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* [PATCH] fprobe: Fix to allocate entry_data_size buffer with rethook instances
@ 2024-02-29 11:22 Masami Hiramatsu (Google)
  2024-02-29 11:28 ` Masami Hiramatsu
  2024-02-29 21:58 ` Jiri Olsa
  0 siblings, 2 replies; 4+ messages in thread
From: Masami Hiramatsu (Google) @ 2024-02-29 11:22 UTC (permalink / raw)
  To: Steven Rostedt, linux-trace-kernel; +Cc: Jiri Olsa, linux-kernel

From: Masami Hiramatsu (Google) <mhiramat@kernel.org>

Fix to allocate fprobe::entry_data_size buffer with rethook instances.
If fprobe doesn't allocate entry_data_size buffer for each rethook instance,
fprobe entry handler can cause a buffer overrun when storing entry data in
entry handler.

Reported-by: Jiri Olsa <olsajiri@gmail.com>
Fixes: 4bbd93455659 ("kprobes: kretprobe scalability improvement")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
 kernel/trace/fprobe.c |   14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
index 6cd2a4e3afb8..9ff018245840 100644
--- a/kernel/trace/fprobe.c
+++ b/kernel/trace/fprobe.c
@@ -189,9 +189,6 @@ static int fprobe_init_rethook(struct fprobe *fp, int num)
 {
 	int size;
 
-	if (num <= 0)
-		return -EINVAL;
-
 	if (!fp->exit_handler) {
 		fp->rethook = NULL;
 		return 0;
@@ -199,15 +196,16 @@ static int fprobe_init_rethook(struct fprobe *fp, int num)
 
 	/* Initialize rethook if needed */
 	if (fp->nr_maxactive)
-		size = fp->nr_maxactive;
+		num = fp->nr_maxactive;
 	else
-		size = num * num_possible_cpus() * 2;
-	if (size <= 0)
+		num *= num_possible_cpus() * 2;
+	if (num <= 0)
 		return -EINVAL;
 
+	size = sizeof(struct fprobe_rethook_node) + fp->entry_data_size;
+
 	/* Initialize rethook */
-	fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler,
-				sizeof(struct fprobe_rethook_node), size);
+	fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler, size, num);
 	if (IS_ERR(fp->rethook))
 		return PTR_ERR(fp->rethook);
 


^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2024-02-29 22:50 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2024-02-29 11:22 [PATCH] fprobe: Fix to allocate entry_data_size buffer with rethook instances Masami Hiramatsu (Google)
2024-02-29 11:28 ` Masami Hiramatsu
2024-02-29 21:58 ` Jiri Olsa
2024-02-29 22:50   ` Masami Hiramatsu

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