fprobe: Fix to allocate entry_data_size buffer with rethook instances

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.

Link: https://lore.kernel.org/all/170920576727.107552.638161246679734051.stgit@devnote2/

Reported-by: Jiri Olsa <olsajiri@gmail.com>
Closes: https://lore.kernel.org/all/Zd9eBn2FTQzYyg7L@krava/
Fixes: 4bbd934556 ("kprobes: kretprobe scalability improvement")
Cc: stable@vger.kernel.org
Tested-by: Jiri Olsa <olsajiri@gmail.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
This commit is contained in:
Masami Hiramatsu (Google) 2024-03-01 09:18:24 +09:00
parent b401b62175
commit 6572786006

View File

@ -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);