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| author | Daniel Borkmann <dborkman@redhat.com> | 2014-06-18 23:46:31 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-07-28 08:08:22 -0700 |
| commit | 97abf5302d11906cf042c5d2c5f87d44084e7fb2 (patch) | |
| tree | 9ae0fd0226568fe956433c750b8400f89f5620d8 /net | |
| parent | 8d7f3e79c3f14ad09c2428b89c92d7480f2c4566 (diff) | |
| download | lwn-97abf5302d11906cf042c5d2c5f87d44084e7fb2.tar.gz lwn-97abf5302d11906cf042c5d2c5f87d44084e7fb2.zip | |
net: sctp: check proc_dointvec result in proc_sctp_do_auth
[ 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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sctp/sysctl.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c index 533b8b2b26ef..dfa532f00d88 100644 --- a/net/sctp/sysctl.c +++ b/net/sctp/sysctl.c @@ -423,8 +423,7 @@ static int proc_sctp_do_auth(struct ctl_table *ctl, int write, 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; |