RAX: ffffffffffffffda RBX: 00007f4f76216f80 RCX: 00007f4f760d7ef9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f4f75c6a120 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 000000000000000b R14: 00007f4f76216f80 R15: 00007fffa14bb5b8 ================================================================== BUG: KASAN: null-ptr-deref in instrument_atomic_read_write include/linux/instrumented.h:101 [inline] BUG: KASAN: null-ptr-deref in atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:167 [inline] BUG: KASAN: null-ptr-deref in __refcount_sub_and_test include/linux/refcount.h:272 [inline] BUG: KASAN: null-ptr-deref in __refcount_dec_and_test include/linux/refcount.h:315 [inline] BUG: KASAN: null-ptr-deref in refcount_dec_and_test include/linux/refcount.h:333 [inline] BUG: KASAN: null-ptr-deref in kref_put include/linux/kref.h:64 [inline] BUG: KASAN: null-ptr-deref in anon_vma_name_put include/linux/mm_inline.h:375 [inline] BUG: KASAN: null-ptr-deref in free_anon_vma_name include/linux/mm_inline.h:406 [inline] BUG: KASAN: null-ptr-deref in vm_area_free_no_check+0x7e/0x140 kernel/fork.c:406 Write of size 4 at addr 0000000000000001 by task syz-executor.0/344 CPU: 1 PID: 344 Comm: syz-executor.0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 __kasan_report mm/kasan/report.c:431 [inline] kasan_report+0xe7/0x140 mm/kasan/report.c:444 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x249/0x2a0 mm/kasan/generic.c:189 __kasan_check_write+0x14/0x20 mm/kasan/shadow.c:37 instrument_atomic_read_write include/linux/instrumented.h:101 [inline] atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:167 [inline] __refcount_sub_and_test include/linux/refcount.h:272 [inline] __refcount_dec_and_test include/linux/refcount.h:315 [inline] refcount_dec_and_test include/linux/refcount.h:333 [inline] kref_put include/linux/kref.h:64 [inline] anon_vma_name_put include/linux/mm_inline.h:375 [inline] free_anon_vma_name include/linux/mm_inline.h:406 [inline] vm_area_free_no_check+0x7e/0x140 kernel/fork.c:406 vm_area_free kernel/fork.c:419 [inline] dup_mmap kernel/fork.c:682 [inline] dup_mm kernel/fork.c:1522 [inline] copy_mm+0xe90/0x13c0 kernel/fork.c:1574 copy_process+0x117c/0x3250 kernel/fork.c:2348 kernel_clone+0x233/0x960 kernel/fork.c:2737 __do_sys_clone kernel/fork.c:2863 [inline] __se_sys_clone kernel/fork.c:2847 [inline] __x64_sys_clone+0x198/0x210 kernel/fork.c:2847 x64_sys_call+0x41f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:57 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f4f760d7ef9 Code: 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 d0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4f75c6a068 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f4f76216f80 RCX: 00007f4f760d7ef9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f4f75c6a120 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 000000000000000b R14: 00007f4f76216f80 R15: 00007fffa14bb5b8 ================================================================== BUG: kernel NULL pointer dereference, address: 0000000000000001 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 10def5067 P4D 10def5067 PUD 10d799067 PMD 0 Oops: 0002 [#1] PREEMPT SMP KASAN CPU: 1 PID: 344 Comm: syz-executor.0 Tainted: G B syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:arch_atomic_fetch_sub arch/x86/include/asm/atomic.h:190 [inline] RIP: 0010:atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:168 [inline] RIP: 0010:__refcount_sub_and_test include/linux/refcount.h:272 [inline] RIP: 0010:__refcount_dec_and_test include/linux/refcount.h:315 [inline] RIP: 0010:refcount_dec_and_test include/linux/refcount.h:333 [inline] RIP: 0010:kref_put include/linux/kref.h:64 [inline] RIP: 0010:anon_vma_name_put include/linux/mm_inline.h:375 [inline] RIP: 0010:free_anon_vma_name include/linux/mm_inline.h:406 [inline] RIP: 0010:vm_area_free_no_check+0x84/0x140 kernel/fork.c:406 Code: 42 80 3c 20 00 74 08 4c 89 ff e8 f7 04 6c 00 4d 8b 3f 4d 85 ff 74 3a 4c 89 ff be 04 00 00 00 e8 e2 06 6c 00 41 bc ff ff ff ff 45 0f c1 27 bf 01 00 00 00 44 89 e6 e8 ca d9 2c 00 41 83 fc 01 RSP: 0018:ffffc90000db7948 EFLAGS: 00010246 RAX: ffff88810de00000 RBX: ffff88810dccb6f0 RCX: ffff88810de00000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00000000ffffffff RBP: ffffc90000db7970 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff0e18a4c R12: 00000000ffffffff R13: ffff88810dccb790 R14: 1ffff11021b996f2 R15: 0000000000000001 FS: 00007f4f75c6a6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000001 CR3: 0000000125f0c000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vm_area_free kernel/fork.c:419 [inline] dup_mmap kernel/fork.c:682 [inline] dup_mm kernel/fork.c:1522 [inline] copy_mm+0xe90/0x13c0 kernel/fork.c:1574 copy_process+0x117c/0x3250 kernel/fork.c:2348 kernel_clone+0x233/0x960 kernel/fork.c:2737 __do_sys_clone kernel/fork.c:2863 [inline] __se_sys_clone kernel/fork.c:2847 [inline] __x64_sys_clone+0x198/0x210 kernel/fork.c:2847 x64_sys_call+0x41f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:57 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f4f760d7ef9 Code: 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 d0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4f75c6a068 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f4f76216f80 RCX: 00007f4f760d7ef9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f4f75c6a120 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 000000000000000b R14: 00007f4f76216f80 R15: 00007fffa14bb5b8 Modules linked in: CR2: 0000000000000001 ---[ end trace beb28f81b65f6446 ]--- RIP: 0010:arch_atomic_fetch_sub arch/x86/include/asm/atomic.h:190 [inline] RIP: 0010:atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:168 [inline] RIP: 0010:__refcount_sub_and_test include/linux/refcount.h:272 [inline] RIP: 0010:__refcount_dec_and_test include/linux/refcount.h:315 [inline] RIP: 0010:refcount_dec_and_test include/linux/refcount.h:333 [inline] RIP: 0010:kref_put include/linux/kref.h:64 [inline] RIP: 0010:anon_vma_name_put include/linux/mm_inline.h:375 [inline] RIP: 0010:free_anon_vma_name include/linux/mm_inline.h:406 [inline] RIP: 0010:vm_area_free_no_check+0x84/0x140 kernel/fork.c:406 Code: 42 80 3c 20 00 74 08 4c 89 ff e8 f7 04 6c 00 4d 8b 3f 4d 85 ff 74 3a 4c 89 ff be 04 00 00 00 e8 e2 06 6c 00 41 bc ff ff ff ff 45 0f c1 27 bf 01 00 00 00 44 89 e6 e8 ca d9 2c 00 41 83 fc 01 RSP: 0018:ffffc90000db7948 EFLAGS: 00010246 RAX: ffff88810de00000 RBX: ffff88810dccb6f0 RCX: ffff88810de00000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00000000ffffffff RBP: ffffc90000db7970 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff0e18a4c R12: 00000000ffffffff R13: ffff88810dccb790 R14: 1ffff11021b996f2 R15: 0000000000000001 FS: 00007f4f75c6a6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000001 CR3: 0000000125f0c000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) 5: 74 08 je 0xf 7: 4c 89 ff mov %r15,%rdi a: e8 f7 04 6c 00 call 0x6c0506 f: 4d 8b 3f mov (%r15),%r15 12: 4d 85 ff test %r15,%r15 15: 74 3a je 0x51 17: 4c 89 ff mov %r15,%rdi 1a: be 04 00 00 00 mov $0x4,%esi 1f: e8 e2 06 6c 00 call 0x6c0706 24: 41 bc ff ff ff ff mov $0xffffffff,%r12d * 2a: f0 45 0f c1 27 lock xadd %r12d,(%r15) <-- trapping instruction 2f: bf 01 00 00 00 mov $0x1,%edi 34: 44 89 e6 mov %r12d,%esi 37: e8 ca d9 2c 00 call 0x2cda06 3c: 41 83 fc 01 cmp $0x1,%r12d