Hi Sebastian The syzbot splat below shows up in recent -next kernels which sorta-kinda wags its finger suggestively at the bpf_net_ctx_get() changes. There's one for __dev_flush() as well: https://lore.kernel.org/r/0000000000009d1d0a061d91b803@xxxxxxxxxx Care to take a look? :) Thanks! -Toke syzbot <syzbot+c226757eb784a9da3e8b@xxxxxxxxxxxxxxxxxxxxxxxxx> writes: > syzbot has found a reproducer for the following issue on: > > HEAD commit: 9ec6ec93f2c1 Add linux-next specific files for 20240724 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=10e71ca1980000 > kernel config: https://syzkaller.appspot.com/x/.config?x=83e9d0906fa0e2bd > dashboard link: https://syzkaller.appspot.com/bug?extid=c226757eb784a9da3e8b > 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=17c0f8e3980000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=151b9919980000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/c0ab2da24b1f/disk-9ec6ec93.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/da6faf16185f/vmlinux-9ec6ec93.xz > kernel image: https://storage.googleapis.com/syzbot-assets/1ad900571155/bzImage-9ec6ec93.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+c226757eb784a9da3e8b@xxxxxxxxxxxxxxxxxxxxxxxxx > > Oops: general protection fault, probably for non-canonical address 0xe3fffb24002e6fe6: 0000 [#1] PREEMPT SMP KASAN PTI > KASAN: maybe wild-memory-access in range [0x1ffff92001737f30-0x1ffff92001737f37] > CPU: 1 UID: 0 PID: 11878 Comm: syz-executor412 Not tainted 6.10.0-next-20240724-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 > RIP: 0010:__cpu_map_flush+0x42/0xd0 > Code: e8 13 8c d6 ff 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 4d 12 3e 00 49 8b 1e 4c 39 f3 74 77 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 2f 12 3e 00 4c 8b 23 48 8d 7b c0 > RSP: 0018:ffffc90000a18b10 EFLAGS: 00010202 > RAX: 03ffff24002e6fe6 RBX: 1ffff92001737f30 RCX: ffff888074dc8000 > RDX: 0000000080000101 RSI: 0000000000000010 RDI: ffffc9000b9bf800 > RBP: dffffc0000000000 R08: ffffffff896d3b5a R09: 1ffffffff1f5f375 > R10: dffffc0000000000 R11: fffffbfff1f5f376 R12: ffffc9000b9bf800 > R13: ffffc9000b9bf820 R14: ffffc9000b9bf800 R15: dffffc0000000000 > FS: 0000555592677380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007fd44da640f0 CR3: 000000001ea68000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <IRQ> > xdp_do_check_flushed+0x136/0x240 net/core/filter.c:4304 > __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 kernel/softirq.c:588 [inline] > invoke_softirq kernel/softirq.c:428 [inline] > __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 > irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 > common_interrupt+0xaa/0xd0 arch/x86/kernel/irq.c:278 > </IRQ> > <TASK> > asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 > RIP: 0010:check_kcov_mode kernel/kcov.c:184 [inline] > RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x70 kernel/kcov.c:207 > Code: 40 d7 03 00 65 8b 15 10 0c 70 7e f7 c2 00 01 ff 00 74 11 f7 c2 00 01 00 00 74 35 83 b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 <83> fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc > RSP: 0018:ffffc9000b9bf8a0 EFLAGS: 00000246 > RAX: ffffffff81410dcc RBX: 0000000000000000 RCX: ffff888074dc8000 > RDX: 0000000000000000 RSI: ffffffff8b942412 RDI: ffffffff8b942328 > RBP: 1ffff92001737f30 R08: ffffffff81410c60 R09: ffffc9000b9bfa70 > R10: 0000000000000003 R11: ffffffff817f7030 R12: ffffffff90294810 > R13: dffffc0000000000 R14: 1ffff92001737f30 R15: ffffffff90d0fbd4 > unwind_next_frame+0x67c/0x2a00 arch/x86/kernel/unwind_orc.c:495 > arch_stack_walk+0x151/0x1b0 arch/x86/kernel/stacktrace.c:25 > stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 > kasan_save_stack mm/kasan/common.c:47 [inline] > kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 > kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 > poison_slab_object+0xe0/0x150 mm/kasan/common.c:240 > __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 > kasan_slab_free include/linux/kasan.h:184 [inline] > slab_free_hook mm/slub.c:2252 [inline] > slab_free mm/slub.c:4473 [inline] > kmem_cache_free+0x145/0x350 mm/slub.c:4548 > __dentry_kill+0x497/0x630 fs/dcache.c:629 > dput+0x19f/0x2b0 fs/dcache.c:852 > __fput+0x5f8/0x8a0 fs/file_table.c:430 > __do_sys_close fs/open.c:1566 [inline] > __se_sys_close fs/open.c:1551 [inline] > __x64_sys_close+0x7f/0x110 fs/open.c:1551 > 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: 0033:0x7fd44d9ed9c0 > Code: ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 80 3d e1 76 07 00 00 74 17 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c > RSP: 002b:00007fff7a1e95b8 EFLAGS: 00000202 ORIG_RAX: 0000000000000003 > RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fd44d9ed9c0 > RDX: 0000000000000e80 RSI: 0000000020000100 RDI: 0000000000000004 > RBP: 00007fff7a1e9600 R08: 00007fff7a1e95e0 R09: 00007fff7a1e95e0 > R10: 00007fff7a1e95e0 R11: 0000000000000202 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > </TASK> > Modules linked in: > ---[ end trace 0000000000000000 ]--- > RIP: 0010:__cpu_map_flush+0x42/0xd0 > Code: e8 13 8c d6 ff 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 4d 12 3e 00 49 8b 1e 4c 39 f3 74 77 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 2f 12 3e 00 4c 8b 23 48 8d 7b c0 > RSP: 0018:ffffc90000a18b10 EFLAGS: 00010202 > RAX: 03ffff24002e6fe6 RBX: 1ffff92001737f30 RCX: ffff888074dc8000 > RDX: 0000000080000101 RSI: 0000000000000010 RDI: ffffc9000b9bf800 > RBP: dffffc0000000000 R08: ffffffff896d3b5a R09: 1ffffffff1f5f375 > R10: dffffc0000000000 R11: fffffbfff1f5f376 R12: ffffc9000b9bf800 > R13: ffffc9000b9bf820 R14: ffffc9000b9bf800 R15: dffffc0000000000 > FS: 0000555592677380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007fd44da640f0 CR3: 000000001ea68000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > ---------------- > Code disassembly (best guess): > 0: e8 13 8c d6 ff call 0xffd68c18 > 5: 4c 89 f0 mov %r14,%rax > 8: 48 c1 e8 03 shr $0x3,%rax > c: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1) > 11: 74 08 je 0x1b > 13: 4c 89 f7 mov %r14,%rdi > 16: e8 4d 12 3e 00 call 0x3e1268 > 1b: 49 8b 1e mov (%r14),%rbx > 1e: 4c 39 f3 cmp %r14,%rbx > 21: 74 77 je 0x9a > 23: 48 89 d8 mov %rbx,%rax > 26: 48 c1 e8 03 shr $0x3,%rax > * 2a: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1) <-- trapping instruction > 2f: 74 08 je 0x39 > 31: 48 89 df mov %rbx,%rdi > 34: e8 2f 12 3e 00 call 0x3e1268 > 39: 4c 8b 23 mov (%rbx),%r12 > 3c: 48 8d 7b c0 lea -0x40(%rbx),%rdi > > > --- > 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.
