audit: type=1326 audit(1763248355.615:14): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=4421 comm="syz-executor.1" exe="/syz-executor.1" sig=31 arch=c000003e syscall=202 compat=0 ip=0x7f13478bfb19 code=0x0 ================================================================== BUG: KASAN: slab-out-of-bounds in nsproxy_free+0x57c/0x5a0 Read of size 8 at addr ffff88800d6c2bf0 by task syz-executor.7/4473 CPU: 0 UID: 0 PID: 4473 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: 0033:0x7fec05823b19 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:00007fec02d78188 EFLAGS: 00000246 ORIG_RAX: 00000000000001b3 RAX: ffffffffffffffda RBX: 00007fec05937020 RCX: 00007fec05823b19 RDX: 0000000000000000 RSI: 0000000000000058 RDI: 00000000200001c0 RBP: 00007fec0587df6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe04758aff R14: 00007fec02d78300 R15: 0000000000022000 The buggy address belongs to the object at ffff88800d6c2bc8 which belongs to the cache nsproxy of size 72 The buggy address is located 40 bytes inside of allocated 72-byte region [ffff88800d6c2bc8, ffff88800d6c2c10) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88800d6c2a90 pfn:0xd6c2 memcg:ffff888019c29c01 flags: 0x100000000000000(node=0|zone=1) page_type: f5(slab) raw: 0100000000000000 ffff88800944cdc0 dead000000000122 0000000000000000 raw: ffff88800d6c2a90 0000000080270015 00000000f5000000 ffff888019c29c01 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88800d6c2a80: fc fc fa fb fb fb fb fb fb fb fb fc fc fc fc 00 ffff88800d6c2b00: 00 00 00 00 00 00 00 00 fc fc fc fc 00 00 00 00 >ffff88800d6c2b80: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ^ ffff88800d6c2c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88800d6c2c80: 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#0: syz-executor.7/4473 Modules linked in: CPU: 0 UID: 0 PID: 4473 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:ffff88801710f9e0 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc90008a62000 RDX: 0000000000040000 RSI: ffffffff813a514e RDI: 0000000000000001 RBP: ffff88800d6c2bec R08: 0000000000000001 R09: ffffed1002e21ef3 R10: 0000000000000001 R11: 0000000000000001 R12: ffff88800d6c2bc0 R13: ffff88800d6c2bec R14: ffff888015c14820 R15: ffff88801cc4a438 FS: 00007fec02d78700(0000) GS:ffff8880e538f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000037913000 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: 0033:0x7fec05823b19 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:00007fec02d78188 EFLAGS: 00000246 ORIG_RAX: 00000000000001b3 RAX: ffffffffffffffda RBX: 00007fec05937020 RCX: 00007fec05823b19 RDX: 0000000000000000 RSI: 0000000000000058 RDI: 00000000200001c0 RBP: 00007fec0587df6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe04758aff R14: 00007fec02d78300 R15: 0000000000022000 irq event stamp: 10785 hardirqs last enabled at (10785): [] irqentry_exit+0x17b/0x650 hardirqs last disabled at (10784): [] handle_softirqs+0x633/0x770 softirqs last enabled at (10084): [] handle_softirqs+0x50c/0x770 softirqs last disabled at (10021): [] __irq_exit_rcu+0xc4/0x100 ---[ end trace 0000000000000000 ]--- Oops: general protection fault, probably for non-canonical address 0xdffffc060e600e91: 0000 [#1] SMP KASAN NOPTI KASAN: probably user-memory-access in range [0x0000003073007488-0x000000307300748f] CPU: 0 UID: 0 PID: 4473 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:ffff88801710f9f8 EFLAGS: 00010213 RAX: dffffc0000000000 RBX: 00000000ffff8880 RCX: ffffc90008a62000 RDX: 000000060e600e91 RSI: ffffffff8144dc85 RDI: 000000307300748f RBP: ffff88800d6c2b60 R08: 0000000000000001 R09: ffffed1002e21ef3 R10: 0000000000000001 R11: 0000000000000001 R12: 000000307300745f R13: ffff88800d6c2bec R14: ffff888015c14820 R15: ffff88801cc4a438 FS: 00007fec02d78700(0000) GS:ffff8880e538f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000037913000 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: 0033:0x7fec05823b19 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:00007fec02d78188 EFLAGS: 00000246 ORIG_RAX: 00000000000001b3 RAX: ffffffffffffffda RBX: 00007fec05937020 RCX: 00007fec05823b19 RDX: 0000000000000000 RSI: 0000000000000058 RDI: 00000000200001c0 RBP: 00007fec0587df6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe04758aff R14: 00007fec02d78300 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:ffff88801710f9f8 EFLAGS: 00010213 RAX: dffffc0000000000 RBX: 00000000ffff8880 RCX: ffffc90008a62000 RDX: 000000060e600e91 RSI: ffffffff8144dc85 RDI: 000000307300748f RBP: ffff88800d6c2b60 R08: 0000000000000001 R09: ffffed1002e21ef3 R10: 0000000000000001 R11: 0000000000000001 R12: 000000307300745f R13: ffff88800d6c2bec R14: ffff888015c14820 R15: ffff88801cc4a438 FS: 00007fec02d78700(0000) GS:ffff8880e538f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000037913000 CR4: 0000000000350ef0 Oops: general protection fault, probably for non-canonical address 0xc00000000d6c2c50: 0000 [#2] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 4499 Comm: syz-executor.2 Tainted: G B D W 6.18.0-rc5-next-20251114 #1 PREEMPT(voluntary) Tainted: [B]=BAD_PAGE, [D]=DIE, [W]=WARN Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:kmem_cache_alloc_noprof+0x352/0x690 Code: c0 0f 84 43 01 00 00 84 c9 0f 85 3b 01 00 00 41 83 f9 ff 0f 85 21 01 00 00 41 b9 ff ff ff ff 41 8b 46 40 49 8b 36 48 8d 4a 40 <49> 8b 1c 00 4c 89 c0 65 48 0f c7 0e 75 a5 41 8b 46 40 0f 0d 0c 03 RSP: 0018:ffff88801710fd90 EFLAGS: 00010246 RAX: 0000000000000020 RBX: ffffea000035b080 RCX: 00000000000010c0 RDX: 0000000000001080 RSI: ffffffff87aae5b0 RDI: ffff888048d6d340 RBP: ffff88801710fdf0 R08: c00000000d6c2c30 R09: 00000000ffffffff R10: ffff88801710fe08 R11: 0000000000000000 R12: 0000000000000cc0 R13: 0000000000000c00 R14: ffff88800944cdc0 R15: ffffffff8144e0d0 FS: 00007f844a55e700(0000) GS:ffff8880e538f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000040 CR3: 00000000378e9000 CR4: 0000000000350ef0 Call Trace: create_new_namespaces+0x30/0x750 __do_sys_setns+0x20b/0x1a90 do_syscall_64+0xbf/0x430 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f844cfea107 Code: 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 34 01 00 00 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:00007f844a55e128 EFLAGS: 00000246 ORIG_RAX: 0000000000000134 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00007f844cfea107 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000005 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f844a55e6bc R13: 000000000000000e R14: 00007f844a55e300 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:ffff88801710f9f8 EFLAGS: 00010213 RAX: dffffc0000000000 RBX: 00000000ffff8880 RCX: ffffc90008a62000 RDX: 000000060e600e91 RSI: ffffffff8144dc85 RDI: 000000307300748f RBP: ffff88800d6c2b60 R08: 0000000000000001 R09: ffffed1002e21ef3 R10: 0000000000000001 R11: 0000000000000001 R12: 000000307300745f R13: ffff88800d6c2bec R14: ffff888015c14820 R15: ffff88801cc4a438 FS: 00007f844a55e700(0000) GS:ffff8880e538f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000040 CR3: 00000000378e9000 CR4: 0000000000350ef0 Oops: general protection fault, probably for non-canonical address 0xc00000000d6c2c50: 0000 [#3] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 4522 Comm: syz-executor.2 Tainted: G B D W 6.18.0-rc5-next-20251114 #1 PREEMPT(voluntary) Tainted: [B]=BAD_PAGE, [D]=DIE, [W]=WARN Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:kmem_cache_alloc_noprof+0x352/0x690 Code: c0 0f 84 43 01 00 00 84 c9 0f 85 3b 01 00 00 41 83 f9 ff 0f 85 21 01 00 00 41 b9 ff ff ff ff 41 8b 46 40 49 8b 36 48 8d 4a 40 <49> 8b 1c 00 4c 89 c0 65 48 0f c7 0e 75 a5 41 8b 46 40 0f 0d 0c 03 RSP: 0018:ffff88800ef1fd90 EFLAGS: 00010246 RAX: 0000000000000020 RBX: ffffea000035b080 RCX: 00000000000010c0 RDX: 0000000000001080 RSI: ffffffff87aae5b0 RDI: ffff88801744b780 RBP: ffff88800ef1fdf0 R08: c00000000d6c2c30 R09: 00000000ffffffff R10: ffff88800ef1fe08 R11: 0000000000000000 R12: 0000000000000cc0 R13: 0000000000000c00 R14: ffff88800944cdc0 R15: ffffffff8144e0d0 FS: 00007f844a51c700(0000) GS:ffff8880e538f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c360401c20 CR3: 00000000378e9000 CR4: 0000000000350ef0 Call Trace: create_new_namespaces+0x30/0x750 __do_sys_setns+0x20b/0x1a90 do_syscall_64+0xbf/0x430 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f844cfea107 Code: 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 34 01 00 00 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:00007f844a51c128 EFLAGS: 00000246 ORIG_RAX: 0000000000000134 RAX: ffffffffffffffda RBX: 00007f844d0fc0e0 RCX: 00007f844cfea107 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000000000ef RBP: 0000000000000005 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe455b0abf R14: 00007f844a51c300 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:ffff88801710f9f8 EFLAGS: 00010213 RAX: dffffc0000000000 RBX: 00000000ffff8880 RCX: ffffc90008a62000 RDX: 000000060e600e91 RSI: ffffffff8144dc85 RDI: 000000307300748f RBP: ffff88800d6c2b60 R08: 0000000000000001 R09: ffffed1002e21ef3 R10: 0000000000000001 R11: 0000000000000001 R12: 000000307300745f R13: ffff88800d6c2bec R14: ffff888015c14820 R15: ffff88801cc4a438 FS: 00007f844a51c700(0000) GS:ffff8880e538f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c360401c20 CR3: 00000000378e9000 CR4: 0000000000350ef0 kmemleak: 4 new suspected memory leaks (see /sys/kernel/debug/kmemleak) ---------------- 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