[PATCH 6/7] scsi: bfa: try to sanitize vendor netlink events

From: Arnd Bergmann
Date: Fri Nov 10 2017 - 10:38:42 EST


bfa_aen_entry_s is passed to user space in a netlink message, but
is defined using a 'struct timeval' and an 'enum' that are not only
different between architectures, but also between 32-bit user space and
64-bit kernels they may run on, as well as depending on the particular
C library that defines timeval.

This changes the in-kernel definition to no longer use the timeval
type directly but instead use two open-coded 'unsigned long' members.
This keeps the existing ABI, but making the variable unsigned also
helps make it work after y2038, until it overflows in 2106.

Since the macro becomes overly complex at this point, I'm changing
it to an inline function for readability.

I'm not changing the 32-bit user-space ABI at this point, to keep the
changes separate, I deally this would be defined using the same
binary layout for all architectures.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/scsi/bfa/bfa_defs_svc.h | 3 ++-
drivers/scsi/bfa/bfad_im.h | 32 ++++++++++++++++++++++----------
2 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/drivers/scsi/bfa/bfa_defs_svc.h b/drivers/scsi/bfa/bfa_defs_svc.h
index e81707f938cb..df1e874015c4 100644
--- a/drivers/scsi/bfa/bfa_defs_svc.h
+++ b/drivers/scsi/bfa/bfa_defs_svc.h
@@ -1455,7 +1455,8 @@ struct bfa_aen_entry_s {
enum bfa_aen_category aen_category;
u32 aen_type;
union bfa_aen_data_u aen_data;
- struct timeval aen_tv;
+ unsigned long aen_tv_sec;
+ unsigned long aen_tv_usec;
u32 seq_num;
u32 bfad_num;
};
diff --git a/drivers/scsi/bfa/bfad_im.h b/drivers/scsi/bfa/bfad_im.h
index c81ec2a77ef5..7f7616c52814 100644
--- a/drivers/scsi/bfa/bfad_im.h
+++ b/drivers/scsi/bfa/bfad_im.h
@@ -131,16 +131,28 @@ struct bfad_im_s {
} while (0)

/* post fc_host vendor event */
-#define bfad_im_post_vendor_event(_entry, _drv, _cnt, _cat, _evt) do { \
- do_gettimeofday(&(_entry)->aen_tv); \
- (_entry)->bfad_num = (_drv)->inst_no; \
- (_entry)->seq_num = (_cnt); \
- (_entry)->aen_category = (_cat); \
- (_entry)->aen_type = (_evt); \
- if ((_drv)->bfad_flags & BFAD_FC4_PROBE_DONE) \
- queue_work((_drv)->im->drv_workq, \
- &(_drv)->im->aen_im_notify_work); \
-} while (0)
+static inline void bfad_im_post_vendor_event(struct bfa_aen_entry_s *entry,
+ struct bfad_s *drv, int cnt,
+ enum bfa_aen_category cat,
+ enum bfa_ioc_aen_event evt)
+{
+ struct timespec64 ts;
+
+ ktime_get_real_ts64(&ts);
+ /*
+ * 'unsigned long aen_tv_sec' overflows in y2106 on 32-bit
+ * architectures, or in 2038 if user space interprets it
+ * as 'signed'.
+ */
+ entry->aen_tv_sec = ts.tv_sec;
+ entry->aen_tv_usec = ts.tv_nsec / NSEC_PER_USEC;
+ entry->bfad_num = drv->inst_no;
+ entry->seq_num = cnt;
+ entry->aen_category = cat;
+ entry->aen_type = evt;
+ if (drv->bfad_flags & BFAD_FC4_PROBE_DONE)
+ queue_work(drv->im->drv_workq, &drv->im->aen_im_notify_work);
+}

struct Scsi_Host *bfad_scsi_host_alloc(struct bfad_im_port_s *im_port,
struct bfad_s *);
--
2.9.0