From d2d8c9fddb1c11ccfa73bf0ad2b1e6b4ea7afdaf Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Wed, 24 Nov 2021 11:14:24 +0900 Subject: af_unix: Copy unix_mkname() into unix_find_(bsd|abstract)(). We should not call unix_mkname() before unix_find_other() and instead do the same thing where necessary based on the address type: - terminating the address with '\0' in unix_find_bsd() - calculating the hash in unix_find_abstract(). Signed-off-by: Kuniyuki Iwashima Signed-off-by: Jakub Kicinski --- net/unix/af_unix.c | 63 ++++++++++++++++++++++-------------------------------- 1 file changed, 25 insertions(+), 38 deletions(-) (limited to 'net/unix') diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index e2413a65bdfc..b97b694cfe89 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -239,19 +239,25 @@ static int unix_validate_addr(struct sockaddr_un *sunaddr, int addr_len) return 0; } +static void unix_mkname_bsd(struct sockaddr_un *sunaddr, int addr_len) +{ + /* This may look like an off by one error but it is a bit more + * subtle. 108 is the longest valid AF_UNIX path for a binding. + * sun_path[108] doesn't as such exist. However in kernel space + * we are guaranteed that it is a valid memory location in our + * kernel address buffer because syscall functions always pass + * a pointer of struct sockaddr_storage which has a bigger buffer + * than 108. + */ + ((char *)sunaddr)[addr_len] = 0; +} + static int unix_mkname(struct sockaddr_un *sunaddr, int len, unsigned int *hashp) { *hashp = 0; if (sunaddr->sun_path[0]) { - /* - * This may look like an off by one error but it is a bit more - * subtle. 108 is the longest valid AF_UNIX path for a binding. - * sun_path[108] doesn't as such exist. However in kernel space - * we are guaranteed that it is a valid memory location in our - * kernel address buffer. - */ - ((char *)sunaddr)[len] = 0; + unix_mkname_bsd(sunaddr, len); len = strlen(sunaddr->sun_path) + offsetof(struct sockaddr_un, sun_path) + 1; return len; @@ -958,13 +964,14 @@ static int unix_release(struct socket *sock) } static struct sock *unix_find_bsd(struct net *net, struct sockaddr_un *sunaddr, - int type) + int addr_len, int type) { struct inode *inode; struct path path; struct sock *sk; int err; + unix_mkname_bsd(sunaddr, addr_len); err = kern_path(sunaddr->sun_path, LOOKUP_FOLLOW, &path); if (err) goto fail; @@ -1002,9 +1009,9 @@ fail: static struct sock *unix_find_abstract(struct net *net, struct sockaddr_un *sunaddr, - int addr_len, int type, - unsigned int hash) + int addr_len, int type) { + unsigned int hash = unix_hash_fold(csum_partial(sunaddr, addr_len, 0)); struct dentry *dentry; struct sock *sk; @@ -1021,15 +1028,14 @@ static struct sock *unix_find_abstract(struct net *net, static struct sock *unix_find_other(struct net *net, struct sockaddr_un *sunaddr, - int addr_len, int type, - unsigned int hash) + int addr_len, int type) { struct sock *sk; if (sunaddr->sun_path[0]) - sk = unix_find_bsd(net, sunaddr, type); + sk = unix_find_bsd(net, sunaddr, addr_len, type); else - sk = unix_find_abstract(net, sunaddr, addr_len, type, hash); + sk = unix_find_abstract(net, sunaddr, addr_len, type); return sk; } @@ -1246,7 +1252,6 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, struct net *net = sock_net(sk); struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr; struct sock *other; - unsigned int hash; int err; err = -EINVAL; @@ -1258,11 +1263,6 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, if (err) goto out; - err = unix_mkname(sunaddr, alen, &hash); - if (err < 0) - goto out; - alen = err; - if (test_bit(SOCK_PASSCRED, &sock->flags) && !unix_sk(sk)->addr) { err = unix_autobind(sk); @@ -1271,7 +1271,7 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, } restart: - other = unix_find_other(net, sunaddr, alen, sock->type, hash); + other = unix_find_other(net, sunaddr, alen, sock->type); if (IS_ERR(other)) { err = PTR_ERR(other); goto out; @@ -1365,7 +1365,6 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, struct sock *newsk = NULL; struct sock *other = NULL; struct sk_buff *skb = NULL; - unsigned int hash; int st; int err; long timeo; @@ -1374,11 +1373,6 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, if (err) goto out; - err = unix_mkname(sunaddr, addr_len, &hash); - if (err < 0) - goto out; - addr_len = err; - if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr) { err = unix_autobind(sk); if (err) @@ -1409,7 +1403,7 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, restart: /* Find listening sock. */ - other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash); + other = unix_find_other(net, sunaddr, addr_len, sk->sk_type); if (IS_ERR(other)) { err = PTR_ERR(other); other = NULL; @@ -1807,9 +1801,7 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg, struct unix_sock *u = unix_sk(sk); DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, msg->msg_name); struct sock *other = NULL; - int namelen = 0; /* fake GCC */ int err; - unsigned int hash; struct sk_buff *skb; long timeo; struct scm_cookie scm; @@ -1829,11 +1821,6 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg, err = unix_validate_addr(sunaddr, msg->msg_namelen); if (err) goto out; - - err = unix_mkname(sunaddr, msg->msg_namelen, &hash); - if (err < 0) - goto out; - namelen = err; } else { sunaddr = NULL; err = -ENOTCONN; @@ -1886,8 +1873,8 @@ restart: if (sunaddr == NULL) goto out_free; - other = unix_find_other(net, sunaddr, namelen, sk->sk_type, - hash); + other = unix_find_other(net, sunaddr, msg->msg_namelen, + sk->sk_type); if (IS_ERR(other)) { err = PTR_ERR(other); other = NULL; -- cgit v1.2.3