linux/net/compat.c
Catalin Marinas f5b93a1a13 net: compat: Update get_compat_msghdr() to match copy_msghdr_from_user() behaviour
commit 91edd096e2 upstream.

Commit db31c55a6f (net: clamp ->msg_namelen instead of returning an
error) introduced the clamping of msg_namelen when the unsigned value
was larger than sizeof(struct sockaddr_storage). This caused a
msg_namelen of -1 to be valid. The native code was subsequently fixed by
commit dbb490b965 (net: socket: error on a negative msg_namelen).

In addition, the native code sets msg_namelen to 0 when msg_name is
NULL. This was done in commit (6a2a2b3ae0 net:socket: set msg_namelen
to 0 if msg_name is passed as NULL in msghdr struct from userland) and
subsequently updated by 08adb7dabd (fold verify_iovec() into
copy_msghdr_from_user()).

This patch brings the get_compat_msghdr() in line with
copy_msghdr_from_user().

Fixes: db31c55a6f (net: clamp ->msg_namelen instead of returning an error)
Cc: David S. Miller <davem@davemloft.net>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[ luis: backported to 3.16: used davem's backport to 3.14 ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
2015-03-24 10:48:46 +00:00

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