[syzbot ci] Re: context_tracking,x86: Defer some IPIs until a user->kernel transition

[syzbot ci]

syzbot ci has tested the following series

[v8] context_tracking,x86: Defer some IPIs until a user->kernel transition
https://lore.kernel.org/all/20260324094801.3...@redhat.com
* [RFC PATCH v8 01/10] objtool: Make validate_call() recognize indirect calls to pv_ops[]
* [RFC PATCH v8 02/10] objtool: Flesh out warning related to pv_ops[] calls
* [RFC PATCH v8 03/10] objtool: Always pass a section to validate_unwind_hints()
* [RFC PATCH v8 04/10] x86/retpoline: Make warn_thunk_thunk .noinstr
* [RFC PATCH v8 05/10] sched/isolation: Mark housekeeping_overridden key as __ro_after_init
* [RFC PATCH v8 06/10] objtool: Add .entry.text validation for static branches
* [RFC PATCH v8 07/10] x86/jump_label: Add ASM support for static_branch_likely()
* [RFC PATCH v8 08/10] x86/mm/pti: Introduce a kernel/user CR3 software signal
* [RFC PATCH v8 09/10] context_tracking,x86: Defer kernel text patching IPIs when tracking CR3 switches
* [RFC PATCH v8 10/10] x86/mm, mm/vmalloc: Defer kernel TLB flush IPIs when tracking CR3 switches

and found the following issues:
* KASAN: slab-out-of-bounds Read in __dynamic_pr_debug
* KASAN: slab-use-after-free Read in __dynamic_dev_dbg

Full report is available here:
https://ci.syzbot.org/series/e1f9c661-db83-4882-8439-ab6d1b3ffe07

***

KASAN: slab-out-of-bounds Read in __dynamic_pr_debug

tree: linux-next
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/next/linux-next
base: f9d6fc9557e68b48253818870d002dc4784cb2f1
arch: amd64
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
config: https://ci.syzbot.org/builds/c63282ed-913a-4673-b0e4-cd21246874b2/config
C repro: https://ci.syzbot.org/findings/5b3af331-6a29-4205-911e-8924b9c54449/c_repro
syz repro: https://ci.syzbot.org/findings/5b3af331-6a29-4205-911e-8924b9c54449/syz_repro

==================================================================
BUG: KASAN: slab-out-of-bounds in string_nocheck lib/vsprintf.c:654 [inline]
BUG: KASAN: slab-out-of-bounds in string+0x231/0x2b0 lib/vsprintf.c:736
Read of size 1 at addr ffff8881663cbca1 by task syz.0.17/5964

CPU: 0 UID: 0 PID: 5964 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xba/0x230 mm/kasan/report.c:482
kasan_report+0x117/0x150 mm/kasan/report.c:595
string_nocheck lib/vsprintf.c:654 [inline]
string+0x231/0x2b0 lib/vsprintf.c:736
vsnprintf+0x739/0xee0 lib/vsprintf.c:2947
va_format lib/vsprintf.c:1722 [inline]
pointer+0x9b7/0x11f0 lib/vsprintf.c:2568
vsnprintf+0x614/0xee0 lib/vsprintf.c:2951
vprintk_store+0x371/0xd50 kernel/printk/printk.c:2255
vprintk_emit+0x192/0x560 kernel/printk/printk.c:2402
_printk+0xdd/0x130 kernel/printk/printk.c:2451
__dynamic_pr_debug+0x1a2/0x260 lib/dynamic_debug.c:879
nfc_llcp_wks_sap net/nfc/llcp_core.c:344 [inline]
nfc_llcp_get_sdp_ssap+0x3a5/0x440 net/nfc/llcp_core.c:420
llcp_sock_bind+0x3d6/0x780 net/nfc/llcp_sock.c:114
__sys_bind_socket net/socket.c:1874 [inline]
__sys_bind+0x2e3/0x410 net/socket.c:1905
__do_sys_bind net/socket.c:1910 [inline]
__se_sys_bind net/socket.c:1908 [inline]
__x64_sys_bind+0x7a/0x90 net/socket.c:1908
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf40 arch/x86/entry/syscall_64.c:98
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5158f9c799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe7ca57bc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 00007f5159215fa0 RCX: 00007f5158f9c799
RDX: 0000000000000060 RSI: 0000200000000080 RDI: 0000000000000004
RBP: 00007f5159032c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5159215fac R14: 00007f5159215fa0 R15: 00007f5159215fa0
</TASK>

Allocated by task 5964:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5657 [inline]
__kmalloc_node_track_caller_noprof+0x558/0x7f0 mm/slub.c:5768
kmemdup_noprof+0x2b/0x70 mm/util.c:138
kmemdup_noprof include/linux/fortify-string.h:765 [inline]
llcp_sock_bind+0x392/0x780 net/nfc/llcp_sock.c:107
__sys_bind_socket net/socket.c:1874 [inline]
__sys_bind+0x2e3/0x410 net/socket.c:1905
__do_sys_bind net/socket.c:1910 [inline]
__se_sys_bind net/socket.c:1908 [inline]
__x64_sys_bind+0x7a/0x90 net/socket.c:1908
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf40 arch/x86/entry/syscall_64.c:98
entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8881663cbca0
which belongs to the cache kmalloc-8 of size 8
The buggy address is located 0 bytes to the right of
allocated 1-byte region [ffff8881663cbca0, ffff8881663cbca1)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8881663cb7e0 pfn:0x1663cb
anon flags: 0x57ff00000000000(node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000000 ffff888100041500 0000000000000000 dead000000000001
raw: ffff8881663cb7e0 0000000080800078 00000000f5000000 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 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid 1 (swapper/0), ts 3460727604, free_ts 3423843770
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x228/0x280 mm/page_alloc.c:1884
prep_new_page mm/page_alloc.c:1892 [inline]
get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3945
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5240
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
alloc_slab_page mm/slub.c:3075 [inline]
allocate_slab+0x86/0x3a0 mm/slub.c:3248
new_slab mm/slub.c:3302 [inline]
___slab_alloc+0xd82/0x1760 mm/slub.c:4656
__slab_alloc+0x65/0x100 mm/slub.c:4779
__slab_alloc_node mm/slub.c:4855 [inline]
slab_alloc_node mm/slub.c:5251 [inline]
__do_kmalloc_node mm/slub.c:5656 [inline]
__kmalloc_noprof+0x46c/0x7e0 mm/slub.c:5669
kmalloc_noprof include/linux/slab.h:961 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
acpi_ns_internalize_name+0x2c9/0x3e0 drivers/acpi/acpica/nsutils.c:331
acpi_ns_get_node_unlocked+0x186/0x480 drivers/acpi/acpica/nsutils.c:666
acpi_ns_get_node+0x76/0xc0 drivers/acpi/acpica/nsutils.c:726
acpi_ns_evaluate+0x283/0x1230 drivers/acpi/acpica/nseval.c:62
acpi_evaluate_object+0x657/0xd50 drivers/acpi/acpica/nsxfeval.c:354
acpi_get_physical_device_location+0xa0/0x2d0 drivers/acpi/utils.c:504
acpi_store_pld_crc drivers/acpi/scan.c:728 [inline]
acpi_device_add+0x6c4/0x940 drivers/acpi/scan.c:787
acpi_add_single_object+0x1621/0x1b70 drivers/acpi/scan.c:1910
page last free pid 1 tgid 1 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1433 [inline]
__free_frozen_pages+0xbf8/0xd70 mm/page_alloc.c:2973
discard_slab mm/slub.c:3346 [inline]
__put_partials+0x146/0x170 mm/slub.c:3886
__slab_free+0x294/0x320 mm/slub.c:5956
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179
kasan_quarantine_remove_cache+0x1ca/0x360 mm/kasan/quarantine.c:364
kmem_cache_shrink+0xd/0x20 mm/slab_common.c:564
acpi_os_purge_cache+0x15/0x20 drivers/acpi/osl.c:1605
acpi_purge_cached_objects+0xd5/0x100 drivers/acpi/acpica/utxface.c:240
acpi_initialize_objects+0x2e/0xb0 drivers/acpi/acpica/utxfinit.c:250
acpi_bus_init+0xaf/0x570 drivers/acpi/bus.c:1367
acpi_init+0xa1/0x1f0 drivers/acpi/bus.c:1456
do_one_initcall+0x250/0x840 init/main.c:1378
do_initcall_level+0x104/0x190 init/main.c:1440
do_initcalls+0x59/0xa0 init/main.c:1456
kernel_init_freeable+0x2a6/0x3d0 init/main.c:1688
kernel_init+0x1d/0x1d0 init/main.c:1578

Memory state around the buggy address:
ffff8881663cbb80: fa fc fc fc fa fc fc fc fa fc fc fc fa fc fc fc
ffff8881663cbc00: fa fc fc fc fa fc fc fc fa fc fc fc fa fc fc fc
>ffff8881663cbc80: fa fc fc fc 01 fc fc fc 00 fc fc fc fa fc fc fc
^
ffff8881663cbd00: fa fc fc fc fa fc fc fc fa fc fc fc fa fc fc fc
ffff8881663cbd80: fa fc fc fc fa fc fc fc fa fc fc fc fa fc fc fc
==================================================================


***

KASAN: slab-use-after-free Read in __dynamic_dev_dbg

tree: linux-next
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/next/linux-next
base: f9d6fc9557e68b48253818870d002dc4784cb2f1
arch: amd64
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
config: https://ci.syzbot.org/builds/c63282ed-913a-4673-b0e4-cd21246874b2/config
syz repro: https://ci.syzbot.org/findings/a49a383b-f0f8-498a-9415-6a927fc7d4b7/syz_repro

==================================================================
BUG: KASAN: slab-use-after-free in dev_driver_string+0x35/0xd0 drivers/base/core.c:2406
Read of size 8 at addr ffff8881137960e0 by task syz.0.17/6043

CPU: 1 UID: 0 PID: 6043 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xba/0x230 mm/kasan/report.c:482
kasan_report+0x117/0x150 mm/kasan/report.c:595
dev_driver_string+0x35/0xd0 drivers/base/core.c:2406
__dynamic_dev_dbg+0x1ae/0x2e0 lib/dynamic_debug.c:906
display_close+0x1f9/0x240 drivers/media/rc/imon.c:576
__fput+0x44f/0xa70 fs/file_table.c:469
task_work_run+0x1d9/0x270 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x69b/0x2310 kernel/exit.c:971
do_group_exit+0x21b/0x2d0 kernel/exit.c:1112
get_signal+0x1284/0x1330 kernel/signal.c:3034
arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2b7/0xf40 arch/x86/entry/syscall_64.c:104
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb43639c799
Code: Unable to access opcode bytes at 0x7fb43639c76f.
RSP: 002b:00007fb4372890e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fb436616188 RCX: 00007fb43639c799
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb436616188
RBP: 00007fb436616180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb436616218 R14: 00007ffeece49910 R15: 00007ffeece499f8
</TASK>

Allocated by task 5990:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_noprof+0x3d1/0x6e0 mm/slub.c:5780
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
usb_set_configuration+0x3c9/0x2110 drivers/usb/core/message.c:2037
usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
usb_probe_device+0x1c4/0x3b0 drivers/usb/core/driver.c:291
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x267/0xaf0 drivers/base/dd.c:661
__driver_probe_device+0x18c/0x320 drivers/base/dd.c:803
driver_probe_device+0x4f/0x240 drivers/base/dd.c:833
__device_attach_driver+0x279/0x430 drivers/base/dd.c:961
bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
__device_attach+0x2c5/0x450 drivers/base/dd.c:1033
device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1088
bus_probe_device+0x12a/0x220 drivers/base/bus.c:574
device_add+0x7b6/0xb70 drivers/base/core.c:3689
usb_new_device+0xa08/0x16f0 drivers/usb/core/hub.c:2695
hub_port_connect drivers/usb/core/hub.c:5567 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x2a1c/0x4f30 drivers/usb/core/hub.c:5953
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
worker_thread+0xda6/0x1360 kernel/workqueue.c:3421
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Freed by task 9:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2540 [inline]
slab_free mm/slub.c:6674 [inline]
kfree+0x1be/0x650 mm/slub.c:6886
device_release+0x9e/0x1d0 drivers/base/core.c:-1
kobject_cleanup lib/kobject.c:689 [inline]
kobject_release lib/kobject.c:720 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x228/0x560 lib/kobject.c:737
usb_disable_device+0x611/0x8d0 drivers/usb/core/message.c:1425
usb_disconnect+0x32f/0x990 drivers/usb/core/hub.c:2345
hub_port_connect drivers/usb/core/hub.c:5407 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x1cc9/0x4f30 drivers/usb/core/hub.c:5953
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
worker_thread+0xda6/0x1360 kernel/workqueue.c:3421
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

The buggy address belongs to the object at ffff888113796000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 224 bytes inside of
freed 2048-byte region [ffff888113796000, ffff888113796800)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x113790
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x17ff00000000040(head|node=0|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 017ff00000000040 ffff888100042000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 017ff00000000040 ffff888100042000 dead000000000122 0000000000000000
head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 017ff00000000003 ffffea00044de401 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6019, tgid 6019 (kworker/0:5), ts 128207296876, free_ts 125356693648
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x228/0x280 mm/page_alloc.c:1884
prep_new_page mm/page_alloc.c:1892 [inline]
get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3945
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5240
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
alloc_slab_page mm/slub.c:3075 [inline]
allocate_slab+0x86/0x3a0 mm/slub.c:3248
new_slab mm/slub.c:3302 [inline]
___slab_alloc+0xd82/0x1760 mm/slub.c:4656
__slab_alloc+0x65/0x100 mm/slub.c:4779
__slab_alloc_node mm/slub.c:4855 [inline]
slab_alloc_node mm/slub.c:5251 [inline]
__do_kmalloc_node mm/slub.c:5656 [inline]
__kmalloc_node_track_caller_noprof+0x5b7/0x7f0 mm/slub.c:5768
kmalloc_reserve+0x136/0x290 net/core/skbuff.c:608
__alloc_skb+0x204/0x390 net/core/skbuff.c:690
alloc_skb include/linux/skbuff.h:1383 [inline]
mld_newpack+0x14c/0xc90 net/ipv6/mcast.c:1775
add_grhead+0x5a/0x2a0 net/ipv6/mcast.c:1886
add_grec+0x1452/0x1740 net/ipv6/mcast.c:2025
mld_send_cr net/ipv6/mcast.c:2148 [inline]
mld_ifc_work+0x6e6/0xe70 net/ipv6/mcast.c:2693
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
worker_thread+0xda6/0x1360 kernel/workqueue.c:3421
page last free pid 5243 tgid 5243 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1433 [inline]
__free_frozen_pages+0xbf8/0xd70 mm/page_alloc.c:2973
discard_slab mm/slub.c:3346 [inline]
__put_partials+0x146/0x170 mm/slub.c:3886
__slab_free+0x294/0x320 mm/slub.c:5956
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_node_noprof+0x427/0x6f0 mm/slub.c:5315
__alloc_skb+0x1d7/0x390 net/core/skbuff.c:679
alloc_skb include/linux/skbuff.h:1383 [inline]
alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6715
sock_alloc_send_pskb+0x878/0x990 net/core/sock.c:2995
unix_dgram_sendmsg+0x460/0x18e0 net/unix/af_unix.c:2130
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
__sys_sendto+0x709/0x7a0 net/socket.c:2206
__do_sys_sendto net/socket.c:2213 [inline]
__se_sys_sendto net/socket.c:2209 [inline]
__x64_sys_sendto+0xde/0x100 net/socket.c:2209
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf40 arch/x86/entry/syscall_64.c:98
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
ffff888113795f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888113796000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888113796080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888113796100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888113796180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


***

If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
Tested-by: syz...@syzkaller.appspotmail.com

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