diff options
| author | Erick Archer <erick.archer@outlook.com> | 2024-04-27 19:23:36 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-07-18 11:39:32 +0200 |
| commit | 03f37e56305156bd25c5c237d1cc7f5c75495ef2 (patch) | |
| tree | 30f61979f7add7f5a1bbf4b12541ea0b17dc7b21 | |
| parent | 74eb7ec7afe976a499484f56e8af020c3260a559 (diff) | |
sctp: prefer struct_size over open coded arithmetic
[ Upstream commit e5c5f3596de224422561d48eba6ece5210d967b3 ]
This is an effort to get rid of all multiplications from allocation
functions in order to prevent integer overflows [1][2].
As the "ids" variable is a pointer to "struct sctp_assoc_ids" and this
structure ends in a flexible array:
struct sctp_assoc_ids {
[...]
sctp_assoc_t gaids_assoc_id[];
};
the preferred way in the kernel is to use the struct_size() helper to
do the arithmetic instead of the calculation "size + size * count" in
the kmalloc() function.
Also, refactor the code adding the "ids_size" variable to avoid sizing
twice.
This way, the code is more readable and safer.
This code was detected with the help of Coccinelle, and audited and
modified manually.
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
Link: https://github.com/KSPP/linux/issues/160 [2]
Signed-off-by: Erick Archer <erick.archer@outlook.com>
Acked-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/PAXPR02MB724871DB78375AB06B5171C88B152@PAXPR02MB7248.eurprd02.prod.outlook.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | net/sctp/socket.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/net/sctp/socket.c b/net/sctp/socket.c index f954d3c8876d..c429a1a2bfe2 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -6801,6 +6801,7 @@ static int sctp_getsockopt_assoc_ids(struct sock *sk, int len, struct sctp_sock *sp = sctp_sk(sk); struct sctp_association *asoc; struct sctp_assoc_ids *ids; + size_t ids_size; u32 num = 0; if (sctp_style(sk, TCP)) @@ -6813,11 +6814,11 @@ static int sctp_getsockopt_assoc_ids(struct sock *sk, int len, num++; } - if (len < sizeof(struct sctp_assoc_ids) + sizeof(sctp_assoc_t) * num) + ids_size = struct_size(ids, gaids_assoc_id, num); + if (len < ids_size) return -EINVAL; - len = sizeof(struct sctp_assoc_ids) + sizeof(sctp_assoc_t) * num; - + len = ids_size; ids = kmalloc(len, GFP_USER | __GFP_NOWARN); if (unlikely(!ids)) return -ENOMEM; |