Hi Sebastian! IIUC syzbot continues to hit this, is it on your radar? On Fri, 12 Jul 2024 09:25:24 -0700 syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 523b23f0bee3 Add linux-next specific files for 20240710 > git tree: linux-next > console+strace: https://syzkaller.appspot.com/x/log.txt?x=13187c7e980000 > kernel config: https://syzkaller.appspot.com/x/.config?x=98dd8c4bab5cdce > dashboard link: https://syzkaller.appspot.com/bug?extid=709e4c85c904bcd62735 > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=106dd859980000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=111637b9980000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/345bcd25ed2f/disk-523b23f0.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/a4508962d345/vmlinux-523b23f0.xz > kernel image: https://storage.googleapis.com/syzbot-assets/4ba5eb555639/bzImage-523b23f0.xz > > The issue was bisected to: > > commit fecef4cd42c689a200bdd39e6fffa71475904bc1 > Author: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> > Date: Thu Jul 4 14:48:15 2024 +0000 > > tun: Assign missing bpf_net_context. > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=164d6f76980000 > final oops: https://syzkaller.appspot.com/x/report.txt?x=154d6f76980000 > console output: https://syzkaller.appspot.com/x/log.txt?x=114d6f76980000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+709e4c85c904bcd62735@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: fecef4cd42c6 ("tun: Assign missing bpf_net_context.") > > ================================================================== > BUG: KASAN: stack-out-of-bounds in bpf_net_ctx_get_all_used_flush_lists include/linux/filter.h:837 [inline] > BUG: KASAN: stack-out-of-bounds in xdp_do_check_flushed+0x231/0x240 net/core/filter.c:4298 > Read of size 4 at addr ffffc90003def7f8 by task syz-executor156/5107 > > CPU: 0 UID: 0 PID: 5107 Comm: syz-executor156 Not tainted 6.10.0-rc7-next-20240710-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 > Call Trace: > <IRQ> > __dump_stack lib/dump_stack.c:94 [inline] > dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 > print_address_description mm/kasan/report.c:377 [inline] > print_report+0x169/0x550 mm/kasan/report.c:488 > kasan_report+0x143/0x180 mm/kasan/report.c:601 > bpf_net_ctx_get_all_used_flush_lists include/linux/filter.h:837 [inline] > xdp_do_check_flushed+0x231/0x240 net/core/filter.c:4298 > __napi_poll+0xe4/0x490 net/core/dev.c:6774 > napi_poll net/core/dev.c:6840 [inline] > net_rx_action+0x89b/0x1240 net/core/dev.c:6962 > handle_softirqs+0x2c4/0x970 kernel/softirq.c:554 > do_softirq+0x11b/0x1e0 kernel/softirq.c:455 > </IRQ> > <TASK> > __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 > local_bh_enable include/linux/bottom_half.h:33 [inline] > tun_get_user+0x2884/0x4720 drivers/net/tun.c:1936 > tun_chr_write_iter+0x113/0x1f0 drivers/net/tun.c:2052 > new_sync_write fs/read_write.c:497 [inline] > vfs_write+0xa72/0xc90 fs/read_write.c:590 > ksys_write+0x1a0/0x2c0 fs/read_write.c:643 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7f26cdb99d90 > Code: 40 00 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d 11 e3 07 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89 > RSP: 002b:00007ffd1139eb08 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f26cdb99d90 > RDX: 000000000000fdef RSI: 0000000020000200 RDI: 00000000000000c8 > RBP: 0000000000000000 R08: 00007ffd1139ec38 R09: 00007ffd1139ec38 > R10: 00007ffd1139ec38 R11: 0000000000000202 R12: 0000000000000000 > R13: 0000000000000000 R14: 00007ffd1139eb40 R15: 00007ffd1139eb30 > </TASK> > > The buggy address belongs to stack of task syz-executor156/5107 > and is located at offset 88 in frame: > do_softirq+0x0/0x1e0 > > This frame has 2 objects: > [32, 40) 'flags.i.i.i105' > [64, 72) 'flags.i.i.i' > > The buggy address belongs to the virtual mapping at > [ffffc90003de8000, ffffc90003df1000) created by: > copy_process+0x5d1/0x3d90 kernel/fork.c:2206 > > The buggy address belongs to the physical page: > page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6b798 > flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) > raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000 > raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 > page dumped because: kasan: bad access detected > page_owner tracks the page as allocated > page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2dc2(GFP_KERNEL|__GFP_HIGHMEM|__GFP_NOWARN|__GFP_ZERO), pid 5089, tgid 5089 (sshd), ts 45267990588, free_ts 13316620078 > set_page_owner include/linux/page_owner.h:32 [inline] > post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1493 > prep_new_page mm/page_alloc.c:1501 [inline] > get_page_from_freelist+0x2ccb/0x2d80 mm/page_alloc.c:3480 > __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4738 > alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2263 > vm_area_alloc_pages mm/vmalloc.c:3584 [inline] > __vmalloc_area_node mm/vmalloc.c:3660 [inline] > __vmalloc_node_range_noprof+0x971/0x1460 mm/vmalloc.c:3841 > alloc_thread_stack_node kernel/fork.c:314 [inline] > dup_task_struct+0x444/0x8c0 kernel/fork.c:1115 > copy_process+0x5d1/0x3d90 kernel/fork.c:2206 > kernel_clone+0x226/0x8f0 kernel/fork.c:2788 > __do_sys_clone kernel/fork.c:2931 [inline] > __se_sys_clone kernel/fork.c:2915 [inline] > __x64_sys_clone+0x258/0x2a0 kernel/fork.c:2915 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > page last free pid 1 tgid 1 stack trace: > reset_page_owner include/linux/page_owner.h:25 [inline] > free_pages_prepare mm/page_alloc.c:1094 [inline] > free_unref_page+0xd22/0xea0 mm/page_alloc.c:2644 > free_contig_range+0x9e/0x160 mm/page_alloc.c:6694 > destroy_args+0x8a/0x890 mm/debug_vm_pgtable.c:1017 > debug_vm_pgtable+0x4be/0x550 mm/debug_vm_pgtable.c:1397 > do_one_initcall+0x248/0x880 init/main.c:1267 > do_initcall_level+0x157/0x210 init/main.c:1329 > do_initcalls+0x3f/0x80 init/main.c:1345 > kernel_init_freeable+0x435/0x5d0 init/main.c:1578 > kernel_init+0x1d/0x2b0 init/main.c:1467 > ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > Memory state around the buggy address: > ffffc90003def680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > ffffc90003def700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > >ffffc90003def780: 00 00 00 00 f1 f1 f1 f1 00 f2 f2 f2 00 f3 f3 f3 > ^ > ffffc90003def800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > ffffc90003def880: f1 f1 f1 f1 00 f3 f3 f3 00 00 00 00 00 00 00 00 > ================================================================== > > > --- > 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 report is already addressed, 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 overwrite report's subsystems, reply with: > #syz set subsystems: new-subsystem > (See the list of subsystem names on the web dashboard) > > If the report is a duplicate of another one, reply with: > #syz dup: exact-subject-of-another-report > > If you want to undo deduplication, reply with: > #syz undup
