* [PATCH] apparmor: fix error check
@ 2020-10-04 14:24 trix
2020-12-21 19:22 ` Nick Desaulniers
2021-02-07 11:27 ` John Johansen
0 siblings, 2 replies; 3+ messages in thread
From: trix @ 2020-10-04 14:24 UTC (permalink / raw)
To: john.johansen, jmorris, serge, natechancellor, ndesaulniers
Cc: linux-security-module, linux-kernel, clang-built-linux, Tom Rix
From: Tom Rix <trix@redhat.com>
clang static analysis reports this representative problem:
label.c:1463:16: warning: Assigned value is garbage or undefined
label->hname = name;
^ ~~~~
In aa_update_label_name(), this the problem block of code
if (aa_label_acntsxprint(&name, ...) == -1)
return res;
On failure, aa_label_acntsxprint() has a more complicated return
that just -1. So check for a negative return.
It was also noted that the aa_label_acntsxprint() main comment refers
to a nonexistent parameter, so clean up the comment.
Fixes: f1bd904175e8 ("apparmor: add the base fns() for domain labels")
Signed-off-by: Tom Rix <trix@redhat.com>
---
security/apparmor/label.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/security/apparmor/label.c b/security/apparmor/label.c
index e68bcedca976..6222fdfebe4e 100644
--- a/security/apparmor/label.c
+++ b/security/apparmor/label.c
@@ -1454,7 +1454,7 @@ bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp)
if (label->hname || labels_ns(label) != ns)
return res;
- if (aa_label_acntsxprint(&name, ns, label, FLAGS_NONE, gfp) == -1)
+ if (aa_label_acntsxprint(&name, ns, label, FLAGS_NONE, gfp) < 0)
return res;
ls = labels_set(label);
@@ -1704,7 +1704,7 @@ int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label,
/**
* aa_label_acntsxprint - allocate a __counted string buffer and print label
- * @strp: buffer to write to. (MAY BE NULL if @size == 0)
+ * @strp: buffer to write to.
* @ns: namespace profile is being viewed from
* @label: label to view (NOT NULL)
* @flags: flags controlling what label info is printed
--
2.18.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] apparmor: fix error check
2020-10-04 14:24 [PATCH] apparmor: fix error check trix
@ 2020-12-21 19:22 ` Nick Desaulniers
2021-02-07 11:27 ` John Johansen
1 sibling, 0 replies; 3+ messages in thread
From: Nick Desaulniers @ 2020-12-21 19:22 UTC (permalink / raw)
To: Tom Rix
Cc: john.johansen, James Morris, Serge E. Hallyn, Nathan Chancellor,
linux-security-module, LKML, clang-built-linux
On Sun, Oct 4, 2020 at 7:24 AM <trix@redhat.com> wrote:
>
> From: Tom Rix <trix@redhat.com>
>
> clang static analysis reports this representative problem:
>
> label.c:1463:16: warning: Assigned value is garbage or undefined
> label->hname = name;
> ^ ~~~~
Right, so if aa_label_acntsxprint() fails, it won't assign to its
first param. In the caller, this means assigning uninitialized memory
(UB) when aa_label_acntsxprint() returns -ENOMEM for example. Thanks
for the patch.
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
>
> In aa_update_label_name(), this the problem block of code
>
> if (aa_label_acntsxprint(&name, ...) == -1)
> return res;
>
> On failure, aa_label_acntsxprint() has a more complicated return
> that just -1. So check for a negative return.
>
> It was also noted that the aa_label_acntsxprint() main comment refers
> to a nonexistent parameter, so clean up the comment.
>
> Fixes: f1bd904175e8 ("apparmor: add the base fns() for domain labels")
> Signed-off-by: Tom Rix <trix@redhat.com>
> ---
> security/apparmor/label.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/security/apparmor/label.c b/security/apparmor/label.c
> index e68bcedca976..6222fdfebe4e 100644
> --- a/security/apparmor/label.c
> +++ b/security/apparmor/label.c
> @@ -1454,7 +1454,7 @@ bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp)
> if (label->hname || labels_ns(label) != ns)
> return res;
>
> - if (aa_label_acntsxprint(&name, ns, label, FLAGS_NONE, gfp) == -1)
> + if (aa_label_acntsxprint(&name, ns, label, FLAGS_NONE, gfp) < 0)
> return res;
>
> ls = labels_set(label);
> @@ -1704,7 +1704,7 @@ int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label,
>
> /**
> * aa_label_acntsxprint - allocate a __counted string buffer and print label
> - * @strp: buffer to write to. (MAY BE NULL if @size == 0)
> + * @strp: buffer to write to.
> * @ns: namespace profile is being viewed from
> * @label: label to view (NOT NULL)
> * @flags: flags controlling what label info is printed
> --
> 2.18.1
>
> --
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--
Thanks,
~Nick Desaulniers
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] apparmor: fix error check
2020-10-04 14:24 [PATCH] apparmor: fix error check trix
2020-12-21 19:22 ` Nick Desaulniers
@ 2021-02-07 11:27 ` John Johansen
1 sibling, 0 replies; 3+ messages in thread
From: John Johansen @ 2021-02-07 11:27 UTC (permalink / raw)
To: trix, jmorris, serge, natechancellor, ndesaulniers
Cc: linux-security-module, linux-kernel, clang-built-linux
On 10/4/20 7:24 AM, trix@redhat.com wrote:
> From: Tom Rix <trix@redhat.com>
>
> clang static analysis reports this representative problem:
>
> label.c:1463:16: warning: Assigned value is garbage or undefined
> label->hname = name;
> ^ ~~~~
>
> In aa_update_label_name(), this the problem block of code
>
> if (aa_label_acntsxprint(&name, ...) == -1)
> return res;
>
> On failure, aa_label_acntsxprint() has a more complicated return
> that just -1. So check for a negative return.
>
> It was also noted that the aa_label_acntsxprint() main comment refers
> to a nonexistent parameter, so clean up the comment.
>
> Fixes: f1bd904175e8 ("apparmor: add the base fns() for domain labels")
> Signed-off-by: Tom Rix <trix@redhat.com>
> ---
> security/apparmor/label.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/security/apparmor/label.c b/security/apparmor/label.c
> index e68bcedca976..6222fdfebe4e 100644
> --- a/security/apparmor/label.c
> +++ b/security/apparmor/label.c
> @@ -1454,7 +1454,7 @@ bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp)
> if (label->hname || labels_ns(label) != ns)
> return res;
>
> - if (aa_label_acntsxprint(&name, ns, label, FLAGS_NONE, gfp) == -1)
> + if (aa_label_acntsxprint(&name, ns, label, FLAGS_NONE, gfp) < 0)
> return res;
>
> ls = labels_set(label);
> @@ -1704,7 +1704,7 @@ int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label,
>
> /**
> * aa_label_acntsxprint - allocate a __counted string buffer and print label
> - * @strp: buffer to write to. (MAY BE NULL if @size == 0)
> + * @strp: buffer to write to.
> * @ns: namespace profile is being viewed from
> * @label: label to view (NOT NULL)
> * @flags: flags controlling what label info is printed
>
sorry it seems I missed replying to this. This patch has been pulled into apparmor-next
^ permalink raw reply [flat|nested] 3+ messages in thread
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2020-10-04 14:24 [PATCH] apparmor: fix error check trix
2020-12-21 19:22 ` Nick Desaulniers
2021-02-07 11:27 ` John Johansen
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