Messages in this thread | | | From | Kuniyuki Iwashima <> | Subject | Re: [PATCH] net: sock: tracing: Fix sock_exceed_buf_limit not to dereference stale pointer | Date | Wed, 6 Jul 2022 09:21:13 -0700 |
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From: Steven Rostedt <rostedt@goodmis.org> Date: Wed, 6 Jul 2022 10:50:40 -0400 > From: "Steven Rostedt (Google)" <rostedt@goodmis.org> > > The trace event sock_exceed_buf_limit saves the prot->sysctl_mem pointer > and then dereferences it in the TP_printk() portion. This is unsafe as the > TP_printk() portion is executed at the time the buffer is read. That is, > it can be seconds, minutes, days, months, even years later. If the proto > is freed, then this dereference will can also lead to a kernel crash. > > Instead, save the sysctl_mem array into the ring buffer and have the > TP_printk() reference that instead. This is the proper and safe way to > read pointers in trace events. > > Link: https://lore.kernel.org/all/20220706052130.16368-12-kuniyu@amazon.com/ > > Cc: stable@vger.kernel.org > Fixes: 3847ce32aea9f ("core: add tracepoints for queueing skb to rcvbuf") > Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Thanks for shipping the proper fix quickly!
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