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:
parent
b401b62175
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6572786006
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@ -189,9 +189,6 @@ static int fprobe_init_rethook(struct fprobe *fp, int num)
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{
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int size;
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if (num <= 0)
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return -EINVAL;
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if (!fp->exit_handler) {
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fp->rethook = NULL;
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return 0;
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@ -199,15 +196,16 @@ static int fprobe_init_rethook(struct fprobe *fp, int num)
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/* Initialize rethook if needed */
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if (fp->nr_maxactive)
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size = fp->nr_maxactive;
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num = fp->nr_maxactive;
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else
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size = num * num_possible_cpus() * 2;
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if (size <= 0)
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num *= num_possible_cpus() * 2;
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if (num <= 0)
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return -EINVAL;
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size = sizeof(struct fprobe_rethook_node) + fp->entry_data_size;
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/* Initialize rethook */
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fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler,
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sizeof(struct fprobe_rethook_node), size);
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fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler, size, num);
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if (IS_ERR(fp->rethook))
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return PTR_ERR(fp->rethook);
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