From: Wang Liang Date: Tue, 16 Sep 2025 07:58:16 +0000 (+0800) Subject: tracing: kprobe-event: Fix null-ptr-deref in trace_kprobe_create_internal() X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=dc3382fffdec2c1d6df5836c88fa37b39cd8651e;p=linux-block.git tracing: kprobe-event: Fix null-ptr-deref in trace_kprobe_create_internal() 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: 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 Function kmemdup() may return NULL in trace_kprobe_create_internal(), add check for it's return value. Link: https://lore.kernel.org/all/20250916075816.3181175-1-wangliang74@huawei.com/ Fixes: 33b4e38baa03 ("tracing: kprobe-event: Allocate string buffers from heap") Signed-off-by: Wang Liang Signed-off-by: Masami Hiramatsu (Google) --- 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) {