[v6.1] KASAN: use-after-free Read in __ext4_check_dir_entry

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 88690811da69 Linux 6.1.92
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=10af994a980000
kernel config: https://syzkaller.appspot.com/x/.config?x=ee57a613e7f5bf6c
dashboard link: https://syzkaller.appspot.com/bug?extid=038172fd3967d56fc244
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8b45ba80e02a/disk-88690811.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ca769d644800/vmlinux-88690811.xz
kernel image: https://storage.googleapis.com/syzbot-assets/26a1d8aecbf6/bzImage-88690811.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+038172...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in __ext4_check_dir_entry+0x6f3/0x870 fs/ext4/dir.c:85
Read of size 2 at addr ffff88805b63e003 by task syz-executor.1/6345

CPU: 0 PID: 6345 Comm: syz-executor.1 Not tainted 6.1.92-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
print_address_description mm/kasan/report.c:284 [inline]
print_report+0x15f/0x4f0 mm/kasan/report.c:395
kasan_report+0x136/0x160 mm/kasan/report.c:495
__ext4_check_dir_entry+0x6f3/0x870 fs/ext4/dir.c:85
ext4_readdir+0x139e/0x3950 fs/ext4/dir.c:258
iterate_dir+0x224/0x560
__do_sys_getdents64 fs/readdir.c:369 [inline]
__se_sys_getdents64+0x209/0x4f0 fs/readdir.c:354
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1f2e67cee9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1f2f3ff0c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007f1f2e7b3fa0 RCX: 00007f1f2e67cee9
RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00007f1f2e6c947f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f1f2e7b3fa0 R15: 00007ffcdc182b48
</TASK>

Allocated by task 4506:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
__kasan_slab_alloc+0x65/0x70 mm/kasan/common.c:328
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook+0x52/0x3a0 mm/slab.h:737
slab_alloc_node mm/slub.c:3398 [inline]
kmem_cache_alloc_node+0x136/0x310 mm/slub.c:3443
__alloc_skb+0xde/0x670 net/core/skbuff.c:505
alloc_skb include/linux/skbuff.h:1271 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x24c/0xa90 drivers/net/netdevsim/dev.c:850
process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
kthread+0x28d/0x320 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

Freed by task 4506:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236
kasan_slab_free include/linux/kasan.h:177 [inline]
slab_free_hook mm/slub.c:1724 [inline]
slab_free_freelist_hook mm/slub.c:1750 [inline]
slab_free mm/slub.c:3661 [inline]
kmem_cache_free+0x292/0x510 mm/slub.c:3683
nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline]
nsim_dev_trap_report_work+0x75d/0xa90 drivers/net/netdevsim/dev.c:850
process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
kthread+0x28d/0x320 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

The buggy address belongs to the object at ffff88805b63e000
which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 3 bytes inside of
240-byte region [ffff88805b63e000, ffff88805b63e0f0)

The buggy address belongs to the physical page:
page:ffffea00016d8f80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5b63e
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 0000000000000000 dead000000000122 ffff888140180280
raw: 0000000000000000 00000000000c000c 00000001ffffffff 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 0x112a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 4506, tgid 4506 (kworker/1:15), ts 254713527765, free_ts 254707684388
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2513
prep_new_page mm/page_alloc.c:2520 [inline]
get_page_from_freelist+0x31a1/0x3320 mm/page_alloc.c:4279
__alloc_pages+0x28d/0x770 mm/page_alloc.c:5547
alloc_slab_page+0x6a/0x150 mm/slub.c:1794
allocate_slab mm/slub.c:1939 [inline]
new_slab+0x84/0x2d0 mm/slub.c:1992
___slab_alloc+0xc20/0x1270 mm/slub.c:3180
__slab_alloc mm/slub.c:3279 [inline]
slab_alloc_node mm/slub.c:3364 [inline]
kmem_cache_alloc_node+0x1cf/0x310 mm/slub.c:3443
__alloc_skb+0xde/0x670 net/core/skbuff.c:505
alloc_skb include/linux/skbuff.h:1271 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x24c/0xa90 drivers/net/netdevsim/dev.c:850
process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
kthread+0x28d/0x320 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1440 [inline]
free_pcp_prepare mm/page_alloc.c:1490 [inline]
free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3358
free_unref_page+0x33/0x3e0 mm/page_alloc.c:3453
mm_free_pgd kernel/fork.c:741 [inline]
__mmdrop+0xb2/0x470 kernel/fork.c:792
mmdrop include/linux/sched/mm.h:50 [inline]
mmdrop_sched include/linux/sched/mm.h:78 [inline]
finish_task_switch+0x2cd/0x810 kernel/sched/core.c:5149
context_switch kernel/sched/core.c:5248 [inline]
__schedule+0x1435/0x4550 kernel/sched/core.c:6558
schedule+0xbf/0x180 kernel/sched/core.c:6634
do_nanosleep+0x192/0x5f0 kernel/time/hrtimer.c:2045
hrtimer_nanosleep+0x24d/0x490 kernel/time/hrtimer.c:2098
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1308 [inline]
__se_sys_clock_nanosleep+0x323/0x3b0 kernel/time/posix-timers.c:1285
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2

Memory state around the buggy address:
ffff88805b63df00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88805b63df80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88805b63e000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88805b63e080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
ffff88805b63e100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
==================================================================


---
This report 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 issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c61bd26ae81a Linux 5.15.160
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15d05cba980000
kernel config: https://syzkaller.appspot.com/x/.config?x=235f0e81ca937c17
dashboard link: https://syzkaller.appspot.com/bug?extid=618531929d48e32a4823

compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:

disk image: https://storage.googleapis.com/syzbot-assets/d61a97eef8b9/disk-c61bd26a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ab4908b4b59b/vmlinux-c61bd26a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d818fd46802b/bzImage-c61bd26a.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:

Reported-by: syzbot+618531...@syzkaller.appspotmail.com

EXT4-fs warning (device loop3): dx_probe:892: inode #2: comm syz-executor.3: dx entry: limit 0 != root limit 124
EXT4-fs warning (device loop3): dx_probe:965: inode #2: comm syz-executor.3: Corrupt directory, running e2fsck is recommended

==================================================================
BUG: KASAN: use-after-free in __ext4_check_dir_entry+0x6f3/0x870 fs/ext4/dir.c:85

Read of size 2 at addr ffff888054770003 by task syz-executor.3/4461

CPU: 0 PID: 4461 Comm: syz-executor.3 Not tainted 5.15.160-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]

dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
print_address_description+0x63/0x3b0 mm/kasan/report.c:248
__kasan_report mm/kasan/report.c:434 [inline]
kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
__ext4_check_dir_entry+0x6f3/0x870 fs/ext4/dir.c:85
ext4_readdir+0x14a6/0x38e0 fs/ext4/dir.c:258
iterate_dir+0x224/0x570

__do_sys_getdents64 fs/readdir.c:369 [inline]
__se_sys_getdents64+0x209/0x4f0 fs/readdir.c:354

do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fd219c9aee9

Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48

RSP: 002b:00007fd21820e0c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007fd219dd1fa0 RCX: 00007fd219c9aee9

RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000008

RBP: 00007fd219ce747f R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000

R13: 000000000000000b R14: 00007fd219dd1fa0 R15: 00007ffd46730b58
</TASK>

Allocated by task 4180:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
__kasan_slab_alloc+0x8e/0xc0 mm/kasan/common.c:467
kasan_slab_alloc include/linux/kasan.h:254 [inline]
slab_post_alloc_hook+0x53/0x380 mm/slab.h:519
slab_alloc_node mm/slub.c:3220 [inline]
slab_alloc mm/slub.c:3228 [inline]
kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233
vm_area_dup kernel/fork.c:357 [inline]
dup_mmap kernel/fork.c:556 [inline]
dup_mm kernel/fork.c:1465 [inline]
copy_mm+0x8d2/0x1370 kernel/fork.c:1517
copy_process+0x1816/0x3ef0 kernel/fork.c:2206
kernel_clone+0x210/0x960 kernel/fork.c:2604
__do_sys_clone kernel/fork.c:2721 [inline]
__se_sys_clone kernel/fork.c:2705 [inline]
__x64_sys_clone+0x23f/0x290 kernel/fork.c:2705
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0

Freed by task 4449:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track+0x4b/0x80 mm/kasan/common.c:46
kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:1705 [inline]
slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731
slab_free mm/slub.c:3499 [inline]
kmem_cache_free+0x91/0x1f0 mm/slub.c:3515
remove_vma mm/mmap.c:188 [inline]
exit_mmap+0x556/0x670 mm/mmap.c:3197
__mmput+0x112/0x3b0 kernel/fork.c:1126
exit_mm+0x688/0x7f0 kernel/exit.c:548
do_exit+0x626/0x2480 kernel/exit.c:859
do_group_exit+0x144/0x310 kernel/exit.c:994
get_signal+0xc66/0x14e0 kernel/signal.c:2889
arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff888054770000
which belongs to the cache vm_area_struct of size 200

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: c61bd26ae81a Linux 5.15.160
git tree: linux-5.15.y

console output: https://syzkaller.appspot.com/x/log.txt?x=10697026980000

kernel config: https://syzkaller.appspot.com/x/.config?x=235f0e81ca937c17
dashboard link: https://syzkaller.appspot.com/bug?extid=618531929d48e32a4823
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16b697d6980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16970abc980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d61a97eef8b9/disk-c61bd26a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ab4908b4b59b/vmlinux-c61bd26a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d818fd46802b/bzImage-c61bd26a.xz

mounted in repro: https://storage.googleapis.com/syzbot-assets/2ef699ed5ea4/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+618531...@syzkaller.appspotmail.com

EXT4-fs warning (device loop0): dx_probe:965: inode #2: comm syz-executor581: Corrupt directory, running e2fsck is recommended

==================================================================
BUG: KASAN: use-after-free in __ext4_check_dir_entry+0x6f3/0x870 fs/ext4/dir.c:85

Read of size 2 at addr ffff8880708f6003 by task syz-executor581/3513

CPU: 1 PID: 3513 Comm: syz-executor581 Not tainted 5.15.160-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
print_address_description+0x63/0x3b0 mm/kasan/report.c:248
__kasan_report mm/kasan/report.c:434 [inline]
kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
__ext4_check_dir_entry+0x6f3/0x870 fs/ext4/dir.c:85
ext4_readdir+0x14a6/0x38e0 fs/ext4/dir.c:258
iterate_dir+0x224/0x570
__do_sys_getdents64 fs/readdir.c:369 [inline]
__se_sys_getdents64+0x209/0x4f0 fs/readdir.c:354
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0

RIP: 0033:0x7fa96dc1e569
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 1b 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa96dbd0218 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007fa96dc9e608 RCX: 00007fa96dc1e569

RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000008

RBP: 00007fa96dc9e600 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa96dc6b62c
R13: 00007fa96dc6b2e0 R14: 00007fa96dc6b528 R15: 6f6f6c2f7665642f
</TASK>

The buggy address belongs to the page:
page:ffffea0001c23d80 refcount:1 mapcount:1 mapping:0000000000000000 index:0x55b157b7a pfn:0x708f6
memcg:ffff888011e84000
anon flags: 0xfff00000080014(uptodate|lru|swapbacked|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000080014 ffffea0001589b48 ffffea0001c23dc8 ffff88801a9ea771
raw: 000000055b157b7a 0000000000000000 0000000100000000 ffff888011e84000

page dumped because: kasan: bad access detected
page_owner tracks the page as allocated

page last allocated via order 0, migratetype Movable, gfp_mask 0x1100cca(GFP_HIGHUSER_MOVABLE), pid 2964, ts 43131601451, free_ts 37232586833
prep_new_page mm/page_alloc.c:2426 [inline]
get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159
__alloc_pages+0x272/0x700 mm/page_alloc.c:5423
alloc_pages_vma+0x39a/0x800 mm/mempolicy.c:2146
wp_page_copy+0x24e/0x2070 mm/memory.c:3026
handle_pte_fault mm/memory.c:4639 [inline]
__handle_mm_fault mm/memory.c:4756 [inline]
handle_mm_fault+0x2a3d/0x5950 mm/memory.c:4854
do_user_addr_fault arch/x86/mm/fault.c:1388 [inline]
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x271/0x740 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568

page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]

free_pages_prepare mm/page_alloc.c:1340 [inline]
free_pcp_prepare mm/page_alloc.c:1391 [inline]
free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317
free_unref_page_list+0x1f7/0x8e0 mm/page_alloc.c:3433
release_pages+0x1bb9/0x1f40 mm/swap.c:963
tlb_batch_pages_flush mm/mmu_gather.c:49 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:240 [inline]
tlb_flush_mmu mm/mmu_gather.c:247 [inline]
tlb_finish_mmu+0x177/0x320 mm/mmu_gather.c:338
exit_mmap+0x3cd/0x670 mm/mmap.c:3188

__mmput+0x112/0x3b0 kernel/fork.c:1126
exit_mm+0x688/0x7f0 kernel/exit.c:548
do_exit+0x626/0x2480 kernel/exit.c:859
do_group_exit+0x144/0x310 kernel/exit.c:994

__do_sys_exit_group kernel/exit.c:1005 [inline]
__se_sys_exit_group kernel/exit.c:1003 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1003

do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:

ffff8880708f5f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8880708f5f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880708f6000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
^
ffff8880708f6080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8880708f6100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.