2023-09-23 02:06:41

by Kees Cook

Subject: [PATCH] ocfs2: Annotate struct ocfs2_replay_map with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct ocfs2_replay_map.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Mark Fasheh <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Joseph Qi <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Cc: Tom Rix <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
---
fs/ocfs2/journal.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
index ce215565d061..604fea3a26ff 100644
--- a/fs/ocfs2/journal.c
+++ b/fs/ocfs2/journal.c
@@ -90,7 +90,7 @@ enum ocfs2_replay_state {
struct ocfs2_replay_map {
unsigned int rm_slots;
enum ocfs2_replay_state rm_state;
- unsigned char rm_replay_slots[];
+ unsigned char rm_replay_slots[] __counted_by(rm_slots);
};

static void ocfs2_replay_map_set_state(struct ocfs2_super *osb, int state)
--
2.34.1

2023-09-23 08:24:40

by Gustavo A. R. Silva

Subject: Re: [PATCH] ocfs2: Annotate struct ocfs2_replay_map with __counted_by

On 9/22/23 11:49, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
>
> As found with Coccinelle[1], add __counted_by for struct ocfs2_replay_map.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Mark Fasheh <[email protected]>
> Cc: Joel Becker <[email protected]>
> Cc: Joseph Qi <[email protected]>
> Cc: Nathan Chancellor <[email protected]>
> Cc: Nick Desaulniers <[email protected]>
> Cc: Tom Rix <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>

Reviewed-by: Gustavo A. R. Silva <[email protected]>

Thanks
--
Gustavo

> ---
> fs/ocfs2/journal.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
> index ce215565d061..604fea3a26ff 100644
> --- a/fs/ocfs2/journal.c
> +++ b/fs/ocfs2/journal.c
> @@ -90,7 +90,7 @@ enum ocfs2_replay_state {
> struct ocfs2_replay_map {
> unsigned int rm_slots;
> enum ocfs2_replay_state rm_state;
> - unsigned char rm_replay_slots[];
> + unsigned char rm_replay_slots[] __counted_by(rm_slots);
> };
>
> static void ocfs2_replay_map_set_state(struct ocfs2_super *osb, int state)

2023-09-25 02:22:40

by Joseph Qi

Subject: Re: [PATCH] ocfs2: Annotate struct ocfs2_replay_map with __counted_by

On 9/23/23 1:49 AM, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
>
> As found with Coccinelle[1], add __counted_by for struct ocfs2_replay_map.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Mark Fasheh <[email protected]>
> Cc: Joel Becker <[email protected]>
> Cc: Joseph Qi <[email protected]>
> Cc: Nathan Chancellor <[email protected]>
> Cc: Nick Desaulniers <[email protected]>
> Cc: Tom Rix <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>

Reviewed-by: Joseph Qi <[email protected]>
> ---
> fs/ocfs2/journal.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
> index ce215565d061..604fea3a26ff 100644
> --- a/fs/ocfs2/journal.c
> +++ b/fs/ocfs2/journal.c
> @@ -90,7 +90,7 @@ enum ocfs2_replay_state {
> struct ocfs2_replay_map {
> unsigned int rm_slots;
> enum ocfs2_replay_state rm_state;
> - unsigned char rm_replay_slots[];
> + unsigned char rm_replay_slots[] __counted_by(rm_slots);
> };
>
> static void ocfs2_replay_map_set_state(struct ocfs2_super *osb, int state)