pkg/symbolizer: Fix parser handling of small hex values

[jodaco]

The parser in symbolizer presently breaks out of the for loop if it receives a hex value, to indicate it has reached the next PC, or the sentinel.

The condition for breaking the loop is:
if len(ln) > 3 && ln[0] == '0' && ln[1] == 'x', this does not catch 0xc, for example

len(ln) >= 3 && ln[0] == '0' && ln[1] == 'x' is correct for such cases.

Fixes #6290

---

Before sending a pull request, please review Contribution Guidelines:
https://github.com/google/syzkaller/blob/master/docs/contributing.md

---

[google-cla]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

[a-nogikh]

Thanks!

Please note the following CI error:

Error: Wrong commit subject format: 'pkg/symbolizer: Fix parser handling of small hex values'. Please use 'main/affected/package: short change description'. See docs/contributing.md for details. Regex pattern used to check commit subjects is '^(Revert "|(([a-z0-9/_.-]+|Makefile|CONTRIBUTORS|README.md)(, )?)+:\ [^A-Z].+[^.]$)'.

The commit title should be pkg/symbolizer: fix parser handling of small hex values.

I am curious though what are the cases when addr2line would return the 0xc (or anything 0x0-0xf). Is it for modules?

[jodaco]

Thanks!

Please note the following CI error:

Error: Wrong commit subject format: 'pkg/symbolizer: Fix parser handling of small hex values'. Please use 'main/affected/package: short change description'. See docs/contributing.md for details. Regex pattern used to check commit subjects is '^(Revert "|(([a-z0-9/_.-]+|Makefile|CONTRIBUTORS|README.md)(, )?)+:\ [^A-Z].+[^.]$)'.

The commit title should be pkg/symbolizer: fix parser handling of small hex values.

I am curious though what are the cases when addr2line would return the 0xc (or anything 0x0-0xf). Is it for modules?

The modules have these values. I'll fix the formatting when I get a chance. addr2line will just return what it was handed, and the parser was ignoring 0x0-0xf in the main for loop and not breaking out when it was supposed to.