From 3cd3a349aa3519b88d29845c0bc36bcbae158e93 Mon Sep 17 00:00:00 2001 From: Mathias Krause Date: Sat, 4 Oct 2014 23:06:39 +0200 Subject: [PATCH] posix-timers: Fix stack info leak in timer_create() commit 6891c4509c792209c44ced55a60f13954cb50ef4 upstream. If userland creates a timer without specifying a sigevent info, we'll create one ourself, using a stack local variable. Particularly will we use the timer ID as sival_int. But as sigev_value is a union containing a pointer and an int, that assignment will only partially initialize sigev_value on systems where the size of a pointer is bigger than the size of an int. On such systems we'll copy the uninitialized stack bytes from the timer_create() call to userland when the timer actually fires and we're going to deliver the signal. Initialize sigev_value with 0 to plug the stack info leak. Found in the PaX patch, written by the PaX Team. Fixes: 5a9fa7307285 ("posix-timers: kill ->it_sigev_signo and...") Signed-off-by: Mathias Krause Cc: Oleg Nesterov Cc: Brad Spengler Cc: PaX Team Link: http://lkml.kernel.org/r/1412456799-32339-1-git-send-email-minipli@googlemail.com Signed-off-by: Thomas Gleixner [bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings --- Reading git-format-patch failed