diff options
| author | Kevin Brodsky <kevin.brodsky@arm.com> | 2023-04-13 12:47:03 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2023-04-14 11:09:27 +0100 |
| commit | c39ef2130491b2382f2c81774c825527d4bdf4e2 (patch) | |
| tree | c092292a7e77f51f4bf7ccc9fe7a10e4346f4b5b /net/core | |
| parent | eaaa4e92397981c65dae7b9a38425b8fa984d674 (diff) | |
net: Ensure ->msg_control_user is used for user buffers
Since commit 1f466e1f15cf ("net: cleanly handle kernel vs user
buffers for ->msg_control"), pointers to user buffers should be
stored in struct msghdr::msg_control_user, instead of the
msg_control field. Most users of msg_control have already been
converted (where user buffers are involved), but not all of them.
This patch attempts to address the remaining cases. An exception is
made for null checks, as it should be safe to use msg_control
unconditionally for that purpose.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/scm.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/net/core/scm.c b/net/core/scm.c index acb7d776fa6e..3cd7dd377e53 100644 --- a/net/core/scm.c +++ b/net/core/scm.c @@ -250,7 +250,10 @@ int put_cmsg(struct msghdr * msg, int level, int type, int len, void *data) } cmlen = min(CMSG_SPACE(len), msg->msg_controllen); - msg->msg_control += cmlen; + if (msg->msg_control_is_user) + msg->msg_control_user += cmlen; + else + msg->msg_control += cmlen; msg->msg_controllen -= cmlen; return 0; @@ -299,7 +302,7 @@ static int scm_max_fds(struct msghdr *msg) void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm) { struct cmsghdr __user *cm = - (__force struct cmsghdr __user *)msg->msg_control; + (__force struct cmsghdr __user *)msg->msg_control_user; unsigned int o_flags = (msg->msg_flags & MSG_CMSG_CLOEXEC) ? O_CLOEXEC : 0; int fdmax = min_t(int, scm_max_fds(msg), scm->fp->count); int __user *cmsg_data = CMSG_USER_DATA(cm); @@ -332,7 +335,7 @@ void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm) cmlen = CMSG_SPACE(i * sizeof(int)); if (msg->msg_controllen < cmlen) cmlen = msg->msg_controllen; - msg->msg_control += cmlen; + msg->msg_control_user += cmlen; msg->msg_controllen -= cmlen; } } |