diff options
| author | Mariusz Kozlowski <m.kozlowski@tuxland.pl> | 2009-07-05 19:48:35 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-07-19 20:38:47 -0700 |
| commit | 3f8fd3f9f677ce452556aca82473b7fcac370830 (patch) | |
| tree | 7afa1b6b3b273530c5d62cfc6bc8444afe5db686 | |
| parent | 2401fe3fbc5bd7db741867102fe355babce76506 (diff) | |
tun/tap: Fix crashes if open() /dev/net/tun and then poll() it. (CVE-2009-1897)
commit 3c8a9c63d5fd738c261bd0ceece04d9c8357ca13 upstream.
Fix NULL pointer dereference in tun_chr_pool() introduced by commit
33dccbb050bbe35b88ca8cf1228dcf3e4d4b3554 ("tun: Limit amount of queued
packets per device") and triggered by this code:
int fd;
struct pollfd pfd;
fd = open("/dev/net/tun", O_RDWR);
pfd.fd = fd;
pfd.events = POLLIN | POLLOUT;
poll(&pfd, 1, 0);
Reported-by: Eugene Kapun <abacabadabacaba@gmail.com>
Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/net/tun.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 1be6a6b2385b..828929212c18 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -486,12 +486,14 @@ static unsigned int tun_chr_poll(struct file *file, poll_table * wait) { struct tun_file *tfile = file->private_data; struct tun_struct *tun = __tun_get(tfile); - struct sock *sk = tun->sk; + struct sock *sk; unsigned int mask = 0; if (!tun) return POLLERR; + sk = tun->sk; + DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name); poll_wait(file, &tun->socket.wait, wait); |