syzbot

 sign-in | mailing list | source | docs
🐞 Open [988] ≡ Subsystems 🐞 Fixed [5242] 🐞 Invalid [12509] ⬇ Missing Backports [83] 📈 Kernel Health 📈 Bug Lifetimes 📈 Fuzzing 📈 Crashes 💬 Send us feedback

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

Status: fixed on 2022/03/08 16:10
Subsystems: bpf
[Documentation on labels]
Reported-by: syzbot+bb73e71cf4b8fd376a4f@syzkaller.appspotmail.com
Fix commit: 218d747a4142 bpf, sockmap: Fix double bpf_prog_put on error case in map_link
First crash: 859d, last: 859d
Cause bisection: introduced by (bisect log) :
commit 38207a5e81230d6ffbdd51e5fa5681be5116dcae
Author: John Fastabend <john.fastabend@gmail.com>
Date: Fri Nov 19 18:14:17 2021 +0000

  bpf, sockmap: Attach map progs to psock early for feature probes

Crash: KASAN: vmalloc-out-of-bounds Read in __bpf_prog_put (log)
Repro: C syz .config
  
▶ ▼ Duplicate bugs (1)
duplicates (1):
Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
KASAN: vmalloc-out-of-bounds Read in __bpf_prog_put bpf C unreliable done 41 856d 873d 0/26 closed as dup on 2022/01/24 11:42
▶ ▼ Discussions (5)
Title Replies (including bot) Last reply
[syzbot] KASAN: vmalloc-out-of-bounds Read in __bpf_prog_put 3 (6) 2022/05/19 15:01
[PATCH 5.16 0000/1039] 5.16.3-rc1 review 1058 (1058) 2022/02/03 14:49
[PATCH 5.15 000/846] 5.15.17-rc1 review 859 (859) 2022/01/27 16:04
[PATCH bpf-next] bpf, sockmap: fix double bpf_prog_put on error case in map_link 3 (3) 2022/01/08 14:10
[syzbot] KASAN: vmalloc-out-of-bounds Read in bpf_prog_put 1 (3) 2022/01/04 21:30
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2022/01/04 21:16 12m john.fastabend@gmail.com patch bpf-next OK

Sample crash report:
==================================================================
BUG: KASAN: vmalloc-out-of-bounds in __bpf_prog_put kernel/bpf/syscall.c:1812 [inline]
BUG: KASAN: vmalloc-out-of-bounds in __bpf_prog_put kernel/bpf/syscall.c:1812 [inline] kernel/bpf/syscall.c:1829
BUG: KASAN: vmalloc-out-of-bounds in bpf_prog_put+0x8c/0x4f0 kernel/bpf/syscall.c:1829 kernel/bpf/syscall.c:1829
Read of size 8 at addr ffffc90000e76038 by task syz-executor020/3641

CPU: 1 PID: 3641 Comm: syz-executor020 Not tainted 5.16.0-rc5-syzkaller #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 lib/dump_stack.c:88 [inline] lib/dump_stack.c:106
 dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106 lib/dump_stack.c:106
 print_address_description+0x65/0x380 mm/kasan/report.c:247 mm/kasan/report.c:247
 __kasan_report mm/kasan/report.c:433 [inline]
 __kasan_report mm/kasan/report.c:433 [inline] mm/kasan/report.c:450
 kasan_report+0x19a/0x1f0 mm/kasan/report.c:450 mm/kasan/report.c:450
 __bpf_prog_put kernel/bpf/syscall.c:1812 [inline]
 __bpf_prog_put kernel/bpf/syscall.c:1812 [inline] kernel/bpf/syscall.c:1829
 bpf_prog_put+0x8c/0x4f0 kernel/bpf/syscall.c:1829 kernel/bpf/syscall.c:1829
 bpf_prog_release+0x37/0x40 kernel/bpf/syscall.c:1837 kernel/bpf/syscall.c:1837
 __fput+0x3fc/0x870 fs/file_table.c:280 fs/file_table.c:280
 task_work_run+0x146/0x1c0 kernel/task_work.c:164 kernel/task_work.c:164
 exit_task_work include/linux/task_work.h:32 [inline]
 exit_task_work include/linux/task_work.h:32 [inline] kernel/exit.c:832
 do_exit+0x705/0x24f0 kernel/exit.c:832 kernel/exit.c:832
 do_group_exit+0x168/0x2d0 kernel/exit.c:929 kernel/exit.c:929
 __do_sys_exit_group+0x13/0x20 kernel/exit.c:940 kernel/exit.c:940
 __se_sys_exit_group+0x10/0x10 kernel/exit.c:938 kernel/exit.c:938
 __x64_sys_exit_group+0x37/0x40 kernel/exit.c:938 kernel/exit.c:938
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_x64 arch/x86/entry/common.c:50 [inline] arch/x86/entry/common.c:80
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f3b90ccd1d9
Code: Unable to access opcode bytes at RIP 0x7f3b90ccd1af.
RSP: 002b:00007ffdeec58318 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f3b90d41330 RCX: 00007f3b90ccd1d9
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffffffffffc4 R09: 00007ffdeec58390
R10: 00007ffdeec58390 R11: 0000000000000246 R12: 00007f3b90d41330
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001
 </TASK>


Memory state around the buggy address:
 ffffc90000e75f00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc90000e75f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>ffffc90000e76000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
                                        ^
 ffffc90000e76080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc90000e76100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/12/18 18:47 upstream 9eaa88c7036e 44068e19 .config console log report syz C ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in bpf_prog_put
2021/12/18 18:13 upstream 9eaa88c7036e 44068e19 .config console log report info ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in bpf_prog_put
* Struck through repros no longer work on HEAD.