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mtd: mtd_torturetest can cause stack overflows

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mtd_torturetest uses the module parm "ebcnt" to control the size of a
stack based array of int's. When "ebcnt" is large, Ex: 1000, it
causes stack overflows on systems with small kernel stacks. The fix
is to move the array from the stack to kmalloc memory.

Signed-off-by: Al Cooper <alcooperx@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
This commit is contained in:
Al Cooper 2013-02-05 09:08:10 -05:00 committed by Artem Bityutskiy
parent eb82038f97
commit 221b1bd3d4
1 changed files with 11 additions and 14 deletions
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25
drivers/mtd/tests/mtd_torturetest.c
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@ -208,7 +208,7 @@ static inline int write_pattern(int ebnum, void *buf)
static int __init tort_init(void)
{
int err = 0, i, infinite = !cycles_count;
int bad_ebs[ebcnt];
int *bad_ebs;
printk(KERN_INFO "\n");
printk(KERN_INFO "=================================================\n");
@ -250,28 +250,24 @@ static int __init tort_init(void)
err = -ENOMEM;
patt_5A5 = kmalloc(mtd->erasesize, GFP_KERNEL);
if (!patt_5A5) {
pr_err("error: cannot allocate memory\n");
if (!patt_5A5)
goto out_mtd;
}
patt_A5A = kmalloc(mtd->erasesize, GFP_KERNEL);
if (!patt_A5A) {
pr_err("error: cannot allocate memory\n");
if (!patt_A5A)
goto out_patt_5A5;
}
patt_FF = kmalloc(mtd->erasesize, GFP_KERNEL);
if (!patt_FF) {
pr_err("error: cannot allocate memory\n");
if (!patt_FF)
goto out_patt_A5A;
}
check_buf = kmalloc(mtd->erasesize, GFP_KERNEL);
if (!check_buf) {
pr_err("error: cannot allocate memory\n");
if (!check_buf)
goto out_patt_FF;
}
bad_ebs = kcalloc(ebcnt, sizeof(*bad_ebs), GFP_KERNEL);
if (!bad_ebs)
goto out_check_buf;
err = 0;
@ -290,7 +286,6 @@ static int __init tort_init(void)
/*
* Check if there is a bad eraseblock among those we are going to test.
*/
memset(&bad_ebs[0], 0, sizeof(int) * ebcnt);
if (mtd_can_have_bb(mtd)) {
for (i = eb; i < eb + ebcnt; i++) {
err = mtd_block_isbad(mtd, (loff_t)i * mtd->erasesize);
@ -394,6 +389,8 @@ out:
pr_info("finished after %u erase cycles\n",
erase_cycles);
kfree(bad_ebs);
out_check_buf:
kfree(check_buf);
out_patt_FF:
kfree(patt_FF);