diff options
| author | Oleksij Rempel <o.rempel@pengutronix.de> | 2023-04-04 09:31:28 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-04-20 12:07:34 +0200 |
| commit | d2136f05690c272dfc9f9d6efcc51d5f53494b33 (patch) | |
| tree | a593c7653affc36740fee494ffce49a4d0bf4fe3 | |
| parent | 5a74a75fc3d306061bc7926edc9a261bb152ba8c (diff) | |
can: j1939: j1939_tp_tx_dat_new(): fix out-of-bounds memory access
commit b45193cb4df556fe6251b285a5ce44046dd36b4a upstream.
In the j1939_tp_tx_dat_new() function, an out-of-bounds memory access
could occur during the memcpy() operation if the size of skb->cb is
larger than the size of struct j1939_sk_buff_cb. This is because the
memcpy() operation uses the size of skb->cb, leading to a read beyond
the struct j1939_sk_buff_cb.
Updated the memcpy() operation to use the size of struct
j1939_sk_buff_cb instead of the size of skb->cb. This ensures that the
memcpy() operation only reads the memory within the bounds of struct
j1939_sk_buff_cb, preventing out-of-bounds memory access.
Additionally, add a BUILD_BUG_ON() to check that the size of skb->cb
is greater than or equal to the size of struct j1939_sk_buff_cb. This
ensures that the skb->cb buffer is large enough to hold the
j1939_sk_buff_cb structure.
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Reported-by: Shuangpeng Bai <sjb7183@psu.edu>
Tested-by: Shuangpeng Bai <sjb7183@psu.edu>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://groups.google.com/g/syzkaller/c/G_LL-C3plRs/m/-8xCi6dCAgAJ
Link: https://lore.kernel.org/all/20230404073128.3173900-1-o.rempel@pengutronix.de
Cc: stable@vger.kernel.org
[mkl: rephrase commit message]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/can/j1939/transport.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c index 9c8c7c5dc9c3..42fb83605d4c 100644 --- a/net/can/j1939/transport.c +++ b/net/can/j1939/transport.c @@ -600,7 +600,10 @@ sk_buff *j1939_tp_tx_dat_new(struct j1939_priv *priv, /* reserve CAN header */ skb_reserve(skb, offsetof(struct can_frame, data)); - memcpy(skb->cb, re_skcb, sizeof(skb->cb)); + /* skb->cb must be large enough to hold a j1939_sk_buff_cb structure */ + BUILD_BUG_ON(sizeof(skb->cb) < sizeof(*re_skcb)); + + memcpy(skb->cb, re_skcb, sizeof(*re_skcb)); skcb = j1939_skb_to_cb(skb); if (swap_src_dst) j1939_skbcb_swap(skcb); |