diff options
| author | Gustavo A. R. Silva <gustavoars@kernel.org> | 2023-10-10 06:46:50 -0600 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2023-12-02 12:32:07 -0800 |
| commit | ac7110d883ff2a25d2b0ae45c909c02d598c33af (patch) | |
| tree | 130f695fadb699befe84d94ba93e83e688a087cd /arch/arm/kernel | |
| parent | 8a3750ecf8104de55c569ffbe844a85aa9d5deaa (diff) | |
atags_proc: Add __counted_by for struct buffer and use struct_size()
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).
While there, use struct_size() helper, instead of the open-coded
version, to calculate the size for the allocation of the whole
flexible structure, including of course, the flexible-array member.
This code was found with the help of Coccinelle, and audited and
fixed manually.
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/ZSVHurzo/4aFQcT3@work
Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'arch/arm/kernel')
| -rw-r--r-- | arch/arm/kernel/atags_proc.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm/kernel/atags_proc.c b/arch/arm/kernel/atags_proc.c index 3ec2afe78423..cd09f8ab93e3 100644 --- a/arch/arm/kernel/atags_proc.c +++ b/arch/arm/kernel/atags_proc.c @@ -7,7 +7,7 @@ struct buffer { size_t size; - char data[]; + char data[] __counted_by(size); }; static ssize_t atags_read(struct file *file, char __user *buf, @@ -54,7 +54,7 @@ static int __init init_atags_procfs(void) WARN_ON(tag->hdr.tag != ATAG_NONE); - b = kmalloc(sizeof(*b) + size, GFP_KERNEL); + b = kmalloc(struct_size(b, data, size), GFP_KERNEL); if (!b) goto nomem; |