This fixes kprobes/uprobes dynamic processing of strings, where

it processes the args but does not update the remaining length
 of the buffer that the string arguments will be placed in. It
 constantly passes in the total size of buffer used instead of
 passing in the remaining size of the buffer used. This could cause
 issues if the strings are larger than the max size of an event
 which could cause the strings to be written beyond what was reserved
 on the buffer.
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Merge tag 'trace-v5.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "This fixes kprobes/uprobes dynamic processing of strings, where it
  processes the args but does not update the remaining length of the
  buffer that the string arguments will be placed in. It constantly
  passes in the total size of buffer used instead of passing in the
  remaining size of the buffer used.

  This could cause issues if the strings are larger than the max size of
  an event which could cause the strings to be written beyond what was
  reserved on the buffer"

* tag 'trace-v5.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: probeevent: Correctly update remaining space in dynamic area
This commit is contained in:
Linus Torvalds 2019-02-13 10:28:17 -08:00
commit b6ea7bcf77

View file

@ -180,10 +180,12 @@ store_trace_args(void *data, struct trace_probe *tp, struct pt_regs *regs,
if (unlikely(arg->dynamic))
*dl = make_data_loc(maxlen, dyndata - base);
ret = process_fetch_insn(arg->code, regs, dl, base);
if (unlikely(ret < 0 && arg->dynamic))
if (unlikely(ret < 0 && arg->dynamic)) {
*dl = make_data_loc(0, dyndata - base);
else
} else {
dyndata += ret;
maxlen -= ret;
}
}
}