On Fri, Mar 22, 2024 at 12:13:29PM -0700, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: ddb2ffdc474a libbpf: Define MFD_CLOEXEC if not available > git tree: bpf > console+strace: https://syzkaller.appspot.com/x/log.txt?x=14ba06a5180000 > kernel config: https://syzkaller.appspot.com/x/.config?x=6fb1be60a193d440 > dashboard link: https://syzkaller.appspot.com/bug?extid=ba82760c63ba37799f70 > 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=115671f1180000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14f14e31180000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/1e40c56954a9/disk-ddb2ffdc.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/738240a7f62b/vmlinux-ddb2ffdc.xz > kernel image: https://storage.googleapis.com/syzbot-assets/2b2e360f1d3a/bzImage-ddb2ffdc.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+ba82760c63ba37799f70@xxxxxxxxxxxxxxxxxxxxxxxxx > > general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] PREEMPT SMP KASAN PTI > KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037] > CPU: 1 PID: 5066 Comm: syz-executor115 Not tainted 6.8.0-syzkaller-05232-gddb2ffdc474a #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 > RIP: 0010:do_misc_fixups kernel/bpf/verifier.c:19609 [inline] > RIP: 0010:bpf_check+0xa19b/0x19010 kernel/bpf/verifier.c:21294 > Code: 48 c1 e8 03 80 3c 08 00 74 12 48 89 df e8 2d 93 50 00 48 b9 00 00 00 00 00 fc ff df 48 8b 1b 48 83 c3 30 48 89 d8 48 c1 e8 03 <0f> b6 04 08 84 c0 0f 85 e3 4c 00 00 8b 1b be 00 00 04 00 21 de 31 > RSP: 0018:ffffc900039671e0 EFLAGS: 00010206 > RAX: 0000000000000006 RBX: 0000000000000030 RCX: dffffc0000000000 > RDX: ffff888018358000 RSI: 0000000000010000 RDI: 0000000000000001 > RBP: ffffc90003967b50 R08: ffffffff81a7a128 R09: ffffffff81a7a365 > R10: 0000000000000004 R11: ffff888018358000 R12: ffffc90000ace072 > R13: 1ffff92000159c0e R14: 1ffff92000159c0e R15: 0000000000010000 > FS: 000055555905c380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00000000111ed398 CR3: 000000002258e000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > bpf_prog_load+0x1667/0x20f0 kernel/bpf/syscall.c:2895 > __sys_bpf+0x4ee/0x810 kernel/bpf/syscall.c:5631 > __do_sys_bpf kernel/bpf/syscall.c:5738 [inline] > __se_sys_bpf kernel/bpf/syscall.c:5736 [inline] > __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5736 > do_syscall_64+0xfb/0x240 > entry_SYSCALL_64_after_hwframe+0x6d/0x75 looks like we might have a fix already: https://lore.kernel.org/bpf/20240322153518.11555-1-puranjay12@xxxxxxxxx/T/#u jirka > RIP: 0033:0x7f425974e3e9 > Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 00 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 b8 ff ff ff f7 d8 64 89 01 48 > RSP: 002b:00007ffe73dd9d38 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 > RAX: ffffffffffffffda RBX: 00007ffe73dd9f18 RCX: 00007f425974e3e9 > RDX: 0000000000000090 RSI: 00000000200000c0 RDI: 0000000000000005 > RBP: 00007f42597c1610 R08: 0000000000000000 R09: 0000000000000000 > R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000000001 > R13: 00007ffe73dd9f08 R14: 0000000000000001 R15: 0000000000000001 > </TASK> > Modules linked in: > ---[ end trace 0000000000000000 ]--- > RIP: 0010:do_misc_fixups kernel/bpf/verifier.c:19609 [inline] > RIP: 0010:bpf_check+0xa19b/0x19010 kernel/bpf/verifier.c:21294 > Code: 48 c1 e8 03 80 3c 08 00 74 12 48 89 df e8 2d 93 50 00 48 b9 00 00 00 00 00 fc ff df 48 8b 1b 48 83 c3 30 48 89 d8 48 c1 e8 03 <0f> b6 04 08 84 c0 0f 85 e3 4c 00 00 8b 1b be 00 00 04 00 21 de 31 > RSP: 0018:ffffc900039671e0 EFLAGS: 00010206 > RAX: 0000000000000006 RBX: 0000000000000030 RCX: dffffc0000000000 > RDX: ffff888018358000 RSI: 0000000000010000 RDI: 0000000000000001 > RBP: ffffc90003967b50 R08: ffffffff81a7a128 R09: ffffffff81a7a365 > R10: 0000000000000004 R11: ffff888018358000 R12: ffffc90000ace072 > R13: 1ffff92000159c0e R14: 1ffff92000159c0e R15: 0000000000010000 > FS: 000055555905c380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00000000111ed398 CR3: 000000002258e000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > ---------------- > Code disassembly (best guess): > 0: 48 c1 e8 03 shr $0x3,%rax > 4: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) > 8: 74 12 je 0x1c > a: 48 89 df mov %rbx,%rdi > d: e8 2d 93 50 00 call 0x50933f > 12: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx > 19: fc ff df > 1c: 48 8b 1b mov (%rbx),%rbx > 1f: 48 83 c3 30 add $0x30,%rbx > 23: 48 89 d8 mov %rbx,%rax > 26: 48 c1 e8 03 shr $0x3,%rax > * 2a: 0f b6 04 08 movzbl (%rax,%rcx,1),%eax <-- trapping instruction > 2e: 84 c0 test %al,%al > 30: 0f 85 e3 4c 00 00 jne 0x4d19 > 36: 8b 1b mov (%rbx),%ebx > 38: be 00 00 04 00 mov $0x40000,%esi > 3d: 21 de and %ebx,%esi > 3f: 31 .byte 0x31 > > > --- > 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. > > 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
