RDMA/cxgb4: Do not dma memory off of the stack

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.

Link: https://lore.kernel.org/r/20191001165611.GA3542072@kroah.com
Reported-by: Nicolas Waisman <nico@semmle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Potnuri Bharat Teja <bharat@chelsio.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This commit is contained in:
Greg KH 2019-10-01 18:56:11 +02:00 committed by Jason Gunthorpe
parent 94635c36f3
commit 3840c5b788
1 changed files with 17 additions and 11 deletions

View File

@ -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;
@ -291,6 +295,7 @@ static int write_tpt_entry(struct c4iw_rdev *rdev, u32 reset_tpt_entry,
mutex_lock(&rdev->stats.lock);
rdev->stats.stag.fail++;
mutex_unlock(&rdev->stats.lock);
kfree(tpt);
return -ENOMEM;
}
mutex_lock(&rdev->stats.lock);
@ -305,28 +310,28 @@ 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 +339,7 @@ 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;
}