Messages in this thread | | | Date | Tue, 27 Feb 2024 14:41:19 +0100 | Subject | Re: [PATCH v2 2/3] platform/x86/amd/pmf: Do not use readl() for policy buffer access | From | Armin Wolf <> |
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Am 27.02.24 um 13:59 schrieb Ilpo Järvinen:
> On Fri, 23 Feb 2024, Armin Wolf wrote: > >> The policy buffer is allocated using normal memory allocation >> functions, so readl() should not be used on it. >> >> Use get_unaligned_le32() instead. >> >> Compile-tested only. >> >> Signed-off-by: Armin Wolf <W_Armin@gmx.de> >> --- >> drivers/platform/x86/amd/pmf/tee-if.c | 5 +++-- >> 1 file changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/platform/x86/amd/pmf/tee-if.c b/drivers/platform/x86/amd/pmf/tee-if.c >> index 16973bebf55f..3220b6580270 100644 >> --- a/drivers/platform/x86/amd/pmf/tee-if.c >> +++ b/drivers/platform/x86/amd/pmf/tee-if.c >> @@ -11,6 +11,7 @@ >> #include <linux/debugfs.h> >> #include <linux/tee_drv.h> >> #include <linux/uuid.h> >> +#include <asm/unaligned.h> >> #include "pmf.h" >> >> #define MAX_TEE_PARAM 4 >> @@ -249,8 +250,8 @@ static int amd_pmf_start_policy_engine(struct amd_pmf_dev *dev) >> u32 cookie, length; >> int res; >> >> - cookie = readl(dev->policy_buf + POLICY_COOKIE_OFFSET); >> - length = readl(dev->policy_buf + POLICY_COOKIE_LEN); >> + cookie = get_unaligned_le32(dev->policy_buf + POLICY_COOKIE_OFFSET); >> + length = get_unaligned_le32(dev->policy_buf + POLICY_COOKIE_LEN); > I don't understand you need _unaligned_ here, the offsets should be dword > aligned, no? > > #define POLICY_COOKIE_OFFSET 0x10 > #define POLICY_COOKIE_LEN 0x14 > Hi,
you are right about this.
However i just noticed that the driver does not validate that the policy buffer is big enough before accessing the data.
I will prepare a separate patch series to address this.
Thanks, Armin Wolf
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