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authorVasiliy Kulikov <segooon@gmail.com>2011-01-13 04:00:00 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-13 19:03:12 +0300
commit65329bf46bf9ddc37845c9a6823a8e8022d305b9 (patch)
tree13a3136917e0518493231e9d1d5e05962a715c44
parent3d130fd03e06672f7700e2cb694b29f9a98227ca (diff)
downloadlinux-65329bf46bf9ddc37845c9a6823a8e8022d305b9.tar.xz
fs/select.c: fix information leak to userspace
On some architectures __kernel_suseconds_t is int. On these archs struct timeval has padding bytes at the end. This struct is copied to userspace with these padding bytes uninitialized. This leads to leaking of contents of kernel stack memory. This bug was added with v2.6.27-rc5-286-gb773ad4. [akpm@linux-foundation.org: avoid the memset on architectures which don't need it] Signed-off-by: Vasiliy Kulikov <segooon@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/select.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/select.c b/fs/select.c
index b7b10aa30861..e56560d2b08a 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -306,6 +306,8 @@ static int poll_select_copy_remaining(struct timespec *end_time, void __user *p,
rts.tv_sec = rts.tv_nsec = 0;
if (timeval) {
+ if (sizeof(rtv) > sizeof(rtv.tv_sec) + sizeof(rtv.tv_usec))
+ memset(&rtv, 0, sizeof(rtv));
rtv.tv_sec = rts.tv_sec;
rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC;