[syzbot] KASAN: use-after-free Read in put_pmu_ctx

syzbot
2022-12-19T08:04:50Z

Hello,

syzbot found the following issue on:

HEAD commit: 13e3c7793e2f Merge tag 'for-netdev' of https://git.kernel...
git tree: bpf
console+strace: https://syzkaller.appspot.com/x/log.txt?x=177df7e0480000
kernel config: https://syzkaller.appspot.com/x/.config?x=b0e91ad4b5f69c47
dashboard link: https://syzkaller.appspot.com/bug?extid=b8e8c01c8ade4fe6e48f
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15e87100480000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16ceeb13880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/373a99daa295/disk-13e3c779.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7fa71ed0fe17/vmlinux-13e3c779.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2842ad5c698b/bzImage-13e3c779.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b8e8c01c8ade4fe6e48f@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x3ee7/0x56d0 kernel/locking/lockdep.c:4925
Read of size 8 at addr ffff8880237d6018 by task syz-executor287/8300

CPU: 0 PID: 8300 Comm: syz-executor287 Not tainted 6.1.0-syzkaller-09661-g13e3c7793e2f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:284 [inline]
print_report+0x15e/0x45d mm/kasan/report.c:395
kasan_report+0xbf/0x1f0 mm/kasan/report.c:495
__lock_acquire+0x3ee7/0x56d0 kernel/locking/lockdep.c:4925
lock_acquire kernel/locking/lockdep.c:5668 [inline]
lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162
put_pmu_ctx kernel/events/core.c:4913 [inline]
put_pmu_ctx+0xad/0x390 kernel/events/core.c:4893
_free_event+0x3c5/0x13d0 kernel/events/core.c:5196
free_event+0x58/0xc0 kernel/events/core.c:5224
__do_sys_perf_event_open+0x66d/0x2980 kernel/events/core.c:12701
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f3a2b1b3f29
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff4215df68 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007f3a2b1b3f29
RDX: 0000000000000000 RSI: 0000000000002070 RDI: 0000000020000480
RBP: 0000000000000000 R08: 0000000000000008 R09: 0000000000000001
R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000012a59
R13: 00007fff4215df7c R14: 00007fff4215df90 R15: 00007fff4215df80
</TASK>

Allocated by task 8300:
kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
____kasan_kmalloc mm/kasan/common.c:371 [inline]
____kasan_kmalloc mm/kasan/common.c:330 [inline]
__kasan_kmalloc+0xa5/0xb0 mm/kasan/common.c:380
kmalloc include/linux/slab.h:580 [inline]
kzalloc include/linux/slab.h:720 [inline]
alloc_perf_context kernel/events/core.c:4693 [inline]
find_get_context+0xcc/0x810 kernel/events/core.c:4763
__do_sys_perf_event_open+0x963/0x2980 kernel/events/core.c:12476
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 5310:
kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:518
____kasan_slab_free mm/kasan/common.c:236 [inline]
____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200
kasan_slab_free include/linux/kasan.h:177 [inline]
slab_free_hook mm/slub.c:1781 [inline]
slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807
slab_free mm/slub.c:3787 [inline]
__kmem_cache_free+0xaf/0x3b0 mm/slub.c:3800
rcu_do_batch kernel/rcu/tree.c:2244 [inline]
rcu_core+0x81f/0x1980 kernel/rcu/tree.c:2504
__do_softirq+0x1fb/0xadc kernel/softirq.c:571

Last potentially related work creation:
kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
__kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488
__call_rcu_common.constprop.0+0x99/0x820 kernel/rcu/tree.c:2753
put_ctx kernel/events/core.c:1180 [inline]
put_ctx+0x116/0x1e0 kernel/events/core.c:1173
perf_event_exit_task_context kernel/events/core.c:13046 [inline]
perf_event_exit_task+0x556/0x760 kernel/events/core.c:13073
do_exit+0xb4d/0x2a30 kernel/exit.c:829
__do_sys_exit kernel/exit.c:917 [inline]
__se_sys_exit kernel/exit.c:915 [inline]
__x64_sys_exit+0x42/0x50 kernel/exit.c:915
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

The buggy address belongs to the object at ffff8880237d6000
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
512-byte region [ffff8880237d6000, ffff8880237d6200)

The buggy address belongs to the physical page:
page:ffffea00008df500 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x237d4
head:ffffea00008df500 order:2 compound_mapcount:0 compound_pincount:0
anon flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffff888012441c80 0000000000000000 dead000000000001
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 2173, tgid 2173 (kworker/u4:3), ts 10211275854, free_ts 0
prep_new_page mm/page_alloc.c:2539 [inline]
get_page_from_freelist+0x10b5/0x2d50 mm/page_alloc.c:4291
__alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5558
alloc_pages+0x1aa/0x270 mm/mempolicy.c:2285
alloc_slab_page mm/slub.c:1851 [inline]
allocate_slab+0x25f/0x350 mm/slub.c:1998
new_slab mm/slub.c:2051 [inline]
___slab_alloc+0xa91/0x1400 mm/slub.c:3193
__slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3292
__slab_alloc_node mm/slub.c:3345 [inline]
slab_alloc_node mm/slub.c:3442 [inline]
__kmem_cache_alloc_node+0x1a4/0x430 mm/slub.c:3491
kmalloc_trace+0x26/0x60 mm/slab_common.c:1062
kmalloc include/linux/slab.h:580 [inline]
kzalloc include/linux/slab.h:720 [inline]
alloc_bprm+0x51/0x900 fs/exec.c:1510
kernel_execve+0xaf/0x500 fs/exec.c:1981
call_usermodehelper_exec_async+0x2e7/0x580 kernel/umh.c:113
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
page_owner free stack trace missing

Memory state around the buggy address:
ffff8880237d5f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880237d5f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880237d6000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880237d6080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880237d6100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

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