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authorShang XiaoJing <shangxiaojing@huawei.com>2022-11-18 04:15:33 +0300
committerMasami Hiramatsu (Google) <mhiramat@kernel.org>2022-11-18 04:15:33 +0300
commite0d75267f59d7084e0468bd68beeb1bf9c71d7c0 (patch)
tree1bd47c93bf076927987d6d5222425c54579ed959 /kernel/trace/kprobe_event_gen_test.c
parent31029a8b2c7e656a0289194ef16415050ae4c4ac (diff)
downloadlinux-e0d75267f59d7084e0468bd68beeb1bf9c71d7c0.tar.xz
tracing: kprobe: Fix potential null-ptr-deref on trace_event_file in kprobe_event_gen_test_exit()
When trace_get_event_file() failed, gen_kretprobe_test will be assigned as the error code. If module kprobe_event_gen_test is removed now, the null pointer dereference will happen in kprobe_event_gen_test_exit(). Check if gen_kprobe_test or gen_kretprobe_test is error code or NULL before dereference them. BUG: kernel NULL pointer dereference, address: 0000000000000012 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 3 PID: 2210 Comm: modprobe Not tainted 6.1.0-rc1-00171-g2159299a3b74-dirty #217 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 RIP: 0010:kprobe_event_gen_test_exit+0x1c/0xb5 [kprobe_event_gen_test] Code: Unable to access opcode bytes at 0xffffffff9ffffff2. RSP: 0018:ffffc900015bfeb8 EFLAGS: 00010246 RAX: ffffffffffffffea RBX: ffffffffa0002080 RCX: 0000000000000000 RDX: ffffffffa0001054 RSI: ffffffffa0001064 RDI: ffffffffdfc6349c RBP: ffffffffa0000000 R08: 0000000000000004 R09: 00000000001e95c0 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000800 R13: ffffffffa0002420 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f56b75be540(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffff9ffffff2 CR3: 000000010874a006 CR4: 0000000000330ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __x64_sys_delete_module+0x206/0x380 ? lockdep_hardirqs_on_prepare+0xd8/0x190 ? syscall_enter_from_user_mode+0x1c/0x50 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Link: https://lore.kernel.org/all/20221108015130.28326-2-shangxiaojing@huawei.com/ Fixes: 64836248dda2 ("tracing: Add kprobe event command generation test module") Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Diffstat (limited to 'kernel/trace/kprobe_event_gen_test.c')
-rw-r--r--kernel/trace/kprobe_event_gen_test.c44
1 files changed, 28 insertions, 16 deletions
diff --git a/kernel/trace/kprobe_event_gen_test.c b/kernel/trace/kprobe_event_gen_test.c
index d81f7c51025c..1c98fafcf333 100644
--- a/kernel/trace/kprobe_event_gen_test.c
+++ b/kernel/trace/kprobe_event_gen_test.c
@@ -73,6 +73,10 @@ static struct trace_event_file *gen_kretprobe_test;
#define KPROBE_GEN_TEST_ARG3 NULL
#endif
+static bool trace_event_file_is_valid(struct trace_event_file *input)
+{
+ return input && !IS_ERR(input);
+}
/*
* Test to make sure we can create a kprobe event, then add more
@@ -217,10 +221,12 @@ static int __init kprobe_event_gen_test_init(void)
ret = test_gen_kretprobe_cmd();
if (ret) {
- WARN_ON(trace_array_set_clr_event(gen_kretprobe_test->tr,
- "kprobes",
- "gen_kretprobe_test", false));
- trace_put_event_file(gen_kretprobe_test);
+ if (trace_event_file_is_valid(gen_kretprobe_test)) {
+ WARN_ON(trace_array_set_clr_event(gen_kretprobe_test->tr,
+ "kprobes",
+ "gen_kretprobe_test", false));
+ trace_put_event_file(gen_kretprobe_test);
+ }
WARN_ON(kprobe_event_delete("gen_kretprobe_test"));
}
@@ -229,24 +235,30 @@ static int __init kprobe_event_gen_test_init(void)
static void __exit kprobe_event_gen_test_exit(void)
{
- /* Disable the event or you can't remove it */
- WARN_ON(trace_array_set_clr_event(gen_kprobe_test->tr,
- "kprobes",
- "gen_kprobe_test", false));
+ if (trace_event_file_is_valid(gen_kprobe_test)) {
+ /* Disable the event or you can't remove it */
+ WARN_ON(trace_array_set_clr_event(gen_kprobe_test->tr,
+ "kprobes",
+ "gen_kprobe_test", false));
+
+ /* Now give the file and instance back */
+ trace_put_event_file(gen_kprobe_test);
+ }
- /* Now give the file and instance back */
- trace_put_event_file(gen_kprobe_test);
/* Now unregister and free the event */
WARN_ON(kprobe_event_delete("gen_kprobe_test"));
- /* Disable the event or you can't remove it */
- WARN_ON(trace_array_set_clr_event(gen_kretprobe_test->tr,
- "kprobes",
- "gen_kretprobe_test", false));
+ if (trace_event_file_is_valid(gen_kretprobe_test)) {
+ /* Disable the event or you can't remove it */
+ WARN_ON(trace_array_set_clr_event(gen_kretprobe_test->tr,
+ "kprobes",
+ "gen_kretprobe_test", false));
+
+ /* Now give the file and instance back */
+ trace_put_event_file(gen_kretprobe_test);
+ }
- /* Now give the file and instance back */
- trace_put_event_file(gen_kretprobe_test);
/* Now unregister and free the event */
WARN_ON(kprobe_event_delete("gen_kretprobe_test"));