On 28/08/24 15:42, Thorsten Blum wrote:
Add the __counted_by compiler attribute to the flexible array member
volumes to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
CONFIG_FORTIFY_SOURCE.
Use struct_size() instead of manually calculating the number of bytes to
allocate for a pnfs_block_deviceaddr with a single volume.
Signed-off-by: Thorsten Blum <thorsten.blum@xxxxxxxxxx>
Looks good --`nr_volumes` is updated just before accessing `volumes[]`.
Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
Thanks
--
Gustavo
---
fs/nfsd/blocklayout.c | 6 ++----
fs/nfsd/blocklayoutxdr.h | 2 +-
2 files changed, 3 insertions(+), 5 deletions(-)
diff --git a/fs/nfsd/blocklayout.c b/fs/nfsd/blocklayout.c
index 3c040c81c77d..08a20e5bcf7f 100644
--- a/fs/nfsd/blocklayout.c
+++ b/fs/nfsd/blocklayout.c
@@ -147,8 +147,7 @@ nfsd4_block_get_device_info_simple(struct super_block *sb,
struct pnfs_block_deviceaddr *dev;
struct pnfs_block_volume *b;
- dev = kzalloc(sizeof(struct pnfs_block_deviceaddr) +
- sizeof(struct pnfs_block_volume), GFP_KERNEL);
+ dev = kzalloc(struct_size(dev, volumes, 1), GFP_KERNEL);
if (!dev)
return -ENOMEM;
gdp->gd_device = dev;
@@ -255,8 +254,7 @@ nfsd4_block_get_device_info_scsi(struct super_block *sb,
const struct pr_ops *ops;
int ret;
- dev = kzalloc(sizeof(struct pnfs_block_deviceaddr) +
- sizeof(struct pnfs_block_volume), GFP_KERNEL);
+ dev = kzalloc(struct_size(dev, volumes, 1), GFP_KERNEL);
if (!dev)
return -ENOMEM;
gdp->gd_device = dev;
diff --git a/fs/nfsd/blocklayoutxdr.h b/fs/nfsd/blocklayoutxdr.h
index b0361e8aa9a7..4e28ac8f1127 100644
--- a/fs/nfsd/blocklayoutxdr.h
+++ b/fs/nfsd/blocklayoutxdr.h
@@ -47,7 +47,7 @@ struct pnfs_block_volume {
struct pnfs_block_deviceaddr {
u32 nr_volumes;
- struct pnfs_block_volume volumes[];
+ struct pnfs_block_volume volumes[] __counted_by(nr_volumes);
};
__be32 nfsd4_block_encode_getdeviceinfo(struct xdr_stream *xdr,
