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Commit 63662139e519ce06090b2759cf4a1d291b9cc0e2

Authored by David Woodhouse
1 parent fe9ab00f83
Exists in smarc-l5.0.0_1.0.0-ga and in 5 other branches imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga

params: Fix potential memory leak in add_sysfs_param() 

On allocation failure, it would fail to free the old attrs array which
was no longer referenced by anything (since it would free the old
module_param_attrs struct on the way out).

Comment the suspicious-looking krealloc() usage to explain why it *isn't*
actually buggy, despite looking like a classic realloc() usage bug.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Showing 1 changed file with 4 additions and 1 deletions Side-by-side Diff

... ... @@ -613,10 +613,13 @@
613 613 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
614 614 GFP_KERNEL);
615 615 if (!new) {
616   - kfree(mk->mp);
  616 + kfree(attrs);
617 617 err = -ENOMEM;
618 618 goto fail;
619 619 }
  620 + /* Despite looking like the typical realloc() bug, this is safe.
  621 + * We *want* the old 'attrs' to be freed either way, and we'll store
  622 + * the new one in the success case. */
620 623 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
621 624 if (!attrs) {
622 625 err = -ENOMEM;