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[PATCH v1] perf parse-events: Avoid erange from hex numbers

Ian Rogers posted 1 patch 2 years, 3 months ago 
tools/perf/util/parse-events.l | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
[PATCH v1] perf parse-events: Avoid erange from hex numbers
Posted by Ian Rogers 2 years, 3 months ago 
We specify that a "num_hex" comprises 1 or more digits, however, that
allows strtoull to fail with ERANGE. Limit the number of hex digits to
being between 1 and 16.

Before:
```
$ perf stat -e 'cpu/rE7574c47490475745/' true
perf: util/parse-events.c:215: fix_raw: Assertion `errno == 0' failed.
Aborted (core dumped)
```

After:
```
$ perf stat -e 'cpu/rE7574c47490475745/' true
event syntax error: 'cpu/rE7574c47490475745/'
                         \___ Bad event or PMU

Unable to find PMU or event on a PMU of 'cpu'

Initial error:
event syntax error: 'cpu/rE7574c47490475745/'
                         \___ unknown term 'rE7574c47490475745' for pmu 'cpu'

valid terms: event,pc,edge,offcore_rsp,ldlat,inv,umask,frontend,cmask,config,config1,config2,config3,name,period,percore,metric-id
Run 'perf list' for a list of valid events

 Usage: perf stat [<options>] [<command>]

    -e, --event <event>   event selector. use 'perf list' to list available events
```

Issue found through fuzz testing.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/parse-events.l | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
index 4ef4b6f171a0..f7df52b22c39 100644
--- a/tools/perf/util/parse-events.l
+++ b/tools/perf/util/parse-events.l
@@ -156,8 +156,8 @@ event_pmu	[^,{}/]+[/][^/]*[/][^,{}/]*
 event		[^,{}/]+
 
 num_dec		[0-9]+
-num_hex		0x[a-fA-F0-9]+
-num_raw_hex	[a-fA-F0-9]+
+num_hex		0x[a-fA-F0-9]{1,16}
+num_raw_hex	[a-fA-F0-9]{1,16}
 name		[a-zA-Z_*?\[\]][a-zA-Z0-9_*?.\[\]!\-]*
 name_tag	[\'][a-zA-Z_*?\[\]][a-zA-Z0-9_*?\-,\.\[\]:=]*[\']
 name_minus	[a-zA-Z_*?][a-zA-Z0-9\-_*?.:]*
-- 
2.42.0.283.g2d96d420d3-goog
Re: [PATCH v1] perf parse-events: Avoid erange from hex numbers
Posted by Ian Rogers 2 years, 2 months ago 
On Thu, Sep 7, 2023 at 2:05 PM Ian Rogers <irogers@google.com> wrote:
>
> We specify that a "num_hex" comprises 1 or more digits, however, that
> allows strtoull to fail with ERANGE. Limit the number of hex digits to
> being between 1 and 16.
>
> Before:
> ```
> $ perf stat -e 'cpu/rE7574c47490475745/' true
> perf: util/parse-events.c:215: fix_raw: Assertion `errno == 0' failed.
> Aborted (core dumped)
> ```
>
> After:
> ```
> $ perf stat -e 'cpu/rE7574c47490475745/' true
> event syntax error: 'cpu/rE7574c47490475745/'
>                          \___ Bad event or PMU
>
> Unable to find PMU or event on a PMU of 'cpu'
>
> Initial error:
> event syntax error: 'cpu/rE7574c47490475745/'
>                          \___ unknown term 'rE7574c47490475745' for pmu 'cpu'
>
> valid terms: event,pc,edge,offcore_rsp,ldlat,inv,umask,frontend,cmask,config,config1,config2,config3,name,period,percore,metric-id
> Run 'perf list' for a list of valid events
>
>  Usage: perf stat [<options>] [<command>]
>
>     -e, --event <event>   event selector. use 'perf list' to list available events
> ```
>
> Issue found through fuzz testing.
>
> Signed-off-by: Ian Rogers <irogers@google.com>

Hi, would be nice to land this.

Thanks!
Ian

> ---
>  tools/perf/util/parse-events.l | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
> index 4ef4b6f171a0..f7df52b22c39 100644
> --- a/tools/perf/util/parse-events.l
> +++ b/tools/perf/util/parse-events.l
> @@ -156,8 +156,8 @@ event_pmu   [^,{}/]+[/][^/]*[/][^,{}/]*
>  event          [^,{}/]+
>
>  num_dec                [0-9]+
> -num_hex                0x[a-fA-F0-9]+
> -num_raw_hex    [a-fA-F0-9]+
> +num_hex                0x[a-fA-F0-9]{1,16}
> +num_raw_hex    [a-fA-F0-9]{1,16}
>  name           [a-zA-Z_*?\[\]][a-zA-Z0-9_*?.\[\]!\-]*
>  name_tag       [\'][a-zA-Z_*?\[\]][a-zA-Z0-9_*?\-,\.\[\]:=]*[\']
>  name_minus     [a-zA-Z_*?][a-zA-Z0-9\-_*?.:]*
> --
> 2.42.0.283.g2d96d420d3-goog
>
Re: [PATCH v1] perf parse-events: Avoid erange from hex numbers
Posted by Namhyung Kim 2 years, 2 months ago 
Hi Ian,

On Fri, Oct 6, 2023 at 8:30 AM Ian Rogers <irogers@google.com> wrote:
>
> On Thu, Sep 7, 2023 at 2:05 PM Ian Rogers <irogers@google.com> wrote:
> >
> > We specify that a "num_hex" comprises 1 or more digits, however, that
> > allows strtoull to fail with ERANGE. Limit the number of hex digits to
> > being between 1 and 16.
> >
> > Before:
> > ```
> > $ perf stat -e 'cpu/rE7574c47490475745/' true
> > perf: util/parse-events.c:215: fix_raw: Assertion `errno == 0' failed.
> > Aborted (core dumped)
> > ```
> >
> > After:
> > ```
> > $ perf stat -e 'cpu/rE7574c47490475745/' true
> > event syntax error: 'cpu/rE7574c47490475745/'
> >                          \___ Bad event or PMU
> >
> > Unable to find PMU or event on a PMU of 'cpu'
> >
> > Initial error:
> > event syntax error: 'cpu/rE7574c47490475745/'
> >                          \___ unknown term 'rE7574c47490475745' for pmu 'cpu'
> >
> > valid terms: event,pc,edge,offcore_rsp,ldlat,inv,umask,frontend,cmask,config,config1,config2,config3,name,period,percore,metric-id
> > Run 'perf list' for a list of valid events
> >
> >  Usage: perf stat [<options>] [<command>]
> >
> >     -e, --event <event>   event selector. use 'perf list' to list available events
> > ```
> >
> > Issue found through fuzz testing.
> >
> > Signed-off-by: Ian Rogers <irogers@google.com>

Acked-by: Namhyung Kim <namhyung@kernel.org>

Thanks,
Namhyung
Re: [PATCH v1] perf parse-events: Avoid erange from hex numbers
Posted by Namhyung Kim 2 years, 2 months ago 
On Fri, Oct 6, 2023 at 12:05 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> Hi Ian,
>
> On Fri, Oct 6, 2023 at 8:30 AM Ian Rogers <irogers@google.com> wrote:
> >
> > On Thu, Sep 7, 2023 at 2:05 PM Ian Rogers <irogers@google.com> wrote:
> > >
> > > We specify that a "num_hex" comprises 1 or more digits, however, that
> > > allows strtoull to fail with ERANGE. Limit the number of hex digits to
> > > being between 1 and 16.
> > >
> > > Before:
> > > ```
> > > $ perf stat -e 'cpu/rE7574c47490475745/' true
> > > perf: util/parse-events.c:215: fix_raw: Assertion `errno == 0' failed.
> > > Aborted (core dumped)
> > > ```
> > >
> > > After:
> > > ```
> > > $ perf stat -e 'cpu/rE7574c47490475745/' true
> > > event syntax error: 'cpu/rE7574c47490475745/'
> > >                          \___ Bad event or PMU
> > >
> > > Unable to find PMU or event on a PMU of 'cpu'
> > >
> > > Initial error:
> > > event syntax error: 'cpu/rE7574c47490475745/'
> > >                          \___ unknown term 'rE7574c47490475745' for pmu 'cpu'
> > >
> > > valid terms: event,pc,edge,offcore_rsp,ldlat,inv,umask,frontend,cmask,config,config1,config2,config3,name,period,percore,metric-id
> > > Run 'perf list' for a list of valid events
> > >
> > >  Usage: perf stat [<options>] [<command>]
> > >
> > >     -e, --event <event>   event selector. use 'perf list' to list available events
> > > ```
> > >
> > > Issue found through fuzz testing.
> > >
> > > Signed-off-by: Ian Rogers <irogers@google.com>
>
> Acked-by: Namhyung Kim <namhyung@kernel.org>

Applied to perf-tools-next, thanks!

Patchew 2.1-devel-b67e4c2

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