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| author | Kees Cook <keescook@chromium.org> | 2023-08-17 16:59:56 -0700 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2023-08-25 16:07:30 -0700 |
| commit | 5f536ac6a5a7b67351e4e5ae4f9e1e57d31268e6 (patch) | |
| tree | ed211e9dde27ef90f078f58cbd6d717dc2a5d0b9 | |
| parent | 76903a9648744c081547c91f31ec3917204b74e5 (diff) | |
| download | lwn-5f536ac6a5a7b67351e4e5ae4f9e1e57d31268e6.tar.gz lwn-5f536ac6a5a7b67351e4e5ae4f9e1e57d31268e6.zip | |
LoadPin: Annotate struct dm_verity_loadpin_trusted_root_digest 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 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
Link: https://lore.kernel.org/r/20230817235955.never.762-kees@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
| -rw-r--r-- | include/linux/dm-verity-loadpin.h | 2 | ||||
| -rw-r--r-- | security/loadpin/loadpin.c | 3 |
2 files changed, 2 insertions, 3 deletions
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); } |