Hi Greg, I noticed this patch has been merged into 3.2, 3.5, 3.6 and 3.8, but it was never queued for 3.0 or 3.4. Seems something went wrong, and I actually can trigger this bug in 3.4 stable kernel. On 2013/4/15 2:33, gregkh@xxxxxxxxxxxxxxxxxxx wrote: > > This is a note to let you know that I've just added the patch titled > > tracing: Fix possible NULL pointer dereferences > > to the 3.8-stable tree which can be found at: > http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary > > The filename of the patch is: > tracing-fix-possible-null-pointer-dereferences.patch > and it can be found in the queue-3.8 subdirectory. > > If you, or anyone else, feels it should not be added to the stable tree, > please let <stable@xxxxxxxxxxxxxxx> know about it. > > >>From 6a76f8c0ab19f215af2a3442870eeb5f0e81998d Mon Sep 17 00:00:00 2001 > From: Namhyung Kim <namhyung.kim@xxxxxxx> > Date: Thu, 11 Apr 2013 15:55:01 +0900 > Subject: tracing: Fix possible NULL pointer dereferences > > From: Namhyung Kim <namhyung.kim@xxxxxxx> > > commit 6a76f8c0ab19f215af2a3442870eeb5f0e81998d upstream. > > Currently set_ftrace_pid and set_graph_function files use seq_lseek > for their fops. However seq_open() is called only for FMODE_READ in > the fops->open() so that if an user tries to seek one of those file > when she open it for writing, it sees NULL seq_file and then panic. > > It can be easily reproduced with following command: > > $ cd /sys/kernel/debug/tracing > $ echo 1234 | sudo tee -a set_ftrace_pid > > In this example, GNU coreutils' tee opens the file with fopen(, "a") > and then the fopen() internally calls lseek(). > > Link: http://lkml.kernel.org/r/1365663302-2170-1-git-send-email-namhyung@xxxxxxxxxx > > Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx> > Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx> > Cc: Ingo Molnar <mingo@xxxxxxxxxx> > Cc: Namhyung Kim <namhyung.kim@xxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > > --- > include/linux/ftrace.h | 2 +- > kernel/trace/ftrace.c | 10 +++++----- > kernel/trace/trace_stack.c | 2 +- > 3 files changed, 7 insertions(+), 7 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html