Messages in this thread | ![/](/images/icornerl.gif) | | Date | Thu, 29 Feb 2024 20:28:14 +0900 | From | Masami Hiramatsu (Google) <> | Subject | Re: [PATCH] fprobe: Fix to allocate entry_data_size buffer with rethook instances |
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On Thu, 29 Feb 2024 20:22:47 +0900 "Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:
> 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. >
Oops, missed a URL.
> Reported-by: Jiri Olsa <olsajiri@gmail.com>
Closes: https://lore.kernel.org/all/Zd9eBn2FTQzYyg7L@krava/
Thanks,
> 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); > > >
-- Masami Hiramatsu (Google) <mhiramat@kernel.org>
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