D. Wythe wrote:
>
>
>
> On 8/13/24 6:07 PM, Jeongjun Park wrote:
> > Since smc_inet6_prot does not initialize ipv6_pinfo_offset, inet6_create()
> > copies an incorrect address value, sk + 0 (offset), to inet_sk(sk)->pinet6.
> >
> > In addition, since inet_sk(sk)->pinet6 and smc_sk(sk)->clcsock practically
> > point to the same address, when smc_create_clcsk() stores the newly
> > created clcsock in smc_sk(sk)->clcsock, inet_sk(sk)->pinet6 is corrupted
> > into clcsock. This causes NULL pointer dereference and various other
> > memory corruptions.
> >
> > To solve this, we need to add a smc6_sock structure for ipv6_pinfo_offset
> > initialization and modify the smc_sock structure.
> >
> > Reported-by: syzbot+f69bfae0a4eb29976e44@xxxxxxxxxxxxxxxxxxxxxxxxx
> > Tested-by: syzbot+f69bfae0a4eb29976e44@xxxxxxxxxxxxxxxxxxxxxxxxx
> > Fixes: d25a92ccae6b ("net/smc: Introduce IPPROTO_SMC")
> > Signed-off-by: Jeongjun Park <aha310510@xxxxxxxxx>
> > ---
> > net/smc/smc.h | 19 ++++++++++---------
> > net/smc/smc_inet.c | 24 +++++++++++++++---------
> > 2 files changed, 25 insertions(+), 18 deletions(-)
> >
> > diff --git a/net/smc/smc.h b/net/smc/smc.h
> > index 34b781e463c4..f4d9338b5ed5 100644
> > --- a/net/smc/smc.h
> > +++ b/net/smc/smc.h
> > @@ -284,15 +284,6 @@ struct smc_connection {
> >
> > struct smc_sock { /* smc sock container */
> > struct sock sk;
> > - struct socket *clcsock; /* internal tcp socket */
> > - void (*clcsk_state_change)(struct sock *sk);
> > - /* original stat_change fct. */
> > - void (*clcsk_data_ready)(struct sock *sk);
> > - /* original data_ready fct. */
> > - void (*clcsk_write_space)(struct sock *sk);
> > - /* original write_space fct. */
> > - void (*clcsk_error_report)(struct sock *sk);
> > - /* original error_report fct. */
> > struct smc_connection conn; /* smc connection */
> > struct smc_sock *listen_smc; /* listen parent */
> > struct work_struct connect_work; /* handle non-blocking connect*/
> > @@ -325,6 +316,16 @@ struct smc_sock { /* smc sock container */
> > /* protects clcsock of a listen
> > * socket
> > * */
> > + struct socket *clcsock; /* internal tcp socket */
> > + void (*clcsk_state_change)(struct sock *sk);
> > + /* original stat_change fct. */
> > + void (*clcsk_data_ready)(struct sock *sk);
> > + /* original data_ready fct. */
> > + void (*clcsk_write_space)(struct sock *sk);
> > + /* original write_space fct. */
> > + void (*clcsk_error_report)(struct sock *sk);
> > + /* original error_report fct. */
> > +
> > };
> >
> > #define smc_sk(ptr) container_of_const(ptr, struct smc_sock, sk)
> > diff --git a/net/smc/smc_inet.c b/net/smc/smc_inet.c
> > index bece346dd8e9..25f34fd65e8d 100644
> > --- a/net/smc/smc_inet.c
> > +++ b/net/smc/smc_inet.c
> > @@ -60,16 +60,22 @@ static struct inet_protosw smc_inet_protosw = {
> > };
> >
> > #if IS_ENABLED(CONFIG_IPV6)
> > +struct smc6_sock {
> > + struct smc_sock smc;
> > + struct ipv6_pinfo np;
> > +};
>
> I prefer to:
>
> struct ipv6_pinfo inet6;
Okay, I'll write a v4 patch and send it to you tomorrow.
Regards,
Jeongjun Park
>
> > +
> > static struct proto smc_inet6_prot = {
> > - .name = "INET6_SMC",
> > - .owner = THIS_MODULE,
> > - .init = smc_inet_init_sock,
> > - .hash = smc_hash_sk,
> > - .unhash = smc_unhash_sk,
> > - .release_cb = smc_release_cb,
> > - .obj_size = sizeof(struct smc_sock),
> > - .h.smc_hash = &smc_v6_hashinfo,
> > - .slab_flags = SLAB_TYPESAFE_BY_RCU,
> > + .name = "INET6_SMC",
> > + .owner = THIS_MODULE,
> > + .init = smc_inet_init_sock,
> > + .hash = smc_hash_sk,
> > + .unhash = smc_unhash_sk,
> > + .release_cb = smc_release_cb,
> > + .obj_size = sizeof(struct smc6_sock),
> > + .h.smc_hash = &smc_v6_hashinfo,
> > + .slab_flags = SLAB_TYPESAFE_BY_RCU,
> > + .ipv6_pinfo_offset = offsetof(struct smc6_sock, np),
> > };
> >
> > static const struct proto_ops smc_inet6_stream_ops = {
> > --
>
