This is a note to let you know that I've just added the patch titled
tracing: Fix panic when lseek() called on "trace" opened for writing
to the 2.6.36-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-panic-when-lseek-called-on-trace-opened-for-writing.patch
and it can be found in the queue-2.6.36 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 364829b1263b44aa60383824e4c1289d83d78ca7 Mon Sep 17 00:00:00 2001
From: Slava Pestov <[email protected]>
Date: Wed, 24 Nov 2010 15:13:16 -0800
Subject: tracing: Fix panic when lseek() called on "trace" opened for writing
From: Slava Pestov <[email protected]>
commit 364829b1263b44aa60383824e4c1289d83d78ca7 upstream.
The file_ops struct for the "trace" special file defined llseek as seq_lseek().
However, if the file was opened for writing only, seq_open() was not called,
and the seek would dereference a null pointer, file->private_data.
This patch introduces a new wrapper for seq_lseek() which checks if the file
descriptor is opened for reading first. If not, it does nothing.
Signed-off-by: Slava Pestov <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
kernel/trace/trace.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2320,11 +2320,19 @@ tracing_write_stub(struct file *filp, co
return count;
}
+static loff_t tracing_seek(struct file *file, loff_t offset, int origin)
+{
+ if (file->f_mode & FMODE_READ)
+ return seq_lseek(file, offset, origin);
+ else
+ return 0;
+}
+
static const struct file_operations tracing_fops = {
.open = tracing_open,
.read = seq_read,
.write = tracing_write_stub,
- .llseek = seq_lseek,
+ .llseek = tracing_seek,
.release = tracing_release,
};
Patches currently in stable-queue which might be from [email protected] are
queue-2.6.36/tracing-fix-panic-when-lseek-called-on-trace-opened-for-writing.patch
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