[PATCH] Fix memory leak in vc_resize/vc_allocate

Memory leaks can happen in the vc_resize() function in drivers/char/vt.c
because of the vc->vc_screenbuf variable overriding in vc_allocate().  The
kmemleak reported trace is as follows:

  <__kmalloc>
  <vc_resize>
  <fbcon_init>
  <visual_init>
  <vc_allocate>
  <con_open>
  <tty_open>
  <chrdev_open>

This patch no longer allocates a screen buffer in vc_allocate() if it was
already allocated by vc_resize().

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index b49f03375439d83a8bee35bffa89ba7a3e484fec..fb75da940b59c971472812795b3094966b5c8b73 100644 (file)
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -737,7 +737,8 @@ int vc_allocate(unsigned int currcons)      /* return 0 on success */
            visual_init(vc, currcons, 1);
            if (!*vc->vc_uni_pagedir_loc)
                con_set_default_unimap(vc);
-           vc->vc_screenbuf = kmalloc(vc->vc_screenbuf_size, GFP_KERNEL);
+           if (!vc->vc_kmalloced)
+               vc->vc_screenbuf = kmalloc(vc->vc_screenbuf_size, GFP_KERNEL);
            if (!vc->vc_screenbuf) {
                kfree(vc);
                vc_cons[currcons].d = NULL;