On Fri, Aug 15, 2025 at 10:26 AM syzbot ci <syzbot+cic1938c6466797c55@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > syzbot ci has tested the following series > > [v3] Signed BPF programs > https://lore.kernel.org/all/20250813205526.2992911-1-kpsingh@xxxxxxxxxx > * [PATCH v3 01/12] bpf: Update the bpf_prog_calc_tag to use SHA256 > * [PATCH v3 02/12] bpf: Implement exclusive map creation > * [PATCH v3 03/12] libbpf: Implement SHA256 internal helper > * [PATCH v3 04/12] libbpf: Support exclusive map creation > * [PATCH v3 05/12] selftests/bpf: Add tests for exclusive maps > * [PATCH v3 06/12] bpf: Return hashes of maps in BPF_OBJ_GET_INFO_BY_FD > * [PATCH v3 07/12] bpf: Move the signature kfuncs to helpers.c > * [PATCH v3 08/12] bpf: Implement signature verification for BPF programs > * [PATCH v3 09/12] libbpf: Update light skeleton for signing > * [PATCH v3 10/12] libbpf: Embed and verify the metadata hash in the loader > * [PATCH v3 11/12] bpftool: Add support for signing BPF programs > * [PATCH v3 12/12] selftests/bpf: Enable signature verification for some lskel tests > > and found the following issue: > general protection fault in bpf_verify_pkcs7_signature > > Full report is available here: > https://ci.syzbot.org/series/67d9a289-da5c-4051-8c3c-cc32b6ccd77d > > *** > > general protection fault in bpf_verify_pkcs7_signature > > tree: bpf-next > URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/bpf/bpf-next.git > base: 07866544e410e4c895a729971e4164861b41fad5 > arch: amd64 > compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 > config: https://ci.syzbot.org/builds/1e87aafb-11dc-48f1-a980-c91551ba52de/config > C repro: https://ci.syzbot.org/findings/0c329233-09a8-4e8b-9e6e-72f234dd85ab/c_repro > syz repro: https://ci.syzbot.org/findings/0c329233-09a8-4e8b-9e6e-72f234dd85ab/syz_repro > > Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN PTI > KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] > CPU: 1 UID: 0 PID: 6001 Comm: syz.0.17 Not tainted 6.17.0-rc1-syzkaller-00022-g07866544e410-dirty #0 PREEMPT(full) > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 > RIP: 0010:bpf_verify_pkcs7_signature+0x31/0x190 kernel/bpf/helpers.c:3835 > Code: 41 56 41 55 41 54 53 48 89 d3 49 89 f6 49 89 ff 48 bd 00 00 00 00 00 fc ff df e8 aa b0 e0 ff 4c 8d 63 08 4c 89 e0 48 c1 e8 03 <0f> b6 04 28 84 c0 0f 85 01 01 00 00 41 80 3c 24 00 74 3d 48 89 d8 > RSP: 0018:ffffc90002f7fa08 EFLAGS: 00010202 > RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffff888020c51cc0 > RDX: 0000000000000000 RSI: ffffc90002f7faa0 RDI: ffffc90002f7fac0 > RBP: dffffc0000000000 R08: 0000000000000018 R09: ffffffff820b8a70 > R10: ffffc90002f7fac0 R11: fffff520005eff5a R12: 0000000000000008 > R13: 0000000000000010 R14: ffffc90002f7faa0 R15: ffffc90002f7fac0 > FS: 00005555895fe500(0000) GS:ffff8881a3c1c000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000001b30b63fff CR3: 0000000028898000 CR4: 00000000000006f0 > Call Trace: > <TASK> > bpf_prog_verify_signature+0x2da/0x3b0 kernel/bpf/syscall.c:2815 > bpf_prog_load+0xcc4/0x19e0 kernel/bpf/syscall.c:2989 > __sys_bpf+0x507/0x860 kernel/bpf/syscall.c:6116 > __do_sys_bpf kernel/bpf/syscall.c:6226 [inline] > __se_sys_bpf kernel/bpf/syscall.c:6224 [inline] > __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6224 > do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] > do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7f0a4558ebe9 > 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 a8 ff ff ff f7 d8 64 89 01 48 > RSP: 002b:00007fff940250b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 > RAX: ffffffffffffffda RBX: 00007f0a457b5fa0 RCX: 00007f0a4558ebe9 > RDX: 00000000000000a8 RSI: 0000200000000140 RDI: 0000000000000005 > RBP: 00007f0a45611e19 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 > R13: 00007f0a457b5fa0 R14: 00007f0a457b5fa0 R15: 0000000000000003 > </TASK> > Modules linked in: > ---[ end trace 0000000000000000 ]--- > RIP: 0010:bpf_verify_pkcs7_signature+0x31/0x190 kernel/bpf/helpers.c:3835 > Code: 41 56 41 55 41 54 53 48 89 d3 49 89 f6 49 89 ff 48 bd 00 00 00 00 00 fc ff df e8 aa b0 e0 ff 4c 8d 63 08 4c 89 e0 48 c1 e8 03 <0f> b6 04 28 84 c0 0f 85 01 01 00 00 41 80 3c 24 00 74 3d 48 89 d8 > RSP: 0018:ffffc90002f7fa08 EFLAGS: 00010202 > RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffff888020c51cc0 > RDX: 0000000000000000 RSI: ffffc90002f7faa0 RDI: ffffc90002f7fac0 > RBP: dffffc0000000000 R08: 0000000000000018 R09: ffffffff820b8a70 > R10: ffffc90002f7fac0 R11: fffff520005eff5a R12: 0000000000000008 > R13: 0000000000000010 R14: ffffc90002f7faa0 R15: ffffc90002f7fac0 > FS: 00005555895fe500(0000) GS:ffff8881a3c1c000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000001b30b63fff CR3: 0000000028898000 CR4: 00000000000006f0 > ---------------- > Code disassembly (best guess): > 0: 41 56 push %r14 > 2: 41 55 push %r13 > 4: 41 54 push %r12 > 6: 53 push %rbx > 7: 48 89 d3 mov %rdx,%rbx > a: 49 89 f6 mov %rsi,%r14 > d: 49 89 ff mov %rdi,%r15 > 10: 48 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%rbp > 17: fc ff df > 1a: e8 aa b0 e0 ff call 0xffe0b0c9 > 1f: 4c 8d 63 08 lea 0x8(%rbx),%r12 > 23: 4c 89 e0 mov %r12,%rax > 26: 48 c1 e8 03 shr $0x3,%rax > * 2a: 0f b6 04 28 movzbl (%rax,%rbp,1),%eax <-- trapping instruction > 2e: 84 c0 test %al,%al > 30: 0f 85 01 01 00 00 jne 0x137 > 36: 41 80 3c 24 00 cmpb $0x0,(%r12) > 3b: 74 3d je 0x7a > 3d: 48 89 d8 mov %rbx,%rax > > > *** > > If these findings have caused you to resend the series or submit a > separate fix, please add the following tag to your commit message: > Tested-by: syzbot@xxxxxxxxxxxxxxxxxxxxxxxxx > diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 596c0fa7fc90..d0d437f38a70 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2801,6 +2801,9 @@ static int bpf_prog_verify_signature(struct bpf_prog *prog, union bpf_attr *attr else key = bpf_lookup_user_key(attr->keyring_id, 0); + if (!key) + return -EINVAL; + sig = kvmemdup_bpfptr(usig, attr->signature_size); if (IS_ERR(sig)) { bpf_key_put(key); Thanks syzbot! - KP > --- > This report is generated by a bot. It may contain errors. > syzbot ci engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx.
