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net: sctp: propagate sysctl errors from proc_do* properly 

sysctl handler proc_sctp_do_hmac_alg(), proc_sctp_do_rto_min() and
proc_sctp_do_rto_max() do not properly reflect some error cases
when writing values via sysctl from internal proc functions such
as proc_dointvec() and proc_dostring().

In all these cases we pass the test for write != 0 and partially
do additional work just to notice that additional sanity checks
fail and we return with hard-coded -EINVAL while proc_do*
functions might also return different errors. So fix this up by
simply testing a successful return of proc_do* right after
calling it.

This also allows to propagate its return value onwards to the user.
While touching this, also fix up some minor style issues.

Fixes: 4f3fdf3bc5 ("sctp: add check rto_min and rto_max in sysctl")
Fixes: 3c68198e75 ("sctp: Make hmac algorithm selection for cookie generation dynamic")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
hifive-unleashed-5.1
Daniel Borkmann 2014-06-19 01:31:30 +02:00 committed by David S. Miller
parent d36a4f4b47
commit ff5e92c1af
1 changed files with 23 additions and 20 deletions
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43
net/sctp/sysctl.c
View File

@ -321,41 +321,40 @@ static int proc_sctp_do_hmac_alg(struct ctl_table *ctl, int write,
loff_t *ppos)
{
struct net *net = current->nsproxy->net_ns;
char tmp[8];
struct ctl_table tbl;
int ret;
int changed = 0;
bool changed = false;
char *none = "none";
char tmp[8];
int ret;
memset(&tbl, 0, sizeof(struct ctl_table));
if (write) {
tbl.data = tmp;
tbl.maxlen = 8;
tbl.maxlen = sizeof(tmp);
} else {
tbl.data = net->sctp.sctp_hmac_alg ? : none;
tbl.maxlen = strlen(tbl.data);
}
ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
if (write) {
ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
if (write && ret == 0) {
#ifdef CONFIG_CRYPTO_MD5
if (!strncmp(tmp, "md5", 3)) {
net->sctp.sctp_hmac_alg = "md5";
changed = 1;
changed = true;
}
#endif
#ifdef CONFIG_CRYPTO_SHA1
if (!strncmp(tmp, "sha1", 4)) {
net->sctp.sctp_hmac_alg = "sha1";
changed = 1;
changed = true;
}
#endif
if (!strncmp(tmp, "none", 4)) {
net->sctp.sctp_hmac_alg = NULL;
changed = 1;
changed = true;
}
if (!changed)
ret = -EINVAL;
}
@ -368,11 +367,10 @@ static int proc_sctp_do_rto_min(struct ctl_table *ctl, int write,
loff_t *ppos)
{
struct net *net = current->nsproxy->net_ns;
int new_value;
struct ctl_table tbl;
unsigned int min = *(unsigned int *) ctl->extra1;
unsigned int max = *(unsigned int *) ctl->extra2;
int ret;
struct ctl_table tbl;
int ret, new_value;
memset(&tbl, 0, sizeof(struct ctl_table));
tbl.maxlen = sizeof(unsigned int);
@ -381,12 +379,15 @@ static int proc_sctp_do_rto_min(struct ctl_table *ctl, int write,
tbl.data = &new_value;
else
tbl.data = &net->sctp.rto_min;
ret = proc_dointvec(&tbl, write, buffer, lenp, ppos);
if (write) {
if (ret || new_value > max || new_value < min)
if (write && ret == 0) {
if (new_value > max || new_value < min)
return -EINVAL;
net->sctp.rto_min = new_value;
}
return ret;
}
@ -395,11 +396,10 @@ static int proc_sctp_do_rto_max(struct ctl_table *ctl, int write,
loff_t *ppos)
{
struct net *net = current->nsproxy->net_ns;
int new_value;
struct ctl_table tbl;
unsigned int min = *(unsigned int *) ctl->extra1;
unsigned int max = *(unsigned int *) ctl->extra2;
int ret;
struct ctl_table tbl;
int ret, new_value;
memset(&tbl, 0, sizeof(struct ctl_table));
tbl.maxlen = sizeof(unsigned int);
@ -408,12 +408,15 @@ static int proc_sctp_do_rto_max(struct ctl_table *ctl, int write,
tbl.data = &new_value;
else
tbl.data = &net->sctp.rto_max;
ret = proc_dointvec(&tbl, write, buffer, lenp, ppos);
if (write) {
if (ret || new_value > max || new_value < min)
if (write && ret == 0) {
if (new_value > max || new_value < min)
return -EINVAL;
net->sctp.rto_max = new_value;
}
return ret;
}