diff options
| author | Len Baker <len.baker@gmx.com> | 2021-09-19 11:45:39 +0200 |
|---|---|---|
| committer | Gustavo A. R. Silva <gustavoars@kernel.org> | 2021-10-20 18:24:31 -0500 |
| commit | 6446c4fb12ecc130ed9b4333372426b305a35e2b (patch) | |
| tree | 9c41c2baaf0b7980a74c8cdd09e1a5507701eddb /fs/aio.c | |
| parent | 98b160c828f312955daa94713a5fca595400b8c3 (diff) | |
| download | lwn-6446c4fb12ecc130ed9b4333372426b305a35e2b.tar.gz lwn-6446c4fb12ecc130ed9b4333372426b305a35e2b.zip | |
aio: Prefer struct_size over open coded arithmetic
As noted in the "Deprecated Interfaces, Language Features, Attributes,
and Conventions" documentation [1], size calculations (especially
multiplication) should not be performed in memory allocator (or similar)
function arguments due to the risk of them overflowing. This could lead
to values wrapping around and a smaller allocation being made than the
caller was expecting. Using those allocations could lead to linear
overflows of heap memory and other misbehaviors.
So, use the struct_size() helper to do the arithmetic instead of the
argument "size + size * count" in the kzalloc() function.
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
Signed-off-by: Len Baker <len.baker@gmx.com>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Diffstat (limited to 'fs/aio.c')
| -rw-r--r-- | fs/aio.c | 3 |
1 files changed, 1 insertions, 2 deletions
@@ -659,8 +659,7 @@ static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm) new_nr = (table ? table->nr : 1) * 4; spin_unlock(&mm->ioctx_lock); - table = kzalloc(sizeof(*table) + sizeof(struct kioctx *) * - new_nr, GFP_KERNEL); + table = kzalloc(struct_size(table, table, new_nr), GFP_KERNEL); if (!table) return -ENOMEM; |