| Message ID | ZRrsYkKIQe8K6F/t@work (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [next] udf: Fix undefined behavior bug in struct udf_fileident_iter | expand |
On Mon, Oct 02, 2023 at 06:14:26PM +0200, Gustavo A. R. Silva wrote: > `struct fileIdentDesc` is a flexible structure, which means that it > contains a flexible-array member at the bottom. This could potentially > lead to an overwrite of the objects following `fi` in `struct > udf_fileident_iter` at run-time. > > Fix this by placing the declaration of object `fi` at the end of > `struct udf_fileident_iter`. > > -Wflex-array-member-not-at-end is coming in GCC-14, and we are getting > ready to enable it globally. > > Fixes: d16076d9b684 ("udf: New directory iteration code") > Cc: stable@vger.kernel.org > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Looks right. Reviewed-by: Kees Cook <keescook@chromium.org>
On Mon 02-10-23 18:14:26, Gustavo A. R. Silva wrote: > `struct fileIdentDesc` is a flexible structure, which means that it > contains a flexible-array member at the bottom. This could potentially > lead to an overwrite of the objects following `fi` in `struct > udf_fileident_iter` at run-time. > > Fix this by placing the declaration of object `fi` at the end of > `struct udf_fileident_iter`. > > -Wflex-array-member-not-at-end is coming in GCC-14, and we are getting > ready to enable it globally. > > Fixes: d16076d9b684 ("udf: New directory iteration code") > Cc: stable@vger.kernel.org > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Thanks for the patch! This is in fact harmless since we never use the impUse field. But I agree it is confusing so I'll merge attached fix instead. Honza
diff --git a/fs/udf/udfdecl.h b/fs/udf/udfdecl.h index 88692512a466..736f591abc89 100644 --- a/fs/udf/udfdecl.h +++ b/fs/udf/udfdecl.h @@ -93,11 +93,11 @@ struct udf_fileident_iter { sector_t loffset; /* Block offset of 'pos' within above * extent */ struct extent_position epos; /* Position after the above extent */ - struct fileIdentDesc fi; /* Copied directory entry */ uint8_t *name; /* Pointer to entry name */ uint8_t *namebuf; /* Storage for entry name in case * the name is split between two blocks */ + struct fileIdentDesc fi; /* Copied directory entry */ }; struct udf_vds_record {
`struct fileIdentDesc` is a flexible structure, which means that it contains a flexible-array member at the bottom. This could potentially lead to an overwrite of the objects following `fi` in `struct udf_fileident_iter` at run-time. Fix this by placing the declaration of object `fi` at the end of `struct udf_fileident_iter`. -Wflex-array-member-not-at-end is coming in GCC-14, and we are getting ready to enable it globally. Fixes: d16076d9b684 ("udf: New directory iteration code") Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> --- fs/udf/udfdecl.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)