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| author | Len Baker <len.baker@gmx.com> | 2021-09-19 11:44:32 +0200 |
|---|---|---|
| committer | Gustavo A. R. Silva <gustavoars@kernel.org> | 2022-04-26 17:20:00 +0200 |
| commit | cc68c613d6eeac921e6ef5987db5c764858fab1c (patch) | |
| tree | a21bdd5f405a235efc394b83787df9d8b3afddcf /fs | |
| parent | Linux 5.18-rc2 (diff) | |
| download | linux-cc68c613d6eeac921e6ef5987db5c764858fab1c.tar.xz linux-cc68c613d6eeac921e6ef5987db5c764858fab1c.zip | |
afs: 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>
Acked-by: David Howells <dhowells@redhat.com>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/afs/security.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/fs/afs/security.c b/fs/afs/security.c index 3c7a8fc4f93f..7c6a63a30394 100644 --- a/fs/afs/security.c +++ b/fs/afs/security.c @@ -219,8 +219,7 @@ void afs_cache_permit(struct afs_vnode *vnode, struct key *key, * yet. */ size++; - new = kzalloc(sizeof(struct afs_permits) + - sizeof(struct afs_permit) * size, GFP_NOFS); + new = kzalloc(struct_size(new, permits, size), GFP_NOFS); if (!new) goto out_put; |