BUG: unable to handle page fault for address: 000003c0ffffea08
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 8451 Comm: syz-executor.1 Not tainted 5.12.0-rc8-next-20210423-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:find_stack lib/stackdepot.c:209 [inline]
RIP: 0010:stack_depot_save+0x12b/0x4e0 lib/stackdepot.c:281
Code: 05 7a 64 b8 0c 89 da 81 e2 ff ff 0f 00 4c 8d 3c d0 4d 8b 37 4d 85 f6 75 11 e9 94 00 00 00 4d 8b 36 4d 85 f6 0f 84 88 00 00 00 <41> 39 5e 08 75 ee 45 3b 66 0c 75 e8 31 c0 49 8b 4c c6 18 48 39 4c
RSP: 0018:ffffc900016ff9c0 EFLAGS: 00010206
RAX: ffff88823b000000 RBX: 00000000b2a81596 RCX: 0000000000000001
RDX: 0000000000081596 RSI: 0000000000000800 RDI: 000000004b135f81
RBP: ffffc900016ffa30 R08: 000000006aa8070e R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 000000000000000e
R13: 000000000000000e R14: 000003c0ffffea00 R15: ffff88823b40acb0
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000003c0ffffea08 CR3: 000000002efdc000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 kasan_save_stack+0x32/0x40 mm/kasan/common.c:40
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357
 ____kasan_slab_free mm/kasan/common.c:360 [inline]
 ____kasan_slab_free mm/kasan/common.c:325 [inline]
 __kasan_slab_free+0xfb/0x130 mm/kasan/common.c:368
 kasan_slab_free include/linux/kasan.h:212 [inline]
 slab_free_hook mm/slub.c:1593 [inline]
 slab_free_freelist_hook+0xdf/0x240 mm/slub.c:1618
 slab_free mm/slub.c:3178 [inline]
 kfree+0xe5/0x7f0 mm/slub.c:4245
 put_mnt_ns fs/namespace.c:4253 [inline]
 put_mnt_ns+0x10e/0x140 fs/namespace.c:4248
 free_nsproxy+0x43/0x4c0 kernel/nsproxy.c:191
 put_nsproxy include/linux/nsproxy.h:105 [inline]
 switch_task_namespaces+0xaf/0xd0 kernel/nsproxy.c:249
 do_exit+0xbf7/0x2a70 kernel/exit.c:825
 do_group_exit+0x125/0x310 kernel/exit.c:923
 __do_sys_exit_group kernel/exit.c:934 [inline]
 __se_sys_exit_group kernel/exit.c:932 [inline]
 __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:932
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665f9
Code: Unable to access opcode bytes at RIP 0x4665cf.
RSP: 002b:00007ffcf146cb98 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000064 RCX: 00000000004665f9
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 00000000004bef0a R08: 000000000000000c R09: 0000000002a5b3bc
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000016
R13: 00007ffcf146de70 R14: 0000000002a5b3bc R15: 00007ffcf146ef80
Modules linked in:
CR2: 000003c0ffffea08
---[ end trace 06fe12447471a9a3 ]---
RIP: 0010:find_stack lib/stackdepot.c:209 [inline]
RIP: 0010:stack_depot_save+0x12b/0x4e0 lib/stackdepot.c:281
Code: 05 7a 64 b8 0c 89 da 81 e2 ff ff 0f 00 4c 8d 3c d0 4d 8b 37 4d 85 f6 75 11 e9 94 00 00 00 4d 8b 36 4d 85 f6 0f 84 88 00 00 00 <41> 39 5e 08 75 ee 45 3b 66 0c 75 e8 31 c0 49 8b 4c c6 18 48 39 4c
RSP: 0018:ffffc900016ff9c0 EFLAGS: 00010206
RAX: ffff88823b000000 RBX: 00000000b2a81596 RCX: 0000000000000001
RDX: 0000000000081596 RSI: 0000000000000800 RDI: 000000004b135f81
RBP: ffffc900016ffa30 R08: 000000006aa8070e R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 000000000000000e
R13: 000000000000000e R14: 000003c0ffffea00 R15: ffff88823b40acb0
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000003c0ffffea08 CR3: 000000002efdc000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400