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author | WANG Cong <xiyou.wangcong@gmail.com> | 2016-08-29 04:28:26 (GMT) |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2016-09-01 04:00:19 (GMT) |
commit | c0338aff2260ea6c092806312dbb154cec07a242 (patch) | |
tree | 78da2b443e5210c8913e17fe15ad9da2ee9680c1 /net/kcm | |
parent | 3b631e52f7c741a1813b6fc631acca25591972a4 (diff) | |
download | linux-c0338aff2260ea6c092806312dbb154cec07a242.tar.xz |
kcm: fix a socket double free
Dmitry reported a double free on kcm socket, which could
be easily reproduced by:
#include <unistd.h>
#include <sys/syscall.h>
int main()
{
int fd = syscall(SYS_socket, 0x29ul, 0x5ul, 0x0ul, 0, 0, 0);
syscall(SYS_ioctl, fd, 0x89e2ul, 0x20a98000ul, 0, 0, 0);
return 0;
}
This is because on the error path, after we install
the new socket file, we call sock_release() to clean
up the socket, which leaves the fd pointing to a freed
socket. Fix this by calling sys_close() on that fd
directly.
Fixes: ab7ac4eb9832 ("kcm: Kernel Connection Multiplexor module")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/kcm')
-rw-r--r-- | net/kcm/kcmsock.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/kcm/kcmsock.c b/net/kcm/kcmsock.c index cb39e05..4116932 100644 --- a/net/kcm/kcmsock.c +++ b/net/kcm/kcmsock.c @@ -13,6 +13,7 @@ #include <linux/socket.h> #include <linux/uaccess.h> #include <linux/workqueue.h> +#include <linux/syscalls.h> #include <net/kcm.h> #include <net/netns/generic.h> #include <net/sock.h> @@ -2029,7 +2030,7 @@ static int kcm_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) if (copy_to_user((void __user *)arg, &info, sizeof(info))) { err = -EFAULT; - sock_release(newsock); + sys_close(info.fd); } } |