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| author |   Ben Pfaff <blp@nicira.com> | 2014-07-09 10:31:22 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2014-07-09 14:33:47 -0700 |
| commit | ac30ef832e6af0505b6f0251a6659adcfa74975e (patch) | |
| tree | 8a65858cef97946794e8ac01e3f82405a85643bb /net | |
| parent | net: mvneta: Fix big endian issue in mvneta_txq_desc_csum() (diff) | |
| download | linux-dev-ac30ef832e6af0505b6f0251a6659adcfa74975e.tar.xz linux-dev-ac30ef832e6af0505b6f0251a6659adcfa74975e.zip | |
netlink: Fix handling of error from netlink_dump().
netlink_dump() returns a negative errno value on error. Until now,
netlink_recvmsg() directly recorded that negative value in sk->sk_err, but
that's wrong since sk_err takes positive errno values. (This manifests as
userspace receiving a positive return value from the recv() system call,
falsely indicating success.) This bug was introduced in the commit that
started checking the netlink_dump() return value, commit b44d211 (netlink:
handle errors from netlink_dump()).
Multithreaded Netlink dumps are one way to trigger this behavior in
practice, as described in the commit message for the userspace workaround
posted here:
http://openvswitch.org/pipermail/dev/2014-June/042339.html
This commit also fixes the same bug in netlink_poll(), introduced in commit
cd1df525d (netlink: add flow control for memory mapped I/O).
Signed-off-by: Ben Pfaff <blp@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netlink/af_netlink.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 15c731f03fa6..e6fac7e3db52 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -636,7 +636,7 @@ static unsigned int netlink_poll(struct file *file, struct socket *sock, while (nlk->cb_running && netlink_dump_space(nlk)) { err = netlink_dump(sk); if (err < 0) { - sk->sk_err = err; + sk->sk_err = -err; sk->sk_error_report(sk); break; } @@ -2483,7 +2483,7 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) { ret = netlink_dump(sk); if (ret) { - sk->sk_err = ret; + sk->sk_err = -ret; sk->sk_error_report(sk); } } |