Commit cf3680b9 authored Feb 14, 2008 by Tejun Heo Committed by Linus Torvalds Feb 26, 2008

printk: fix possible printk overrun



printk recursion detection prepends message to printk_buf and offsets
printk_buf when actual message is printed but it forgets to trim buffer
length accordingly. This can result in overrun in extreme cases. Fix it.

[ mingo@elte.hu:

  bug was introduced by me via:

   commit 32a76006
   Author: Ingo Molnar <mingo@elte.hu>
   Date:   Fri Jan 25 21:07:58 2008 +0100

       printk: make printk more robust by not allowing recursion
]

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent bfa274e2

kernel/printk.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -666,7 +666,7 @@ asmlinkage int vprintk(const char *fmt, va_list args)
		}
		/* Emit the output into the temporary buffer */
		printed_len += vscnprintf(printk_buf + printed_len,
		sizeof(printk_buf), fmt, args);
		sizeof(printk_buf) - printed_len, fmt, args);

		/*
		* Copy the output into log_buf. If the caller didn't provide

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