syzbot


KASAN: use-after-free Write in reuseport_array_free

Status: auto-obsoleted due to no activity on 2025/08/05 06:47
First crash: 109d, last: 109d

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in atomic_try_cmpxchg include/asm-generic/atomic-instrumented.h:693 [inline]
BUG: KASAN: use-after-free in queued_write_lock include/asm-generic/qrwlock.h:92 [inline]
BUG: KASAN: use-after-free in __raw_write_lock_bh include/linux/rwlock_api_smp.h:204 [inline]
BUG: KASAN: use-after-free in _raw_write_lock_bh+0x81/0xe0 kernel/locking/spinlock.c:319
Write of size 4 at addr ffff8881e496b6a0 by task syz.4.867/3314

CPU: 1 PID: 3314 Comm: syz.4.867 Not tainted 5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 __dump_stack+0x1e/0x20 lib/dump_stack.c:77
 dump_stack+0x15b/0x1b8 lib/dump_stack.c:118
 print_address_description+0x8d/0x4c0 mm/kasan/report.c:384
 __kasan_report+0xef/0x120 mm/kasan/report.c:516
 kasan_report+0x30/0x60 mm/kasan/common.c:653
 check_memory_region_inline mm/kasan/generic.c:141 [inline]
 check_memory_region+0x274/0x280 mm/kasan/generic.c:191
 __kasan_check_write+0x14/0x20 mm/kasan/common.c:99
 atomic_try_cmpxchg include/asm-generic/atomic-instrumented.h:693 [inline]
 queued_write_lock include/asm-generic/qrwlock.h:92 [inline]
 __raw_write_lock_bh include/linux/rwlock_api_smp.h:204 [inline]
 _raw_write_lock_bh+0x81/0xe0 kernel/locking/spinlock.c:319
 reuseport_array_free+0xbd/0x1b0 kernel/bpf/reuseport_array.c:130
 map_create+0x433/0x980 kernel/bpf/syscall.c:639
 __do_sys_bpf kernel/bpf/syscall.c:2873 [inline]
 __se_sys_bpf+0x2dc/0x570 kernel/bpf/syscall.c:2849
 __x64_sys_bpf+0x7b/0x90 kernel/bpf/syscall.c:2849
 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7f516ff62969
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f516e5cb038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f5170189fa0 RCX: 00007f516ff62969
RDX: 0000000000000050 RSI: 0000200000000300 RDI: 0000000000000000
RBP: 00007f516ffe4ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f5170189fa0 R15: 00007fff8ca29688

Allocated by task 3002:
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 __kasan_kmalloc+0x162/0x200 mm/kasan/common.c:529
 kasan_slab_alloc+0x12/0x20 mm/kasan/common.c:537
 slab_post_alloc_hook mm/slab.h:584 [inline]
 slab_alloc_node mm/slub.c:2829 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 kmem_cache_alloc+0xe2/0x270 mm/slub.c:2842
 kmem_cache_zalloc include/linux/slab.h:680 [inline]
 net_alloc net/core/net_namespace.c:424 [inline]
 copy_net_ns+0x13f/0x520 net/core/net_namespace.c:476
 create_new_namespaces+0x49c/0x590 kernel/nsproxy.c:103
 copy_namespaces+0x17e/0x1c0 kernel/nsproxy.c:161
 copy_process+0x1194/0x2cf0 kernel/fork.c:2055
 _do_fork+0x190/0x860 kernel/fork.c:2399
 __do_sys_clone kernel/fork.c:2557 [inline]
 __se_sys_clone kernel/fork.c:2538 [inline]
 __x64_sys_clone+0x12e/0x160 kernel/fork.c:2538
 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Freed by task 3002:
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 kasan_set_free_info mm/kasan/common.c:345 [inline]
 __kasan_slab_free+0x1c3/0x280 mm/kasan/common.c:487
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:496
 slab_free_hook mm/slub.c:1455 [inline]
 slab_free_freelist_hook+0xb7/0x180 mm/slub.c:1494
 slab_free mm/slub.c:3080 [inline]
 kmem_cache_free+0x10c/0x2c0 mm/slub.c:3096
 net_free net/core/net_namespace.c:452 [inline]
 net_drop_ns net/core/net_namespace.c:459 [inline]
 copy_net_ns+0x42a/0x520 net/core/net_namespace.c:499
 create_new_namespaces+0x49c/0x590 kernel/nsproxy.c:103
 copy_namespaces+0x17e/0x1c0 kernel/nsproxy.c:161
 copy_process+0x1194/0x2cf0 kernel/fork.c:2055
 _do_fork+0x190/0x860 kernel/fork.c:2399
 __do_sys_clone kernel/fork.c:2557 [inline]
 __se_sys_clone kernel/fork.c:2538 [inline]
 __x64_sys_clone+0x12e/0x160 kernel/fork.c:2538
 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

The buggy address belongs to the object at ffff8881e496b600
 which belongs to the cache net_namespace of size 4352
The buggy address is located 160 bytes inside of
 4352-byte region [ffff8881e496b600, ffff8881e496c700)
The buggy address belongs to the page:
page:ffffea0007925a00 refcount:1 mapcount:0 mapping:ffff8881f5d02f00 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5d02f00
raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL)
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook mm/page_alloc.c:2165 [inline]
 prep_new_page+0x35e/0x370 mm/page_alloc.c:2171
 get_page_from_freelist+0x1296/0x1310 mm/page_alloc.c:3794
 __alloc_pages_nodemask+0x202/0x4b0 mm/page_alloc.c:4894
 alloc_slab_page+0x3c/0x3b0 mm/slub.c:343
 allocate_slab mm/slub.c:1683 [inline]
 new_slab+0x93/0x420 mm/slub.c:1749
 new_slab_objects mm/slub.c:2505 [inline]
 ___slab_alloc+0x29e/0x420 mm/slub.c:2667
 __slab_alloc+0x63/0xa0 mm/slub.c:2707
 slab_alloc_node mm/slub.c:2792 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 kmem_cache_alloc+0x12c/0x270 mm/slub.c:2842
 kmem_cache_zalloc include/linux/slab.h:680 [inline]
 net_alloc net/core/net_namespace.c:424 [inline]
 copy_net_ns+0x13f/0x520 net/core/net_namespace.c:476
 create_new_namespaces+0x49c/0x590 kernel/nsproxy.c:103
 copy_namespaces+0x17e/0x1c0 kernel/nsproxy.c:161
 copy_process+0x1194/0x2cf0 kernel/fork.c:2055
 _do_fork+0x190/0x860 kernel/fork.c:2399
 __do_sys_clone kernel/fork.c:2557 [inline]
 __se_sys_clone kernel/fork.c:2538 [inline]
 __x64_sys_clone+0x12e/0x160 kernel/fork.c:2538
 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1176 [inline]
 __free_pages_ok+0x7e4/0x910 mm/page_alloc.c:1438
 free_the_page mm/page_alloc.c:4956 [inline]
 __free_pages+0x8c/0x110 mm/page_alloc.c:4962
 __free_slab+0x218/0x2d0 mm/slub.c:1774
 free_slab mm/slub.c:1789 [inline]
 discard_slab mm/slub.c:1795 [inline]
 unfreeze_partials+0x165/0x1a0 mm/slub.c:2288
 put_cpu_partial+0xc1/0x180 mm/slub.c:2324
 __slab_free+0x2be/0x380 mm/slub.c:2971
 do_slab_free mm/slub.c:3068 [inline]
 ___cache_free+0xbb/0xd0 mm/slub.c:3087
 qlink_free+0x23/0x30 mm/kasan/quarantine.c:148
 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:167
 quarantine_reduce+0x1a8/0x200 mm/kasan/quarantine.c:260
 __kasan_kmalloc+0x42/0x200 mm/kasan/common.c:507
 kasan_slab_alloc+0x12/0x20 mm/kasan/common.c:537
 slab_post_alloc_hook mm/slab.h:584 [inline]
 slab_alloc_node mm/slub.c:2829 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 kmem_cache_alloc+0xe2/0x270 mm/slub.c:2842
 getname_flags+0xb9/0x500 fs/namei.c:141
 user_path_at_empty+0x2f/0x50 fs/namei.c:2703
 do_readlinkat+0xd4/0x480 fs/stat.c:398

Memory state around the buggy address:
 ffff8881e496b580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881e496b600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881e496b680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff8881e496b700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881e496b780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
================================================================================
UBSAN: array-index-out-of-bounds in kernel/locking/qspinlock.c:129:9
index 16382 is out of range for type 'unsigned long[8]'
CPU: 1 PID: 3314 Comm: syz.4.867 Tainted: G    B             5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 __dump_stack+0x1e/0x20 lib/dump_stack.c:77
 dump_stack+0x15b/0x1b8 lib/dump_stack.c:118
 ubsan_epilogue+0xf/0x60 lib/ubsan.c:148
 __ubsan_handle_out_of_bounds+0xdf/0xf0 lib/ubsan.c:356
 decode_tail kernel/locking/qspinlock.c:129 [inline]
 __pv_queued_spin_lock_slowpath+0xaec/0xb70 kernel/locking/qspinlock.c:467
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:642 [inline]
 queued_spin_lock_slowpath+0x47/0x50 arch/x86/include/asm/qspinlock.h:50
 queued_spin_lock include/asm-generic/qspinlock.h:81 [inline]
 queued_write_lock_slowpath+0x1fc/0x230 kernel/locking/qrwlock.c:67
 queued_write_lock include/asm-generic/qrwlock.h:95 [inline]
 __raw_write_lock_bh include/linux/rwlock_api_smp.h:204 [inline]
 _raw_write_lock_bh+0xd6/0xe0 kernel/locking/spinlock.c:319
 reuseport_array_free+0xbd/0x1b0 kernel/bpf/reuseport_array.c:130
 map_create+0x433/0x980 kernel/bpf/syscall.c:639
 __do_sys_bpf kernel/bpf/syscall.c:2873 [inline]
 __se_sys_bpf+0x2dc/0x570 kernel/bpf/syscall.c:2849
 __x64_sys_bpf+0x7b/0x90 kernel/bpf/syscall.c:2849
 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7f516ff62969
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f516e5cb038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f5170189fa0 RCX: 00007f516ff62969
RDX: 0000000000000050 RSI: 0000200000000300 RDI: 0000000000000000
RBP: 00007f516ffe4ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f5170189fa0 R15: 00007fff8ca29688
================================================================================
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#2] PREEMPT SMP KASAN
CPU: 1 PID: 3314 Comm: syz.4.867 Tainted: G    B D           5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:__write_once_size include/linux/compiler.h:295 [inline]
RIP: 0010:__pv_queued_spin_lock_slowpath+0x2c8/0xb70 kernel/locking/qspinlock.c:470
Code: 00 74 18 49 89 d7 48 89 d7 e8 a4 39 45 00 48 be 00 00 00 00 00 fc ff df 4c 89 fa 4c 8b 7c 24 10 4c 03 3a 4c 89 f8 48 c1 e8 03 <80> 3c 30 00 74 08 4c 89 ff e8 1a 3a 45 00 48 8b 44 24 20 49 89 07
RSP: 0018:ffff8881ce3a7a80 EFLAGS: 00010206
RAX: 000000000000b114 RBX: ffff8881e496b6a4 RCX: 00000000000588a0
RDX: ffffffff85457f00 RSI: dffffc0000000000 RDI: 0000000000080000
RBP: ffff8881ce3a7b70 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed1039c74eac R11: 1ffff11039c74eac R12: 1ffff1103edeb109
R13: 1ffff1103c92d6d4 R14: ffff8881f6f58854 R15: 00000000000588a0
FS:  00007f516e5cb6c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3a83c3cbac CR3: 00000001e6a2f000 CR4: 00000000003406a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff1 DR7: 0000000000000600
Call Trace:
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:642 [inline]
 queued_spin_lock_slowpath+0x47/0x50 arch/x86/include/asm/qspinlock.h:50
 queued_spin_lock include/asm-generic/qspinlock.h:81 [inline]
 queued_write_lock_slowpath+0x1fc/0x230 kernel/locking/qrwlock.c:67
 queued_write_lock include/asm-generic/qrwlock.h:95 [inline]
 __raw_write_lock_bh include/linux/rwlock_api_smp.h:204 [inline]
 _raw_write_lock_bh+0xd6/0xe0 kernel/locking/spinlock.c:319
 reuseport_array_free+0xbd/0x1b0 kernel/bpf/reuseport_array.c:130
 map_create+0x433/0x980 kernel/bpf/syscall.c:639
 __do_sys_bpf kernel/bpf/syscall.c:2873 [inline]
 __se_sys_bpf+0x2dc/0x570 kernel/bpf/syscall.c:2849
 __x64_sys_bpf+0x7b/0x90 kernel/bpf/syscall.c:2849
 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7f516ff62969
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f516e5cb038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f5170189fa0 RCX: 00007f516ff62969
RDX: 0000000000000050 RSI: 0000200000000300 RDI: 0000000000000000
RBP: 00007f516ffe4ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f5170189fa0 R15: 00007fff8ca29688
Modules linked in:
----------------
Code disassembly (best guess):
   0:	00 74 18 49          	add    %dh,0x49(%rax,%rbx,1)
   4:	89 d7                	mov    %edx,%edi
   6:	48 89 d7             	mov    %rdx,%rdi
   9:	e8 a4 39 45 00       	call   0x4539b2
   e:	48 be 00 00 00 00 00 	movabs $0xdffffc0000000000,%rsi
  15:	fc ff df
  18:	4c 89 fa             	mov    %r15,%rdx
  1b:	4c 8b 7c 24 10       	mov    0x10(%rsp),%r15
  20:	4c 03 3a             	add    (%rdx),%r15
  23:	4c 89 f8             	mov    %r15,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	80 3c 30 00          	cmpb   $0x0,(%rax,%rsi,1) <-- trapping instruction
  2e:	74 08                	je     0x38
  30:	4c 89 ff             	mov    %r15,%rdi
  33:	e8 1a 3a 45 00       	call   0x453a52
  38:	48 8b 44 24 20       	mov    0x20(%rsp),%rax
  3d:	49 89 07             	mov    %rax,(%r15)

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/05/07 06:46 android12-5.4 cd8e74fa0fa3 350f4ffc .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-perf-kasan KASAN: use-after-free Write in reuseport_array_free
* Struck through repros no longer work on HEAD.