process 'syz-executor.5' launched './file1' with NULL argv: empty string added
==================================================================
BUG: KASAN: slab-use-after-free in nsproxy_free+0x57c/0x5a0
Read of size 8 at addr ffff88801e925c30 by task syz-executor.3/5170
CPU: 1 UID: 0 PID: 5170 Comm: syz-executor.3 Not tainted 6.18.0-rc5-next-20251114 #1 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
dump_stack_lvl+0xca/0x120
print_report+0xcb/0x610
kasan_report+0xca/0x100
nsproxy_free+0x57c/0x5a0
create_new_namespaces+0x585/0x750
copy_namespaces+0x45c/0x580
copy_process+0x26e4/0x72a0
kernel_clone+0xea/0x7f0
__do_sys_clone3+0x1f5/0x280
do_syscall_64+0xbf/0x430
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc66f567b19
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc66ca7a188 EFLAGS: 00000246 ORIG_RAX: 00000000000001b3
RAX: ffffffffffffffda RBX: 00007fc66f67b1a0 RCX: 00007fc66f567b19
RDX: 0000000000000000 RSI: 0000000000000058 RDI: 0000000020005880
RBP: 00007fc66f5c1f6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff3bbad1bf R14: 00007fc66ca7a300 R15: 0000000000022000
Allocated by task 4781:
kasan_save_stack+0x24/0x50
kasan_save_track+0x14/0x30
__kasan_kmalloc+0x7f/0x90
copy_time_ns+0xf6/0x5f0
create_new_namespaces+0x466/0x750
copy_namespaces+0x45c/0x580
copy_process+0x26e4/0x72a0
kernel_clone+0xea/0x7f0
__do_sys_clone3+0x1f5/0x280
do_syscall_64+0xbf/0x430
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 428:
kasan_save_stack+0x24/0x50
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3a/0x60
__kasan_slab_free+0x43/0x70
kmem_cache_free_bulk+0x22a/0x450
kvfree_rcu_bulk+0x13b/0x2f0
kfree_rcu_work+0xe8/0x160
process_one_work+0x8e1/0x19c0
worker_thread+0x67e/0xe90
kthread+0x3c8/0x740
ret_from_fork+0x67a/0x7a0
ret_from_fork_asm+0x1a/0x30
Last potentially related work creation:
kasan_save_stack+0x24/0x50
kasan_record_aux_stack+0x89/0xa0
kvfree_call_rcu+0x39/0x3c0
free_time_ns+0x10e/0x1c0
nsproxy_free+0x3e3/0x5a0
switch_task_namespaces+0x102/0x120
copy_process+0x2765/0x72a0
kernel_clone+0xea/0x7f0
__do_sys_clone3+0x1f5/0x280
do_syscall_64+0xbf/0x430
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff88801e925c00
which belongs to the cache kmalloc-cg-256 of size 256
The buggy address is located 48 bytes inside of
freed 256-byte region [ffff88801e925c00, ffff88801e925d00)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88801e925c00 pfn:0x1e924
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88800e05b301
flags: 0x100000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0100000000000040 ffff888008c4b000 ffffea00007e7d00 0000000000000002
raw: ffff88801e925c00 000000000010000f 00000000f5000000 ffff88800e05b301
head: 0100000000000040 ffff888008c4b000 ffffea00007e7d00 0000000000000002
head: ffff88801e925c00 000000000010000f 00000000f5000000 ffff88800e05b301
head: 0100000000000001 ffffea00007a4901 00000000ffffffff 00000000ffffffff
head: 000000000000000e 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88801e925b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88801e925b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88801e925c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88801e925c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88801e925d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: lib/refcount.c:28 at refcount_warn_saturate+0x10d/0x210, CPU#1: syz-executor.3/5170
Modules linked in:
CPU: 1 UID: 0 PID: 5170 Comm: syz-executor.3 Tainted: G B 6.18.0-rc5-next-20251114 #1 PREEMPT(voluntary)
Tainted: [B]=BAD_PAGE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:refcount_warn_saturate+0x10d/0x210
Code: 15 0c 04 31 ff 89 de e8 51 22 1f ff 84 db 75 9f e8 78 27 1f ff c6 05 0e 15 0c 04 01 90 48 c7 c7 a0 07 03 85 e8 54 43 e4 fe 90 <0f> 0b 90 90 e9 7c ff ff ff e8 55 27 1f ff 0f b6 1d e9 14 0c 04 31
RSP: 0018:ffff88801e1779e0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9000b0e2000
RDX: 0000000000040000 RSI: ffffffff813a514e RDI: 0000000000000001
RBP: ffff88801e925c2c R08: 0000000000000001 R09: ffffed1003c2eef3
R10: 0000000000000001 R11: 0000000000000001 R12: ffff88801e925c00
R13: ffff88801e925c2c R14: ffff8880200b9c70 R15: ffff88801a345bb8
FS: 00007fc66ca7a700(0000) GS:ffff8880e548f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000001741e000 CR4: 0000000000350ef0
Call Trace:
nsproxy_free+0x4d3/0x5a0
create_new_namespaces+0x585/0x750
copy_namespaces+0x45c/0x580
copy_process+0x26e4/0x72a0
kernel_clone+0xea/0x7f0
__do_sys_clone3+0x1f5/0x280
do_syscall_64+0xbf/0x430
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc66f567b19
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc66ca7a188 EFLAGS: 00000246 ORIG_RAX: 00000000000001b3
RAX: ffffffffffffffda RBX: 00007fc66f67b1a0 RCX: 00007fc66f567b19
RDX: 0000000000000000 RSI: 0000000000000058 RDI: 0000000020005880
RBP: 00007fc66f5c1f6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff3bbad1bf R14: 00007fc66ca7a300 R15: 0000000000022000
irq event stamp: 7719
hardirqs last enabled at (7719): [] irqentry_exit+0x17b/0x650
hardirqs last disabled at (7718): [] handle_softirqs+0x633/0x770
softirqs last enabled at (7204): [] handle_softirqs+0x50c/0x770
softirqs last disabled at (7173): [] __irq_exit_rcu+0xc4/0x100
---[ end trace 0000000000000000 ]---
Oops: general protection fault, probably for non-canonical address 0xdffffc000000002e: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000170-0x0000000000000177]
CPU: 1 UID: 0 PID: 5170 Comm: syz-executor.3 Tainted: G B W 6.18.0-rc5-next-20251114 #1 PREEMPT(voluntary)
Tainted: [B]=BAD_PAGE, [W]=WARN
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:nsproxy_free+0x28a/0x5a0
Code: 02 00 00 4c 8b 65 28 4d 85 e4 74 43 e8 7f 56 30 00 49 8d bc 24 78 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 f7 02 00 00 49 8b 9c 24 78 01 00 00 bf 08 00 00
RSP: 0018:ffff88801e1779f8 EFLAGS: 00010217
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffc9000b0e2000
RDX: 000000000000002e RSI: ffffffff8144dd61 RDI: 0000000000000174
RBP: ffff88800c5ca9c0 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff8664ed57 R11: ffff88801698f5e0 R12: fffffffffffffffc
R13: ffff88800c3ce81c R14: ffff8880200b9c70 R15: ffff88801a345bb8
FS: 00007fc66ca7a700(0000) GS:ffff8880e548f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000001741e000 CR4: 0000000000350ef0
Call Trace:
create_new_namespaces+0x585/0x750
copy_namespaces+0x45c/0x580
copy_process+0x26e4/0x72a0
kernel_clone+0xea/0x7f0
__do_sys_clone3+0x1f5/0x280
do_syscall_64+0xbf/0x430
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc66f567b19
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc66ca7a188 EFLAGS: 00000246 ORIG_RAX: 00000000000001b3
RAX: ffffffffffffffda RBX: 00007fc66f67b1a0 RCX: 00007fc66f567b19
RDX: 0000000000000000 RSI: 0000000000000058 RDI: 0000000020005880
RBP: 00007fc66f5c1f6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff3bbad1bf R14: 00007fc66ca7a300 R15: 0000000000022000
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:nsproxy_free+0x28a/0x5a0
Code: 02 00 00 4c 8b 65 28 4d 85 e4 74 43 e8 7f 56 30 00 49 8d bc 24 78 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 f7 02 00 00 49 8b 9c 24 78 01 00 00 bf 08 00 00
RSP: 0018:ffff88801e1779f8 EFLAGS: 00010217
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffc9000b0e2000
RDX: 000000000000002e RSI: ffffffff8144dd61 RDI: 0000000000000174
RBP: ffff88800c5ca9c0 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff8664ed57 R11: ffff88801698f5e0 R12: fffffffffffffffc
R13: ffff88800c3ce81c R14: ffff8880200b9c70 R15: ffff88801a345bb8
FS: 00007fc66ca7a700(0000) GS:ffff8880e548f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000001741e000 CR4: 0000000000350ef0
mac80211_hwsim: wmediumd released netlink socket, switching to perfect channel medium
mac80211_hwsim: wmediumd released netlink socket, switching to perfect channel medium
mac80211_hwsim: wmediumd released netlink socket, switching to perfect channel medium
syz-executor.0 (5222) used greatest stack depth: 23648 bytes left
mac80211_hwsim: wmediumd released netlink socket, switching to perfect channel medium
mac80211_hwsim: wmediumd released netlink socket, switching to perfect channel medium
----------------
Code disassembly (best guess):
0: 02 00 add (%rax),%al
2: 00 4c 8b 65 add %cl,0x65(%rbx,%rcx,4)
6: 28 4d 85 sub %cl,-0x7b(%rbp)
9: e4 74 in $0x74,%al
b: 43 e8 7f 56 30 00 rex.XB callq 0x305690
11: 49 8d bc 24 78 01 00 lea 0x178(%r12),%rdi
18: 00
19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
20: fc ff df
23: 48 89 fa mov %rdi,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
2e: 0f 85 f7 02 00 00 jne 0x32b
34: 49 8b 9c 24 78 01 00 mov 0x178(%r12),%rbx
3b: 00
3c: bf .byte 0xbf
3d: 08 00 or %al,(%rax)