| Message ID | 20191001153917.GA3498459@kroah.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | cxgb4: do not dma memory off of the stack | expand |
On Tuesday, October 10/01/19, 2019 at 21:09:17 +0530, Greg KH wrote: > Nicolas pointed out that the cxgb4 driver is doing dma off of the stack, > which is generally considered a very bad thing. On some architectures > it could be a security problem, but odds are none of them actually run > this driver, so it's just a "normal" bug. > > Resolve this by allocating the memory for a message off of the heap > instead of the stack. kmalloc() always will give us a proper memory > location that DMA will work correctly from. > > Reported-by: Nicolas Waisman <nico@semmle.com> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > --- > > Note, test-built only, I don't have this hardware to actually run this > code at all. Thanks for the patch. Tests with HW ran fine. Tested-by: Potnuri Bharat Teja <bharat@chelsio.com> > > diff --git a/drivers/infiniband/hw/cxgb4/mem.c b/drivers/infiniband/hw/cxgb4/mem.c > index aa772ee0706f..b2bd3de81dcd 100644 > --- a/drivers/infiniband/hw/cxgb4/mem.c > +++ b/drivers/infiniband/hw/cxgb4/mem.c > @@ -275,13 +275,17 @@ static int write_tpt_entry(struct c4iw_rdev *rdev, u32 reset_tpt_entry, > struct sk_buff *skb, struct c4iw_wr_wait *wr_waitp) > { > int err; > - struct fw_ri_tpte tpt; > + struct fw_ri_tpte *tpt; > u32 stag_idx; > static atomic_t key; > > if (c4iw_fatal_error(rdev)) > return -EIO; > > + tpt = kmalloc(sizeof(*tpt), GFP_KERNEL); > + if (!tpt) > + return -ENOMEM; > + > stag_state = stag_state > 0; > stag_idx = (*stag) >> 8; > > @@ -305,28 +309,28 @@ static int write_tpt_entry(struct c4iw_rdev *rdev, u32 reset_tpt_entry, > > /* write TPT entry */ > if (reset_tpt_entry) > - memset(&tpt, 0, sizeof(tpt)); > + memset(tpt, 0, sizeof(*tpt)); > else { > - tpt.valid_to_pdid = cpu_to_be32(FW_RI_TPTE_VALID_F | > + tpt->valid_to_pdid = cpu_to_be32(FW_RI_TPTE_VALID_F | > FW_RI_TPTE_STAGKEY_V((*stag & FW_RI_TPTE_STAGKEY_M)) | > FW_RI_TPTE_STAGSTATE_V(stag_state) | > FW_RI_TPTE_STAGTYPE_V(type) | FW_RI_TPTE_PDID_V(pdid)); > - tpt.locread_to_qpid = cpu_to_be32(FW_RI_TPTE_PERM_V(perm) | > + tpt->locread_to_qpid = cpu_to_be32(FW_RI_TPTE_PERM_V(perm) | > (bind_enabled ? FW_RI_TPTE_MWBINDEN_F : 0) | > FW_RI_TPTE_ADDRTYPE_V((zbva ? FW_RI_ZERO_BASED_TO : > FW_RI_VA_BASED_TO))| > FW_RI_TPTE_PS_V(page_size)); > - tpt.nosnoop_pbladdr = !pbl_size ? 0 : cpu_to_be32( > + tpt->nosnoop_pbladdr = !pbl_size ? 0 : cpu_to_be32( > FW_RI_TPTE_PBLADDR_V(PBL_OFF(rdev, pbl_addr)>>3)); > - tpt.len_lo = cpu_to_be32((u32)(len & 0xffffffffUL)); > - tpt.va_hi = cpu_to_be32((u32)(to >> 32)); > - tpt.va_lo_fbo = cpu_to_be32((u32)(to & 0xffffffffUL)); > - tpt.dca_mwbcnt_pstag = cpu_to_be32(0); > - tpt.len_hi = cpu_to_be32((u32)(len >> 32)); > + tpt->len_lo = cpu_to_be32((u32)(len & 0xffffffffUL)); > + tpt->va_hi = cpu_to_be32((u32)(to >> 32)); > + tpt->va_lo_fbo = cpu_to_be32((u32)(to & 0xffffffffUL)); > + tpt->dca_mwbcnt_pstag = cpu_to_be32(0); > + tpt->len_hi = cpu_to_be32((u32)(len >> 32)); > } > err = write_adapter_mem(rdev, stag_idx + > (rdev->lldi.vr->stag.start >> 5), > - sizeof(tpt), &tpt, skb, wr_waitp); > + sizeof(*tpt), tpt, skb, wr_waitp); > > if (reset_tpt_entry) { > c4iw_put_resource(&rdev->resource.tpt_table, stag_idx); > @@ -334,6 +338,7 @@ static int write_tpt_entry(struct c4iw_rdev *rdev, u32 reset_tpt_entry, > rdev->stats.stag.cur -= 32; > mutex_unlock(&rdev->stats.lock); > } > + kfree(tpt); > return err; > } >
diff --git a/drivers/infiniband/hw/cxgb4/mem.c b/drivers/infiniband/hw/cxgb4/mem.c index aa772ee0706f..b2bd3de81dcd 100644 --- a/drivers/infiniband/hw/cxgb4/mem.c +++ b/drivers/infiniband/hw/cxgb4/mem.c @@ -275,13 +275,17 @@ static int write_tpt_entry(struct c4iw_rdev *rdev, u32 reset_tpt_entry, struct sk_buff *skb, struct c4iw_wr_wait *wr_waitp) { int err; - struct fw_ri_tpte tpt; + struct fw_ri_tpte *tpt; u32 stag_idx; static atomic_t key; if (c4iw_fatal_error(rdev)) return -EIO; + tpt = kmalloc(sizeof(*tpt), GFP_KERNEL); + if (!tpt) + return -ENOMEM; + stag_state = stag_state > 0; stag_idx = (*stag) >> 8; @@ -305,28 +309,28 @@ static int write_tpt_entry(struct c4iw_rdev *rdev, u32 reset_tpt_entry, /* write TPT entry */ if (reset_tpt_entry) - memset(&tpt, 0, sizeof(tpt)); + memset(tpt, 0, sizeof(*tpt)); else { - tpt.valid_to_pdid = cpu_to_be32(FW_RI_TPTE_VALID_F | + tpt->valid_to_pdid = cpu_to_be32(FW_RI_TPTE_VALID_F | FW_RI_TPTE_STAGKEY_V((*stag & FW_RI_TPTE_STAGKEY_M)) | FW_RI_TPTE_STAGSTATE_V(stag_state) | FW_RI_TPTE_STAGTYPE_V(type) | FW_RI_TPTE_PDID_V(pdid)); - tpt.locread_to_qpid = cpu_to_be32(FW_RI_TPTE_PERM_V(perm) | + tpt->locread_to_qpid = cpu_to_be32(FW_RI_TPTE_PERM_V(perm) | (bind_enabled ? FW_RI_TPTE_MWBINDEN_F : 0) | FW_RI_TPTE_ADDRTYPE_V((zbva ? FW_RI_ZERO_BASED_TO : FW_RI_VA_BASED_TO))| FW_RI_TPTE_PS_V(page_size)); - tpt.nosnoop_pbladdr = !pbl_size ? 0 : cpu_to_be32( + tpt->nosnoop_pbladdr = !pbl_size ? 0 : cpu_to_be32( FW_RI_TPTE_PBLADDR_V(PBL_OFF(rdev, pbl_addr)>>3)); - tpt.len_lo = cpu_to_be32((u32)(len & 0xffffffffUL)); - tpt.va_hi = cpu_to_be32((u32)(to >> 32)); - tpt.va_lo_fbo = cpu_to_be32((u32)(to & 0xffffffffUL)); - tpt.dca_mwbcnt_pstag = cpu_to_be32(0); - tpt.len_hi = cpu_to_be32((u32)(len >> 32)); + tpt->len_lo = cpu_to_be32((u32)(len & 0xffffffffUL)); + tpt->va_hi = cpu_to_be32((u32)(to >> 32)); + tpt->va_lo_fbo = cpu_to_be32((u32)(to & 0xffffffffUL)); + tpt->dca_mwbcnt_pstag = cpu_to_be32(0); + tpt->len_hi = cpu_to_be32((u32)(len >> 32)); } err = write_adapter_mem(rdev, stag_idx + (rdev->lldi.vr->stag.start >> 5), - sizeof(tpt), &tpt, skb, wr_waitp); + sizeof(*tpt), tpt, skb, wr_waitp); if (reset_tpt_entry) { c4iw_put_resource(&rdev->resource.tpt_table, stag_idx); @@ -334,6 +338,7 @@ static int write_tpt_entry(struct c4iw_rdev *rdev, u32 reset_tpt_entry, rdev->stats.stag.cur -= 32; mutex_unlock(&rdev->stats.lock); } + kfree(tpt); return err; }
Nicolas pointed out that the cxgb4 driver is doing dma off of the stack, which is generally considered a very bad thing. On some architectures it could be a security problem, but odds are none of them actually run this driver, so it's just a "normal" bug. Resolve this by allocating the memory for a message off of the heap instead of the stack. kmalloc() always will give us a proper memory location that DMA will work correctly from. Reported-by: Nicolas Waisman <nico@semmle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- Note, test-built only, I don't have this hardware to actually run this code at all.