| Message ID | alpine.LNX.2.00.1207222335200.31033@swampdragon.chaosbits.net |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Jesper Juhl <jj@chaosbits.net> Date: Sun, 22 Jul 2012 23:37:20 +0200 (CEST) > 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> Applied and queued up for -stable, thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/compat.c b/net/compat.c index 1b96281..74ed1d7 100644 --- a/net/compat.c +++ b/net/compat.c @@ -221,6 +221,8 @@ int put_cmsg_compat(struct msghdr *kmsg, int level, int type, int len, void *dat { 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, int level, int type, int len, void *dat } 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;
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> --- net/compat.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)