[syzbot] [bpf?] KMSAN: uninit-value in ___bpf_prog_run (4)

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Dec 26, 2023, 10:59:21 AM12/26/23
to and...@kernel.org, a...@kernel.org, b...@vger.kernel.org, dan...@iogearbox.net, hao...@google.com, john.fa...@gmail.com, jo...@kernel.org, kps...@kernel.org, linux-...@vger.kernel.org, marti...@linux.dev, s...@google.com, so...@kernel.org, syzkall...@googlegroups.com, yongho...@linux.dev
Hello,

syzbot found the following issue on:

HEAD commit: 55cb5f43689d Merge tag 'trace-v6.7-rc6' of git://git.kerne..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1275e59ee80000
kernel config: https://syzkaller.appspot.com/x/.config?x=4a65fa9f077ead01
dashboard link: https://syzkaller.appspot.com/bug?extid=853242d9c9917165d791
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ab88d88fa1d1/disk-55cb5f43.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/587fd1186192/vmlinux-55cb5f43.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c7bbb5741191/bzImage-55cb5f43.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+853242...@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in ___bpf_prog_run+0x8a26/0xdb80 kernel/bpf/core.c:2037
___bpf_prog_run+0x8a26/0xdb80 kernel/bpf/core.c:2037
__bpf_prog_run512+0xb5/0xe0 kernel/bpf/core.c:2203
bpf_dispatcher_nop_func include/linux/bpf.h:1196 [inline]
__bpf_prog_run include/linux/filter.h:651 [inline]
bpf_prog_run include/linux/filter.h:658 [inline]
bpf_test_run+0x482/0xb00 net/bpf/test_run.c:423
bpf_prog_test_run_skb+0x14e5/0x1f20 net/bpf/test_run.c:1045
bpf_prog_test_run+0x6af/0xac0 kernel/bpf/syscall.c:4040
__sys_bpf+0x649/0xd60 kernel/bpf/syscall.c:5401
__do_sys_bpf kernel/bpf/syscall.c:5487 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5485 [inline]
__x64_sys_bpf+0xa0/0xe0 kernel/bpf/syscall.c:5485
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

Uninit was stored to memory at:
___bpf_prog_run+0x8567/0xdb80
__bpf_prog_run512+0xb5/0xe0 kernel/bpf/core.c:2203
bpf_dispatcher_nop_func include/linux/bpf.h:1196 [inline]
__bpf_prog_run include/linux/filter.h:651 [inline]
bpf_prog_run include/linux/filter.h:658 [inline]
bpf_test_run+0x482/0xb00 net/bpf/test_run.c:423
bpf_prog_test_run_skb+0x14e5/0x1f20 net/bpf/test_run.c:1045
bpf_prog_test_run+0x6af/0xac0 kernel/bpf/syscall.c:4040
__sys_bpf+0x649/0xd60 kernel/bpf/syscall.c:5401
__do_sys_bpf kernel/bpf/syscall.c:5487 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5485 [inline]
__x64_sys_bpf+0xa0/0xe0 kernel/bpf/syscall.c:5485
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

Local variable stack created at:
__bpf_prog_run512+0x45/0xe0 kernel/bpf/core.c:2203
bpf_dispatcher_nop_func include/linux/bpf.h:1196 [inline]
__bpf_prog_run include/linux/filter.h:651 [inline]
bpf_prog_run include/linux/filter.h:658 [inline]
bpf_test_run+0x482/0xb00 net/bpf/test_run.c:423

CPU: 1 PID: 13775 Comm: syz-executor.3 Not tainted 6.7.0-rc6-syzkaller-00022-g55cb5f43689d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
=====================================================


---
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syzbot

unread,
Jan 22, 2024, 2:46:21 AMJan 22
to and...@kernel.org, a...@kernel.org, b...@vger.kernel.org, dan...@iogearbox.net, hao...@google.com, john.fa...@gmail.com, jo...@kernel.org, kps...@kernel.org, linux-...@vger.kernel.org, marti...@linux.dev, s...@google.com, so...@kernel.org, syzkall...@googlegroups.com, yongho...@linux.dev
syzbot has found a reproducer for the following issue on:

HEAD commit: 9f8413c4a66f Merge tag 'cgroup-for-6.8' of git://git.kerne..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1493fa3de80000
kernel config: https://syzkaller.appspot.com/x/.config?x=656820e61b758b15
dashboard link: https://syzkaller.appspot.com/bug?extid=853242d9c9917165d791
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=139d21e7e80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12d6066fe80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/79d9f2f4b065/disk-9f8413c4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/cbc68430d9c6/vmlinux-9f8413c4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9740ad9fc172/bzImage-9f8413c4.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+853242...@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in ___bpf_prog_run+0xa766/0xdb80 kernel/bpf/core.c:2037
___bpf_prog_run+0xa766/0xdb80 kernel/bpf/core.c:2037
__bpf_prog_run512+0xb5/0xe0 kernel/bpf/core.c:2203
bpf_dispatcher_nop_func include/linux/bpf.h:1196 [inline]
__bpf_prog_run include/linux/filter.h:651 [inline]
bpf_prog_run include/linux/filter.h:658 [inline]
bpf_test_run+0x482/0xb00 net/bpf/test_run.c:423
bpf_prog_test_run_skb+0x14e5/0x1f20 net/bpf/test_run.c:1045
bpf_prog_test_run+0x6af/0xac0 kernel/bpf/syscall.c:4040
__sys_bpf+0x649/0xd60 kernel/bpf/syscall.c:5401
__do_sys_bpf kernel/bpf/syscall.c:5487 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5485 [inline]
__x64_sys_bpf+0xa0/0xe0 kernel/bpf/syscall.c:5485
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x6d/0x140 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

Uninit was stored to memory at:
___bpf_prog_run+0x8567/0xdb80
__bpf_prog_run512+0xb5/0xe0 kernel/bpf/core.c:2203
bpf_dispatcher_nop_func include/linux/bpf.h:1196 [inline]
__bpf_prog_run include/linux/filter.h:651 [inline]
bpf_prog_run include/linux/filter.h:658 [inline]
bpf_test_run+0x482/0xb00 net/bpf/test_run.c:423
bpf_prog_test_run_skb+0x14e5/0x1f20 net/bpf/test_run.c:1045
bpf_prog_test_run+0x6af/0xac0 kernel/bpf/syscall.c:4040
__sys_bpf+0x649/0xd60 kernel/bpf/syscall.c:5401
__do_sys_bpf kernel/bpf/syscall.c:5487 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5485 [inline]
__x64_sys_bpf+0xa0/0xe0 kernel/bpf/syscall.c:5485
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x6d/0x140 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

Local variable stack created at:
__bpf_prog_run512+0x45/0xe0 kernel/bpf/core.c:2203
bpf_dispatcher_nop_func include/linux/bpf.h:1196 [inline]
__bpf_prog_run include/linux/filter.h:651 [inline]
bpf_prog_run include/linux/filter.h:658 [inline]
bpf_test_run+0x482/0xb00 net/bpf/test_run.c:423

CPU: 0 PID: 5010 Comm: syz-executor315 Not tainted 6.7.0-syzkaller-00562-g9f8413c4a66f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
=====================================================


---
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