Hello, syzbot found the following issue on: HEAD commit: d7b3af5a77e8 Add linux-next specific files for 20230728 git tree: linux-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=101a8319a80000 kernel config: https://syzkaller.appspot.com/x/.config?x=62dd327c382e3fe dashboard link: https://syzkaller.appspot.com/bug?extid=8ada0057e69293a05fd4 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=146dbe31a80000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11656a7ea80000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/5efa5e68267f/disk-d7b3af5a.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/b1f5d3e10263/vmlinux-d7b3af5a.xz kernel image: https://storage.googleapis.com/syzbot-assets/57cab469d186/bzImage-d7b3af5a.xz The issue was bisected to: commit 9f78bf330a66cd400b3e00f370f597e9fa939207 Author: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> Date: Thu Feb 16 08:30:47 2023 +0000 xsk: support use vaddr as ring bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13541155a80000 final oops: https://syzkaller.appspot.com/x/report.txt?x=10d41155a80000 console output: https://syzkaller.appspot.com/x/log.txt?x=17541155a80000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+8ada0057e69293a05fd4@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: 9f78bf330a66 ("xsk: support use vaddr as ring") ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 5078 at lib/refcount.c:28 refcount_warn_saturate+0x140/0x1f0 lib/refcount.c:28 Modules linked in: CPU: 0 PID: 5078 Comm: kworker/0:3 Not tainted 6.5.0-rc3-next-20230728-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023 Workqueue: events drain_vmap_area_work RIP: 0010:refcount_warn_saturate+0x140/0x1f0 lib/refcount.c:28 Code: 0a 31 ff 89 de e8 f0 3e 65 fd 84 db 0f 85 6e ff ff ff e8 b3 43 65 fd 48 c7 c7 c0 33 c8 8a c6 05 64 ce 74 0a 01 e8 60 99 2b fd <0f> 0b e9 4f ff ff ff e8 94 43 65 fd 0f b6 1d 4a ce 74 0a 31 ff 89 RSP: 0018:ffffc90000007d88 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000100 RDX: ffff88807190d940 RSI: ffffffff814d5b56 RDI: 0000000000000001 RBP: ffff888071110460 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff888071110460 R13: ffff8880710d24e8 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555557361650 CR3: 00000000476b6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> __refcount_sub_and_test include/linux/refcount.h:283 [inline] __refcount_dec_and_test include/linux/refcount.h:315 [inline] refcount_dec_and_test include/linux/refcount.h:333 [inline] xp_put_pool+0x8a/0x1e0 net/xdp/xsk_buff_pool.c:286 xsk_destruct+0x95/0x140 net/xdp/xsk.c:1601 __sk_destruct+0x4d/0x770 net/core/sock.c:2163 rcu_do_batch kernel/rcu/tree.c:2139 [inline] rcu_core+0x7fb/0x1bb0 kernel/rcu/tree.c:2403 __do_softirq+0x218/0x965 kernel/softirq.c:553 invoke_softirq kernel/softirq.c:427 [inline] __irq_exit_rcu kernel/softirq.c:632 [inline] irq_exit_rcu+0xb7/0x120 kernel/softirq.c:644 common_interrupt+0xae/0xd0 arch/x86/kernel/irq.c:247 </IRQ> <TASK> asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:636 RIP: 0010:stack_trace_consume_entry+0xaf/0x160 kernel/stacktrace.c:93 Code: c0 03 38 d0 7c 08 84 d2 0f 85 90 00 00 00 8b 43 0c 85 c0 75 53 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 80 3c 02 00 <0f> 85 92 00 00 00 8d 45 01 89 43 10 48 8b 03 48 8d 2c e8 48 b8 00 RSP: 0018:ffffc90003d7f6d8 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffffc90003d7f7b8 RCX: 0000000000000000 RDX: 1ffff920007afef7 RSI: ffffffff81cffbd8 RDI: ffffc90003d7f7c4 RBP: 0000000000000000 R08: ffffc90003d7f72c R09: ffffffff8f40e62e R10: ffffc90003d7f6f8 R11: 000000000000e4d6 R12: ffffffff8174c470 R13: ffffc90003d7f7b8 R14: 0000000000000000 R15: ffff88807190d940 arch_stack_walk+0x7f/0xf0 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x96/0xd0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:128 __reset_page_owner+0x5a/0x190 mm/page_owner.c:149 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1160 [inline] free_unref_page_prepare+0x508/0xb90 mm/page_alloc.c:2383 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2478 kasan_depopulate_vmalloc_pte+0x63/0x80 mm/kasan/shadow.c:427 apply_to_pte_range mm/memory.c:2735 [inline] apply_to_pmd_range mm/memory.c:2779 [inline] apply_to_pud_range mm/memory.c:2815 [inline] apply_to_p4d_range mm/memory.c:2851 [inline] __apply_to_page_range+0x5ed/0xdb0 mm/memory.c:2885 kasan_release_vmalloc+0xa8/0xc0 mm/kasan/shadow.c:544 __purge_vmap_area_lazy+0x8b9/0x2160 mm/vmalloc.c:1770 drain_vmap_area_work+0x54/0xd0 mm/vmalloc.c:1804 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2603 worker_thread+0x687/0x1110 kernel/workqueue.c:2754 kthread+0x33a/0x430 kernel/kthread.c:389 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 </TASK> ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 38 d0 cmp %dl,%al 2: 7c 08 jl 0xc 4: 84 d2 test %dl,%dl 6: 0f 85 90 00 00 00 jne 0x9c c: 8b 43 0c mov 0xc(%rbx),%eax f: 85 c0 test %eax,%eax 11: 75 53 jne 0x66 13: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1a: fc ff df 1d: 48 89 da mov %rbx,%rdx 20: 48 c1 ea 03 shr $0x3,%rdx 24: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) * 28: 0f 85 92 00 00 00 jne 0xc0 <-- trapping instruction 2e: 8d 45 01 lea 0x1(%rbp),%eax 31: 89 43 10 mov %eax,0x10(%rbx) 34: 48 8b 03 mov (%rbx),%rax 37: 48 8d 2c e8 lea (%rax,%rbp,8),%rbp 3b: 48 rex.W 3c: b8 .byte 0xb8 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection If the bug is already fixed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to change bug's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the bug is a duplicate of another bug, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
