Re: [PATCH][sas] Fix potential NULL pointer dereference bug in sas_smp_get_phy_events()
On 28/07/07, James Bottomley <[EMAIL PROTECTED]> wrote:
> On Fri, 2007-07-27 at 23:27 +0200, Jesper Juhl wrote:
> > In sas_smp_get_phy_events() we never test if the call to
> > alloc_smp_req(RPEL_REQ_SIZE) succeeds or fails. That means we run
> > the risk of dereferencing a NULL pointer if it does fail. Far
> > better to test if we got NULL back and in that case return -ENOMEM
> > just as we already do for the other memory allocation in that
> > function.
> > This patch reworks the memory allocation a bit to deal with it
> > (compile tested only).
> >
> >
> > Signed-off-by: Jesper Juhl <[EMAIL PROTECTED]>
> > ---
> >
> > drivers/scsi/libsas/sas_expander.c | 11 +--
> > 1 files changed, 9 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/scsi/libsas/sas_expander.c
> > b/drivers/scsi/libsas/sas_expander.c
> > index b500f0c..85f5145 100644
> > --- a/drivers/scsi/libsas/sas_expander.c
> > +++ b/drivers/scsi/libsas/sas_expander.c
> > @@ -507,14 +507,21 @@ static int sas_dev_present_in_domain(struct
> > asd_sas_port *port,
> > int sas_smp_get_phy_events(struct sas_phy *phy)
> > {
> > int res;
> > + u8 *req;
> > + u8 *resp;
> > struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
> > struct domain_device *dev = sas_find_dev_by_rphy(rphy);
> > - u8 *req = alloc_smp_req(RPEL_REQ_SIZE);
> > - u8 *resp = kzalloc(RPEL_RESP_SIZE, GFP_KERNEL);
> >
> > + resp = kzalloc(RPEL_RESP_SIZE, GFP_KERNEL);
>
> Actually, this should be alloc_smp_resp(RPEL_RESP_SIZE);
>
> > if (!resp)
> > return -ENOMEM;
> >
> > + req = alloc_smp_req(RPEL_REQ_SIZE);
> > + if (!req) {
> > + res = -ENOMEM;
> > + goto out;
> > + }
>
> Just for the sake of being the same as all the rest of the code, the
> sequence should be
>
> req = alloc_smp_req(xxx_REQ_SIZE);
> if (!req)
> return -ENOMEM;
>
> resp = alloc_smp_resp(xxx_RESP_SIZE);
> if (!resp) {
> kfree(req);
> return -ENOMEM;
> }
>
> (allocate request then response).
>
Fair enough. It makes the code a bit larger though :
My way, as per the original patch:
textdata bss dec hex filename
13820 0 8 138283604 drivers/scsi/libsas/sas_expander.o
Your way, as per this patch:
textdata bss dec hex filename
13832 0 8 138403610 drivers/scsi/libsas/sas_expander.o
I hope this patch is acceptable :
In sas_smp_get_phy_events() we never test if the call to
alloc_smp_req(RPEL_REQ_SIZE) succeeds or fails. That means we run
the risk of dereferencing a NULL pointer if it does fail. Far
better to test if we got NULL back and in that case return -ENOMEM
just as we already do for the other memory allocation in that
function.
This patch should take care of it (compile tested only).
Signed-off-by: Jesper Juhl <[EMAIL PROTECTED]>
---
drivers/scsi/libsas/sas_expander.c | 13 ++---
1 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/libsas/sas_expander.c
b/drivers/scsi/libsas/sas_expander.c
index b500f0c..e98d2b9 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -507,14 +507,21 @@ static int sas_dev_present_in_domain(struct asd_sas_port
*port,
int sas_smp_get_phy_events(struct sas_phy *phy)
{
int res;
+ u8 *req;
+ u8 *resp;
struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
struct domain_device *dev = sas_find_dev_by_rphy(rphy);
- u8 *req = alloc_smp_req(RPEL_REQ_SIZE);
- u8 *resp = kzalloc(RPEL_RESP_SIZE, GFP_KERNEL);
- if (!resp)
+ req = alloc_smp_req(RPEL_REQ_SIZE);
+ if (!req)
return -ENOMEM;
+ resp = alloc_smp_resp(RPEL_RESP_SIZE);
+ if (!resp) {
+ kfree(req);
+ return -ENOMEM;
+ }
+
req[1] = SMP_REPORT_PHY_ERR_LOG;
req[9] = phy->number;
> It looks like disc_resp could use a little love too (it's using the req
> alloc routines).
>
I'll take a look at that later.
--
Jesper Juhl <[EMAIL PROTECTED]>
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Re: [PATCH][sas] Fix potential NULL pointer dereference bug in sas_smp_get_phy_events()
On Fri, 2007-07-27 at 23:27 +0200, Jesper Juhl wrote:
> In sas_smp_get_phy_events() we never test if the call to
> alloc_smp_req(RPEL_REQ_SIZE) succeeds or fails. That means we run
> the risk of dereferencing a NULL pointer if it does fail. Far
> better to test if we got NULL back and in that case return -ENOMEM
> just as we already do for the other memory allocation in that
> function.
> This patch reworks the memory allocation a bit to deal with it
> (compile tested only).
>
>
> Signed-off-by: Jesper Juhl <[EMAIL PROTECTED]>
> ---
>
> drivers/scsi/libsas/sas_expander.c | 11 +--
> 1 files changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/libsas/sas_expander.c
> b/drivers/scsi/libsas/sas_expander.c
> index b500f0c..85f5145 100644
> --- a/drivers/scsi/libsas/sas_expander.c
> +++ b/drivers/scsi/libsas/sas_expander.c
> @@ -507,14 +507,21 @@ static int sas_dev_present_in_domain(struct
> asd_sas_port *port,
> int sas_smp_get_phy_events(struct sas_phy *phy)
> {
> int res;
> + u8 *req;
> + u8 *resp;
> struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
> struct domain_device *dev = sas_find_dev_by_rphy(rphy);
> - u8 *req = alloc_smp_req(RPEL_REQ_SIZE);
> - u8 *resp = kzalloc(RPEL_RESP_SIZE, GFP_KERNEL);
>
> + resp = kzalloc(RPEL_RESP_SIZE, GFP_KERNEL);
Actually, this should be alloc_smp_resp(RPEL_RESP_SIZE);
> if (!resp)
> return -ENOMEM;
>
> + req = alloc_smp_req(RPEL_REQ_SIZE);
> + if (!req) {
> + res = -ENOMEM;
> + goto out;
> + }
Just for the sake of being the same as all the rest of the code, the
sequence should be
req = alloc_smp_req(xxx_REQ_SIZE);
if (!req)
return -ENOMEM;
resp = alloc_smp_resp(xxx_RESP_SIZE);
if (!resp) {
kfree(req);
return -ENOMEM;
}
(allocate request then response).
It looks like disc_resp could use a little love too (it's using the req
alloc routines).
James
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[PATCH][sas] Fix potential NULL pointer dereference bug in sas_smp_get_phy_events()
Hello,
In sas_smp_get_phy_events() we never test if the call to
alloc_smp_req(RPEL_REQ_SIZE) succeeds or fails. That means we run
the risk of dereferencing a NULL pointer if it does fail. Far
better to test if we got NULL back and in that case return -ENOMEM
just as we already do for the other memory allocation in that
function.
This patch reworks the memory allocation a bit to deal with it
(compile tested only).
Signed-off-by: Jesper Juhl <[EMAIL PROTECTED]>
---
drivers/scsi/libsas/sas_expander.c | 11 +--
1 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/libsas/sas_expander.c
b/drivers/scsi/libsas/sas_expander.c
index b500f0c..85f5145 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -507,14 +507,21 @@ static int sas_dev_present_in_domain(struct asd_sas_port
*port,
int sas_smp_get_phy_events(struct sas_phy *phy)
{
int res;
+ u8 *req;
+ u8 *resp;
struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
struct domain_device *dev = sas_find_dev_by_rphy(rphy);
- u8 *req = alloc_smp_req(RPEL_REQ_SIZE);
- u8 *resp = kzalloc(RPEL_RESP_SIZE, GFP_KERNEL);
+ resp = kzalloc(RPEL_RESP_SIZE, GFP_KERNEL);
if (!resp)
return -ENOMEM;
+ req = alloc_smp_req(RPEL_REQ_SIZE);
+ if (!req) {
+ res = -ENOMEM;
+ goto out;
+ }
+
req[1] = SMP_REPORT_PHY_ERR_LOG;
req[9] = phy->number;
PS. Please keep me on Cc when replying.
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