| From | Greg Kroah-Hartman <> | Subject | [ 100/122] net: Fix references to out-of-scope variables in put_cmsg_compat() | Date | Tue, 7 Aug 2012 15:26:28 -0700 |
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From: Greg KH <gregkh@linuxfoundation.org>
3.5-stable review patch. If anyone has any objections, please let me know.
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From: Jesper Juhl <jj@chaosbits.net>
[ Upstream commit 818810472b129004c16fc51bf0a570b60776bfb7 ]
In net/compat.c::put_cmsg_compat() we may assign 'data' the address of either the 'ctv' or 'cts' local variables inside the 'if (!COMPAT_USE_64BIT_TIME)' branch.
Those variables go out of scope at the end of the 'if' statement, so when we use 'data' further down in 'copy_to_user(CMSG_COMPAT_DATA(cm), data, cmlen - sizeof(struct compat_cmsghdr))' there's no telling what it may be refering to - not good.
Fix the problem by simply giving 'ctv' and 'cts' function scope.
Signed-off-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/compat.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/net/compat.c +++ b/net/compat.c @@ -221,6 +221,8 @@ int put_cmsg_compat(struct msghdr *kmsg, { struct compat_cmsghdr __user *cm = (struct compat_cmsghdr __user *) kmsg->msg_control; struct compat_cmsghdr cmhdr; + struct compat_timeval ctv; + struct compat_timespec cts[3]; int cmlen; if (cm == NULL || kmsg->msg_controllen < sizeof(*cm)) { @@ -229,8 +231,6 @@ int put_cmsg_compat(struct msghdr *kmsg, } if (!COMPAT_USE_64BIT_TIME) { - struct compat_timeval ctv; - struct compat_timespec cts[3]; if (level == SOL_SOCKET && type == SCM_TIMESTAMP) { struct timeval *tv = (struct timeval *)data; ctv.tv_sec = tv->tv_sec;
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