==================================================================
BUG: KASAN: slab-out-of-bounds in nsproxy_free+0x57c/0x5a0
Read of size 8 at addr ffff8880170ca8f0 by task syz-executor.7/4459
CPU: 1 UID: 0 PID: 4459 Comm: syz-executor.7 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: 0033:0x7f1ce1565b19
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:00007f1cdeaba188 EFLAGS: 00000246 ORIG_RAX: 00000000000001b3
RAX: ffffffffffffffda RBX: 00007f1ce1679020 RCX: 00007f1ce1565b19
RDX: 0000000000000000 RSI: 0000000000000058 RDI: 0000000020005880
RBP: 00007f1ce15bff6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffbcbfed0f R14: 00007f1cdeaba300 R15: 0000000000022000
The buggy address belongs to the object at ffff8880170ca8f0
which belongs to the cache nsproxy of size 72
The buggy address is located 0 bytes inside of
allocated 72-byte region [ffff8880170ca8f0, ffff8880170ca938)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880170ca618 pfn:0x170ca
memcg:ffff888015b5f401
flags: 0x100000000000000(node=0|zone=1)
page_type: f5(slab)
raw: 0100000000000000 ffff88800944cdc0 dead000000000122 0000000000000000
raw: ffff8880170ca618 000000008027001c 00000000f5000000 ffff888015b5f401
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8880170ca780: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880170ca800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880170ca880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff8880170ca900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880170ca980: 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.7/4459
Modules linked in:
CPU: 1 UID: 0 PID: 4459 Comm: syz-executor.7 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:ffff88800b2df9e0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9000c02d000
RDX: 0000000000040000 RSI: ffffffff813a514e RDI: 0000000000000001
RBP: ffff8880170ca8ec R08: 0000000000000001 R09: ffffed100165bef3
R10: 0000000000000001 R11: 0000000000000001 R12: ffff8880170ca8c0
R13: ffff8880170ca8ec R14: ffff8880198ea8a0 R15: ffff888048bdbff8
FS: 00007f1cdeaba700(0000) GS:ffff8880e548f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558d2f2c58 CR3: 000000000d2a2000 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: 0033:0x7f1ce1565b19
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:00007f1cdeaba188 EFLAGS: 00000246 ORIG_RAX: 00000000000001b3
RAX: ffffffffffffffda RBX: 00007f1ce1679020 RCX: 00007f1ce1565b19
RDX: 0000000000000000 RSI: 0000000000000058 RDI: 0000000020005880
RBP: 00007f1ce15bff6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffbcbfed0f R14: 00007f1cdeaba300 R15: 0000000000022000
irq event stamp: 11015
hardirqs last enabled at (11015): [] irqentry_exit+0x17b/0x650
hardirqs last disabled at (11014): [] handle_softirqs+0x633/0x770
softirqs last enabled at (10704): [] netlink_release+0xfbc/0x1fa0
softirqs last disabled at (10702): [] netlink_release+0xf19/0x1fa0
---[ end trace 0000000000000000 ]---
Oops: general protection fault, probably for non-canonical address 0xe0000beb4f434206: 0000 [#1] SMP KASAN NOPTI
KASAN: probably user-memory-access in range [0x00007f5a7a1a1030-0x00007f5a7a1a1037]
CPU: 1 UID: 0 PID: 4459 Comm: syz-executor.7 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+0x1ab/0x5a0
Code: 0f 85 b4 03 00 00 4c 8b 65 38 4d 85 e4 74 41 e8 5b 57 30 00 49 8d 7c 24 30 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 b8 03 00 00 49 8b 5c 24 30 bf 08 00 00 00 48 89
RSP: 0018:ffff88800b2df9f8 EFLAGS: 00010216
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc9000c02d000
RDX: 00000feb4f434206 RSI: ffffffff8144dc85 RDI: 00007f5a7a1a1030
RBP: ffff8880170ca750 R08: 0000000000000001 R09: ffffed100165bef3
R10: 0000000000000001 R11: 0000000000000001 R12: 00007f5a7a1a1000
R13: ffff8880170ca8ec R14: ffff8880198ea8a0 R15: ffff888048bdbff8
FS: 00007f1cdeaba700(0000) GS:ffff8880e548f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558d2f2c58 CR3: 000000000d2a2000 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: 0033:0x7f1ce1565b19
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:00007f1cdeaba188 EFLAGS: 00000246 ORIG_RAX: 00000000000001b3
RAX: ffffffffffffffda RBX: 00007f1ce1679020 RCX: 00007f1ce1565b19
RDX: 0000000000000000 RSI: 0000000000000058 RDI: 0000000020005880
RBP: 00007f1ce15bff6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffbcbfed0f R14: 00007f1cdeaba300 R15: 0000000000022000
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:nsproxy_free+0x1ab/0x5a0
Code: 0f 85 b4 03 00 00 4c 8b 65 38 4d 85 e4 74 41 e8 5b 57 30 00 49 8d 7c 24 30 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 b8 03 00 00 49 8b 5c 24 30 bf 08 00 00 00 48 89
RSP: 0018:ffff88800b2df9f8 EFLAGS: 00010216
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc9000c02d000
RDX: 00000feb4f434206 RSI: ffffffff8144dc85 RDI: 00007f5a7a1a1030
RBP: ffff8880170ca750 R08: 0000000000000001 R09: ffffed100165bef3
R10: 0000000000000001 R11: 0000000000000001 R12: 00007f5a7a1a1000
R13: ffff8880170ca8ec R14: ffff8880198ea8a0 R15: ffff888048bdbff8
FS: 00007f1cdeaba700(0000) GS:ffff8880e548f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558d2f2c58 CR3: 000000000d2a2000 CR4: 0000000000350ef0
Bluetooth: hci0: command 0x0406 tx timeout
Bluetooth: hci1: command 0x0406 tx timeout
Bluetooth: hci2: command 0x0406 tx timeout
Bluetooth: hci3: command 0x0406 tx timeout
Bluetooth: hci5: command 0x0406 tx timeout
Bluetooth: hci7: command 0x0406 tx timeout
Bluetooth: hci4: command 0x0406 tx timeout
Bluetooth: hci6: command 0x0406 tx timeout
loop5: detected capacity change from 0 to 255
nfs: Unknown parameter '#$'
loop5: detected capacity change from 0 to 255
loop5: detected capacity change from 0 to 255
nfs: Unknown parameter '#$'
----------------
Code disassembly (best guess):
0: 0f 85 b4 03 00 00 jne 0x3ba
6: 4c 8b 65 38 mov 0x38(%rbp),%r12
a: 4d 85 e4 test %r12,%r12
d: 74 41 je 0x50
f: e8 5b 57 30 00 callq 0x30576f
14: 49 8d 7c 24 30 lea 0x30(%r12),%rdi
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 b8 03 00 00 jne 0x3ec
34: 49 8b 5c 24 30 mov 0x30(%r12),%rbx
39: bf 08 00 00 00 mov $0x8,%edi
3e: 48 rex.W
3f: 89 .byte 0x89