netlink: 20 bytes leftover after parsing attributes in process `syz-executor.6'. netlink: 20 bytes leftover after parsing attributes in process `syz-executor.6'. ================================================================== BUG: KASAN: null-ptr-deref in ip6_pol_route+0x602/0x11a0 Read of size 4 at addr 0000000000000dcc by task syz-executor.0/4081 CPU: 0 UID: 0 PID: 4081 Comm: syz-executor.0 Tainted: G W 6.17.0-rc3-next-20250829 #1 PREEMPT(voluntary) Tainted: [W]=WARN Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack_lvl+0xca/0x120 kasan_report+0xca/0x100 kasan_check_range+0x39/0x1b0 ip6_pol_route+0x602/0x11a0 fib6_rule_lookup+0x70/0x300 ip6_route_output_flags+0x2ee/0x5c0 ip6_dst_lookup_tail+0x302/0x11e0 ip6_dst_lookup_flow+0x8f/0x1d0 ip6_sk_dst_lookup_flow+0x401/0x6c0 udpv6_sendmsg+0x1731/0x2ad0 inet6_sendmsg+0x109/0x150 ____sys_sendmsg+0x7b2/0xc20 ___sys_sendmsg+0x10f/0x1b0 __sys_sendmsg+0x150/0x200 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd64296eb19 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:00007fd63fee4188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fd642a81f60 RCX: 00007fd64296eb19 RDX: 0000000000000800 RSI: 0000000020000280 RDI: 0000000000000004 RBP: 00007fd6429c8f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffcaae4614f R14: 00007fd63fee4300 R15: 0000000000022000 ================================================================== Oops: general protection fault, probably for non-canonical address 0xdffffc00000001b9: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000dc8-0x0000000000000dcf] CPU: 0 UID: 0 PID: 4081 Comm: syz-executor.0 Tainted: G B W 6.17.0-rc3-next-20250829 #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:ip6_pol_route+0x617/0x11a0 Code: 00 00 4c 8d b2 cc 0d 00 00 48 89 14 24 4c 89 f7 e8 ae 71 83 fd 4c 89 f1 48 8b 14 24 48 b8 00 00 00 00 00 fc ff df 48 c1 e9 03 <0f> b6 0c 01 4c 89 f0 83 e0 07 83 c0 03 38 c8 7c 10 84 c9 74 0c 4c RSP: 0018:ffff88801b107560 EFLAGS: 00010213 RAX: dffffc0000000000 RBX: ffff888016220f00 RCX: 00000000000001b9 RDX: 0000000000000000 RSI: ffffffff81afcfee RDI: 0000000000000007 RBP: ffff888016f0c740 R08: 0000000000000001 R09: fffffbfff0f11c90 R10: 0000000000000000 R11: 0000000000000001 R12: 000000004919e000 R13: 0000000000000080 R14: 0000000000000dcc R15: ffff88801b1075e0 kmemleak: Found object by alias at 0x607f1a6390ec CPU: 1 UID: 0 PID: 4068 Comm: syz-executor.7 Tainted: G B W 6.17.0-rc3-next-20250829 #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 Call Trace: dump_stack_lvl+0xca/0x120 __lookup_object+0x94/0xb0 delete_object_full+0x27/0x70 free_percpu+0x30/0x1160 futex_hash_free+0x38/0xc0 mmput+0x2d3/0x390 do_exit+0x79d/0x2970 do_group_exit+0xd3/0x2a0 __x64_sys_exit_group+0x3e/0x50 x64_sys_call+0x18c5/0x18d0 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff277112b19 Code: Unable to access opcode bytes at 0x7ff277112aef. RSP: 002b:00007fffa886cc28 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000000000000001e RCX: 00007ff277112b19 RDX: 00007ff2770c572b RSI: ffffffffffffffbc RDI: 0000000000000000 RBP: 0000000000000000 R08: 00007ff27722a238 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000001 R14: 0000000000000001 R15: 00007fffa886cd10 kmemleak: Object (percpu) 0x607f1a6390e8 (size 8): kmemleak: comm "syz-executor.1", pid 4069, jiffies 4294827061 kmemleak: min_count = 1 kmemleak: count = 0 kmemleak: flags = 0x21 kmemleak: checksum = 0 kmemleak: backtrace: pcpu_alloc_noprof+0x87a/0x1170 __alloc_workqueue+0x74b/0x1820 alloc_workqueue_noprof+0xc7/0x200 loop_configure+0xf73/0x1590 lo_ioctl+0x66d/0x1c70 blkdev_ioctl+0x27c/0x6c0 __x64_sys_ioctl+0x18f/0x210 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f FS: 00007fd63fee4700(0000) GS:ffff8880e55dd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc046adf48 CR3: 0000000042119000 CR4: 0000000000350ef0 Call Trace: fib6_rule_lookup+0x70/0x300 ip6_route_output_flags+0x2ee/0x5c0 ip6_dst_lookup_tail+0x302/0x11e0 ip6_dst_lookup_flow+0x8f/0x1d0 ip6_sk_dst_lookup_flow+0x401/0x6c0 udpv6_sendmsg+0x1731/0x2ad0 inet6_sendmsg+0x109/0x150 ____sys_sendmsg+0x7b2/0xc20 ___sys_sendmsg+0x10f/0x1b0 __sys_sendmsg+0x150/0x200 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd64296eb19 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:00007fd63fee4188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fd642a81f60 RCX: 00007fd64296eb19 RDX: 0000000000000800 RSI: 0000000020000280 RDI: 0000000000000004 RBP: 00007fd6429c8f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffcaae4614f R14: 00007fd63fee4300 R15: 0000000000022000 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:ip6_pol_route+0x617/0x11a0 Code: 00 00 4c 8d b2 cc 0d 00 00 48 89 14 24 4c 89 f7 e8 ae 71 83 fd 4c 89 f1 48 8b 14 24 48 b8 00 00 00 00 00 fc ff df 48 c1 e9 03 <0f> b6 0c 01 4c 89 f0 83 e0 07 83 c0 03 38 c8 7c 10 84 c9 74 0c 4c RSP: 0018:ffff88801b107560 EFLAGS: 00010213 RAX: dffffc0000000000 RBX: ffff888016220f00 RCX: 00000000000001b9 RDX: 0000000000000000 RSI: ffffffff81afcfee RDI: 0000000000000007 RBP: ffff888016f0c740 R08: 0000000000000001 R09: fffffbfff0f11c90 R10: 0000000000000000 R11: 0000000000000001 R12: 000000004919e000 R13: 0000000000000080 R14: 0000000000000dcc R15: ffff88801b1075e0 FS: 00007fd63fee4700(0000) GS:ffff8880e55dd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc046adf48 CR3: 0000000042119000 CR4: 0000000000350ef0 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 4c 8d b2 cc 0d 00 00 lea 0xdcc(%rdx),%r14 9: 48 89 14 24 mov %rdx,(%rsp) d: 4c 89 f7 mov %r14,%rdi 10: e8 ae 71 83 fd callq 0xfd8371c3 15: 4c 89 f1 mov %r14,%rcx 18: 48 8b 14 24 mov (%rsp),%rdx 1c: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 23: fc ff df 26: 48 c1 e9 03 shr $0x3,%rcx * 2a: 0f b6 0c 01 movzbl (%rcx,%rax,1),%ecx <-- trapping instruction 2e: 4c 89 f0 mov %r14,%rax 31: 83 e0 07 and $0x7,%eax 34: 83 c0 03 add $0x3,%eax 37: 38 c8 cmp %cl,%al 39: 7c 10 jl 0x4b 3b: 84 c9 test %cl,%cl 3d: 74 0c je 0x4b 3f: 4c rex.WR