| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.15 040/109] net: sctp: check proc_dointvec result in proc_sctp_do_auth | Date | Sat, 26 Jul 2014 12:02:02 -0700 |
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3.15-stable review patch. If anyone has any objections, please let me know.
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From: Daniel Borkmann <dborkman@redhat.com>
[ Upstream commit 24599e61b7552673dd85971cf5a35369cd8c119e ]
When writing to the sysctl field net.sctp.auth_enable, it can well be that the user buffer we handed over to proc_dointvec() via proc_sctp_do_auth() handler contains something other than integers.
In that case, we would set an uninitialized 4-byte value from the stack to net->sctp.auth_enable that can be leaked back when reading the sysctl variable, and it can unintentionally turn auth_enable on/off based on the stack content since auth_enable is interpreted as a boolean.
Fix it up by making sure proc_dointvec() returned sucessfully.
Fixes: b14878ccb7fa ("net: sctp: cache auth_enable per endpoint") Reported-by: Florian Westphal <fwestpha@redhat.com> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/sctp/sysctl.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- a/net/sctp/sysctl.c +++ b/net/sctp/sysctl.c @@ -423,8 +423,7 @@ static int proc_sctp_do_auth(struct ctl_ tbl.data = &net->sctp.auth_enable; ret = proc_dointvec(&tbl, write, buffer, lenp, ppos); - - if (write) { + if (write && ret == 0) { struct sock *sk = net->sctp.ctl_sock; net->sctp.auth_enable = new_value;
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