From: Junwei Hu hujunwei4@huawei.com
The ipvs module parse the user buffer and save it to sysctl, then check if the value is valid. invalid value occurs over a period of time. Here, I add a variable, struct ctl_table tmp, used to read the value from the user buffer, and save only when it is valid. I delete proc_do_sync_mode and use extra1/2 in table for the proc_dointvec_minmax call.
Fixes: f73181c8288f ("ipvs: add support for sync threads") Signed-off-by: Junwei Hu hujunwei4@huawei.com Acked-by: Julian Anastasov ja@ssi.bg Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org (cherry picked from commit 1b90af292e71b20d03b837d39406acfbdc5d4b2a) [Julian: Backport by changing SYSCTL_ZERO/SYSCTL_ONE to zero/one] Signed-off-by: Julian Anastasov ja@ssi.bg --- net/netfilter/ipvs/ip_vs_ctl.c | 70 +++++++++++++++++----------------- 1 file changed, 36 insertions(+), 34 deletions(-)
diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c index ecc16d8c1cc3..4e78c2a6a3ca 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -1648,6 +1648,7 @@ static int ip_vs_zero_all(struct netns_ipvs *ipvs) #ifdef CONFIG_SYSCTL
static int zero; +static int one = 1; static int three = 3;
static int @@ -1659,12 +1660,18 @@ proc_do_defense_mode(struct ctl_table *table, int write, int val = *valp; int rc;
- rc = proc_dointvec(table, write, buffer, lenp, ppos); + struct ctl_table tmp = { + .data = &val, + .maxlen = sizeof(int), + .mode = table->mode, + }; + + rc = proc_dointvec(&tmp, write, buffer, lenp, ppos); if (write && (*valp != val)) { - if ((*valp < 0) || (*valp > 3)) { - /* Restore the correct value */ - *valp = val; + if (val < 0 || val > 3) { + rc = -EINVAL; } else { + *valp = val; update_defense_level(ipvs); } } @@ -1678,33 +1685,20 @@ proc_do_sync_threshold(struct ctl_table *table, int write, int *valp = table->data; int val[2]; int rc; + struct ctl_table tmp = { + .data = &val, + .maxlen = table->maxlen, + .mode = table->mode, + };
- /* backup the value first */ memcpy(val, valp, sizeof(val)); - - rc = proc_dointvec(table, write, buffer, lenp, ppos); - if (write && (valp[0] < 0 || valp[1] < 0 || - (valp[0] >= valp[1] && valp[1]))) { - /* Restore the correct value */ - memcpy(valp, val, sizeof(val)); - } - return rc; -} - -static int -proc_do_sync_mode(struct ctl_table *table, int write, - void __user *buffer, size_t *lenp, loff_t *ppos) -{ - int *valp = table->data; - int val = *valp; - int rc; - - rc = proc_dointvec(table, write, buffer, lenp, ppos); - if (write && (*valp != val)) { - if ((*valp < 0) || (*valp > 1)) { - /* Restore the correct value */ - *valp = val; - } + rc = proc_dointvec(&tmp, write, buffer, lenp, ppos); + if (write) { + if (val[0] < 0 || val[1] < 0 || + (val[0] >= val[1] && val[1])) + rc = -EINVAL; + else + memcpy(valp, val, sizeof(val)); } return rc; } @@ -1717,12 +1711,18 @@ proc_do_sync_ports(struct ctl_table *table, int write, int val = *valp; int rc;
- rc = proc_dointvec(table, write, buffer, lenp, ppos); + struct ctl_table tmp = { + .data = &val, + .maxlen = sizeof(int), + .mode = table->mode, + }; + + rc = proc_dointvec(&tmp, write, buffer, lenp, ppos); if (write && (*valp != val)) { - if (*valp < 1 || !is_power_of_2(*valp)) { - /* Restore the correct value */ + if (val < 1 || !is_power_of_2(val)) + rc = -EINVAL; + else *valp = val; - } } return rc; } @@ -1782,7 +1782,9 @@ static struct ctl_table vs_vars[] = { .procname = "sync_version", .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_do_sync_mode, + .proc_handler = proc_dointvec_minmax, + .extra1 = &zero, + .extra2 = &one, }, { .procname = "sync_ports",