From patchwork Mon Nov 22 19:34:38 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: ide: fix use after free in ide-acpi Date: Mon, 22 Nov 2010 09:34:38 -0000 From: Mariusz Kozlowski X-Patchwork-Id: 72586 Message-Id: <1290454478-5443-1-git-send-email-mk@lab.zgora.pl> To: "David S. Miller" Cc: linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, Mariusz Kozlowski out_obj points to kfreed memory and we dereference that pointer in DEBPRINT/printk. Signed-off-by: Mariusz Kozlowski --- drivers/ide/ide-acpi.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/ide/ide-acpi.c b/drivers/ide/ide-acpi.c index c26c119..2af8cb4 100644 --- a/drivers/ide/ide-acpi.c +++ b/drivers/ide/ide-acpi.c @@ -416,21 +416,21 @@ void ide_acpi_get_timing(ide_hwif_t *hwif) out_obj = output.pointer; if (out_obj->type != ACPI_TYPE_BUFFER) { - kfree(output.pointer); DEBPRINT("Run _GTM: error: " "expected object type of ACPI_TYPE_BUFFER, " "got 0x%x\n", out_obj->type); + kfree(output.pointer); return; } if (!out_obj->buffer.length || !out_obj->buffer.pointer || out_obj->buffer.length != sizeof(struct GTM_buffer)) { - kfree(output.pointer); printk(KERN_ERR "%s: unexpected _GTM length (0x%x)[should be 0x%zx] or " "addr (0x%p)\n", __func__, out_obj->buffer.length, sizeof(struct GTM_buffer), out_obj->buffer.pointer); + kfree(output.pointer); return; }