| Message ID | 20230817235955.never.762-kees@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | LoadPin: Annotate struct dm_verity_loadpin_trusted_root_digest with __counted_by | expand |
On Thu, 17 Aug 2023 16:59:56 -0700, 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 dm_verity_loadpin_trusted_root_digest. > Additionally, since the element count member must be set before accessing > the annotated flexible array member, move its initialization earlier. > > [...] Applied to for-next/hardening, thanks! [1/1] LoadPin: Annotate struct dm_verity_loadpin_trusted_root_digest with __counted_by https://git.kernel.org/kees/c/5f536ac6a5a7 Take care,
diff --git a/include/linux/dm-verity-loadpin.h b/include/linux/dm-verity-loadpin.h index 552b817ab102..3ac6dbaeaa37 100644 --- a/include/linux/dm-verity-loadpin.h +++ b/include/linux/dm-verity-loadpin.h @@ -12,7 +12,7 @@ extern struct list_head dm_verity_loadpin_trusted_root_digests; struct dm_verity_loadpin_trusted_root_digest { struct list_head node; unsigned int len; - u8 data[]; + u8 data[] __counted_by(len); }; #if IS_ENABLED(CONFIG_SECURITY_LOADPIN_VERITY) diff --git a/security/loadpin/loadpin.c b/security/loadpin/loadpin.c index ebae964f7cc9..a9d40456a064 100644 --- a/security/loadpin/loadpin.c +++ b/security/loadpin/loadpin.c @@ -336,6 +336,7 @@ static int read_trusted_verity_root_digests(unsigned int fd) rc = -ENOMEM; goto err; } + trd->len = len; if (hex2bin(trd->data, d, len)) { kfree(trd); @@ -343,8 +344,6 @@ static int read_trusted_verity_root_digests(unsigned int fd) goto err; } - trd->len = len; - list_add_tail(&trd->node, &dm_verity_loadpin_trusted_root_digests); }
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 dm_verity_loadpin_trusted_root_digest. Additionally, since the element count member must be set before accessing the annotated flexible array member, move its initialization earlier. [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: dm-devel@redhat.com Cc: Paul Moore <paul@paul-moore.com> Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: linux-security-module@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> --- include/linux/dm-verity-loadpin.h | 2 +- security/loadpin/loadpin.c | 3 +-- 2 files changed, 2 insertions(+), 3 deletions(-)