2023-10-05 16:29:37

by Kees Cook

[permalink] [raw]
Subject: [PATCH v2] nvmet-fc: Annotate struct nvmet_fc_tgt_queue 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 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
nvmet_fc_tgt_queue. Additionally, since the element count member must
be set before accessing the annotated flexible array member, move its
initialization earlier.

Cc: James Smart <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Sagi Grimberg <[email protected]>
Cc: [email protected]
Reviewed-by: Gustavo A. R. Silva <[email protected]>
Reviewed-by: Chaitanya Kulkarni <[email protected]>
Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by: Kees Cook <[email protected]>
---
v1 https://lore.kernel.org/all/[email protected]/
v2
- move comment to line above (hch)
- add reviewed-bys
---
drivers/nvme/target/fc.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/target/fc.c b/drivers/nvme/target/fc.c
index 1ab6601fdd5c..bd59990b5250 100644
--- a/drivers/nvme/target/fc.c
+++ b/drivers/nvme/target/fc.c
@@ -146,7 +146,8 @@ struct nvmet_fc_tgt_queue {
struct workqueue_struct *work_q;
struct kref ref;
struct rcu_head rcu;
- struct nvmet_fc_fcp_iod fod[]; /* array of fcp_iods */
+ /* array of fcp_iods */
+ struct nvmet_fc_fcp_iod fod[] __counted_by(sqsize);
} __aligned(sizeof(unsigned long long));

struct nvmet_fc_hostport {
--
2.34.1