:1627 [inline]
slabs_destroy+0x89/0xc0 mm/slab.c:1647
cache_flusharray mm/slab.c:3418 [inline]
___cache_free+0x4ba/0x600 mm/slab.c:3480
qlink_free mm/kasan/quarantine.c:146 [inline]
qlist_free_all+0x4e/0x110 mm/kasan/quarantine.c:165
kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272
__kasan_slab_alloc+0x8b/0xa0 mm/kasan/common.c:444
kasan_slab_alloc include/linux/kasan.h:254 [inline]
slab_post_alloc_hook mm/slab.h:519 [inline]
slab_alloc mm/slab.c:3323 [inline]
kmem_cache_alloc+0x25f/0x540 mm/slab.c:3507
prepare_kernel_cred+0x27/0x8a0 kernel/cred.c:724
call_usermodehelper_exec_async+0x10e/0x580 kernel/umh.c:91
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Memory state around the buggy address:
ffff888017c0f500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888017c0f580: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff888017c0f600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888017c0f680: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff888017c0f700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

\
 
 \ /
  Last update: 2021-07-29 19:17    [W:0.040 / U:0.928 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site