diff options
| author | Eric Dumazet <edumazet@google.com> | 2016-12-02 09:44:53 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-12-02 14:10:14 -0500 |
| commit | b98b0bc8c431e3ceb4b26b0dfc8db509518fb290 (patch) | |
| tree | 1df6d58e0f2c836a2808658830a3425e169645e6 | |
| parent | 5b01014759991887b1e450c9def01e58c02ab81b (diff) | |
| download | lwn-b98b0bc8c431e3ceb4b26b0dfc8db509518fb290.tar.gz lwn-b98b0bc8c431e3ceb4b26b0dfc8db509518fb290.zip | |
net: avoid signed overflows for SO_{SND|RCV}BUFFORCE
CAP_NET_ADMIN users should not be allowed to set negative
sk_sndbuf or sk_rcvbuf values, as it can lead to various memory
corruptions, crashes, OOM...
Note that before commit 82981930125a ("net: cleanups in
sock_setsockopt()"), the bug was even more serious, since SO_SNDBUF
and SO_RCVBUF were vulnerable.
This needs to be backported to all known linux kernels.
Again, many thanks to syzkaller team for discovering this gem.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/core/sock.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/core/sock.c b/net/core/sock.c index 5e3ca414357e..00a074dbfe9b 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -715,7 +715,7 @@ int sock_setsockopt(struct socket *sock, int level, int optname, val = min_t(u32, val, sysctl_wmem_max); set_sndbuf: sk->sk_userlocks |= SOCK_SNDBUF_LOCK; - sk->sk_sndbuf = max_t(u32, val * 2, SOCK_MIN_SNDBUF); + sk->sk_sndbuf = max_t(int, val * 2, SOCK_MIN_SNDBUF); /* Wake up sending tasks if we upped the value. */ sk->sk_write_space(sk); break; @@ -751,7 +751,7 @@ set_rcvbuf: * returning the value we actually used in getsockopt * is the most desirable behavior. */ - sk->sk_rcvbuf = max_t(u32, val * 2, SOCK_MIN_RCVBUF); + sk->sk_rcvbuf = max_t(int, val * 2, SOCK_MIN_RCVBUF); break; case SO_RCVBUFFORCE: |