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author | Daniel Borkmann <dborkman@redhat.com> | 2014-06-19 01:31:30 +0200 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2014-06-18 17:03:07 -0700 |
commit | ff5e92c1affe7166b3f6e7073e648ed65a6e2e59 (patch) | |
tree | 3e4c1685968ba9ea18fd763ea04bc0b3f3c87cef | |
parent | d36a4f4b472334562b8e7252e35d3d770db83815 (diff) | |
download | linux-stable-ff5e92c1affe7166b3f6e7073e648ed65a6e2e59.tar.gz linux-stable-ff5e92c1affe7166b3f6e7073e648ed65a6e2e59.tar.bz2 linux-stable-ff5e92c1affe7166b3f6e7073e648ed65a6e2e59.zip |
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: 4f3fdf3bc59c ("sctp: add check rto_min and rto_max in sysctl")
Fixes: 3c68198e7511 ("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>
-rw-r--r-- | net/sctp/sysctl.c | 43 |
1 files changed, 23 insertions, 20 deletions
diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c index dcb19592761e..cc12162ba091 100644 --- a/net/sctp/sysctl.c +++ b/net/sctp/sysctl.c @@ -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; } |