[syzbot ci] Re: bpf: Fix UAF due to concurrent consumption of waiting_for_gp_ttrace

[syzbot ci <syzbot+ci24e276239a9170a6@syzkaller.appspotmail.com>]

syzbot ci has tested the following series

[v1] bpf: Fix UAF due to concurrent consumption of waiting_for_gp_ttrace
https://lore.kernel.org/all/20260826103615.932094-1-pulehui@huaweicloud.com
* [PATCH bpf] bpf: Fix UAF due to concurrent consumption of waiting_for_gp_ttrace

and found the following issues:
* BUG: unable to handle kernel NULL pointer dereference in rcu_core
* BUG: unable to handle kernel paging request in corrupted
* WARNING in mntput_no_expire_slowpath
* kernel BUG in free_percpu

Full report is available here:
https://ci.syzbot.org/series/cfb01d47-3cc7-43a6-99e6-c4a0c6e6ce89

***

BUG: unable to handle kernel NULL pointer dereference in rcu_core

tree:      bpf
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/bpf/bpf.git
base:      75b0a6db4300e4c2c9e97a0848deaa7acfb42fb7
arch:      amd64
compiler:  Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/187f4142-010e-469f-b2d4-8ce60c1dd2c5/config
syz repro: https://ci.syzbot.org/findings/5ac25989-0260-4506-a08a-25fa6e4957e7/syz_repro

BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 800000016a651067 P4D 800000016a651067 PUD 0 
Oops: Oops: 0010 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 5776 Comm: syz.0.18 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
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc90000a08db8 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000028
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffe8ffffc2c5d0
RBP: ffffc90000a08f20 R08: ffffffff81ad5526 R09: 0000000000000000
R10: ffffc90000a08c70 R11: 0000000000000000 R12: ffffe8ffffc2c5d0
R13: dffffc0000000000 R14: ffffffff81ad5526 R15: ffffe8ffffc2c5d8
FS:  00005555813d0500(0000) GS:ffff8882a8f2d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000105338000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 rcu_do_batch kernel/rcu/tree.c:2645 [inline]
 rcu_core+0x794/0x10b0 kernel/rcu/tree.c:2897
 handle_softirqs+0x226/0x860 kernel/softirq.c:645
 __do_softirq kernel/softirq.c:679 [inline]
 invoke_softirq kernel/softirq.c:519 [inline]
 __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:767
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:784
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_release+0x2d7/0x3c0 kernel/locking/lockdep.c:5911
Code: a2 cc 11 00 00 00 00 eb b5 e8 55 12 34 0a f7 c3 00 02 00 00 74 b9 65 48 8b 05 ad 5d cc 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 8a 17 37 0a cc 48 8d 3d b2 b3 b8
RSP: 0018:ffffc900039dfa68 EFLAGS: 00000282
RAX: 4b32b4bcbbad6400 RBX: 0000000000000287 RCX: 0000000000000046
RDX: 0000000000000000 RSI: ffffffff8e4d8901 RDI: ffffffff8c4cd780
RBP: ffff88810b5d29a8 R08: ffffffff821d972f R09: 0000000000000000
R10: 0000000000000000 R11: ffff8881162fe9b8 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8881162fe9b8 R15: ffff88810b5d1e00
 _inline_copy_from_user include/linux/uaccess.h:169 [inline]
 _copy_from_user+0x28/0xb0 lib/usercopy.c:18
 copy_from_user include/linux/uaccess.h:222 [inline]
 generic_map_update_batch+0x668/0xae0 kernel/bpf/syscall.c:2101
 bpf_map_do_batch+0x391/0x630 kernel/bpf/syscall.c:5781
 __sys_bpf+0xbe5/0xd90 kernel/bpf/syscall.c:-1
 __do_sys_bpf kernel/bpf/syscall.c:6486 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6483 [inline]
 __x64_sys_bpf+0xba/0xd0 kernel/bpf/syscall.c:6483
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7febdab9e0d9
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:00007ffc5722f5a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007febdae25fa0 RCX: 00007febdab9e0d9
RDX: 0000000000000038 RSI: 00002000000003c0 RDI: 000000000000001a
RBP: 00007febdac35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007febdae25fac R14: 00007febdae25fa0 R15: 00007febdae25fa0
 </TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace 0000000000000000 ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc90000a08db8 EFLAGS: 00010246

RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000028
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffe8ffffc2c5d0
RBP: ffffc90000a08f20 R08: ffffffff81ad5526 R09: 0000000000000000
R10: ffffc90000a08c70 R11: 0000000000000000 R12: ffffe8ffffc2c5d0
R13: dffffc0000000000 R14: ffffffff81ad5526 R15: ffffe8ffffc2c5d8
FS:  00005555813d0500(0000) GS:ffff8882a8f2d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000105338000 CR4: 00000000000006f0
----------------
Code disassembly (best guess):
   0:	a2 cc 11 00 00 00 00 	movabs %al,0xb5eb0000000011cc
   7:	eb b5
   9:	e8 55 12 34 0a       	call   0xa341263
   e:	f7 c3 00 02 00 00    	test   $0x200,%ebx
  14:	74 b9                	je     0xffffffcf
  16:	65 48 8b 05 ad 5d cc 	mov    %gs:0x11cc5dad(%rip),%rax        # 0x11cc5dcb
  1d:	11
  1e:	48 3b 44 24 28       	cmp    0x28(%rsp),%rax
  23:	75 44                	jne    0x69
  25:	fb                   	sti
  26:	48 83 c4 30          	add    $0x30,%rsp
* 2a:	5b                   	pop    %rbx <-- trapping instruction
  2b:	41 5c                	pop    %r12
  2d:	41 5d                	pop    %r13
  2f:	41 5e                	pop    %r14
  31:	41 5f                	pop    %r15
  33:	5d                   	pop    %rbp
  34:	e9 8a 17 37 0a       	jmp    0xa3717c3
  39:	cc                   	int3
  3a:	48                   	rex.W
  3b:	8d                   	.byte 0x8d
  3c:	3d                   	.byte 0x3d
  3d:	b2 b3                	mov    $0xb3,%dl
  3f:	b8                   	.byte 0xb8


***

BUG: unable to handle kernel paging request in corrupted

tree:      bpf
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/bpf/bpf.git
base:      75b0a6db4300e4c2c9e97a0848deaa7acfb42fb7
arch:      amd64
compiler:  Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/187f4142-010e-469f-b2d4-8ce60c1dd2c5/config
syz repro: https://ci.syzbot.org/findings/d4bc6f3a-dacb-412b-ac9d-51a5c1dbc4a4/syz_repro

kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
BUG: unable to handle page fault for address: ffff888173315c00
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0011) - permissions violation
PGD 1acd0067 P4D 1acd0067 PUD 1acd5067 PMD 80000001732000e3 
Oops: Oops: 0011 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 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
RIP: 0010:0xffff888173315c00
Code: ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <80> 5b 31 73 81 88 ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RSP: 0018:ffffc90000007d60 EFLAGS: 00010246
RAX: 1ffffd1ffff8f783 RBX: ffffe8ffffc7bc18 RCX: ffffffff8e88ef80
RDX: 0000000000000100 RSI: ffff888174548380 RDI: ffffffff81f86ab8
RBP: ffffe8ffffc7bc10 R08: 0000000000000100 R09: 0000000000000000
R10: 0000000000000000 R11: ffff888173315c00 R12: e5894855fa1e0ff3
R13: ffff888173315c00 R14: ffffffff81f86ab0 R15: ffffe8ffffc7bc18
FS:  0000000000000000(0000) GS:ffff88818d92d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff888173315c00 CR3: 000000010b9a2000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 </TASK>
Modules linked in:
CR2: ffff888173315c00
---[ end trace 0000000000000000 ]---
RIP: 0010:0xffff888173315c00
Code: ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <80> 5b 31 73 81 88 ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RSP: 0018:ffffc90000007d60 EFLAGS: 00010246
RAX: 1ffffd1ffff8f783 RBX: ffffe8ffffc7bc18 RCX: ffffffff8e88ef80
RDX: 0000000000000100 RSI: ffff888174548380 RDI: ffffffff81f86ab8
RBP: ffffe8ffffc7bc10 R08: 0000000000000100 R09: 0000000000000000
R10: 0000000000000000 R11: ffff888173315c00 R12: e5894855fa1e0ff3
R13: ffff888173315c00 R14: ffffffff81f86ab0 R15: ffffe8ffffc7bc18
FS:  0000000000000000(0000) GS:ffff88818d92d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff888173315c00 CR3: 000000010b9a2000 CR4: 00000000000006f0
----------------
Code disassembly (best guess), 2 bytes skipped:
* 28:	80 5b 31 73          	sbbb   $0x73,0x31(%rbx) <-- trapping instruction
  2c:	81 88 ff ff 00 00 00 	orl    $0x0,0xffff(%rax)
  33:	00 00 00


***

WARNING in mntput_no_expire_slowpath

tree:      bpf
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/bpf/bpf.git
base:      75b0a6db4300e4c2c9e97a0848deaa7acfb42fb7
arch:      amd64
compiler:  Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/187f4142-010e-469f-b2d4-8ce60c1dd2c5/config
syz repro: https://ci.syzbot.org/findings/f322b4d1-7f66-454a-80ff-6ed13eb274aa/syz_repro

------------[ cut here ]------------
count < 0
WARNING: fs/namespace.c:1353 at mntput_no_expire_slowpath+0x845/0xbf0 fs/namespace.c:1353, CPU#1: syz.0.20/5861
Modules linked in:
CPU: 1 UID: 0 PID: 5861 Comm: syz.0.20 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
RIP: 0010:mntput_no_expire_slowpath+0x845/0xbf0 fs/namespace.c:1353
Code: 01 00 00 00 bf 08 00 00 00 48 c7 c2 c0 48 ce 8e e8 a0 18 39 ff e9 47 fc ff ff e8 36 4e 72 ff e9 4a fa ff ff e8 2c 4e 72 ff 90 <0f> 0b 90 e9 68 fa ff ff e8 1e 4e 72 ff e8 69 83 fe ff e8 64 f7 ff
RSP: 0018:ffffc90003cdfba0 EFLAGS: 00010293
RAX: ffffffff8254bf34 RBX: dffffc0000000000 RCX: ffff888113571e00
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 0000000000000000
RBP: ffffc90003cdfc88 R08: ffffffff8254cacc R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8e814988 R12: ffff8881016c3600
R13: 0000000000000003 R14: 00000000ffffffff R15: 0000000000000002
FS:  00007fa12e5946c0(0000) GS:ffff8882a8f2d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555579145a28 CR3: 0000000176282000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 mntput fs/namespace.c:1421 [inline]
 cleanup_mnt+0x30c/0x460 fs/namespace.c:1313
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x73a/0x2360 kernel/exit.c:1009
 __do_sys_exit kernel/exit.c:1119 [inline]
 __se_sys_exit kernel/exit.c:1117 [inline]
 __x64_sys_exit+0x40/0x40 kernel/exit.c:1117
 x64_sys_call+0x18b4/0x18d0 arch/x86/include/generated/asm/syscalls_64.h:61
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa12d79e0d9
Code: Unable to access opcode bytes at 0x7fa12d79e0af.
RSP: 002b:00007fa12e593fd8 EFLAGS: 00000246 ORIG_RAX: 000000000000003c
RAX: ffffffffffffffda RBX: 00007fa12da25fa0 RCX: 00007fa12d79e0d9
RDX: 00007fa12e5949c8 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fa12d835024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa12da26038 R14: 00007fa12da25fa0 R15: 00007ffe0f572ca8
 </TASK>


***

kernel BUG in free_percpu

tree:      bpf
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/bpf/bpf.git
base:      75b0a6db4300e4c2c9e97a0848deaa7acfb42fb7
arch:      amd64
compiler:  Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/187f4142-010e-469f-b2d4-8ce60c1dd2c5/config
syz repro: https://ci.syzbot.org/findings/40ff44c7-989e-4e59-a57c-7d669c0abd76/syz_repro

------------[ cut here ]------------
kernel BUG at mm/vmalloc.c:835!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 3326 Comm: kworker/u9:4 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
Workqueue: events_unbound bpf_map_free_deferred
RIP: 0010:vmalloc_to_page+0x67c/0x6b0 mm/vmalloc.c:835
Code: 51 fb ff ff e8 b5 a8 a2 ff 42 80 7c 2d 00 00 0f 85 5c fb ff ff e9 5f fb ff ff e8 9f a8 a2 ff e9 ae fb ff ff e8 95 a8 a2 ff 90 <0f> 0b e8 8d a8 a2 ff e9 64 fa ff ff e8 83 a8 a2 ff 48 b8 00 00 00
RSP: 0018:ffffc90000007cc0 EFLAGS: 00010246
RAX: ffffffff822464cb RBX: 5440ddc2e3d42741 RCX: ffff888110ad5a00
RDX: 0000000000000100 RSI: 0000000000000100 RDI: ffffc90000000000
RBP: ffffe8fee467b538 R08: 0000000000000100 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff81f86890 R12: 0000000000a881bb
R13: dffffc0000000000 R14: ffffc90000000000 R15: ffffffff8e946000
FS:  0000000000000000(0000) GS:ffff88818d92d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000100000000 CR3: 000000001c4e4000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 pcpu_addr_to_page mm/percpu-vm.c:373 [inline]
 pcpu_chunk_addr_search mm/percpu.c:1612 [inline]
 free_percpu+0x1fa/0xfe0 mm/percpu.c:2246
 free_one kernel/bpf/memalloc.c:262 [inline]
 free_all kernel/bpf/memalloc.c:275 [inline]
 __free_final_rcu+0x151/0x210 kernel/bpf/memalloc.c:287
 rcu_do_batch kernel/rcu/tree.c:2645 [inline]
 rcu_core+0x794/0x10b0 kernel/rcu/tree.c:2897
 handle_softirqs+0x226/0x860 kernel/softirq.c:645
 __do_softirq kernel/softirq.c:679 [inline]
 invoke_softirq kernel/softirq.c:519 [inline]
 __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:767
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:784
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_acquire+0x222/0x350 kernel/locking/lockdep.c:5890
Code: ff ff ff e8 f0 43 34 0a f7 44 24 08 00 02 00 00 0f 84 39 ff ff ff 65 48 8b 05 42 8f cc 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d d7 e1 b8
RSP: 0018:ffffc90006dc77e8 EFLAGS: 00000286
RAX: b973d41dfa964800 RBX: 0000000000000000 RCX: 8000000000000001
RDX: 00000000fa315d19 RSI: ffffffff8e4d8901 RDI: ffffffff8c4cd780
RBP: ffffffff823e19a8 R08: ffffffff823e19a8 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8eb5a1e0 R12: 0000000000000002
R13: ffffffff8eb5a1e0 R14: 0000000000000000 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 rcu_read_lock include/linux/rcupdate.h:840 [inline]
 get_non_dying_memcg_start mm/memcontrol.c:817 [inline]
 mod_memcg_state+0x64/0x190 mm/memcontrol.c:879
 account_kmem_nmi_safe mm/memcontrol.c:3057 [inline]
 obj_cgroup_uncharge_pages mm/memcontrol.c:3073 [inline]
 __refill_obj_stock+0x559/0x6c0 mm/memcontrol.c:3459
 __memcg_slab_free_hook+0x2bc/0x470 mm/memcontrol.c:3649
 memcg_slab_free_hook mm/slub.c:2475 [inline]
 slab_free mm/slub.c:6374 [inline]
 kfree+0x3d6/0x640 mm/slub.c:6692
 free_one kernel/bpf/memalloc.c:264 [inline]
 free_all kernel/bpf/memalloc.c:275 [inline]
 drain_mem_cache+0x643/0x8e0 kernel/bpf/memalloc.c:653
 bpf_mem_alloc_destroy+0x142/0x550 kernel/bpf/memalloc.c:766
 trie_free+0x134/0x160 kernel/bpf/lpm_trie.c:652
 bpf_map_free+0x19d/0x3f0 kernel/bpf/syscall.c:896
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa88/0x14c0 kernel/workqueue.c:3405
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:vmalloc_to_page+0x67c/0x6b0 mm/vmalloc.c:835
Code: 51 fb ff ff e8 b5 a8 a2 ff 42 80 7c 2d 00 00 0f 85 5c fb ff ff e9 5f fb ff ff e8 9f a8 a2 ff e9 ae fb ff ff e8 95 a8 a2 ff 90 <0f> 0b e8 8d a8 a2 ff e9 64 fa ff ff e8 83 a8 a2 ff 48 b8 00 00 00
RSP: 0018:ffffc90000007cc0 EFLAGS: 00010246
RAX: ffffffff822464cb RBX: 5440ddc2e3d42741 RCX: ffff888110ad5a00
RDX: 0000000000000100 RSI: 0000000000000100 RDI: ffffc90000000000
RBP: ffffe8fee467b538 R08: 0000000000000100 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff81f86890 R12: 0000000000a881bb
R13: dffffc0000000000 R14: ffffc90000000000 R15: ffffffff8e946000
FS:  0000000000000000(0000) GS:ffff88818d92d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000100000000 CR3: 000000000e946000 CR4: 00000000000006f0
----------------
Code disassembly (best guess), 3 bytes skipped:
   0:	e8 f0 43 34 0a       	call   0xa3443f5
   5:	f7 44 24 08 00 02 00 	testl  $0x200,0x8(%rsp)
   c:	00
   d:	0f 84 39 ff ff ff    	je     0xffffff4c
  13:	65 48 8b 05 42 8f cc 	mov    %gs:0x11cc8f42(%rip),%rax        # 0x11cc8f5d
  1a:	11
  1b:	48 3b 44 24 58       	cmp    0x58(%rsp),%rax
  20:	75 33                	jne    0x55
  22:	fb                   	sti
  23:	48 83 c4 60          	add    $0x60,%rsp
* 27:	5b                   	pop    %rbx <-- trapping instruction
  28:	41 5c                	pop    %r12
  2a:	41 5d                	pop    %r13
  2c:	41 5e                	pop    %r14
  2e:	41 5f                	pop    %r15
  30:	5d                   	pop    %rbp
  31:	c3                   	ret
  32:	cc                   	int3
  33:	cc                   	int3
  34:	cc                   	int3
  35:	cc                   	int3
  36:	cc                   	int3
  37:	48                   	rex.W
  38:	8d                   	.byte 0x8d
  39:	3d                   	.byte 0x3d
  3a:	d7                   	xlat   %ds:(%rbx)
  3b:	e1 b8                	loope  0xfffffff5


***

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: syzbot@syzkaller.appspotmail.com

---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@googlegroups.com.

To test a fix for this bug, please reply with `#syz test`
(on a separate line) and attach the patch to the email.

Notes:
- The patch will be applied on top of the tested series (as an
  incremental fix).
- To test a new version of the whole series, please send it directly
  to syzbot@lists.linux.dev.
- Arguments like custom git repos and branches are not supported.