syzbot


KASAN: vmalloc-out-of-bounds Read in __text_poke

Status: upstream: reported on 2022/02/14 18:45
Reported-by: syzbot+ecb1e7e51c52f68f7481@syzkaller.appspotmail.com
Fix commit: d24d2a2b0a81 bpf: bpf_prog_pack: Set proper size before freeing ro_header
Patched on: [ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-leak ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce ci-upstream-kmsan-gce-386 ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu2-riscv64]
First crash: 137d, last: 62d

Sample crash report:
==================================================================
BUG: KASAN: vmalloc-out-of-bounds in memcmp+0x16f/0x1c0 lib/string.c:770
Read of size 8 at addr ffffffffa0601f40 by task syz-executor.0/10382

CPU: 1 PID: 10382 Comm: syz-executor.0 Not tainted 5.18.0-rc1-syzkaller-14467-gc317ab71facc #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description.constprop.0.cold+0xf/0x495 mm/kasan/report.c:313
 print_report mm/kasan/report.c:429 [inline]
 kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491
 memcmp+0x16f/0x1c0 lib/string.c:770
 memcmp include/linux/fortify-string.h:404 [inline]
 __text_poke+0x5a2/0x8c0 arch/x86/kernel/alternative.c:1094
 text_poke_copy+0x66/0xa0 arch/x86/kernel/alternative.c:1170
 bpf_arch_text_copy+0x21/0x40 arch/x86/net/bpf_jit_comp.c:2458
 bpf_jit_binary_pack_finalize+0x44/0x110 kernel/bpf/core.c:1140
 bpf_int_jit_compile+0xa74/0x13e0 arch/x86/net/bpf_jit_comp.c:2414
 bpf_prog_select_runtime+0x2da/0x4b0 kernel/bpf/core.c:2208
 bpf_prog_load+0xfe6/0x2250 kernel/bpf/syscall.c:2579
 __sys_bpf+0x674/0x56b0 kernel/bpf/syscall.c:4889
 __do_sys_bpf kernel/bpf/syscall.c:4993 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4991 [inline]
 __x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:4991
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fdb052890e9
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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fdb063f2168 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fdb0539bf60 RCX: 00007fdb052890e9
RDX: 0000000000000080 RSI: 0000000020000300 RDI: 0000000000000005
RBP: 00007fdb052e308d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc9a6d586f R14: 00007fdb063f2300 R15: 0000000000022000
 </TASK>

Memory state around the buggy address:
 ffffffffa0601e00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffffffa0601e80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>ffffffffa0601f00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
                                           ^
 ffffffffa0601f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffffffa0602000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
==================================================================

Crashes (5):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-bpf-next-kasan-gce 2022/04/27 09:27 bpf-next c317ab71facc 1fa34c1b .config log report info KASAN: vmalloc-out-of-bounds Read in __text_poke
ci-upstream-bpf-next-kasan-gce 2022/04/21 14:20 bpf-next e1a34e19ea96 d4befee1 .config log report info KASAN: vmalloc-out-of-bounds Read in __text_poke
ci-upstream-bpf-next-kasan-gce 2022/03/06 11:22 bpf-next c344b9fc2108 7bdd8b2c .config log report info KASAN: vmalloc-out-of-bounds Read in __text_poke
ci-upstream-bpf-next-kasan-gce 2022/02/11 11:44 bpf-next e5313968c41b 0b33604d .config log report info KASAN: vmalloc-out-of-bounds Read in __text_poke
ci-upstream-linux-next-kasan-gce-root 2022/03/20 07:30 linux-next 91265a6da44d e2d91b1d .config log report info KASAN: vmalloc-out-of-bounds Read in __text_poke