bonding: fix NULL pointer dereference in actor_port_prio setting

Liang reported an issue where setting a slave’s actor_port_prio to
predefined values such as 0, 255, or 65535 would cause a system crash.

The problem occurs because in bond_opt_parse(), when the provided value
matches a predefined table entry, the function returns that table entry,
which does not contain slave information. Later, in
bond_option_actor_port_prio_set(), calling bond_slave_get_rtnl() leads
to a NULL pointer dereference.

Since actor_port_prio is defined as a u16 and initialized to the default
value of 255 in ad_initialize_port(), there is no need for the
bond_actor_port_prio_tbl. Using the BOND_OPTFLAG_RAWVAL flag is sufficient.

Fixes: 6b6dc81ee7e8 ("bonding: add support for per-port LACP actor priority")
Reported-by: Liang Li <liali@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://patch.msgid.link/20251105072620.164841-1-liuhangbin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/bonding/bond_options.c b/drivers/net/bonding/bond_options.c
index 495a87f2ea7c8b5f78cea8ccb96933a6cad3e325..384499c869b8da9f036c43eb081095f1bf2141af 100644 (file)
--- a/drivers/net/bonding/bond_options.c
+++ b/drivers/net/bonding/bond_options.c
@@ -225,13 +225,6 @@ static const struct bond_opt_value bond_ad_actor_sys_prio_tbl[] = {
        { NULL,      -1,    0},
 };
 
-static const struct bond_opt_value bond_actor_port_prio_tbl[] = {
-       { "minval",  0,     BOND_VALFLAG_MIN},
-       { "maxval",  65535, BOND_VALFLAG_MAX},
-       { "default", 255,   BOND_VALFLAG_DEFAULT},
-       { NULL,      -1,    0},
-};
-
 static const struct bond_opt_value bond_ad_user_port_key_tbl[] = {
        { "minval",  0,     BOND_VALFLAG_MIN | BOND_VALFLAG_DEFAULT},
        { "maxval",  1023,  BOND_VALFLAG_MAX},
@@ -497,7 +490,7 @@ static const struct bond_option bond_opts[BOND_OPT_LAST] = {
                .id = BOND_OPT_ACTOR_PORT_PRIO,
                .name = "actor_port_prio",
                .unsuppmodes = BOND_MODE_ALL_EX(BIT(BOND_MODE_8023AD)),
-               .values = bond_actor_port_prio_tbl,
+               .flags = BOND_OPTFLAG_RAWVAL,
                .set = bond_option_actor_port_prio_set,
        },
        [BOND_OPT_AD_ACTOR_SYSTEM] = {