This is a note to let you know that I've just added the patch titled net: sctp: propagate sysctl errors from proc_do* properly to the 3.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-sctp-propagate-sysctl-errors-from-proc_do-properly.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Sat Jul 26 10:08:04 PDT 2014 From: Daniel Borkmann <dborkman@xxxxxxxxxx> Date: Thu, 19 Jun 2014 01:31:30 +0200 Subject: net: sctp: propagate sysctl errors from proc_do* properly From: Daniel Borkmann <dborkman@xxxxxxxxxx> [ Upstream commit ff5e92c1affe7166b3f6e7073e648ed65a6e2e59 ] 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@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/sctp/sysctl.c | 43 +++++++++++++++++++++++-------------------- 1 file changed, 23 insertions(+), 20 deletions(-) --- a/net/sctp/sysctl.c +++ b/net/sctp/sysctl.c @@ -307,41 +307,40 @@ static int proc_sctp_do_hmac_alg(struct 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; } @@ -354,11 +353,10 @@ static int proc_sctp_do_rto_min(struct c 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); @@ -367,12 +365,15 @@ static int proc_sctp_do_rto_min(struct c 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; } @@ -381,11 +382,10 @@ static int proc_sctp_do_rto_max(struct c 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); @@ -394,12 +394,15 @@ static int proc_sctp_do_rto_max(struct c 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; } Patches currently in stable-queue which might be from dborkman@xxxxxxxxxx are queue-3.14/net-sctp-fix-information-leaks-in-ulpevent-layer.patch queue-3.14/net-sctp-propagate-sysctl-errors-from-proc_do-properly.patch queue-3.14/net-sctp-check-proc_dointvec-result-in-proc_sctp_do_auth.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html