On Tue, 16 Sep 2025 15:58:16 +0800
Wang Liang <wanglian...@huawei.com> wrote:
> A crash was observed with the following output:
>
> Oops: general protection fault, probably for non-canonical address
> 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI
> KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
> CPU: 1 UID: 0 PID: 2899 Comm: syz.2.399 Not tainted 6.17.0-rc5+ #5
> PREEMPT(none)
> RIP: 0010:trace_kprobe_create_internal+0x3fc/0x1440
> kernel/trace/trace_kprobe.c:911
> Call Trace:
> <TASK>
> trace_kprobe_create_cb+0xa2/0xf0 kernel/trace/trace_kprobe.c:1089
> trace_probe_create+0xf1/0x110 kernel/trace/trace_probe.c:2246
> dyn_event_create+0x45/0x70 kernel/trace/trace_dynevent.c:128
> create_or_delete_trace_kprobe+0x5e/0xc0 kernel/trace/trace_kprobe.c:1107
> trace_parse_run_command+0x1a5/0x330 kernel/trace/trace.c:10785
> vfs_write+0x2b6/0xd00 fs/read_write.c:684
> ksys_write+0x129/0x240 fs/read_write.c:738
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0x5d/0x2d0 arch/x86/entry/syscall_64.c:94
> </TASK>
>
> Function kmemdup() may return NULL in trace_kprobe_create_internal(), add
> check for it's return value.
Oops, thanks for fixing!
Let me pick this!
>
> Fixes: 33b4e38baa03 ("tracing: kprobe-event: Allocate string buffers from
> heap")
> Signed-off-by: Wang Liang <wanglian...@huawei.com>
> ---
> kernel/trace/trace_kprobe.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index ccae62d4fb91..fa60362a3f31 100644
> --- a/kernel/trace/trace_kprobe.c
> +++ b/kernel/trace/trace_kprobe.c
> @@ -908,6 +908,8 @@ static int trace_kprobe_create_internal(int argc, const
> char *argv[],
> return -EINVAL;
> }
> buf = kmemdup(&argv[0][1], len + 1, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> buf[len] = '\0';
> ret = kstrtouint(buf, 0, &maxactive);
> if (ret || !maxactive) {
> --
> 2.34.1
>
--
Masami Hiramatsu (Google) <mhira...@kernel.org>
