syzbot


KASAN: use-after-free Read in oom_kill_process

Status: fixed on 2019/03/06 07:43
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+7fbbfa368521945f0e3d@syzkaller.appspotmail.com
Fix commit: cefc7ef3c87d mm, oom: fix use-after-free in oom_kill_process
First crash: 1985d, last: 1985d
Discussions (10)
Title Replies (including bot) Last reply
[PATCH 3.16 000/202] 3.16.66-rc1 review 205 (205) 2019/04/28 15:45
[PATCH 4.4 00/65] 4.4.173-stable review 73 (73) 2019/02/05 15:12
[PATCH 4.20 00/80] 4.20.7-stable review 84 (84) 2019/02/05 14:43
[PATCH 4.14 00/46] 4.14.98-stable review 51 (51) 2019/02/05 14:42
[PATCH 3.18 00/31] 3.18.134-stable review 36 (36) 2019/02/05 14:41
[PATCH 4.9 00/30] 4.9.155-stable review 36 (36) 2019/02/05 11:38
[PATCH 4.19 00/74] 4.19.20-stable review 77 (77) 2019/02/05 06:14
[PATCH v3 1/2] mm, oom: fix use-after-free in oom_kill_process 8 (8) 2019/01/24 08:13
[PATCH v2 1/2] mm, oom: fix use-after-free in oom_kill_process 4 (4) 2019/01/23 04:41
KASAN: use-after-free Read in oom_kill_process 0 (1) 2019/01/21 06:45

Sample crash report:
kmem: usage 0kB, limit 9007199254740988kB, failcnt 0
Memory cgroup stats for /syz1: cache:28KB rss:274692KB rss_huge:190464KB shmem:64KB mapped_file:0KB dirty:0KB writeback:0KB swap:0KB inactive_anon:222780KB active_anon:4152KB inactive_file:0KB active_file:0KB unevictable:47872KB
oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=syz1,mems_allowed=0-1,oom_memcg=/syz1,task_memcg=/syz1,task=syz-executor1,pid=15858,uid=0
Memory cgroup out of memory: Kill process 15858 (syz-executor1) score 1148 or sacrifice child
==================================================================
BUG: KASAN: use-after-free in oom_kill_process.cold+0x484/0x9d4 mm/oom_kill.c:978
Read of size 8 at addr ffff8880595f6c40 by task syz-executor1/15817

CPU: 1 PID: 15817 Comm: syz-executor1 Not tainted 5.0.0-rc2+ #29
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+0x1db/0x2d0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135
 oom_kill_process.cold+0x484/0x9d4 mm/oom_kill.c:978
 out_of_memory+0x885/0x1420 mm/oom_kill.c:1133
 mem_cgroup_out_of_memory+0x160/0x210 mm/memcontrol.c:1393
 mem_cgroup_oom mm/memcontrol.c:1721 [inline]
 try_charge+0xd44/0x19b0 mm/memcontrol.c:2283
 memcg_kmem_charge_memcg+0x7c/0x130 mm/memcontrol.c:2591
 memcg_kmem_charge+0x13b/0x340 mm/memcontrol.c:2624
 __alloc_pages_nodemask+0x7b8/0xdc0 mm/page_alloc.c:4559
 __alloc_pages include/linux/gfp.h:473 [inline]
 __alloc_pages_node include/linux/gfp.h:486 [inline]
 alloc_pages_node include/linux/gfp.h:500 [inline]
 alloc_thread_stack_node kernel/fork.c:246 [inline]
 dup_task_struct kernel/fork.c:849 [inline]
 copy_process+0x847/0x8710 kernel/fork.c:1753
 _do_fork+0x1a9/0x1170 kernel/fork.c:2227
 __do_sys_clone kernel/fork.c:2334 [inline]
 __se_sys_clone kernel/fork.c:2328 [inline]
 __x64_sys_clone+0xbf/0x150 kernel/fork.c:2328
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457ec9
Code: 6d b7 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 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f36f091cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000457ec9
RDX: 9999999999999999 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 000000000073bf00 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f36f091d6d4
R13: 00000000004be2a0 R14: 00000000004ce760 R15: 00000000ffffffff

Allocated by task 15809:
 save_stack+0x45/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 __kasan_kmalloc mm/kasan/common.c:496 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469
 kasan_kmalloc mm/kasan/common.c:504 [inline]
 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:411
 kmem_cache_alloc_node+0x144/0x710 mm/slab.c:3633
 alloc_task_struct_node kernel/fork.c:158 [inline]
 dup_task_struct kernel/fork.c:845 [inline]
 copy_process+0x405b/0x8710 kernel/fork.c:1753
 _do_fork+0x1a9/0x1170 kernel/fork.c:2227
 __do_sys_clone kernel/fork.c:2334 [inline]
 __se_sys_clone kernel/fork.c:2328 [inline]
 __x64_sys_clone+0xbf/0x150 kernel/fork.c:2328
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 15817:
 save_stack+0x45/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466
 __cache_free mm/slab.c:3487 [inline]
 kmem_cache_free+0x86/0x260 mm/slab.c:3749
 free_task_struct kernel/fork.c:163 [inline]
 free_task+0x170/0x1f0 kernel/fork.c:458
 __put_task_struct+0x2e0/0x630 kernel/fork.c:731
 put_task_struct+0x4b/0x60 include/linux/sched/task.h:98
 oom_kill_process.cold+0x93a/0x9d4 mm/oom_kill.c:990
 out_of_memory+0x885/0x1420 mm/oom_kill.c:1133
 mem_cgroup_out_of_memory+0x160/0x210 mm/memcontrol.c:1393
 mem_cgroup_oom mm/memcontrol.c:1721 [inline]
 try_charge+0xd44/0x19b0 mm/memcontrol.c:2283
 memcg_kmem_charge_memcg+0x7c/0x130 mm/memcontrol.c:2591
 memcg_kmem_charge+0x13b/0x340 mm/memcontrol.c:2624
 __alloc_pages_nodemask+0x7b8/0xdc0 mm/page_alloc.c:4559
 __alloc_pages include/linux/gfp.h:473 [inline]
 __alloc_pages_node include/linux/gfp.h:486 [inline]
 alloc_pages_node include/linux/gfp.h:500 [inline]
 alloc_thread_stack_node kernel/fork.c:246 [inline]
 dup_task_struct kernel/fork.c:849 [inline]
 copy_process+0x847/0x8710 kernel/fork.c:1753
 _do_fork+0x1a9/0x1170 kernel/fork.c:2227
 __do_sys_clone kernel/fork.c:2334 [inline]
 __se_sys_clone kernel/fork.c:2328 [inline]
 __x64_sys_clone+0xbf/0x150 kernel/fork.c:2328
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8880595f6540
 which belongs to the cache task_struct(33:syz1) of size 6080
The buggy address is located 1792 bytes inside of
 6080-byte region [ffff8880595f6540, ffff8880595f7d00)
The buggy address belongs to the page:
page:ffffea0001657d80 count:1 mapcount:0 mapping:ffff888091f65840 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffffea00028b3288 ffffea0002612788 ffff888091f65840
raw: 0000000000000000 ffff8880595f6540 0000000100000001 ffff888057fe2b00
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff888057fe2b00

Memory state around the buggy address:
 ffff8880595f6b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880595f6b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880595f6c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff8880595f6c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880595f6d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
protocol 88fb is buggy, dev hsr_slave_0
protocol 88fb is buggy, dev hsr_slave_1
protocol 88fb is buggy, dev hsr_slave_0
protocol 88fb is buggy, dev hsr_slave_1

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/01/16 21:26 upstream 47bfa6d9dc8c d538790b .config console log report ci-upstream-kasan-gce-selinux-root
* Struck through repros no longer work on HEAD.